UseSWIG¶
This file provides support for SWIG. It is assumed that FindSWIG
module has already been loaded.
CMake Commands¶
The following command is defined for use with SWIG:
- swig_add_library¶
Added in version 3.8.
Define swig module with given name and specified language:
swig_add_library(<name> [TYPE <SHARED|MODULE|STATIC|USE_BUILD_SHARED_LIBS>] LANGUAGE <language> [NO_PROXY] [OUTPUT_DIR <directory>] [OUTFILE_DIR <directory>] SOURCES <file>... )Targets created with the
swig_add_librarycommand have the same capabilities as targets created with theadd_library()command, so those targets can be used with any command expecting a target (e.g.target_link_libraries()).Changed in version 3.13: This command creates a target with the specified
<name>when policyCMP0078is set toNEW. Otherwise, the legacy behavior will choose a different target name and store it in theSWIG_MODULE_<name>_REAL_NAMEvariable.Changed in version 3.15: Alternate library name (set with the
OUTPUT_NAMEproperty, for example) will be passed on toPythonandCSharpwrapper libraries.Changed in version 3.21: Generated library use standard naming conventions for
CSharplanguage when policyCMP0122is set toNEW. Otherwise, the legacy behavior is applied.Note
For multi-config generators, this module does not support configuration-specific files generated by
SWIG. All build configurations must result in the same generated source file.Note
For Makefile Generators, if, for some sources, the
USE_SWIG_DEPENDENCIESproperty isFALSE,swig_add_librarydoes not track file dependencies, so depending on the<name>_swig_compilationcustom target is required for targets which require theswig-generated files to exist. Other generators may depend on the source files that would be generated by SWIG.TYPESHARED,MODULEandSTATIChave the same semantic as for theadd_library()command. IfUSE_BUILD_SHARED_LIBSis specified, the library type will beSTATICorSHAREDbased on whether the current value of theBUILD_SHARED_LIBSvariable isON. If no type is specified,MODULEwill be used.LANGUAGESpecify the target language.
Added in version 3.1: Go and Lua language support.
Added in version 3.2: R language support.
Added in version 3.18: Fortran language support.
NO_PROXYAdded in version 3.12.
Prevent the generation of the wrapper layer (swig
-noproxyoption).OUTPUT_DIRAdded in version 3.12.
Specify where to write the language specific files (swig
-outdiroption). If not given, theCMAKE_SWIG_OUTDIRvariable will be used. If neither is specified, the default depends on the value of theUseSWIG_MODULE_VERSIONvariable as follows:If
UseSWIG_MODULE_VERSIONis 1 or is undefined, output is written to theCMAKE_CURRENT_BINARY_DIRdirectory.If
UseSWIG_MODULE_VERSIONis 2, a dedicated directory will be used. The path of this directory can be retrieved from theSWIG_SUPPORT_FILES_DIRECTORYtarget property.
OUTFILE_DIRAdded in version 3.12.
Specify an output directory name where the generated source file will be placed (swig
-ooption). If not specified, theSWIG_OUTFILE_DIRvariable will be used. If neither is specified,OUTPUT_DIRorCMAKE_SWIG_OUTDIRis used instead.SOURCESList of sources for the library. Files with extension
.iwill be identified as sources for theSWIGtool. Other files will be handled in the standard way.Added in version 3.14: This behavior can be overridden by specifying the variable
SWIG_SOURCE_FILE_EXTENSIONS.
Note
If
UseSWIG_MODULE_VERSIONis set to 2, it is strongly recommended to use a dedicated directory unique to the target when either theOUTPUT_DIRoption or theCMAKE_SWIG_OUTDIRvariable are specified. The output directory contents are erased as part of the target build, so to prevent interference between targets or losing other important files, each target should have its own dedicated output directory.
Properties on Source Files¶
Source file properties on module files must be set before the invocation
of the swig_add_library command to specify special behavior of SWIG and
ensure generated files will receive the required settings.
CPLUSPLUSCall SWIG in c++ mode. For example:
set_property(SOURCE mymod.i PROPERTY CPLUSPLUS ON) swig_add_library(mymod LANGUAGE python SOURCES mymod.i)
SWIG_FLAGSDeprecated since version 3.12: Replaced with the fine-grained properties that follow.
Pass custom flags to the SWIG executable.
INCLUDE_DIRECTORIES,COMPILE_DEFINITIONSandCOMPILE_OPTIONSAdded in version 3.12.
Add custom flags to SWIG compiler and have same semantic as properties
INCLUDE_DIRECTORIES,COMPILE_DEFINITIONSandCOMPILE_OPTIONS.USE_TARGET_INCLUDE_DIRECTORIESAdded in version 3.13.
If set to
TRUE, contents of target propertyINCLUDE_DIRECTORIESwill be forwarded toSWIGcompiler. If set toFALSEtarget propertyINCLUDE_DIRECTORIESwill be ignored. If not set, target propertySWIG_USE_TARGET_INCLUDE_DIRECTORIESwill be considered.GENERATED_INCLUDE_DIRECTORIES,GENERATED_COMPILE_DEFINITIONSandGENERATED_COMPILE_OPTIONSAdded in version 3.12.
Add custom flags to the C/C++ generated source. They will fill, respectively, properties
INCLUDE_DIRECTORIES,COMPILE_DEFINITIONSandCOMPILE_OPTIONSof generated C/C++ file.DEPENDSAdded in version 3.12.
Specify additional dependencies to the source file.
USE_SWIG_DEPENDENCIESAdded in version 3.20.
If set to
TRUE, implicit dependencies are generated by theswigtool itself. This property is only meaningful for Makefile, Ninja,Xcode, and Visual Studio (Visual Studio 12 2013and above) generators. Default value isFALSE.Added in version 3.21: Added the support of
Xcodegenerator.Added in version 3.22: Added the support of Visual Studio Generators.
SWIG_MODULE_NAMESpecify the actual import name of the module in the target language. This is required if it cannot be scanned automatically from source or different from the module file basename. For example:
set_property(SOURCE mymod.i PROPERTY SWIG_MODULE_NAME mymod_realname)
Changed in version 3.14: If policy
CMP0086is set toNEW,-module <module_name>is passed toSWIGcompiler.OUTPUT_DIRAdded in version 3.19.
Specify where to write the language specific files (swig
-outdiroption) for the considered source file. If not specified, the other ways to define the output directory applies (seeOUTPUT_DIRoption ofswig_add_library()command).OUTFILE_DIRAdded in version 3.19.
Specify an output directory where the generated source file will be placed (swig
-ooption) for the considered source file. If not specified,OUTPUT_DIRsource property will be used. If neither are specified, the other ways to define output file directory applies (seeOUTFILE_DIRoption ofswig_add_library()command).
Properties on Targets¶
Target library properties can be set to apply same configuration to all SWIG input files.
SWIG_INCLUDE_DIRECTORIES,SWIG_COMPILE_DEFINITIONSandSWIG_COMPILE_OPTIONSAdded in version 3.12.
These properties will be applied to all SWIG input files and have same semantic as target properties
INCLUDE_DIRECTORIES,COMPILE_DEFINITIONSandCOMPILE_OPTIONS.set (UseSWIG_TARGET_NAME_PREFERENCE STANDARD) swig_add_library(mymod LANGUAGE python SOURCES mymod.i) set_property(TARGET mymod PROPERTY SWIG_COMPILE_DEFINITIONS MY_DEF1 MY_DEF2) set_property(TARGET mymod PROPERTY SWIG_COMPILE_OPTIONS -bla -blb)
SWIG_USE_TARGET_INCLUDE_DIRECTORIESAdded in version 3.13.
If set to
TRUE, contents of target propertyINCLUDE_DIRECTORIESwill be forwarded toSWIGcompiler. If set toFALSEor not defined, target propertyINCLUDE_DIRECTORIESwill be ignored. This behavior can be overridden by specifying source propertyUSE_TARGET_INCLUDE_DIRECTORIES.SWIG_GENERATED_INCLUDE_DIRECTORIES,SWIG_GENERATED_COMPILE_DEFINITIONSandSWIG_GENERATED_COMPILE_OPTIONSAdded in version 3.12.
These properties will populate, respectively, properties
INCLUDE_DIRECTORIES,COMPILE_DEFINITIONSandCOMPILE_FLAGSof all generated C/C++ files.SWIG_DEPENDSAdded in version 3.12.
Add dependencies to all SWIG input files.
Read-only Target Properties¶
The following target properties are output properties and can be used to get
information about support files generated by SWIG interface compilation.
SWIG_SUPPORT_FILESAdded in version 3.12.
This output property list of wrapper files generated during SWIG compilation.
set (UseSWIG_TARGET_NAME_PREFERENCE STANDARD) swig_add_library(mymod LANGUAGE python SOURCES mymod.i) get_property(support_files TARGET mymod PROPERTY SWIG_SUPPORT_FILES)
Note
Only most principal support files are listed. In case some advanced features of
SWIGare used (for example%template), associated support files may not be listed. Prefer to use theSWIG_SUPPORT_FILES_DIRECTORYproperty to handle support files.SWIG_SUPPORT_FILES_DIRECTORYAdded in version 3.12.
This output property specifies the directory where support files will be generated.
Note
When source property
OUTPUT_DIRis defined, multiple directories can be specified as part ofSWIG_SUPPORT_FILES_DIRECTORY.
CMake Variables¶
Some variables can be set to customize the behavior of swig_add_library
as well as SWIG:
UseSWIG_MODULE_VERSIONAdded in version 3.12.
Specify different behaviors for
UseSWIGmodule.Set to 1 or undefined: Legacy behavior is applied.
Set to 2: A new strategy is applied regarding support files: the output directory of support files is erased before
SWIGinterface compilation.
CMAKE_SWIG_FLAGSAdd flags to all swig calls.
CMAKE_SWIG_OUTDIRSpecify where to write the language specific files (swig
-outdiroption).SWIG_OUTFILE_DIRAdded in version 3.8.
Specify an output directory name where the generated source file will be placed. If not specified,
CMAKE_SWIG_OUTDIRis used.SWIG_MODULE_<name>_EXTRA_DEPSSpecify extra dependencies for the generated module for
<name>.SWIG_SOURCE_FILE_EXTENSIONSAdded in version 3.14.
Specify a list of source file extensions to override the default behavior of considering only
.ifiles as sources for theSWIGtool. For example:set(SWIG_SOURCE_FILE_EXTENSIONS ".i" ".swg")
SWIG_USE_SWIG_DEPENDENCIESAdded in version 3.20.
If set to
TRUE, implicit dependencies are generated by theswigtool itself. This variable is only meaningful for Makefile, Ninja,Xcode, and Visual Studio (Visual Studio 12 2013and above) generators. Default value isFALSE.Source file property
USE_SWIG_DEPENDENCIES, if not defined, will be initialized with the value of this variable.Added in version 3.21: Added the support of
Xcodegenerator.Added in version 3.22: Added the support of Visual Studio Generators.
Deprecated Commands¶
- swig_link_libraries¶
Deprecated since version 3.13: Use
target_link_libraries()with the standard target name, or with${SWIG_MODULE_<name>_REAL_NAME}for legacy target naming.Link libraries to swig module:
swig_link_libraries(<name> <item>...)
This command has same capabilities as
target_link_libraries()command.Note
When policy
CMP0078is set toNEW,swig_add_library()creates a standard target with the specified<name>andtarget_link_libraries()must be used instead of this command.With the legacy behavior (when
CMP0078is set toOLDand theUseSWIG_TARGET_NAME_PREFERENCEvariable is set to"LEGACY", or in CMake versions prior to 3.12), it is preferable to usetarget_link_libraries(${SWIG_MODULE_<name>_REAL_NAME} ...)instead of this command.