1.1   License

SIP is licensed under the same terms as Python itself. SIP places no restrictions on the license you may apply to the bindings you create.

1.2   Features

SIP, and the bindings it produces, have the following features.

• bindings are fast to load and minimise memory consumption especially when only a small sub-set of a large library is being used
• automatic conversion between standard Python and C/C++ data types
• overloading of functions and methods with different argument signatures
• access to a C++ class's protected methods
• the ability to define a Python class that is a sub-class of a C++ class, including abstract C++ classes
• Python sub-classes can implement the __dtor__(self) method which will be called from the C++ class's virtual destructor
• support for ordinary C++ functions, class methods, static class methods, virtual class methods and abstract class methods
• the ability to re-implement C++ virtual and abstract methods in Python
• support for global and class variables
• support for global and class operators
• support for C++ namespaces
• support for C++ templates
• support for C++ exceptions and wrapping them as Python exceptions
• the ability to define mappings between C++ classes and similar Python data types that are automatically invoked
• the ability to automatically exploit any available run time type information to ensure that the class of a Python instance object matches the class of the corresponding C++ instance
• full support of the Python global interpreter lock, including the ability to specify that a C++ function of method may block, therefore allowing the lock to be released and other Python threads to run
• support for the concept of ownership of a C++ instance (i.e. what part of the code is responsible for calling the instance's destructor) and how the ownership may change during the execution of an application
• the ability to generate bindings for a C++ class library that itself is built on another C++ class library which also has had bindings generated so that the different bindings integrate and share code properly
• a sophisticated versioning system that allows the full lifetime of a C++ class library, including any platform specific or optional features, to be described in a single set of specification files
• the ability to include documentation in the specification files which can be extracted and subsequently processed by external tools
• the ability to include copyright notices and licensing information in the specification files that is automatically included in all generated source code
• a build system, written in Python, that you can extend to configure, compile and install your own bindings without worrying about platform specific issues
• support for building your extensions using distutils
• SIP, and the bindings it produces, runs under UNIX, Linux, Windows and MacOS/X

1.3   SIP Components

SIP comprises a number of different components.

• The SIP code generator (sip or sip.exe). This processes .sip specification files and generates C or C++ bindings. It is covered in detail in Using SIP.
• The SIP header file (sip.h). This contains definitions and data structures needed by the generated C and C++ code.
• The SIP module (sip.so or sip.pyd). This is a Python extension module that is imported automatically by SIP generated bindings and provides them with some common utility functions. See also Using the SIP Module in Applications.
• The SIP build system (sipconfig.py). This is a pure Python module that is created when SIP is configured and encapsulates all the necessary information about your system including relevant directory names, compiler and linker flags, and version numbers. It also includes several Python classes and functions which help you write configuration scripts for your own bindings. It is covered in detail in The SIP Build System.
• The SIP distutils extension (sipdistutils.py). This is a distutils extension that can be used to build your extension modules using distutils and is an alternative to writing configuration scripts with the SIP build system. This can be as simple as adding your .sip files to the list of files needed to build the extension module. It is covered in detail in Building Your Extension with distutils.

1.4   Qt Support

SIP has specific support for the creation of bindings based on Trolltech's Qt toolkit.

The SIP code generator understands the signal/slot type safe callback mechanism that Qt uses to connect objects together. This allows applications to define new Python signals, and allows any Python callable object to be used as a slot.

SIP itself does not require Qt to be installed.

2.1   SIP v4.4

• The SIP_BUILD C preprocessor symbol has been removed.
• sipConvertToCpp(), sipIsSubClassInstance() and the old Generated Type Convertors have been deprecated. The functions sipCanConvertToInstance(), sipConvertToInstance(), sipForceConvertToInstance(), sipConvertFromInstance(), sipConvertFromNewInstance(), sipCanConvertToMappedType(), sipConvertToMappedType(), sipForceConvertToMappedType() and sipConvertFromMappedType() should be used instead. Handwritten %ConvertFromTypeCode and %ConvertToTypeCode now has the responsibility for using these to implement the Transfer and TransferBack annotations.

3.1   Downloading SIP

You can get the latest release of the SIP source code from http://www.riverbankcomputing.co.uk/sip/download.php.

SIP is also included with all of the major Linux distributions. However, it may be a version or two out of date.

You may also find more up to date pre-compiled binaries on SourceForge.

3.2   Configuring SIP

After unpacking the source package (either a .tar.gz or a .zip file depending on your platform) you should then check for any README files that relate to your platform.

Next you need to configure SIP by executing the configure.py script. For example:

python configure.py

This assumes that the Python interpreter is on your path. Something like the following may be appropriate on Windows:

c:\python25\python configure.py

If you have multiple versions of Python installed then make sure you use the interpreter for which you wish SIP to generate bindings for.

The full set of command line options is:

The configure.py script takes many other options that allows the build system to be finely tuned. These are of the form name=value or name+=value. The -h option will display each supported name, although not all are applicable to all platforms.

The name=value form means that value will replace the existing value of name.

The name+=value form means that value will be appended to the existing value of name.

For example, the following will disable support for C++ exceptions (and so reduce the size of module binaries) when used with GCC:

python configure.py CXXFLAGS+=-fno-exceptions

A pure Python module called sipconfig.py is generated by configure.py. This defines each name and its corresponding value. Looking at it will give you a good idea of how the build system uses the different options. It is covered in detail in The SIP Build System.

c:\python25\python configure.py -p win32-g++

c:\python25\python configure.py -p win32-borland

coff2omf python25.lib python25_bcpp.lib

3.3   Building SIP

The next step is to build SIP by running your platform's make command. For example:

make

The final step is to install SIP by running the following command:

make install

(Depending on your system you may require root or administrator privileges.)

This will install the various SIP components.

4.1   A Simple C++ Example

We start with a simple example. Let's say you have a (fictional) C++ library that implements a single class called Word. The class has one constructor that takes a \0 terminated character string as its single argument. The class has one method called reverse() which takes no arguments and returns a \0 terminated character string. The interface to the class is defined in a header file called word.h which might look something like this:

// Define the interface to the word library.

class Word {
    const char *the_word;

public:
    Word(const char *w);

    char *reverse() const;
};

The corresponding SIP specification file would then look something like this:

// Define the SIP wrapper to the word library.

%Module word 0

class Word {

%TypeHeaderCode
#include <word.h>
%End

public:
    Word(const char *w);

    char *reverse() const;
};

Obviously a SIP specification file looks very much like a C++ (or C) header file, but SIP does not include a full C++ parser. Let's look at the differences between the two files.

• The %Module directive has been added [1]. This is used to name the Python module that is being created and to give it a generation number. In this example these are word and 0 respectively. The generation number is effectively the version number of the module.
• The %TypeHeaderCode directive has been added. The text between this and the following %End directive is included literally in the code that SIP generates. Normally it is used, as in this case, to #include the corresponding C++ (or C) header file [2].
• The declaration of the private variable this_word has been removed. SIP does not support access to either private or protected instance variables.

If we want to we can now generate the C++ code in the current directory by running the following command:

sip -c . word.sip

However, that still leaves us with the task of compiling the generated code and linking it against all the necessary libraries. It's much easier to use the SIP build system to do the whole thing.

Using the SIP build system is simply a matter of writing a small Python script. In this simple example we will assume that the word library we are wrapping and it's header file are installed in standard system locations and will be found by the compiler and linker without having to specify any additional flags. In a more realistic example your Python script may take command line options, or search a set of directories to deal with different configurations and installations.

This is the simplest script (conventionally called configure.py):

import os
import sipconfig

# The name of the SIP build file generated by SIP and used by the build
# system.
build_file = "word.sbf"

# Get the SIP configuration information.
config = sipconfig.Configuration()

# Run SIP to generate the code.
os.system(" ".join([config.sip_bin, "-c", ".", "-b", build_file, "word.sip"]))

# Create the Makefile.
makefile = sipconfig.SIPModuleMakefile(config, build_file)

# Add the library we are wrapping.  The name doesn't include any platform
# specific prefixes or extensions (e.g. the "lib" prefix on UNIX, or the
# ".dll" extension on Windows).
makefile.extra_libs = ["word"]

# Generate the Makefile itself.
makefile.generate()

Hopefully this script is self-documenting. The key parts are the Configuration and SIPModuleMakefile classes. The build system contains other Makefile classes, for example to build programs or to call other Makefiles in sub-directories.

After running the script (using the Python interpreter the extension module is being created for) the generated C++ code and Makefile will be in the current directory.

To compile and install the extension module, just run the following commands [3]:

make
make install

That's all there is to it.

See Building Your Extension with distutils for an example of how to build this example using distutils.

4.2   A Simple C Example

Let's now look at a very similar example of wrapping a fictional C library:

/* Define the interface to the word library. */

struct Word {
    const char *the_word;
};

struct Word *create_word(const char *w);
char *reverse(struct Word *word);

The corresponding SIP specification file would then look something like this:

/* Define the SIP wrapper to the word library. */

%CModule word 0

struct Word {

%TypeHeaderCode
#include <word.h>
%End

    const char *the_word;
};

struct Word *create_word(const char *w) /Factory/;
char *reverse(struct Word *word);

Again, let's look at the differences between the two files.

• The %CModule directive has been added. This has the same syntax as the %Module directive used in the previous example but tells SIP that the library being wrapped is implemented in C rather than C++.
• The %TypeHeaderCode directive has been added.
• The Factory annotation has been added to the create_word() function. This tells SIP that a newly created structure is being returned and it is owned by Python.

The configure.py build system script described in the previous example can be used for this example without change.

4.3   A More Complex C++ Example

In this last example we will wrap a fictional C++ library that contains a class that is derived from a Qt class. This will demonstrate how SIP allows a class hierarchy to be split across multiple Python extension modules, and will introduce SIP's versioning system.

The library contains a single C++ class called Hello which is derived from Qt's QLabel class. It behaves just like QLabel except that the text in the label is hard coded to be Hello World. To make the example more interesting we'll also say that the library only supports Qt v3.0 and later, and also includes a function called setDefault() that is not implemented in the Windows version of the library.

The hello.h header file looks something like this:

// Define the interface to the hello library.

#include <qlabel.h>
#include <qwidget.h>
#include <qstring.h>

class Hello : public QLabel {
    // This is needed by the Qt Meta-Object Compiler.
    Q_OBJECT

public:
    Hello(QWidget *parent, const char *name = 0, WFlags f = 0);

private:
    // Prevent instances from being copied.
    Hello(const Hello &);
    Hello &operator=(const Hello &);
};

#if !defined(Q_OS_WIN)
void setDefault(const QString &def);
#endif

The corresponding SIP specification file would then look something like this:

// Define the SIP wrapper to the hello library.

%Module hello 0

%Import qt/qtmod.sip

%If (Qt_3_0_0 -)

class Hello : QLabel {

%TypeHeaderCode
#include <hello.h>
%End

public:
    Hello(QWidget *parent /TransferThis/, const char *name = 0, WFlags f = 0);

private:
    Hello(const Hello &);
};

%If (!WS_WIN)
void setDefault(const QString &def);
%End

%End

Again we look at the differences, but we'll skip those that we've looked at in previous examples.

• The %Import directive has been added to specify that we are extending the class hierarchy defined in the file qt/qtmod.sip. This file is part of PyQt. The build system will take care of finding the file's exact location.
• The %If directive has been added to specify that everything [4] up to the matching %End directive only applies to Qt v3.0 and later. Qt_3_0_0 is a tag defined in qtmod.sip [5] using the %Timeline directive. %Timeline is used to define a tag for each version of a library's API you are wrapping allowing you to maintain all the different versions in a single SIP specification. The build system provides support to configure.py scripts for working out the correct tags to use according to which version of the library is actually installed.
• The public keyword used in defining the super-classes has been removed. This is not supported by SIP.
• The TransferThis annotation has been added to the first argument of the constructor. It specifies that if the argument is not 0 (i.e. the Hello instance being constructed has a parent) then ownership of the instance is transferred from Python to C++. It is needed because Qt maintains objects (i.e. instances derived from the QObject class) in a hierachy. When an object is destroyed all of its children are also automatically destroyed. It is important, therefore, that the Python garbage collector doesn't also try and destroy them. This is covered in more detail in Ownership of Objects. SIP provides many other annotations that can be applied to arguments, functions and classes. Multiple annotations are separated by commas. Annotations may have values.
• The = operator has been removed. This operator is not supported by SIP.
• The %If directive has been added to specify that everything up to the matching %End directive does not apply to Windows. WS_WIN is another tag defined by PyQt, this time using the %Platforms directive. Tags defined by the %Platforms directive are mutually exclusive, i.e. only one may be valid at a time [6].

One question you might have at this point is why bother to define the private copy constructor when it can never be called from Python? The answer is to prevent the automatic generation of a public copy constructor.

We now look at the configure.py script. This is a little different to the script in the previous examples for two related reasons.

Firstly, PyQt includes a pure Python module called pyqtconfig that extends the SIP build system for modules, like our example, that build on top of PyQt. It deals with the details of which version of Qt is being used (i.e. it determines what the correct tags are) and where it is installed. This is called a module's configuration module.

Secondly, we generate a configuration module (called helloconfig) for our own hello module. There is no need to do this, but if there is a chance that somebody else might want to extend your C++ library then it would make life easier for them.

Now we have two scripts. First the configure.py script:

import os
import sipconfig
import pyqtconfig

# The name of the SIP build file generated by SIP and used by the build
# system.
build_file = "hello.sbf"

# Get the PyQt configuration information.
config = pyqtconfig.Configuration()

# Get the extra SIP flags needed by the imported qt module.  Note that
# this normally only includes those flags (-x and -t) that relate to SIP's
# versioning system.
qt_sip_flags = config.pyqt_qt_sip_flags

# Run SIP to generate the code.  Note that we tell SIP where to find the qt
# module's specification files using the -I flag.
os.system(" ".join([config.sip_bin, "-c", ".", "-b", build_file, "-I", config.pyqt_sip_dir, qt_sip_flags, "hello.sip"]))

# We are going to install the SIP specification file for this module and
# its configuration module.
installs = []

installs.append(["hello.sip", os.path.join(config.default_sip_dir, "hello")])

installs.append(["helloconfig.py", config.default_mod_dir])

# Create the Makefile.  The QtModuleMakefile class provided by the
# pyqtconfig module takes care of all the extra preprocessor, compiler and
# linker flags needed by the Qt library.
makefile = pyqtconfig.QtModuleMakefile(
    configuration=config,
    build_file=build_file,
    installs=installs
)

# Add the library we are wrapping.  The name doesn't include any platform
# specific prefixes or extensions (e.g. the "lib" prefix on UNIX, or the
# ".dll" extension on Windows).
makefile.extra_libs = ["hello"]

# Generate the Makefile itself.
makefile.generate()

# Now we create the configuration module.  This is done by merging a Python
# dictionary (whose values are normally determined dynamically) with a
# (static) template.
content = {
    # Publish where the SIP specifications for this module will be
    # installed.
    "hello_sip_dir":    config.default_sip_dir,

    # Publish the set of SIP flags needed by this module.  As these are the
    # same flags needed by the qt module we could leave it out, but this
    # allows us to change the flags at a later date without breaking
    # scripts that import the configuration module.
    "hello_sip_flags":  qt_sip_flags
}

# This creates the helloconfig.py module from the helloconfig.py.in
# template and the dictionary.
sipconfig.create_config_module("helloconfig.py", "helloconfig.py.in", content)

Next we have the helloconfig.py.in template script:

import pyqtconfig

# These are installation specific values created when Hello was configured.
# The following line will be replaced when this template is used to create
# the final configuration module.
# @SIP_CONFIGURATION@

class Configuration(pyqtconfig.Configuration):
    """The class that represents Hello configuration values.
    """
    def __init__(self, sub_cfg=None):
        """Initialise an instance of the class.

        sub_cfg is the list of sub-class configurations.  It should be None
        when called normally.
        """
        # This is all standard code to be copied verbatim except for the
        # name of the module containing the super-class.
        if sub_cfg:
            cfg = sub_cfg
        else:
            cfg = []

        cfg.append(_pkg_config)

        pyqtconfig.Configuration.__init__(self, cfg)

class HelloModuleMakefile(pyqtconfig.QtModuleMakefile):
    """The Makefile class for modules that %Import hello.
    """
    def finalise(self):
        """Finalise the macros.
        """
        # Make sure our C++ library is linked.
        self.extra_libs.append("hello")

        # Let the super-class do what it needs to.
        pyqtconfig.QtModuleMakefile.finalise(self)

Again, we hope that the scripts are self documenting.

4.4   Ownership of Objects

When a C++ instance is wrapped a corresponding Python object is created. The Python object behaves as you would expect in regard to garbage collection - it is garbage collected when its reference count reaches zero. What then happens to the corresponding C++ instance? The obvious answer might be that the instance's destructor is called. However the library API may say that when the instance is passed to a particular function, the library takes ownership of the instance, i.e. responsibility for calling the instance's destructor is transferred from the SIP generated module to the library.

Ownership of an instance may also be associated with another instance. The implication being that the owned instance will automatically be destroyed if the owning instance is destroyed. SIP keeps track of these relationships to ensure that Python's cyclic garbage collector can detect and break any reference cycles between the owning and owned instances. The association is implemented as the owning instance taking a reference to the owned instance.

The TransferThis, Transfer and TransferBack annotations are used to specify where, and it what direction, transfers of ownership happen. It is very important that these are specified correctly to avoid crashes (where both Python and C++ call the destructor) and memory leaks (where neither Python and C++ call the destructor).

This applies equally to C structures where the structure is returned to the heap using the free() function.

See also sipTransferTo() and sipTransferBack().

4.5   Support for Wide Characters

SIP v4.6 introduced support for wide characters (i.e. the wchar_t type). Python's C API includes support for converting between unicode objects and wide character strings and arrays. When converting from a unicode object to wide characters SIP creates the string or array on the heap (using memory allocated using sipMalloc()). This then raises the problem of how this memory is subsequently freed.

The following describes how SIP handles this memory in the different situations where this is an issue.

• When a wide string or array is passed to a function or method then the memory is freed (using sipFree()) after than function or method returns.
• When a wide string or array is returned from a virtual method then SIP does not free the memory until the next time the method is called.
• When an assignment is made to a wide string or array instance variable then SIP does not first free the instance's current string or array.

4.6   The Python Global Interpreter Lock

Python's Global Interpretor Lock (GIL) must be acquired before calls can be made to the Python API. It should also be released when a potentially blocking call to C/C++ library is made in order to allow other Python threads to be executed. In addition, some C/C++ libraries may implement their own locking strategies that conflict with the GIL causing application deadlocks. SIP provides ways of specifying when the GIL is released and acquired to ensure that locking problems can be avoided.

SIP always ensures that the GIL is acquired before making calls to the Python API. By default SIP does not release the GIL when making calls to the C/C++ library being wrapped. The ReleaseGIL annotation can be used to override this behaviour when required.

If SIP is given the -g command line option then the default behaviour is changed and SIP releases the GIL every time is makes calls to the C/C++ library being wrapped. The HoldGIL annotation can be used to override this behaviour when required.

6.1   Syntax Definition

The following is a semi-formal description of the syntax of a specification file.

specification ::= {module-statement}

module-statement ::= [module-directive | statement]

module-directive ::= [%CModule | %Copying | %Doc |
        %ExportedDoc | %ExportedHeaderCode | %Feature |
        %Import | %Include | %License | %MappedType |
        mapped-type-template | %Module | %ModuleCode |
        %ModuleHeaderCode | %OptionalInclude | %Platforms |
        %PreInitialisationCode | %PostInitialisationCode |
        sip-option-list | %Timeline | %UnitCode]

sip-option-list :: %SIPOptions ( option-list )

option-list ::= option [, option-list]

statement :: [class-statement | function | variable]

class-statement :: [%If | class | class-template | enum |
        namespace | opaque-class | operator | struct | typedef |
        exception]

class ::= class name [: super-classes] [class-annotations]
        { {class-line} };

super-classes ::= name [, super-classes]

class-line ::= [class-statement | %BIGetReadBufferCode |
        %BIGetWriteBufferCode | %BIGetSegCountCode |
        %BIGetCharBufferCode | %ConvertToSubClassCode |
        %ConvertToTypeCode | %GCClearCode | %GCTraverseCode |
        %TypeCode | %TypeHeaderCode | constructor | destructor |
        method | static-method | virtual-method | special-method |
        operator | virtual-operator | class-variable | public: |
        public slots: | protected: | protected slots: |
        private: | private slots: | signals:]

constructor ::= [explicit] name ( [argument-list] )
        [exceptions] [function-annotations]
        [c++-constructor-signature] ; [%MethodCode]

c++-constructor-signature ::= [( [argument-list] )]

destructor ::= [virtual] ~ name () [exceptions] [= 0]
        [function-annotations] ; [%MethodCode]
        [%VirtualCatcherCode]

method ::= type name ( [argument-list] ) [const]
        [exceptions] [= 0] [function-annotations] [c++-signature]
        ; [%MethodCode]

c++-signature ::= [ type ( [argument-list] )]

static-method ::= static function

virtual-method ::= virtual type name ( [argument-list] )
        [const] [exceptions] [= 0] [function-annotations]
        [c++-signature] ; [%MethodCode] [%VirtualCatcherCode]

special-method ::= type special-method-name
        ( [argument-list] ) [function-annotations] ;
        [%MethodCode]

special-method-name ::= [ __abs__ | __add__ | __and__ |
        __call__ | __cmp__ | __contains__ | __delitem__ |
        __div__ | __eq__ | __float__ | __ge__ |
        __getitem__ | __gt__ | __hash__ | __iadd__ |
        __iand__ | __idiv__ | __ilshift__ | __imod__ |
        __imul__ | __int__ | __invert__ | __ior__ |
        __irshift__ | __isub__ | __ixor__ | __le__ |
        __len__ | __long__ | __lshift__ | __lt__ |
        __mod__ | __mul__ | __ne__ | __neg__ |
        __nonzero__ | __or__ | __pos__ | __repr__ |
        __rshift__ | __setitem__ | __str__ | __sub__ |
        __xor__]

operator ::= operator-type
        ( [argument-list] ) [const] [exceptions]
        [function-annotations] ; [%MethodCode]

virtual-operator ::= virtual operator-type
        ( [argument-list] ) [const] [exceptions] [= 0]
        [function-annotations] ; [%MethodCode]
        [%VirtualCatcherCode]

operatator-type ::= [ operator-function | operator-cast ]

operator-function ::= type operator operator-name

operator-cast ::= operator type

operator-name ::= [+ | - | * | / | % | & |
        | | ^ | << | >> | += | -= | *= |
        /= | %= | &= | |= | ^= | <<= | >>= |
        ~ | () | [] | < | <= | == | != |
        > | >>=]

class-variable ::= [static] variable

class-template :: = template < type-list > class

mapped-type-template :: = template < type-list >
        %MappedType

enum ::= enum [name] [enum-annotations] { {enum-line} };

enum-line ::= [%If | name [enum-annotations] ,

function ::= type name ( [argument-list] ) [exceptions]
        [function-annotations] ; [%MethodCode]

namespace ::= namespace name { {namespace-line} };

namespace-line ::= [%TypeHeaderCode | statement]

opaque-class ::= class scoped-name ;

struct ::= struct name { {class-line} };

typedef ::= typedef [typed-name | function-pointer] ;

variable::= typed-name [variable-annotations] ; [%AccessCode]
        [%GetCode] [%SetCode]

exception ::= %Exception exception-name [exception-base] {
        [%TypeHeaderCode] %RaiseCode };`

exception-name ::= scoped-name

exception-base ::= ( [exception-name | python-exception] )

python-exception ::= [SIP_Exception | SIP_StopIteration |
        SIP_StandardError | SIP_ArithmeticError |
        SIP_LookupError | SIP_AssertionError |
        SIP_AttributeError | SIP_EOFError |
        SIP_FloatingPointError | SIP_EnvironmentError |
        SIP_IOError | SIP_OSError | SIP_ImportError |
        SIP_IndexError | SIP_KeyError | SIP_KeyboardInterrupt |
        SIP_MemoryError | SIP_NameError | SIP_OverflowError |
        SIP_RuntimeError | SIP_NotImplementedError |
        SIP_SyntaxError | SIP_IndentationError | SIP_TabError |
        SIP_ReferenceError | SIP_SystemError | SIP_SystemExit |
        SIP_TypeError | SIP_UnboundLocalError |
        SIP_UnicodeError | SIP_UnicodeEncodeError |
        SIP_UnicodeDecodeError | SIP_UnicodeTranslateError |
        SIP_ValueError | SIP_ZeroDivisionError |
        SIP_WindowsError | SIP_VMSError]

exceptions ::= throw ( [exception-list] )

exception-list ::= scoped-name [, exception-list]

argument-list ::= argument [, argument-list] [, ...]

argument ::= [type [name] [argument-annotations]
        [default-value] | SIP_ANYSLOT [default-value] | SIP_QOBJECT |
        SIP_RXOBJ_CON | SIP_RXOBJ_DIS | SIP_SIGNAL [default-value] |
        SIP_SLOT [default-value] | SIP_SLOT_CON | SIP_SLOT_DIS]

default-value ::= = expression

expression ::= [value | value binary-operator expression]

value ::= [unary-operator] simple-value

simple-value ::= [scoped-name | function-call | real-value |
        integer-value | boolean-value | string-value |
        character-value]

typed-name::= type name

function-pointer::= type (* name )( [type-list] )

type-list ::= type [, type-list]

function-call ::= scoped-name ( [value-list] )

value-list ::= value [, value-list]

real-value ::= a floating point number

integer-value ::= a number

boolean-value ::= [true | false]

string-value ::= " {character} "

character-value ::= ` character `

unary-operator ::= [! | ~ | - | +]

binary-operator ::= [- | + | * | / | & | |]

argument-annotations ::= see Argument Annotations

class-annotations ::= see Class Annotations

enum-annotations ::= see Enum Annotations

function-annotations ::= see Function Annotations

variable-annotations ::= see Variable Annotations

type ::= [const] base-type {*} [&]

type-list ::= type [, type-list]

base-type ::= [scoped-name | template | struct scoped-name |
        short | unsigned short | int | unsigned |
        unsigned int | long | unsigned long | float |
        double | bool | char | signed char |
        unsigned char | void | wchar_t | SIP_PYCALLABLE |
        SIP_PYDICT | SIP_PYLIST | SIP_PYOBJECT | SIP_PYSLICE |
        SIP_PYTUPLE | SIP_PYTYPE]

scoped-name ::= name [:: scoped-name]

template ::= scoped-name < type-list >

name ::= _A-Za-z {_A-Za-z0-9}

Here is a short list of differences between C++ and the subset supported by SIP that might trip you up.

• SIP does not support the use of [] in types. Use pointers instead.
• A global operator can only be defined if its first argument is a class or a named enum that has been wrapped in the same module.
• Variables declared outside of a class are effectively read-only.
• A class's list of super-classes doesn't not include any access specifier (e.g. public).

6.2   Variable Numbers of Arguments

SIP supports the use of ... as the last part of a function signature. Any remaining arguments are collected as a Python tuple.

6.3   Additional SIP Types

SIP supports a number of additional data types that can be used in Python signatures.

bool connectItem(int id, const QObject *receiver, const char *member);

bool connectItem(int, SIP_RXOBJ_CON, SIP_SLOT_CON(int));

7.1   %AccessCode

%AccessCode
    code
%End

This directive is used immediately after the declaration of an instance of a wrapped class or structure, or a pointer to such an instance. You use it to provide handwritten code that overrides the default behaviour.

For example:

class Klass;

Klass *klassInstance;
%AccessCode
    // In this contrived example the C++ library we are wrapping defines
    // klassInstance as Klass ** (which SIP doesn't support) so we
    // explicitly dereference it.
    if (klassInstance && *klassInstance)
        return *klassInstance;

    // This will get converted to None.
    return 0;
%End

7.2   %BIGetCharBufferCode

%BIGetCharBufferCode
    code
%End

This directive (along with %BIGetReadBufferCode, %BIGetSegCountCode and %BIGetWriteBufferCode) is used to specify code that implements Python's buffer interface. See the section Buffer Object Structures for the details.

The following variables are made available to the handwritten code:

type *sipCpp

This is a pointer to the structure or class instance. Its type is a pointer to the structure or class.

void **sipPtrPtr

This is the pointer used to return the address of the character buffer.

SIP_SSIZE_T sipRes

The handwritten code should set this to the length of the character buffer or -1 if there was an error.

SIP_SSIZE_T sipSegment

This is the number of the segment of the character buffer.

PyObject *sipSelf

This is the Python object that wraps the the structure or class instance, i.e. self.

7.3   %BIGetReadBufferCode

%BIGetReadBufferCode
    code
%End

This directive (along with %BIGetCharBufferCode, %BIGetSegCountCode and %BIGetWriteBufferCode) is used to specify code that implements Python's buffer interface.

The following variables are made available to the handwritten code:

type *sipCpp

This is a pointer to the structure or class instance. Its type is a pointer to the structure or class.

void **sipPtrPtr

This is the pointer used to return the address of the read buffer.

SIP_SSIZE_T sipRes

The handwritten code should set this to the length of the read buffer or -1 if there was an error.

SIP_SSIZE_T sipSegment

This is the number of the segment of the read buffer.

PyObject *sipSelf

This is the Python object that wraps the the structure or class instance, i.e. self.

7.4   %BIGetSegCountCode

%BIGetSegCountCode
    code
%End

This directive (along with %BIGetCharBufferCode, %BIGetReadBufferCode and %BIGetWriteBufferCode) is used to specify code that implements Python's buffer interface.

The following variables are made available to the handwritten code:

type *sipCpp

This is a pointer to the structure or class instance. Its type is a pointer to the structure or class.

SIP_SSIZE_T *sipLenPtr

This is the pointer used to return the total length in bytes of all segments of the buffer.

SIP_SSIZE_T sipRes

The handwritten code should set this to the number of segments that make up the buffer.

PyObject *sipSelf

This is the Python object that wraps the the structure or class instance, i.e. self.

7.5   %BIGetWriteBufferCode

%BIGetWriteBufferCode
    code
%End

This directive (along with %BIGetCharBufferCode, %BIGetReadBufferCode and %BIGetSegCountCode is used to specify code that implements Python's buffer interface.

The following variables are made available to the handwritten code:

type *sipCpp

This is a pointer to the structure or class instance. Its type is a pointer to the structure or class.

void **sipPtrPtr

This is the pointer used to return the address of the write buffer.

SIP_SSIZE_T sipRes

The handwritten code should set this to the length of the write buffer or -1 if there was an error.

SIP_SSIZE_T sipSegment

This is the number of the segment of the write buffer.

PyObject *sipSelf

This is the Python object that wraps the the structure or class instance, i.e. self.

7.6   %CModule

%CModule name [version]

This directive is used to identify that the library being wrapped is a C library and to define the name of the module and it's optional version number.

See the %Module directive for an explanation of the version number.

For example:

%CModule dbus 1

7.7   %ConvertFromTypeCode

%ConvertFromTypeCode
    code
%End

This directive is used as part of the %MappedType directive to specify the handwritten code that converts an instance of a mapped type to a Python object.

The following variables are made available to the handwritten code:

type *sipCpp

This is a pointer to the instance of the mapped type to be converted. It will never be zero as the conversion from zero to Py_None is handled before the handwritten code is called.

PyObject *sipTransferObj

This specifies any desired ownership changes to the returned object. If it is NULL then the ownership should be left unchanged. If it is Py_None then ownership should be transferred to Python. Otherwise ownership should be transferred to C/C++ and the returned object associated with sipTransferObj. The code can choose to interpret these changes in any way. For example, if the code is converting a C++ container of wrapped classes to a Python list it is likely that the ownership changes should be made to each element of the list.

The handwritten code must explicitly return a PyObject *. If there was an error then a Python exception must be raised and NULL returned.

The following example converts a QList<QWidget *> instance to a Python list of QWidget instances:

%ConvertFromTypeCode
    PyObject *l;

    // Create the Python list of the correct length.
    if ((l = PyList_New(sipCpp -> size())) == NULL)
        return NULL;

    // Go through each element in the C++ instance and convert it to a
    // wrapped QWidget.
    for (int i = 0; i < sipCpp -> size(); ++i)
    {
        QWidget *w = sipCpp -> at(i);
        PyObject *wobj;

        // Get the Python wrapper for the QWidget instance, creating a new
        // one if necessary, and handle any ownership transfer.
        if ((wobj = sipConvertFromInstance(w, sipClass_QWidget, sipTransferObj)) == NULL)
        {
            // There was an error so garbage collect the Python list.
            Py_DECREF(l);
            return NULL;
        }

        // Add the wrapper to the list.
        PyList_SET_ITEM(l, i, wobj);
    }

    // Return the Python list.
    return l;
%End

7.8   %ConvertToSubClassCode

%ConvertToSubClassCode
    code
%End

When SIP needs to wrap a C++ class instance it first checks to make sure it hasn't already done so. If it has then it just returns a new reference to the corresponding Python object. Otherwise it creates a new Python object of the appropriate type. In C++ a function may be defined to return an instance of a certain class, but can often return a sub-class instead.

This directive is used to specify handwritten code that exploits any available real-time type information (RTTI) to see if there is a more specific Python type that can be used when wrapping the C++ instance. The RTTI may be provided by the compiler or by the C++ instance itself.

The directive is included in the specification of one of the classes that the handwritten code handles the type conversion for. It doesn't matter which one, but a sensible choice would be the one at the root of that class hierarchy in the module.

Note that if a class hierarchy extends over a number of modules then this directive should be used in each of those modules to handle the part of the hierarchy defined in that module. SIP will ensure that the different pieces of code are called in the right order to determine the most specific Python type to use.

The following variables are made available to the handwritten code:

type *sipCpp

This is a pointer to the C++ class instance.

void **sipCppRet

When the sub-class is derived from more than one super-class then it is possible that the C++ address of the instance as the sub-class is different to that of the super-class. If so, then this must be set to the C++ address of the instance when cast (usually using static_cast) from the super-class to the sub-class.

sipWrapperType *sipClass

The handwritten code must set this to the SIP generated Python type object that corresponds to the class instance. (The type object for class Klass is sipClass_Klass.) If the RTTI of the class instance isn't recognised then sipClass must be set to NULL. The code doesn't have to recognise the exact class, only the most specific sub-class that it can.

The handwritten code must not explicitly return.

The following example shows the sub-class conversion code for QEvent based class hierarchy in PyQt:

class QEvent
{
%ConvertToSubClassCode
    // QEvent sub-classes provide a unique type ID.
    switch (sipCpp -> type())
    {
    case QEvent::Timer:
        sipClass = sipClass_QTimerEvent;
        break;

    case QEvent::KeyPress:
    case QEvent::KeyRelease:
        sipClass = sipClass_QKeyEvent;
        break;

    // Skip the remaining event types to keep the example short.

    default:
        // We don't recognise the type.
        sipClass = NULL;
    }
%End

    // The rest of the class specification.

};

The SIP API includes the sipMapIntToClass() and sipMapStringToClass() functions that convert integer and string based RTTI to Python type objects based on ordered lookup tables.

7.9   %ConvertToTypeCode

%ConvertToTypeCode
    code
%End

This directive is used to specify the handwritten code that converts a Python object to a mapped type instance and to handle any ownership transfers. It is used as part of the %MappedType directive and as part of a class specification. The code is also called to determine if the Python object is of the correct type prior to conversion.

When used as part of a class specification it can automatically convert additional types of Python object. For example, PyQt uses it in the specification of the QString class to allow Python string objects and unicode objects to be used wherever QString instances are expected.

The following variables are made available to the handwritten code:

int *sipIsErr

If this is NULL then the code is being asked to check the type of the Python object. The check must not have any side effects. Otherwise the code is being asked to convert the Python object and a non-zero value should be returned through this pointer if an error occurred during the conversion.

PyObject *sipPy

This is the Python object to be converted.

type **sipCppPtr

This is a pointer through which the address of the mapped type instance (or zero if appropriate) is returned. Its value is undefined if sipIsErr is NULL.

PyObject *sipTransferObj

This specifies any desired ownership changes to sipPy. If it is NULL then the ownership should be left unchanged. If it is Py_None then ownership should be transferred to Python. Otherwise ownership should be transferred to C/C++ and sipPy associated with sipTransferObj. The code can choose to interpret these changes in any way.

The handwritten code must explicitly return an int the meaning of which depends on the value of sipIsErr.

If sipIsErr is NULL then a non-zero value is returned if the Python object has a type that can be converted to the mapped type. Otherwise zero is returned.

If sipIsErr is not NULL then a combination of the following flags is returned.

• SIP_TEMPORARY is set to indicate that the returned instance is a temporary and should be released to avoid a memory leak.
• SIP_DERIVED_CLASS is set to indicate that the type of the returned instance is a derived class. See Generated Derived Classes.

The following example converts a Python list of QPoint instances to a QList<QPoint> instance:

%ConvertToTypeCode
    // See if we are just being asked to check the type of the Python
    // object.
    if (!sipIsErr)
    {
        // Checking whether or not None has been passed instead of a list
        // has already been done.
        if (!PyList_Check(sipPy))
            return 0;

        // Check the type of each element.  We specify SIP_NOT_NONE to
        // disallow None because it is a list of QPoint, not of a pointer
        // to a QPoint, so None isn't appropriate.
        for (int i = 0; i < PyList_GET_SIZE(sipPy); ++i)
            if (!sipCanConvertToInstance(PyList_GET_ITEM(sipPy, i),
                                         sipClass_QPoint, SIP_NOT_NONE))
                return 0;

        // The type is valid.
        return 1;
    }

    // Create the instance on the heap.
    QList<QPoint> *ql = new QList<QPoint>;

    for (int i = 0; i < PyList_GET_SIZE(sipPy); ++i)
    {
        QPoint *qp;
        int state;

        // Get the address of the element's C++ instance.  Note that, in
        // this case, we don't apply any ownership changes to the list
        // elements, only to the list itself.
        qp = reinterpret_cast<QPoint *>(sipConvertToInstance(
                                                PyList_GET_ITEM(sipPy, i),
                                                sipClass_QPoint, 0,
                                                SIP_NOT_NONE,
                                                &state, sipIsErr));

        // Deal with any errors.
        if (*sipIsErr)
        {
            sipReleaseInstance(qp, sipClass_QPoint, state);

            // Tidy up.
            delete ql;

            // There is no temporary instance.
            return 0;
        }

        ql -> append(*qp);

        // A copy of the QPoint was appended to the list so we no longer
        // need it.  It may be a temporary instance that should be
        // destroyed, or a wrapped instance that should not be destroyed.
        // sipReleaseInstance() will do the right thing.
        sipReleaseInstance(qp, sipClass_QPoint, state);
    }

    // Return the instance.
    *sipCppPtr = ql;

    // The instance should be regarded as temporary (and be destroyed as
    // soon as it has been used) unless it has been transferred from
    // Python.  sipGetState() is a convenience function that implements
    // this common transfer behaviour.
    return sipGetState(sipTransferObj);
%End

When used in a class specification the handwritten code replaces the code that would normally be automatically generated. This means that the handwritten code must also handle instances of the class itself and not just the additional types that are being supported. This should be done by making calls to sipCanConvertToInstance() to check the object type and sipConvertToInstance() to convert the object. The SIP_NO_CONVERTORS flag must be passed to both these functions to prevent recursive calls to the handwritten code.

7.10   %Copying

%Copying
    text
%End

This directive is used to specify some arbitrary text that will be included at the start of all source files generated by SIP. It is normally used to include copyright and licensing terms.

For example:

%Copying
Copyright (c) 2007 Riverbank Computing Limited
%End

7.11   %Doc

%Doc
    text
%End

This directive is used to specify some arbitrary text that will be extracted by SIP when the -d command line option is used. The directive can be specified any number of times and SIP will concatenate all the separate pieces of text in the order that it sees them.

Documentation that is specified using this directive is local to the module in which it appears. It is ignored by modules that %Import it. Use the %ExportedDoc directive for documentation that should be included by all modules that %Import this one.

For example:

%Doc
<h1>An Example</h1>
<p>
This fragment of documentation is HTML and is local to the module in
which it is defined.
</p>
%End

7.12   %End

This isn't a directive in itself, but is used to terminate a number of directives that allow a block of handwritten code or text to be specified.

7.13   %Exception

%Exception name [(base-exception)]
{
    [*header-code]
    raise-code
};

This directive is used to define new Python exceptions, or to provide a stub for existing Python exceptions. It allows handwritten code to be provided that implements the translation between C++ exceptions and Python exceptions. The arguments to throw () specifiers must either be names of classes or the names of Python exceptions defined by this directive.

name is the name of the exception.

base-exception is the optional base exception. This may be either one of the standard Python exceptions or one defined with a previous %Exception directive.

header-code is the optional %TypeHeaderCode used to specify any external interface to the exception being defined.

raise-code is the %RaiseCode used to specify the handwritten code that converts a reference to the C++ exception to the Python exception.

For example:

%Exception std::exception(SIP_Exception) /PyName=StdException/
{
%TypeHeaderCode
#include <exception>
%End
%RaiseCode
        const char *detail = sipExceptionReference.what();

        SIP_BLOCK_THREADS
        PyErr_SetString(sipException_StdException, detail);
        SIP_UNBLOCK_THREADS
%End
};

In this example we map the standard C++ exception to a new Python exception. The new exception is called StdException and is derived from the standard Python exception Exception.

7.14   %ExportedDoc

%ExportedDoc
    text
%End

This directive is used to specify some arbitrary text that will be extracted by SIP when the -d command line option is used. The directive can be specified any number of times and SIP will concatenate all the separate pieces of text in the order that it sees them.

Documentation that is specified using this directive will also be included by modules that %Import it.

For example:

%ExportedDoc
==========
An Example
==========

This fragment of documentation is reStructuredText and will appear in the
module in which it is defined and all modules that %Import it.
%End

7.15   %ExportedHeaderCode

%ExportedHeaderCode
    code
%End

This directive is used to specify handwritten code, typically the declarations of types, that is placed in a header file that is included by all generated code for all modules. It should not include function declarations because Python modules should not explicitly call functions in another Python module.

See also %ModuleCode and %ModuleHeaderCode.

7.16   %Feature

%Feature name

This directive is used to declare a feature. Features (along with %Platforms and %Timeline) are used by the %If directive to control whether or not parts of a specification are processed or ignored.

Features are mutually independent of each other - any combination of features may be enabled or disable. By default all features are enabled. The SIP -x command line option is used to disable a feature.

If a feature is enabled then SIP will automatically generate a corresponding C preprocessor symbol for use by handwritten code. The symbol is the name of the feature prefixed by SIP_FEATURE_.

For example:

%Feature FOO_SUPPORT

%If (FOO_SUPPORT)
void foo();
%End

7.17   %GCClearCode

%GCClearCode
    code
%End

Python has a cyclic garbage collector which can identify and release unneeded objects even when their reference counts are not zero. If a wrapped C structure or C++ class keeps its own reference to a Python object then, if the garbage collector is to do its job, it needs to provide some handwritten code to traverse and potentially clear those embedded references.

See the section Supporting cyclic garbage collection in Embedding and Extending the Python Interpreter for the details.

This directive is used to specify the code that clears any embedded references. (See %GCTraverseCode for specifying the code that traverses any embedded references.)

The following variables are made available to the handwritten code:

type *sipCpp

This is a pointer to the structure or class instance. Its type is a pointer to the structure or class.

int sipRes

The handwritten code should set this to the result to be returned.

The following simplified example is taken from PyQt. The QCustomEvent class allows arbitary data to be attached to the event. In PyQt this data is always a Python object and so should be handled by the garbage collector:

%GCClearCode
    PyObject *obj;

    // Get the object.
    obj = reinterpret_cast<PyObject *>(sipCpp -> data());

    // Clear the pointer.
    sipCpp -> setData(0);

    // Clear the reference.
    Py_XDECREF(obj);

    // Report no error.
    sipRes = 0;
%End

7.18   %GCTraverseCode

%GCTraverseCode
    code
%End

This directive is used to specify the code that traverses any embedded references for Python's cyclic garbage collector. (See %GCClearCode for a full explanation.)

The following variables are made available to the handwritten code:

type *sipCpp

This is a pointer to the structure or class instance. Its type is a pointer to the structure or class.

visitproc sipVisit

This is the visit function provided by the garbage collector.

void *sipArg

This is the argument to the visit function provided by the garbage collector.

int sipRes

The handwritten code should set this to the result to be returned.

The following simplified example is taken from PyQt's QCustomEvent class:

%GCTraverseCode
    PyObject *obj;

    // Get the object.
    obj = reinterpret_cast<PyObject *>(sipCpp -> data());

    // Call the visit function if there was an object.
    if (obj)
        sipRes = sipVisit(obj, sipArg);
    else
        sipRes = 0;
%End

7.19   %GetCode

%GetCode
    code
%End

This directive is used after the declaration of a C++ class variable or C structure member to specify handwritten code to convert it to a Python object. It is usually used to handle types that SIP cannot deal with automatically.

The following variables are made available to the handwritten code:

type *sipCpp

This is a pointer to the structure or class instance. Its type is a pointer to the structure or class. It is not made available if the variable being wrapped is a static class variable.

PyObject *sipPy

The handwritten code must set this to the Python representation of the class variable or structure member. If there is an error then the code must raise an exception and set this to NULL.

For example:

struct Entity
{
    /*
     * In this contrived example the C library we are wrapping actually
     * defines this as char buffer[100] which SIP cannot handle
     * automatically.
     */
    char *buffer;
%GetCode
        sipPy = PyString_FromStringAndSize(sipCpp -> buffer, 100);
%End
%SetCode
        char *ptr;
        int length;

        if (PyString_AsStringAndSize(sipPy, &ptr, &length) == -1)
            sipErr = 1;
        else if (length != 100)
        {
            /*
             * Raise an exception because the length isn't exactly right.
             */

            PyErr_SetString(PyExc_ValueError, "an Entity.buffer must be exactly 100 bytes");
            sipErr = 1;
        }
        else
            memcpy(sipCpp -> buffer, ptr, 100);
%End
}

7.20   %If

%If (expression)
    specification
%End

where

expression ::= [ored-qualifiers | range]

ored-qualifiers ::= [qualifier | qualifier || ored-qualifiers]

qualifier ::= [!] [feature | platform]

range ::= [version] - [version]

This directive is used in conjunction with features (see %Feature), platforms (see %Platforms) and versions (see %Timeline) to control whether or not parts of a specification are processed or not.

A range of versions means all versions starting with the lower bound up to but excluding the upper bound. If the lower bound is omitted then it is interpreted as being before the earliest version. If the upper bound is omitted then it is interpreted as being after the latest version.

For example:

%Feature SUPPORT_FOO
%Platforms {WIN32_PLATFORM POSIX_PLATFORM MACOS_PLATFORM}
%Timeline {V1_0 V1_1 V2_0 V3_0}

%If (!SUPPORT_FOO)
    // Process this if the SUPPORT_FOO feature is disabled.
%End

%If (POSIX_PLATFORM || MACOS_PLATFORM)
    // Process this if either the POSIX_PLATFORM or MACOS_PLATFORM
    // platforms are enabled.
%End

%If (V1_0 - V2_0)
    // Process this if either V1_0 or V1_1 is enabled.
%End

%If (V2_0 - )
    // Process this if either V2_0 or V3_0 is enabled.
%End

%If ( - )
    // Always process this.
%End

Note that this directive is not implemented as a preprocessor. Only the following parts of a specification are affected by it:

• class
• %ConvertFromTypeCode
• %ConvertToSubClassCode
• %ConvertToTypeCode
• enum
• %ExportedHeaderCode
• functions
• %GCClearCode
• %GCTraverseCode
• %If
• %MappedType
• %MethodCode
• %ModuleCode
• %ModuleHeaderCode
• namespace
• %PostInitialisationCode
• %PreInitialisationCode
• struct
• typedef
• %TypeCode
• %TypeHeaderCode
• %UnitCode
• variables
• %VirtualCatcherCode

Also note that the only way to specify the logical and of qualifiers is to use nested %If directives.

7.21   %Import

%Import filename

This directive is used to import the specification of another module. This is needed if the current module makes use of any types defined in the imported module, e.g. as an argument to a function, or to sub-class.

If filename cannot be opened then SIP prepends filename with the name of the directory containing the current specification file (i.e. the one containing the %Import directive) and tries again. If this also fails then SIP prepends filename with each of the directories, in turn, specified by the -I command line option.

For example:

%Import qt/qtmod.sip

7.22   %Include

%Include filename

This directive is used to include contents of another file as part of the specification of the current module. It is the equivalent of the C preprocessor's #include directive and is used to structure a large module specification into manageable pieces.

%Include follows the same search process as %Import when trying to open filename.

For example:

%Include qwidget.sip

7.23   %License

%License /license-annotations/

This directive is used to specify the contents of an optional license dictionary. The license dictionary is called __license__ and is stored in the module dictionary. The elements of the dictionary are specified using the Licensee, Signature, Timestamp and Type annotations. Only the Type annotation is compulsory.

Note that this directive isn't an attempt to impose any licensing restrictions on a module. It is simply a method for easily embedding licensing information in a module so that it is accessible to Python scripts.

For example:

%License /Type="GPL"/

7.24   %MappedType

template<type-list>
%MappedType type
{
    [header-code]
    [convert-to-code]
    [convert-from-code]
};

%MappedType type
{
    [header-code]
    [convert-to-code]
    [convert-from-code]
};

This directive is used to define an automatic mapping between a C or C++ type and a Python type. It can be used as part of a template, or to map a specific type.

When used as part of a template type cannot itself refer to a template. Any occurrences of any of the type names (but not any * or &) in type-list will be replaced by the actual type names used when the template is instantiated. Template mapped types are instantiated automatically as required (unlike template classes which are only instantiated using typedef).

Any explicit mapped type will be used in preference to any template that maps the same type, ie. a template will not be automatically instantiated if there is an explicit mapped type.

header-code is the %TypeHeaderCode used to specify the library interface to the type being mapped.

convert-to-code is the %ConvertToTypeCode used to specify the handwritten code that converts a Python object to an instance of the mapped type.

convert-from-code is the %ConvertFromTypeCode used to specify the handwritten code that converts an instance of the mapped type to a Python object.

For example:

template<Type *>
%MappedType QList
{
%TypeHeaderCode
// Include the library interface to the type being mapped.
#include <qlist.h>
%End

%ConvertToTypeCode
    // See if we are just being asked to check the type of the Python
    // object.
    if (sipIsErr == NULL)
    {
        // Check it is a list.
        if (!PyList_Check(sipPy))
            return 0;

        // Now check each element of the list is of the type we expect.
        // The template is for a pointer type so we don't disallow None.
        for (int i = 0; i < PyList_GET_SIZE(sipPy); ++i)
            if (!sipCanConvertToInstance(PyList_GET_ITEM(sipPy, i),
                                         sipClass_Type, 0))
                return 0;

        return 1;
    }

    // Create the instance on the heap.
    QList<Type *> *ql = new QList<Type *>;

    for (int i = 0; i < PyList_GET_SIZE(sipPy); ++i)
    {
        // Use the SIP API to convert the Python object to the
        // corresponding C++ instance.  Note that we apply any ownership
        // transfer to the list itself, not the individual elements.
        Type *t = reinterpret_cast<Type *>(sipConvertToInstance(
                                            PyList_GET_ITEM(sipPy, i),
                                            sipClass_Type, 0, 0, 0,
                                            sipIsErr));

        if (*sipIsErr)
        {
            // Tidy up.
            delete ql;

            // There is nothing on the heap.
            return 0;
        }

        // Add the pointer to the C++ instance.
        ql -> append(t);
    }

    // Return the instance on the heap.
    *sipCppPtr = ql;

    // Apply the normal transfer.
    return sipGetState(sipTransferObj);
%End

%ConvertFromTypeCode
    PyObject *l;

    // Create the Python list of the correct length.
    if ((l = PyList_New(sipCpp -> size())) == NULL)
        return NULL;

    // Go through each element in the C++ instance and convert it to the
    // corresponding Python object.
    for (int i = 0; i < sipCpp -> size(); ++i)
    {
        Type *t = sipCpp -> at(i);
        PyObject *tobj;

        if ((tobj = sipConvertFromInstance(t, sipClass_Type, sipTransferObj)) == NULL)
        {
            // There was an error so garbage collect the Python list.
            Py_DECREF(l);
            return NULL;
        }

        PyList_SET_ITEM(l, i, tobj);
    }

    // Return the Python list.
    return l;
%End
}

Using this we can use, for example, QList<QObject *> throughout the module's specification files (and in any module that imports this one). The generated code will automatically map this to and from a Python list of QObject instances when appropriate.

7.25   %MethodCode

%MethodCode
    code
%End

This directive is used as part of the specification of a global function, class method, operator, constructor or destructor to specify handwritten code that replaces the normally generated call to the function being wrapped. It is usually used to handle argument types and results that SIP cannot deal with automatically.

The specified code is embedded in-line after the function's arguments have been successfully converted from Python objects to their C or C++ equivalents. The specified code must not include any return statements.

In the context of a destructor the specified code is embedded in-line in the Python type's deallocation function. Unlike other contexts it supplements rather than replaces the normally generated code, so it must not include code to return the C structure or C++ class instance to the heap. The code is only called if ownership of the structure or class is with Python.

The specified code must also handle the Python Global Interpreter Lock (GIL). If compatibility with SIP v3.x is required then the GIL must be released immediately before the C++ call and reacquired immediately afterwards as shown in this example fragment:

Py_BEGIN_ALLOW_THREADS
sipCpp -> foo();
Py_END_ALLOW_THREADS

If compatibility with SIP v3.x is not required then this is optional but should be done if the C++ function might block the current thread or take a significant amount of time to execute. (See The Python Global Interpreter Lock and the ReleaseGIL and HoldGIL annotations.)

The following variables are made available to the handwritten code:

type a0

There is a variable for each argument of the Python signature (excluding any self argument) named a0, a1, etc. The type of the variable is the same as the type defined in the specification with the following exceptions:

• if the argument is only used to return a value (e.g. it is an int * without an In annotation) then the type has one less level of indirection (e.g. it will be an int)
• if the argument is a structure or class (or a reference or a pointer to a structure or class) then type will always be a pointer to the structure or class.

Note that handwritten code for destructors never has any arguments.

PyObject *a0Wrapper

This variable is made available only if the corresponding argument wraps a C structure or C++ class instance and the GetWrapper annotation is specified. The variable is a pointer to the Python object that wraps the argument.

type *sipCpp

If the directive is used in the context of a class constructor then this must be set by the handwritten code to the constructed instance. In any other context then this is a pointer to the C structure or C++ class instance. Its type is a pointer to the structure or class.

int sipIsErr

The handwritten code should set this to a non-zero value, and raise an appropriate Python exception, if an error is detected.

sipIsErr is not provided for destructors.

type sipRes

The handwritten code should set this to the result to be returned. The type of the variable is the same as the type defined in the Python signature in the specification with the following exception:

• if the argument is a structure or class (or a reference or a pointer to a structure or class) then type will always be a pointer to the structure or class.

sipRes is not provided for inplace operators (e.g. += or __imul__) as their results are handled automatically, nor for class constructors.

PyObject *sipSelf

If the directive is used in the context of a class constructor or method then this is the Python object that wraps the the structure or class instance, i.e. self.

bool sipSelfWasArg

This is only made available for non-abstract, virtual methods. It is set if self was explicitly passed as the first argument of the method rather than being bound to the method. In other words, the call was:

Klass.foo(self, ...)

rather than:

self.foo(...)

The following is a complete example:

class Klass
{
public:
    virtual int foo(SIP_PYTUPLE);
%MethodCode
        // The C++ API takes a 2 element array of integers but passing a
        // two element tuple is more Pythonic.

        int iarr[2];

        if (PyArg_ParseTuple(a0, "ii", &iarr[0], &iarr[1]))
        {
            Py_BEGIN_ALLOW_THREADS
            sipRes = sipSelfWasArg ? sipCpp -> Klass::foo(iarr)
                                   : sipCpp -> foo(iarr);
            Py_END_ALLOW_THREADS
        }
        else
        {
            // PyArg_ParseTuple() will have raised the exception.
            sipIsErr = 1;
        }
%End
};

As the example is a virtual method [7], note the use of sipSelfWasArg to determine exactly which implementation of foo() to call.

If a method is in the protected section of a C++ class then the call should instead be:

sipRes = sipCpp -> sipProtectVirt_foo(sipSelfWasArg, iarr);

If a method is in the protected section of a C++ class but is not virtual then the call should instead be:

sipRes = sipCpp -> sipProtect_foo(iarr);

7.26   %Module

%Module name [version]

This directive is used to identify that the library being wrapped is a C++ library and to define the name of the module and it's optional version number.

The name may contain periods to specify that the module is part of a Python package.

The optional version number is useful if you (or others) might create other modules that build on this module, i.e. if another module might %Import this module. Under the covers, a module exports an API that is used by modules that %Import it and the API is given a version number. A module built on that module knows the version number of the API that it is expecting. If, when the modules are imported at run-time, the version numbers do not match then a Python exception is raised. The dependent module must then be re-built using the correct specification files for the base module.

The version number should be incremented whenever a module is changed. Some changes don't affect the exported API, but it is good practice to change the version number anyway.

For example:

%Module qt 5

7.27   %ModuleCode

%ModuleCode
    code
%End

This directive is used to specify handwritten code, typically the implementations of utility functions, that can be called by other handwritten code in the module.

For example:

%ModuleCode
// Print an object on stderr for debugging purposes.
void dump_object(PyObject *o)
{
    PyObject_Print(o, stderr, 0);
    fprintf(stderr, "\n");
}
%End

See also %ExportedHeaderCode and %ModuleHeaderCode.

7.28   %ModuleHeaderCode

%ModuleHeaderCode
    code
%End

This directive is used to specify handwritten code, typically the declarations of utility functions, that is placed in a header file that is included by all generated code for the same module.

For example:

%ModuleHeaderCode
void dump_object(PyObject *o);
%End

See also %ExportedHeaderCode and %ModuleCode.

7.29   %OptionalInclude

%OptionalInclude filename

This directive is identical to the %Include directive except that SIP silently continues processing if filename could not be opened.

For example:

%OptionalInclude license.sip

7.30   %Platforms

%Platforms {name name ...}

This directive is used to declare a set of platforms. Platforms (along with %Feature and %Timeline) are used by the %If directive to control whether or not parts of a specification are processed or ignored.

Platforms are mutually exclusive - only one platform can be enabled at a time. By default all platforms are disabled. The SIP -t command line option is used to enable a platform.

For example:

%Platforms {WIN32_PLATFORM POSIX_PLATFORM MACOS_PLATFORM}

%If (WIN32_PLATFORM)
void undocumented();
%End

%If (POSIX_PLATFORM)
void documented();
%End

7.31   %PostInitialisationCode

%PostInitialisationCode
    code
%End

This directive is used to specify handwritten code that is embedded in-line at the very end of the generated module initialisation code.

The following variables are made available to the handwritten code:

PyObject *sipModule

This is the module object returned by Py_InitModule().

PyObject *sipModuleDict

This is the module's dictionary object returned by Py_ModuleGetDict().

For example:

%PostInitialisationCode
    // The code will be executed when the module is first imported and
    // after all other initialisation has been completed.
%End

7.32   %PreInitialisationCode

%PreInitialisationCode
    code
%End

This directive is used to specify handwritten code that is embedded in-line at the very start of the generated module initialisation code.

For example:

%PreInitialisationCode
    // The code will be executed when the module is first imported and
    // before other initialisation has been completed.
%End

7.33   %RaiseCode

%RaiseCode
    code
%End

This directive is used as part of the definition of an exception using the %Exception directive to specify handwritten code that raises a Python exception when a C++ exception has been caught. The code is embedded in-line as the body of a C++ catch () clause.

The specified code must handle the Python Global Interpreter Lock (GIL) if necessary. The GIL must be acquired before any calls to the Python API and released after the last call as shown in this example fragment:

SIP_BLOCK_THREADS
PyErr_SetNone(PyErr_Exception);
SIP_UNBLOCK_THREADS

Finally, the specified code must not include any return statements.

The following variable is made available to the handwritten code:

type &sipExceptionRef

This is a reference to the caught C++ exception. The type of the reference is the same as the type defined in the throw () specifier.

See the %Exception directive for an example.

7.34   %SetCode

%SetCode
    code
%End

This directive is used after the declaration of a C++ class variable or C structure member to specify handwritten code to convert it from a Python object. It is usually used to handle types that SIP cannot deal with automatically.

The following variables are made available to the handwritten code:

type *sipCpp

This is a pointer to the structure or class instance. Its type is a pointer to the structure or class. It is not made available if the variable being wrapped is a static class variable.

int sipErr

If the conversion failed then the handwritten code should raise a Python exception and set this to a non-zero value. Its initial value will be automatically set to zero.

PyObject *sipPy

This is the Python object that the handwritten code should convert.

See the %GetCode directive for an example.

7.35   %SIPOptions

This directive sets one or more options that controls different aspects of SIP's behaviour. In this version all the available options are provided specifically to support PyQt and so are not documented.

7.36   %Timeline

%Timeline {name name ...}

This directive is used to declare a set of versions released over a period of time. Versions (along with %Feature and %Platforms) are used by the %If directive to control whether or not parts of a specification are processed or ignored.

Versions are mutually exclusive - only one version can be enabled at a time. By default all versions are disabled. The SIP -t command line option is used to enable a version.

For example:

%Timeline {V1_0 V1_1 V2_0 V3_0}

%If (V1_0 - V2_0)
void foo();
%End

%If (V2_0 -)
void foo(int = 0);
%End

%Timeline can be used any number of times in a module to allow multiple libraries to be wrapped in the same module.

7.37   %TypeCode

%TypeCode
    code
%End

This directive is used as part of the specification of a C structure or a C++ class to specify handwritten code, typically the implementations of utility functions, that can be called by other handwritten code in the structure or class.

For example:

class Klass
{
%TypeCode
// Print an instance on stderr for debugging purposes.
static void dump_klass(const Klass *k)
{
    fprintf(stderr,"Klass %s at %p\n", k -> name(), k);
}
%End

    // The rest of the class specification.

};

Because the scope of the code is normally within the generated file that implements the type, any utility functions would normally be declared static. However a naming convention should still be adopted to prevent clashes of function names within a module in case the SIP -j command line option is used.

7.38   %TypeHeaderCode

%TypeHeaderCode
    code
%End

This directive is used to specify handwritten code that defines the interface to a C or C++ type being wrapped, either a structure, a class, or a template. It is used within a class definition or a %MappedType directive.

Normally code will be a pre-processor #include statement.

For example:

// Wrap the Klass class.
class Klass
{
%TypeHeaderCode
#include <klass.h>
%End

    // The rest of the class specification.
};

7.39   %UnitCode

%UnitCode
    code
%End

This directive is used to specify handwritten code that it included at the very start of a generated compilation unit (ie. C or C++ source file). It is typically used to #include a C++ precompiled header file.

7.40   %VirtualCatcherCode

%VirtualCatcherCode
    code
%End

For most classes there are corresponding generated derived classes that contain reimplementations of the class's virtual methods. These methods (which SIP calls catchers) determine if there is a corresponding Python reimplementation and call it if so. If there is no Python reimplementation then the method in the original class is called instead.

This directive is used to specify handwritten code that replaces the normally generated call to the Python reimplementation and the handling of any returned results. It is usually used to handle argument types and results that SIP cannot deal with automatically.

This directive can also be used in the context of a class destructor to specify handwritten code that is embedded in-line in the internal derived class's destructor.

In the context of a method the Python Global Interpreter Lock (GIL) is automatically acquired before the specified code is executed and automatically released afterwards.

In the context of a destructor the specified code must handle the GIL. The GIL must be acquired before any calls to the Python API and released after the last call as shown in this example fragment:

SIP_BLOCK_THREADS
Py_DECREF(obj);
SIP_UNBLOCK_THREADS

The following variables are made available to the handwritten code in the context of a method:

type a0

There is a variable for each argument of the C++ signature named a0, a1, etc. The type of the variable is the same as the type defined in the specification.

int sipIsErr

The handwritten code should set this to a non-zero value, and raise an appropriate Python exception, if an error is detected.

PyObject *sipMethod

This object is the Python reimplementation of the virtual C++ method. It is normally passed to sipCallMethod().

type sipRes

The handwritten code should set this to the result to be returned. The type of the variable is the same as the type defined in the C++ signature in the specification.

No variables are made available in the context of a destructor.

For example:

class Klass
{
public:
    virtual int foo(SIP_PYTUPLE) [int (int *)];
%MethodCode
        // The C++ API takes a 2 element array of integers but passing a
        // two element tuple is more Pythonic.

        int iarr[2];

        if (PyArg_ParseTuple(a0, "ii", &iarr[0], &iarr[1]))
        {
            Py_BEGIN_ALLOW_THREADS
            sipRes = sipCpp -> Klass::foo(iarr);
            Py_END_ALLOW_THREADS
        }
        else
        {
            // PyArg_ParseTuple() will have raised the exception.
            sipIsErr = 1;
        }
%End
%VirtualCatcherCode
        // Convert the 2 element array of integers to the two element
        // tuple.

        PyObject *result;

        result = sipCallMethod(&sipIsErr, sipMethod, "ii", a0[0], a0[1]);

        if (result != NULL)
        {
            // Convert the result to the C++ type.
            sipParseResult(&sipIsErr, sipMethod, result, "i", &sipRes);

            Py_DECREF(result);
        }
%End
};

8.1   Argument Annotations

// The wrapper for this function will also accept an integer argument
// which Python will automatically convert to a floating point number.
void foo(double);

// The wrapper for this function will never get used.
void foo(int);

// The wrapper for this function will only accept floating point numbers.
void foo(double /Constrained/);

// The wrapper for this function will be used for anything that Python can
// convert to an integer, except for floating point numbers.
void foo(int);

8.2   Class Annotations

static void sipDelayedDtors(const sipDelayedDtor *dd_list);

8.3   Enum Annotations

8.4   Exception Annotations

8.5   Function Annotations

8.6   License Annotations

8.7   Variable Annotations

9.1   SIP_API_MAJOR_NR

This is a C preprocessor symbol that defines the major number of the SIP API. Its value is a number. There is no direct relationship between this and the SIP version number.

9.2   SIP_API_MINOR_NR

This is a C preprocessor symbol that defines the minor number of the SIP API. Its value is a number. There is no direct relationship between this and the SIP version number.

9.3   SIP_BLOCK_THREADS

This is a C preprocessor macro that will make sure the Python Global Interpreter Lock (GIL) is acquired. Python API calls must only be made when the GIL has been acquired. There must be a corresponding SIP_UNBLOCK_THREADS at the same lexical scope.

9.4   SIP_SSIZE_T

This is a C preprocessor macro that is defined as Py_ssize_t for Python v2.5 and later, and as int for earlier versions of Python. It makes it easier to write PEP 353 compliant handwritten code.

9.5   SIP_UNBLOCK_THREADS

This is a C preprocessor macro that will restore the Python Global Interpreter Lock (GIL) to the state it was prior to the corresponding SIP_BLOCK_THREADS.

9.6   SIP_VERSION

This is a C preprocessor symbol that defines the SIP version number represented as a 3 part hexadecimal number (e.g. v4.0.0 is represented as 0x040000).

9.7   SIP_VERSION_STR

This is a C preprocessor symbol that defines the SIP version number represented as a string. For development snapshots it will start with snapshot-.

9.8   sipBadCatcherResult()

void sipBadCatcherResult(PyObject *method)

This raises a Python exception when the result of a Python reimplementation of a C++ method doesn't have the expected type. It is normally called by handwritten code specified with the %VirtualCatcherCode directive. method is the Python method and would normally be the supplied sipMethod.

9.9   sipBadLengthForSlice()

void sipBadLengthForSlice(SIP_SSIZE_T seqlen, SIP_SSIZE_T slicelen)

This raises a Python exception when the length of a slice object is inappropriate for a sequence-like object. It is normally called by handwritten code specified for __setitem__() methods. seqlen is the length of the sequence. slicelen is the length of the slice. With versions of Python prior to v2.5 the arguments have type int.

9.10   sipBuildResult()

PyObject *sipBuildResult(int *iserr, const char *format, ...)

This creates a Python object based on a format string and associated values in a similar way to the Python Py_BuildValue() function. If there was an error then NULL is returned and a Python exception is raised. If iserr is not NULL then the location it points to is set to a non-zero value. format is the string of format characters.

If format begins and ends with parentheses then a tuple of objects is created. If format contains more than one format character then parentheses must be specified.

In the following description the first letter is the format character, the entry in parentheses is the Python object type that the format character will create, and the entry in brackets are the types of the C/C++ values to be passed.

a (string) [char *, int]

Convert a C/C++ character array and its length to a Python string. If the array is NULL then the length is ignored and the result is Py_None.

b (boolean) [int]

Convert a C/C++ int to a Python boolean.

c (string) [char]

Convert a C/C++ char to a Python string.

d (float) [double]

Convert a C/C++ double to a Python floating point number.

e (integer) [enum]

Convert an anonymous C/C++ enum to a Python integer.

f (float) [float]

Convert a C/C++ float to a Python floating point number.

h (integer) [short]

Convert a C/C++ short to a Python integer.

i (integer) [int]

Convert a C/C++ int to a Python integer.

l (long) [long]

Convert a C/C++ long to a Python integer.

m (long) [unsigned long]

Convert a C/C++ unsigned long to a Python long.

n (long) [long long]

Convert a C/C++ long long to a Python long.

o (long) [unsigned long long]

Convert a C/C++ unsigned long long to a Python long.

s (string) [char *]

Convert a C/C++ '\0' terminated string to a Python string. If the string pointer is NULL then the result is Py_None.

t (long) [unsigned short]

Convert a C/C++ unsigned short to a Python long.

u (long) [unsigned int]

Convert a C/C++ unsigned int to a Python long.

w (unicode) [wchar_t]

Convert a C/C++ wide character to a Python unicode object.

x (unicode) [wchar_t *]

Convert a C/C++ L'\0' terminated wide character string to a Python unicode object. If the string pointer is NULL then the result is Py_None.

A (unicode) [wchar_t *, int]

Convert a C/C++ wide character array and its length to a Python unicode object. If the array is NULL then the length is ignored and the result is Py_None.

B (wrapped instance) [type *, sipWrapperType *, PyObject *]

Convert a new C structure or a new C++ class instance to a Python class instance object. Ownership of the structure or instance is determined by the PyObject * argument. If it is NULL and the instance has already been wrapped then the ownership is unchanged. If it is NULL or Py_None then ownership will be with Python. Otherwise ownership will be with C/C++ and the instance associated with the PyObject * argument. The Python class is influenced by any applicable %ConvertToSubClassCode code.

C (wrapped instance) [type *, sipWrapperType *, PyObject *]

Convert a C structure or a C++ class instance to a Python class instance object. If the structure or class instance has already been wrapped then the result is a new reference to the existing class instance object. Ownership of the structure or instance is determined by the PyObject * argument. If it is NULL and the instance has already been wrapped then the ownership is unchanged. If it is NULL and the instance is newly wrapped then ownership will be with C/C++. If it is Py_None then ownership is transferred to Python via a call to sipTransferBack(). Otherwise ownership is transferred to C/C++ and the instance associated with the PyObject * argument via a call to sipTransferTo(). The Python class is influenced by any applicable %ConvertToSubClassCode code.

D (object) [type *, const sipMappedType *, PyObject *]

Convert a C structure or a C++ class instance wrapped as a mapped type to a Python object. Ownership of the structure or instance is determined by the PyObject * argument. If it is NULL then the ownership is unchanged. If it is Py_None then ownership is transferred to Python via a call to sipTransferBack(). Otherwise ownership is transferred to C/C++ and the instance associated with the PyObject * argument via a call to sipTransferTo().

E (wrapped enum) [enum, PyTypeObject *]

Convert a named C/C++ enum to an instance of the corresponding Python named enum type.

M (wrapped instance) [type *, sipWrapperType *]

Convert a C structure or a C++ class instance to a Python class instance object. If the structure or class instance has already been wrapped then the result is a new reference to the existing class instance object. If the instance has already been wrapped then the ownership is unchanged. If the instance is newly wrapped then ownership will be with C/C++. The Python class is influenced by any applicable %ConvertToSubClassCode code. This is deprecated from SIP v4.4.

N (wrapped instance) [type *, sipWrapperType *]

Convert a C structure or a C++ class instance to a Python class instance object. This should not be used if the structure or class instance might already have been wrapped. Ownership of the structure or instance will be with Python. The Python class is influenced by any applicable %ConvertToSubClassCode code. This is deprecated from SIP v4.4.

O (wrapped instance) [type *, sipWrapperType *]

Convert a C structure or a C++ class instance to a Python class instance object. If the structure or class instance has already been wrapped then the result is a new reference to the existing class instance object. Ownership of the structure or instance will be with C/C++. This is deprecated from SIP v4.4.

P (wrapped instance) [type *, sipWrapperType *]

Convert a C structure or a C++ class instance to a Python class instance object. This should not be used if the structure or class instance might already have been wrapped. Ownership of the structure or instance will be with Python. This is deprecated from SIP v4.4.

R (object) [PyObject *]

The result is value passed without any conversions. The reference count is unaffected, i.e. a reference is taken.

S (object) [PyObject *]

The result is value passed without any conversions. The reference count is incremented.

T (object) [void *, PyObject *(*)(void *cppptr)]

Convert a C structure or a C++ class instance to a Python object using a convertor function. See Generated Type Convertors. This is deprecated from SIP v4.4.

V (sip.voidptr) [void *]

Convert a C/C++ void * Python sip.voidptr object.

9.11   sipCallMethod()

PyObject *sipCallMethod(int *iserr, PyObject *method, const char *format, ...)

This calls a Python method passing a tuple of arguments based on a format string and associated values in a similar way to the Python PyObject_CallObject() function. If there was an error then NULL is returned and a Python exception is raised. If iserr is not NULL then the location it points to is set to a non-zero value. method is the Python bound method to call. format is the string of format characters (see sipBuildResult()).

This is normally called by handwritten code specified with the %VirtualCatcherCode directive with method being the supplied sipMethod.

9.12   sipCanConvertToInstance()

int sipCanConvertToInstance(PyObject *obj, sipWrapperType *type, int flags)

This returns a non-zero value if a Python object can be converted to an instance of a C structure or C++ class. obj is the Python object. type is the generated type corresponding to the C/C++ type being checked. flags is any combination of the following values used to fine tune the check.

• SIP_NOT_NONE causes the check to fail if obj is None.
• SIP_NO_CONVERTORS suppresses the use of of any %ConvertToTypeCode for type.

9.13   sipCanConvertToMappedType()

int sipCanConvertToMappedType(PyObject *obj, const sipMappedType *mt, int flags)

This returns a non-zero value if a Python object can be converted to an instance of a C structure or C++ class which has been implemented as a mapped type. obj is the Python object. mt is an opaque structure returned by sipFindMappedType(). flags is any combination of the following values used to fine tune the check.

• SIP_NOT_NONE causes the check to fail if obj is None.

9.14   sipClassName()

PyObject *sipClassName(PyObject *obj)

This returns the class name of a wrapped instance as a Python string. It comes with a reference.

9.15   sipConnectRx()

PyObject *sipConnectRx(PyObject *sender, const char *signal, PyObject *receiver, const char *slot, int type)

This connects a signal to a signal or slot and returns Py_True if the signal was connected or Py_False if not. If there was some other error then a Python exception is raised and NULL is returned. sender is the wrapped QObject derived instance that emits the signal. signal is the typed name of the signal. receiver is the wrapped QObject derived instance or Python callable that the signal is connected to. slot is the typed name of the slot, or NULL if receiver is a Python callable. type is the type of connection and is cast from Qt::ConnectionType. It is normally only used by PyQt to implement QObject.connect().

9.16   sipConvertFromInstance()

PyObject *sipConvertFromInstance(void *cpp, sipWrapperType *type, PyObject *transferObj)

Convert a C structure or a C++ class instance to a Python class instance object. cpp is the C/C++ instance. If the instance has already been wrapped then the result is a new reference to the existing instance object. type is the generated type corresponding to the C/C++ type. transferObj controls the ownership of the returned value. If the structure or class instance has already been wrapped then the result is a new reference to the existing class instance object. If it is NULL and the instance has already been wrapped then the ownership is unchanged. If it is NULL and the instance is newly wrapped then ownership will be with C/C++. If it is Py_None then ownership is transferred to Python via a call to sipTransferBack(). Otherwise ownership is transferred to C/C++ and the instance associated with transferObj via a call to sipTransferTo(). The Python class is influenced by any applicable %ConvertToSubClassCode code.

9.17   sipConvertFromMappedType()

PyObject *sipConvertFromMappedType(void *cpp, const sipMappedType *mt, PyObject *transferObj)

Convert a C structure or a C++ class instance wrapped as a mapped type to a Python object. cpp is the C/C++ instance. mt is the opaque structure returned by sipFindMappedType(). transferObj controls any ownership changes to obj. If it is NULL then the ownership is unchanged. If it is Py_None then ownership is transferred to Python via a call to sipTransferBack(). Otherwise ownership is transferred to C/C++ and the instance associated with the PyObject * argument via a call to sipTransferTo().

9.18   sipConvertFromNamedEnum()

PyObject *sipConvertFromNamedEnum(int eval, PyTypeObject *type)

Convert a named C/C++ enum to an instance of the corresponding Python named enum type. eval is the enumerated value to convert. type is the generated Python type object (see Generated Named Enum Type Objects).

9.19   sipConvertFromNewInstance()

PyObject *sipConvertFromNewInstance(void *cpp, sipWrapperType *type, PyObject *transferObj)

Convert a new C structure or a new C++ class instance to a Python class instance object. cpp is the C/C++ instance. type is the generated type corresponding to the C/C++ type. transferObj controls the ownership of the returned value. If it is NULL or Py_None then ownership will be with Python. Otherwise ownership will be with C/C++ and the instance associated with transferObj. The Python class is influenced by any applicable %ConvertToSubClassCode code.

9.20   sipConvertFromSequenceIndex()

SIP_SSIZE_T sipConvertFromSequenceIndex(SIP_SSIZE_T idx, SIP_SSIZE_T len)

This converts a Python sequence index (i.e. where a negative value refers to the offset from the end of the sequence) to a C/C++ array index. If the index was out of range then a negative value is returned and a Python exception raised. With versions of Python prior to v2.5 the result and the arguments have type int.

9.21   sipConvertFromSliceObject()

int sipConvertFromSliceObject(PyObject *slice, SIP_SSIZE_T length, SIP_SSIZE_T *start, SIP_SSIZE_T *stop, SIP_SSIZE_T *step, SIP_SSIZE_T *slicelength)

This is a thin wrapper around the Python PySlice_GetIndicesEx() function provided to make it easier to write handwritten code that is compatible with SIP v3.x and versions of Python earlier that v2.3.

9.22   sipConvertToCpp()

void *sipConvertToCpp(PyObject *obj, sipWrapperType *type, int *iserr)

This function is deprecated from SIP v4.4. It is equivalent to:

sipConvertToInstance(obj, type, NULL, SIP_NO_CONVERTORS, NULL, iserr);

9.23   sipConvertToInstance()

void *sipConvertToInstance(PyObject *obj, sipWrapperType *type, PyObject *transferObj, int flags, int *state, int *iserr)

This converts a Python object to an instance of a C structure or C++ class assuming that a previous call to sipCanConvertToInstance() has been successful. obj is the Python object. type is the generated type corresponding to the C/C++ type returned. It may be any class in the object's class hierarchy. transferObj controls any ownership changes to obj. If it is NULL then the ownership is unchanged. If it is Py_None then ownership is transferred to Python via a call to sipTransferBack(). Otherwise ownership is transferred to C/C++ and obj associated with transferObj via a call to sipTransferTo(). flags is any combination of the following values used to fine tune the check.

• SIP_NOT_NONE causes the check to fail if obj is None.
• SIP_NO_CONVERTORS suppresses the use of of any %ConvertToTypeCode for type.

If state is not NULL then the location it points to is set to describe the state of the returned C/C++ instance and is the value returned by any %ConvertToTypeCode. The calling code must then release the value at some point to prevent a memory leak by calling sipReleaseInstance(). If there is an error then the location iserr points to is set to a non-zero value. If it was initially a non-zero value then the conversion isn't attempted in the first place. (This allows several calls to be made that share the same error flag so that it only needs to be tested once rather than after each call.)

9.24   sipConvertToMappedType()

void *sipConvertToMappedType(PyObject *obj, const sipMappedType *mt, PyObject *transferObj, int flags, int *state, int *iserr)

This converts a Python object to an instance of a C structure or C++ class that is implemented as a mapped type assuming that a previous call to sipCanConvertToMappedType() has been successful. obj is the Python object. mt is the opaque structure returned by sipFindMappedType(). transferObj controls any ownership changes to obj. If it is NULL then the ownership is unchanged. If it is Py_None then ownership is transferred to Python via a call to sipTransferBack(). Otherwise ownership is transferred to C/C++ and obj associated with transferObj via a call to sipTransferTo(). flags is any combination of the following values used to fine tune the check.

• SIP_NOT_NONE causes the check to fail if obj is None.

If state is not NULL then the location it points to is set to describe the state of the returned C/C++ instance and is the value returned by any %ConvertToTypeCode. The calling code must then release the value at some point to prevent a memory leak by calling sipReleaseMappedType(). If there is an error then the location iserr points to is set to a non-zero value. If it was initially a non-zero value then the conversion isn't attempted in the first place. (This allows several calls to be made that share the same error flag so that it only needs to be tested once rather than after each call.)

9.25   sipDisconnectRx()

PyObject *sipDisconnectRx(PyObject *sender, const char *signal, PyObject *receiver, const char *slot)

This disconnects a signal from a signal or slot and returns Py_True if the signal was disconnected or Py_False if not. If there was some other error then a Python exception is raised and NULL is returned. sender is the wrapped QObject derived instance that emits the signal. signal is the typed name of the signal. receiver is the wrapped QObject derived instance or Python callable that the signal is connected to. slot is the typed name of the slot, or NULL if receiver is a Python callable. It is normally only used by PyQt to implement QObject.disconnect().

9.26   sipEmitSignal()

int sipEmitSignal(PyObject *txobj, const char *signal, PyObject *args)

This emits a signal and returns zero if there was no error. If there was an error then a Python exception is raised and a negative value is returned. txobj is the wrapped QObject derived instance that emits the signal. signal is the typed name of the signal. args is a Python tuple of the signal arguments. It is normally only used by PyQt to implement QObject.emit().

9.27   sipExportSymbol()

int sipExportSymbol(const char *name, void *sym)

Python does not allow extension modules to directly access symbols in another extension module. This exports a symbol, referenced by a name, that can subsequently be imported, using sipImportSymbol(), by another module. name is the name of the symbol and sym is its value. Zero is returned if there was no error. A negative value is returned if name is already associated with a symbol or there was some other error.

9.28   sipFindClass()

sipWrapperType *sipFindClass(const char *type)

This returns a pointer to the generated type corresponding to a C/C++ type. type is the C/C++ declaration of the type. NULL is returned if the C/C++ type doesn't exist. The value of the pointer will not change and may be saved in a static cache.

9.29   sipFindMappedType()

const sipMappedType *sipFindMappedType(const char *type)

This returns a pointer to an opaque structure describing a mapped type. type is the C/C++ declaration of the type. NULL is returned if the mapped type doesn't exist. The value of the pointer will not change and may be saved in a static cache.

9.30   sipFindNamedEnum()

PyTypeObject *sipFindNamedEnum(const char *type)

This returns a pointer to the generated type corresponding to a named C/C++ enum. type is the C/C++ declaration of the enum. NULL is returned if the named C/C++ enum doesn't exist. The value of the pointer will not change and may be saved in a static cache.

9.31   sipForceConvertToInstance()

void *sipForceConvertToInstance(PyObject *obj, sipWrapperType *type, PyObject *transferObj, int flags, int *state, int *iserr)

This converts a Python object to an instance of a C structure or C++ class by calling sipCanConvertToInstance() and, if it is successfull, calling sipConvertToInstance(). See sipConvertToInstance() for a full description of the arguments.

9.32   sipForceConvertToMappedType()

void *sipForceConvertToMappedType(PyObject *obj, const sipMappedType *mt, PyObject *transferObj, int flags, int *state, int *iserr)

This converts a Python object to an instance of a C structure or C++ class which has been implemented as a mapped type by calling sipCanConvertToMappedType() and, if it is successfull, calling sipConvertToMappedType(). See sipConvertToMappedType() for a full description of the arguments.

9.33   sipFree()

void sipFree(void *mem)

This returns an area of memory allocated by sipMalloc() to the heap. mem is a pointer to the area of memory.

9.34   sipGetSender()

const void *sipGetSender()

This returns a pointer to the last QObject instance that emitted a Qt signal. It is normally only used by PyQt to implement QObject.sender().

9.35   sipGetWrapper()

PyObject *sipGetWrapper(void *cppptr, sipWrapperType *type)

This returns a borrowed reference to the wrapped instance object for a C structure or C++ class instance. If the structure or class instance hasn't been wrapped then NULL is returned (and no Python exception is raised). cppptr is the pointer to the structure or class instance. type is the generated type corresponding to the C/C++ type.

9.36   sipImportSymbol()

void *sipImportSymbol(const char *name)

Python does not allow extension modules to directly access symbols in another extension module. This imports a symbol, referenced by a name, that has previously been exported, using sipExportSymbol(), by another module. name is the name of the symbol. The value of the symbol is returned if there was no error. NULL is returned if there is no such symbol.

9.37   sipIntTypeClassMap

This C structure is used with sipMapIntToClass() to define a mapping between integer based RTTI and generated type objects. The structure elements are as follows.

int typeInt

The integer RTTI.

sipWrapperType **pyType.

A pointer to the corresponding Python type object.

9.38   sipIsSubClassInstance()

int sipIsSubClassInstance(PyObject *obj, sipWrapperType *type)

This function is deprecated from SIP v4.4. It is equivalent to:

sipCanConvertToInstance(obj, type, SIP_NOT_NONE | SIP_NO_CONVERTORS);

9.39   sipLong_AsUnsignedLong()

unsigned long sipLong_AsUnsignedLong(PyObject *obj)

This function is a thin wrapper around PyLong_AsUnsignedLong() that works around a bug in Python v2.3.x and earlier when converting integer objects.

9.40   sipMalloc()

void *sipMalloc(size_t nbytes)

This allocates an area of memory of size nytes on the heap using the Python PyMem_Malloc() function. If there was an error then NULL is returned and a Python exception raised. See sipFree().

9.41   sipMapIntToClass()

sipWrapperType *sipMapIntToClass(int type, const sipIntTypeClassMap *map, int maplen)

This is used in %ConvertToSubClassCode code as a convenient way of converting integer based RTTI to the corresponding Python type object. type is the RTTI. map is the table of known RTTI and the corresponding type objects (see sipIntTypeClassMap). The entries in the table must be sorted in ascending order of RTTI. maplen is the number of entries in the table. The corresponding Python type object is returned, or NULL if type wasn't in map.

9.42   sipMapStringToClass()

sipWrapperType *sipMapStringToClass(char *type, const sipStringTypeClassMap *map, int maplen)

This is used in %ConvertToSubClassCode code as a convenient way of converting '\0' terminated string based RTTI to the corresponding Python type object. type is the RTTI. map is the table of known RTTI and the corresponding type objects (see sipStringTypeClassMap). The entries in the table must be sorted in ascending order of RTTI. maplen is the number of entries in the table. The corresponding Python type object is returned, or NULL if type wasn't in map.

9.43   sipParseResult()

int sipParseResult(int *iserr, PyObject *method, PyObject *result, const char *format, ...)

This converts a Python object (usually returned by a method) to C/C++ based on a format string and associated values in a similar way to the Python PyArg_ParseTuple() function. If there was an error then a negative value is returned and a Python exception is raised. If iserr is not NULL then the location it points to is set to a non-zero value. method is the Python bound method that returned the result object. format is the string of format characters.

This is normally called by handwritten code specified with the %VirtualCatcherCode directive with method being the supplied sipMethod and result being the value returned by sipCallMethod().

If format begins and ends with parentheses then result must be a Python tuple and the rest of format is applied to the tuple contents.

In the following description the first letter is the format character, the entry in parentheses is the Python object type that the format character will convert, and the entry in brackets are the types of the C/C++ values to be passed.

a (string) [char **, int *]

Convert a Python string to a C/C++ character array and its length. If the Python object is Py_None then the array and length are NULL and zero respectively.

b (integer) [bool *]

Convert a Python integer to a C/C++ bool.

c (string) [char *]

Convert a Python string of length 1 to a C/C++ char.

d (float) [double *]

Convert a Python floating point number to a C/C++ double.

e (integer) [enum *]

Convert a Python integer to an anonymous C/C++ enum.

f (float) [float *]

Convert a Python floating point number to a C/C++ float.

h (integer) [short *]

Convert a Python integer to a C/C++ short.

i (integer) [int *]

Convert a Python integer to a C/C++ int.

l (long) [long *]

Convert a Python long to a C/C++ long.

m (long) [unsigned long *]

Convert a Python long to a C/C++ unsigned long.

n (long) [long long *]

Convert a Python long to a C/C++ long long.

o (long) [unsigned long long *]

Convert a Python long to a C/C++ unsigned long long.

s (string) [char **]

Convert a Python string to a C/C++ '\0' terminated string. If the Python object is Py_None then the string is NULL.

t (long) [unsigned short *]

Convert a Python long to a C/C++ unsigned short.

u (long) [unsigned int *]

Convert a Python long to a C/C++ unsigned int.

w (unicode) [wchar_t *]

Convert a Python unicode object of length 1 to a C/C++ wide character.

x (unicode) [wchar_t **]

Convert a Python unicode object to a C/C++ L'\0' terminated wide character string. If the Python object is Py_None then the string is NULL.

A (unicode) [wchar_t **, int *]

Convert a Python unicode object to a C/C++ wide character array and its length. If the Python object is Py_None then the array and length are NULL and zero respectively.

Cf (wrapped class) [sipWrapperType *, int *, void **]

Convert a Python object to a C structure or a C++ class instance and return its state as described in sipConvertToInstance(). f is a combination of the following flags encoded as an ASCII character by adding 0 to the combined value:

0x01 disallows the conversion of Py_None to NULL

0x02 implements the Factory annotation

0x04 suppresses the return of the state of the returned C/C++

instance. Note that the int * used to return the state is not passed if this flag is specified.

Df (mapped type) [const sipMappedType *, int *, void **]

Convert a Python object to a C structure or a C++ class instance implemented as a mapped type and return its state as described in sipConvertToMappedType(). f is a combination of the following flags encoded as an ASCII character by adding 0 to the combined value:

0x01 disallows the conversion of Py_None to NULL

0x02 implements the Factory annotation

0x04 suppresses the return of the state of the returned C/C++

instance. Note that the int * used to return the state is not passed if this flag is specified.

E (wrapped enum) [PyTypeObject *, enum *]

Convert a Python named enum type to the corresponding C/C++ enum.

L (object) [type *(*)(PyObject *obj, int *iserr), void **]

Convert a Python object to a C structure or a C++ class instance using a convertor function. See Generated Type Convertors. This is deprecated from SIP v4.4.

M (object) [type *(*)(PyObject *obj, int *iserr), void **]

Convert a Python object to a C structure or a C++ class instance using a convertor function. If the structure or class instance pointer is NULL then return an error. See Generated Type Convertors. This is deprecated from SIP v4.4.

N (object) [PyTypeObject *, PyObject **]

A Python object is checked to see if it is a certain type and then returned without any conversions. The reference count is incremented. The Python object may be Py_None.

O (object) [PyObject **]

A Python object is returned without any conversions. The reference count is incremented.

T (object) [PyTypeObject *, PyObject **]

A Python object is checked to see if it is a certain type and then returned without any conversions. The reference count is incremented. The Python object may not be Py_None.

V (sip.voidptr) [void *]

Convert a Python sip.voidptr object to a C/C++ void *.

Z (object) []

Check that a Python object is Py_None. No value is returned.

9.44   sipReleaseInstance()

void sipReleaseInstance(void *cpp, sipWrapperType *type, int state)

This destroys a wrapped C/C++ instance if it was a temporary instance. It is called after a call to either sipConvertToInstance() or sipForceConvertToInstance(). cpp is the wrapped C/C++ instance. type is the generated type corresponding to cpp. state describes the state of the instance.

9.45   sipReleaseMappedType()

void sipReleaseMappedType(void *cpp, const sipMappedType *mt, int state)

This destroys a wrapped C/C++ mapped type if it was a temporary instance. It is called after a call to either sipConvertToMappedType() or sipForceConvertToMappedType(). cpp is the wrapped C/C++ instance. mt is the opaque structure returned by sipFindMappedType(). state describes the state of the instance.

9.46   sipStringTypeClassMap

This C structure is used with sipMapStringToClass() to define a mapping between '\0' terminated string based RTTI and generated type objects. The structure elements are as follows.

char *typeString

The '\0' terminated string RTTI.

sipWrapperType **pyType.

A pointer to the corresponding Python type object.

9.47   sipTransfer()

void sipTransfer(PyObject *obj, int tocpp)

This function is deprecated from SIP v4.3. If tocpp is non-zero then the equivalent call is:

sipTransferTo(obj, obj);

If tocpp is zero then the equivalent call is:

sipTransferBack(obj);

9.48   sipTransferBack()

void sipTransferBack(PyObject *obj)

This transfers ownership of a Python wrapped instance to Python (see Ownership of Objects). obj is the wrapped instance. In addition, any association of the instance with regard to the cyclic garbage collector with another instance is removed.

9.49   sipTransferTo()

void sipTransferTo(PyObject *obj, PyObject *owner)

This transfers ownership of a Python wrapped instance to C++ (see Ownership of Objects). obj is the wrapped instance. owner is an optional wrapped instance that obj becomes associated with with regard to the cyclic garbage collector. If owner is NULL then no such association is made. If owner is the same value as obj then any reference cycles involving obj can never be detected or broken by the cyclic garbage collector. Responsibility for calling the C++ instance's destructor is always transfered to C++.

9.50   sipWrapper

This is a C structure that represents a Python wrapped instance. It is an extension of the Python PyObject structure and so may be safely cast to PyObject. It includes a member called user which is of type PyObject *. This can be used for any purpose by handwritten code and will automatically be garbage collected at the appropriate time.

9.51   sipWrapper_Check()

int sipWrapper_Check(PyObject *obj)

This returns a non-zero value if a Python object is a wrapped instance. obj is the Python object.

9.52   sipWrapperType

This is a C structure that represents a SIP generated type object. It is an extension of the Python PyTypeObject structure (which is itself an extension of the Python PyObject structure) and so may be safely cast to PyTypeObject (and PyObject).

9.53   Generated Type Convertors

These functions are deprecated from SIP v4.4.

SIP generates functions for all types being wrapped (including mapped types defined with the %MappedType directive) that convert a Python object to the C structure or C++ class instance. The name of this convertor is the name of the structure or class prefixed by sipForceConvertTo_.

void *sipForceConvertTo_*class*(PyObject *obj, int *iserr)

obj is the Python object to convert. If obj is NULL or the location pointed to by iserr is non-zero then the conversion is not attempted and NULL is returned. If there was an error then the location pointed to by iserr is set to a non-zero value, a Python exception is raised, and NULL is returned.

SIP also generates functions for mapped types that convert a C structure or C++ class instance to a Python object. The name of this convertor is the name of the structure or class prefixed by sipConvertFrom_.

PyObject *sipConvertFrom_*class*(void *cppptr)

cppptr is a pointer to the C structure or C++ class instance to convert. If there was an error then NULL is returned and a Python exception raised.

The convertor functions of all imported types are available to handwritten code.

9.54   Generated Type Objects

SIP generates a type object for each C structure or C++ class being wrapped. These are sipWrapperType structures and are used extensively by the SIP API.

These objects are named with the structure or class name prefixed by sipClass_. For example, the type object for class Klass is sipClass_Klass.

The type objects of all imported classes are available to handwritten code.

9.55   Generated Named Enum Type Objects

SIP generates a type object for each named enum being wrapped. These are PyTypeObject structures. (Anonymous enums are wrapped as Python integers.)

These objects are named with the fully qualified enum name (i.e. including any enclosing scope) prefixed by sipEnum_. For example, the type object for enum Enum defined in class Klass is sipEnum_Klass_Enum.

The type objects of all imported named enums are available to handwritten code.

9.56   Generated Derived Classes

For most C++ classes being wrapped SIP generates a derived class with the same name prefixed by sip. For example, the derived class for class Klass is sipKlass.

If a C++ class doesn't have any virtual or protected methods in it or any of it's super-class hierarchy, or does not emit any Qt signals, then a derived class is not generated.

Most of the time handwritten code should ignore the derived classes. The only exception is that handwritten constructor code specified using the %MethodCode directive should call the derived class's constructor (which has the same C++ signature) rather then the wrapped class's constructor.

9.57   Generated Exception Objects

SIP generates a Python object for each exception defined with the %Exception_ directive.

These objects are named with the fully qualified exception name (i.e. including any enclosing scope) prefixed by sipException_. For example, the type object for enum Except defined in class Klass is sipException_Klass_Except.

The objects of all imported exceptions are available to handwritten code.

11.1   sipconfig Functions

create_config_module(module, template, content, macros=None)

This creates a configuration module (e.g. pyqtconfig) from a template file and a string.

module is the name of the configuration module file to create.

template is the name of the template file.

content is a string which replaces every occurence of the pattern @SIP_CONFIGURATION@ in the template file. The content string is usually created from a Python dictionary using sipconfig.create_content(). content may also be a dictionary, in which case sipconfig.create_content() is automatically called to convert it to a string.

macros is an optional dictionary of platform specific build macros. It is only used if sipconfig.create_content() is called automatically to convert a content dictionary to a string.

create_content(dict, macros=None)

This converts a Python dictionary to a string that can be parsed by the Python interpreter and converted back to an equivalent dictionary. It is typically used to generate the content string for sipconfig.create_config_module().

dict is the Python dictionary to convert.

macros is the optional dictionary of platform specific build macros.

Returns the dictionary as a string.

create_wrapper(script, wrapper, gui=0)

This creates a platform dependent executable wrapper around a Python script.

script is the full pathname of the script.

wrapper is the pathname of the wrapper to create.

gui is non-zero if a GUI enabled version of the interpreter should be used on platforms that require it.

Returns the platform specific name of the wrapper.

error(msg)

This displays an error message on stderr and calls sys.exit() with a value of 1.

msg is the text of the message and should not include any newline characters.

format(msg, leftmargin=0, rightmargin=78)

This formats a message by inserting newline characters at appropriate places.

msg is the text of the message and should not include any newline characters.

leftmargin is the optional position of the left margin.

rightmargin is the optional position of the right margin.

inform(msg)

This displays an information message on stdout.

msg is the text of the message and should not include any newline characters.

parse_build_macros(filename, names, overrides=None, properties=None)

This parses a qmake compatible file of build system macros and converts it to a dictionary. A macro is a name/value pair. The dictionary is returned or None if any of the overrides was invalid.

filename is the name of the file to parse.

names is a list of the macro names to extract from the file.

overrides is an optional list of macro names and values that modify those found in the file. They are of the form name=value (in which case the value replaces the value found in the file) or name+=value (in which case the value is appended to the value found in the file).

properties is an optional dictionary of property name and values that are used to resolve any expressions of the form $[name] in the file.

read_version(filename, description, numdefine=None, strdefine=None)

This extracts version information for a package from a file, usually a C or C++ header file. The version information must each be specified as a #define of a numeric (hexadecimal or decimal) value and/or a string value.

filename is the name of the file to read.

description is a descriptive name of the package used in error messages.

numdefine is the optional name of the #define of the version as a number. If it is None then the numeric version is ignored.

strdefine is the optional name of the #define of the version as a string. If it is None then the string version is ignored.

Returns a tuple of the numeric and string versions. sipconfig.error() is called if either were required but could not be found.

version_to_sip_tag(version, tags, description)

This converts a version number to a SIP version tag. SIP uses the %Timeline directive to define the chronology of the different versions of the C/C++ library being wrapped. Typically it is not necessary to define a version tag for every version of the library, but only for those versions that affect the library's API as SIP sees it.

version is the numeric version number of the C/C++ library being wrapped. If it is negative then the latest version is assumed. (This is typically useful if a snapshot is indicated by a negative version number.)

tags is the dictionary of SIP version tags keyed by the corresponding C/C++ library version number. The tag used is the one with the smallest key (i.e. earliest version) that is greater than version.

description is a descriptive name of the C/C++ library used in error messages.

Returns the SIP version tag. sipconfig.error() is called if the C/C++ library version number did not correspond to a SIP version tag.

version_to_string(v)

This converts a 3 part version number encoded as a hexadecimal value to a string.

v is the version number.

Returns a string.

11.2   sipconfig Classes

Configuration

This class encapsulates configuration values that can be accessed as instance objects. A sub-class may provide a dictionary of additional configuration values in its constructor the elements of which will have precedence over the super-class's values.

The following configuration values are provided:

default_bin_dir

The name of the directory where executables should be installed by default.

default_mod_dir

The name of the directory where SIP generated modules should be installed by default.

default_sip_dir

The name of the base directory where the .sip files for SIP generated modules should be installed by default. A sub-directory with the same name as the module should be created and its .sip files should be installed in the sub-directory. The .sip files only need to be installed if you might want to build other bindings based on them.

platform

The name of the platform/compiler for which the build system has been configured for.

py_conf_inc_dir

The name of the directory containing the pyconfig.h header file.

py_inc_dir

The name of the directory containing the Python.h header file.

py_lib_dir

The name of the directory containing the Python interpreter library.

py_version

The Python version as a 3 part hexadecimal number (e.g. v2.3.3 is represented as 0x020303).

sip_bin

The full pathname of the SIP executable.

sip_config_args

The command line passed to configure.py when SIP was configured.

sip_inc_dir

The name of the directory containing the sip.h header file.

sip_mod_dir

The name of the directory containing the SIP module.

sip_version

The SIP version as a 3 part hexadecimal number (e.g. v4.0.0 is represented as 0x040000).

sip_version_str

The SIP version as a string. For development snapshots it will start with snapshot-.

universal

The name of the MacOS/X SDK used when creating universal binaries.

__init__(self, sub_cfg=None)

Initialise the instance.

sub_cfg is an optional list of sub-class configurations. It should only be used by the __init__() method of a sub-class to append its own dictionary of configuration values before passing the list to its super-class.

build_macros(self)

Return the dictionary of platform specific build macros.

set_build_macros(self, macros)

Set the dictionary of platform specific build macros to be use when generating Makefiles. Normally there is no need to change the default macros.

Makefile

This class encapsulates a Makefile. It is intended to be sub-classed to generate Makefiles for particular purposes. It handles all platform and compiler specific flags, but allows them to be adjusted to suit the requirements of a particular module or program. These are defined using a number of macros which can be accessed as instance objects.

The following instance objects are provided to help in fine tuning the generated Makefile:

chkdir

A string that will check for the existence of a directory.

config

A reference to the configuration argument that was passed to the constructor.

console

A reference to the console argument that was passed to the constructor.

copy

A string that will copy a file.

extra_cflags

A list of additional flags passed to the C compiler.

extra_cxxflags

A list of additional flags passed to the C++ compiler.

extra_defines

A list of additional macro names passed to the C/C++ preprocessor.

extra_include_dirs

A list of additional include directories passed to the C/C++ preprocessor.

extra_lflags

A list of additional flags passed to the linker.

extra_lib_dirs

A list of additional library directories passed to the linker.

extra_libs

A list of additional libraries passed to the linker. The names of the libraries must be in platform neutral form (i.e. without any platform specific prefixes, version numbers or extensions).

generator

A string that defines the platform specific style of Makefile. The only supported values are UNIX and something else that is not UNIX.

mkdir

A string that will create a directory.

rm

A string that will remove a file.

__init__(self, configuration, console=0, qt=0, opengl=0, python=0, threaded=0, warnings=None, debug=0, dir=None, makefile="Makefile", installs=None, universal='')

Initialise the instance.

configuration is the current configuration and is an instance of the Configuration class or a sub-class.

console is set if the target is a console (rather than GUI) target. This only affects Windows and is ignored on other platforms.

qt is set if the target uses Qt. For Qt v4 a list of Qt libraries may be specified and a simple non-zero value implies QtCore and QtGui.

opengl is set if the target uses OpenGL.

python is set if the target uses Python.h.

threaded is set if the target requires thread support. It is set automatically if the target uses Qt and Qt has thread support enabled.

warnings is set if compiler warning messages should be enabled. The default of None means that warnings are enabled for SIP v4.x and disabled for SIP v3.x.

debug is set if debugging symbols should be generated.

dir is the name of the directory where build files are read from and Makefiles are written to. The default of None means the current directory is used.

makefile is the name of the generated Makefile.

installs is a list of extra install targets. Each element is a two part list, the first of which is the source and the second is the destination. If the source is another list then it is a list of source files and the destination is a directory.

universal is the name of the SDK if universal binaries are to be created under MacOS/X.

clean_build_file_objects(self, mfile, build)

This generates the Makefile commands that will remove any files generated during the build of the default target.

mfile is the Python file object of the Makefile.

build is the dictionary created from parsing the build file.

finalise(self)

This is called just before the Makefile is generated to ensure that it is fully configured. It must be reimplemented by a sub-class.

generate(self)

This generates the Makefile.

generate_macros_and_rules(self, mfile)

This is the default implementation of the Makefile macros and rules generation.

mfile is the Python file object of the Makefile.

generate_target_clean(self, mfile)

This is the default implementation of the Makefile clean target generation.

mfile is the Python file object of the Makefile.

generate_target_default(self, mfile)

This is the default implementation of the Makefile default target generation.

mfile is the Python file object of the Makefile.

generate_target_install(self, mfile)

This is the default implementation of the Makefile install target generation.

mfile is the Python file object of the Makefile.

install_file(self, mfile, src, dst, strip=0)

This generates the Makefile commands to install one or more files to a directory.

mfile is the Python file object of the Makefile.

src is the name of a single file to install or a list of a number of files to install.

dst is the name of the destination directory.

strip is set if the files should be stripped of unneeded symbols after having been installed.

optional_list(self, name)

This returns an optional Makefile macro as a list.

name is the name of the macro.

Returns the macro as a list.

optional_string(self, name, default="")

This returns an optional Makefile macro as a string.

name is the name of the macro.

default is the optional default value of the macro.

Returns the macro as a string.

parse_build_file(self, filename)

This parses a build file (created with the -b SIP command line option) and converts it to a dictionary. It can also validate an existing dictionary created through other means.

filename is the name of the build file, or is a dictionary to be validated. A valid dictionary will contain the name of the target to build (excluding any platform specific extension) keyed by target; the names of all source files keyed by sources; and, optionally, the names of all header files keyed by headers.

Returns a dictionary corresponding to the parsed build file.

platform_lib(self, clib, framework=0)

This converts a library name to a platform specific form.

clib is the name of the library in cannonical form.

framework is set if the library is implemented as a MacOS framework.

Return the platform specific name.

ready(self)

This is called to ensure that the Makefile is fully configured. It is normally called automatically when needed.

required_string(self, name)

This returns a required Makefile macro as a string.

name is the name of the macro.

Returns the macro as a string. An exception is raised if the macro does not exist or has an empty value.

ModuleMakefile(Makefile)

This class encapsulates a Makefile to build a generic Python extension module.

__init__(self, configuration, build_file, install_dir=None, static=0, console=0, opengl=0, threaded=0, warnings=None, debug=0, dir=None, makefile="Makefile", installs=None, strip=1, export_all=0, universal='')

Initialise the instance.

configuration - see sipconfig.Makefile.__init__().

build_file is the name of the build file. Build files are generated using the -b SIP command line option.

install_dir is the name of the directory where the module will be optionally installed.

static is set if the module should be built as a static library (see Builtin Modules and Custom Interpreters).

console - see sipconfig.Makefile.__init__().

qt - see sipconfig.Makefile.__init__().

opengl - see sipconfig.Makefile.__init__().

threaded - see sipconfig.Makefile.__init__().

warnings - see sipconfig.Makefile.__init__().

debug - see sipconfig.Makefile.__init__().

dir - see sipconfig.Makefile.__init__().

makefile - see sipconfig.Makefile.__init__().

installs - see sipconfig.Makefile.__init__().

strip is set if the module should be stripped of unneeded symbols after installation. It is ignored if either debug or static is set, or if the platform doesn't support it.

export_all is set if all of the module's symbols should be exported rather than just the module's initialisation function. Exporting all symbols increases the size of the module and slows down module load times but may avoid problems with modules that use C++ exceptions. All symbols are exported if either debug or static is set, or if the platform doesn't support it.

finalise(self)

This is a reimplementation of sipconfig.Makefile.finalise().

generate_macros_and_rules(self, mfile)

This is a reimplementation of sipconfig.Makefile.generate_macros_and_rules().

generate_target_clean(self, mfile)

This is a reimplementation of sipconfig.Makefile.generate_target_clean().

generate_target_default(self, mfile)

This is a reimplementation of sipconfig.Makefile.generate_target_default().

generate_target_install(self, mfile)

This is a reimplementation of sipconfig.Makefile.generate_target_install().

module_as_lib(self, mname)

This returns the name of a SIP v3.x module for when it is used as a library to be linked against. An exception will be raised if it is used with SIP v4.x modules.

mname is the name of the module.

Returns the corresponding library name.

ParentMakefile(Makefile)

This class encapsulates a Makefile that sits above a number of other Makefiles in sub-directories.

__init__(self, configuration, subdirs, dir=None, makefile="Makefile", installs=None)

Initialise the instance.

configuration - see sipconfig.Makefile.__init__().

subdirs is the sequence of sub-directories.

dir - see sipconfig.Makefile.__init__().

makefile - see sipconfig.Makefile.__init__().

installs - see sipconfig.Makefile.__init__().

generate_macros_and_rules(self, mfile)

This is a reimplementation of sipconfig.Makefile.generate_macros_and_rules().

generate_target_clean(self, mfile)

This is a reimplementation of sipconfig.Makefile.generate_target_clean().

generate_target_default(self, mfile)

This is a reimplementation of sipconfig.Makefile.generate_target_default().

generate_target_install(self, mfile)

This is a reimplementation of sipconfig.Makefile.generate_target_install().

ProgramMakefile(Makefile)

This class encapsulates a Makefile to build an executable program.

__init__(self, configuration, build_file=None, install_dir=None, console=0, qt=0, opengl=0, python=0, threaded=0, warnings=None, debug=0, dir=None, makefile="Makefile", installs=None, universal='')

Initialise the instance.

configuration - see sipconfig.Makefile.__init__().

build_file is the name of the optional build file. Build files are generated using the -b SIP command line option.

install_dir is the name of the directory where the executable program will be optionally installed.

console - see sipconfig.Makefile.__init__().

qt - see sipconfig.Makefile.__init__().

opengl - see sipconfig.Makefile.__init__().

python - see sipconfig.Makefile.__init__().

threaded - see sipconfig.Makefile.__init__().

warnings - see sipconfig.Makefile.__init__().

debug - see sipconfig.Makefile.__init__().

dir - see sipconfig.Makefile.__init__().

makefile - see sipconfig.Makefile.__init__().

installs - see sipconfig.Makefile.__init__().

build_command(self, source)

This creates a single command line that will create an executable program from a single source file.

source is the name of the source file.

Returns a tuple of the name of the executable that will be created and the command line.

finalise(self)

This is a reimplementation of sipconfig.Makefile.finalise().

generate_macros_and_rules(self, mfile)

This is a reimplementation of sipconfig.Makefile.generate_macros_and_rules().

generate_target_clean(self, mfile)

This is a reimplementation of sipconfig.Makefile.generate_target_clean().

generate_target_default(self, mfile)

This is a reimplementation of sipconfig.Makefile.generate_target_default().

generate_target_install(self, mfile)

This is a reimplementation of sipconfig.Makefile.generate_target_install().

PythonModuleMakefile(Makefile)

This class encapsulates a Makefile that installs a pure Python module.

__init__(self, configuration, dstdir, srcdir=None, dir=None, makefile="Makefile", installs=None)

Initialise the instance.

configuration - see sipconfig.Makefile.__init__().

dstdir is the name of the directory in which the module's Python code will be installed.

srcdir is the name of the directory (relative to dir) containing the module's Python code. It defaults to the same directory.

dir - see sipconfig.Makefile.__init__().

makefile - see sipconfig.Makefile.__init__().

installs - see sipconfig.Makefile.__init__().

generate_macros_and_rules(self, mfile)

This is a reimplementation of sipconfig.Makefile.generate_macros_and_rules().

generate_target_install(self, mfile)

This is a reimplementation of sipconfig.Makefile.generate_target_install().

SIPModuleMakefile(ModuleMakefile)

This class encapsulates a Makefile to build a SIP generated Python extension module.

finalise(self)

This is a reimplementation of sipconfig.Makefile.finalise().