clibgen.generateLibraryDefinition - Create definition file for C++ library - MATLAB (original) (raw)

Create definition file for C++ library

Syntax

Description

The clibgen.generateLibraryDefinition function creates a_definition file_ with a .m file extension used to generate a MATLAB® interface to a C++ library. Use this function to:

After creating the definition file, you optionally can modify the contents to include functionality that the function cannot automatically define. For information about using a library definition file, see Define MATLAB Interface for C++ Library.

You need a C++ compiler that MATLAB supports. You must build the interface library using the same compiler that was used to build the C++ library. If your library is completely defined by source files (does not use a compiled library file), then you can choose any supported C++ compiler to build the interface library. For information about your C++ compilers, type:

Call the build function on the definition file to create the MATLAB interface file.

clibgen.generateLibraryDefinition([InterfaceGenerationFiles](#mw%5Fa70591c4-d914-458b-b1e7-5a664c9b787a),[Libraries](#mw%5F8845b894-1356-420c-8e81-5296ea2ed151)=LibraryFiles) creates a definition file defined byInterfaceGenerationFiles andLibraryFiles.

The name of the definition file is define_`libName`_.m (since R2022b). By default, libName is the name of the first file specified in InterfaceGenerationFiles. For example, if you specify a header file named mylibrary.hpp, then the function creates a definition file named definemylibrary.m. If you specify more than one interface generation file, then you must use theInterfaceName name-value argument to specify_libName_.

example

clibgen.generateLibraryDefinition([InterfaceGenerationFiles](#mw%5Fa70591c4-d914-458b-b1e7-5a664c9b787a),[SupportingSourceFiles](#mw%5F6aaafb9b-719c-492f-bcbd-559f6623ddf0%5Fsep%5Fmw%5F814380ce-a2fe-44a4-b9ab-81cdfcacdce6)=SourceFiles) for a library defined by multiple header files, source files, and, if required, compiled library files.

clibgen.generateLibraryDefinition([InterfaceGenerationFiles](#mw%5Fa70591c4-d914-458b-b1e7-5a664c9b787a)) for a library completely defined byInterfaceGenerationFiles. If your library includes a compiled library file, then you must specify a Libraries argument.

example

clibgen.generateLibraryDefinition(___,[Name=Value](#namevaluepairarguments)) creates the file using one or more name-value arguments. Use this option with any of the input argument combinations in the previous syntaxes.

Examples

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The files for this example are in a MATLAB examples folder. Generate the library definition filedefinematrixOperations.m from thematrixOperations.hpp header file on Windows®. For a Linux® example, see Header and C++ Compiled Library Files on Linux.

Create an InterfaceGenerationFiles argumenthFile with the full path to the header file.

hFile = fullfile(matlabroot,"extern","examples","cpp_interface","matrixOperations.hpp");

The header file includes another header file. Create anIncludePath argument iPath with the full path to the folder containing the included header file.

iPath = fullfile(matlabroot,"extern","examples","cpp_interface");

Create a Libraries argument libFile with the full path to the compiled library file.

libFile = fullfile(matlabroot,"extern","examples","cpp_interface", ... "win64","mingw64","matrixOperations.lib");

Create the definematrixOperations.m library definition file.

clibgen.generateLibraryDefinition(hFile,IncludePath=iPath,Libraries=libFile)

C++ compiler set to 'MinGW64 Compiler (C++)'. Definition file definematrixOperations.m contains definitions for 10 constructs supported by MATLAB.

 

To include the 5 undefined constructs in the interface, uncomment and complete the definitions in definematrixOperations.m. To build the interface, call build(definematrixOperations).

The files for this example are in a MATLAB examples folder. Generate a library definition file nameddefinematrixOps.m from thematrixOperations.hpp andmatrixOperations.cpp files.

Create an InterfaceGenerationFiles argumenthFile with the full path to the header filematrixOperations.hpp.

hFile = fullfile(matlabroot,"extern","examples","cpp_interface","matrixOperations.hpp");

The header file includes another header file. Create anIncludePath argument iPath with the full path to the folder containing the included header file.

iPath = fullfile(matlabroot,"extern","examples","cpp_interface");

Create a SupportingSourceFiles argumentcFile with the full path to the C++ source filematrixOperations.cpp.

cFile = fullfile(matlabroot,"extern","examples","cpp_interface","matrixOperations.cpp");

Create the definematrixOps.m library definition file by setting the InterfaceName argument to"matrixOps".

clibgen.generateLibraryDefinition(hFile, ... SupportingSourceFiles=cFile, ... IncludePath=iPath, ... InterfaceName="matrixOps")

C++ compiler set to 'MinGW64 Compiler (C++)'. Definition file definematrixOps.m contains definitions for 10 constructs supported by MATLAB.

 

To include the 5 undefined constructs in the interface, uncomment and complete the definitions in definematrixOps.m. To build the interface, call build(definematrixOps).

Generate the library definition file defineschool.m from the school.hpp header file.

clibgen.generateLibraryDefinition(fullfile(matlabroot,"extern","examples", ... "cpp_interface","school.hpp"))

C++ compiler set to 'MinGW64 Compiler (C++)'. Definition file defineschool.m contains definitions for 21 constructs supported by MATLAB.

To include the 1 undefined construct in the interface, uncomment and complete the definitions in defineschool.m. To build the interface, call build(defineschool).

Input Arguments

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Files to generate the interface, specified as a string array, character vector, or cell array of character vectors. If not in the current folder or on your MATLAB path, then the argument includes the full or relative path to the file. For more information, see "Files in Your Library" in Tips.

Files for specifying InterfaceGenerationFiles andSupportingSourceFiles arguments are:

These files must contain declarations of all the functions exported by the library. You should be able to compile them in a C++ development environment and use the functionality in C++ applications. If the library is completely defined by the header files (header-only library), then you do not need to specify the Libraries argument.

If the main header file contains #include statements for header files in different folders, then use theIncludePath argument to specify these paths.

If you provide a single header filename, then the function looks for a library with the same name, in the same folder as the header file. The library must have a platform-specific filename extension. If the library has a different name or is not in the same folder, then use theLibraries argument.

The function writes the interface files in a subfolder in the current folder, unless you specify the OutputFolder argument. The name of the subfolder is the name of the first header file without a file extension. For example, this statement creates the interface library file in the subfolder myHeader in the current folder.

clibgen.generateLibraryDefinition("myHeader.hpp")

Example: "sample.hpp"

Data Types: char | string | cell

Name-Value Arguments

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Specify optional pairs of arguments asName1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Before R2021a, use commas to separate each name and value, and enclose Name in quotes.

Example: clibgen.generateLibraryDefinition( ... ["hfile1.hpp","hfile2.hpp"], ... Libraries="hfile1.lib", ... IncludePath="C:\mylib\include", ... InterfaceName="mylib", ... OutputFolder="C:\work", ... DefinedMacros=["mymacro1","mymacro2=0"], ... UndefinedMacros="mymacro3", ... OverwriteExistingDefinitionFiles=true);

File Selection

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Compiled library filenames, specified as a string array, character vector, or cell array of character vectors. This value is required except if the library is completely defined by the files specified by the InterfaceGenerationFiles argument and the SupportingSourceFiles name-value argument.

A library is one of these:

For example, this statement creates definesample.m using sample.hpp in the current folder andmyLib.lib in the C:\myLib folder and writes the definition file in the current folder.

clibgen.generateLibraryDefinition("sample.hpp",Libraries="C:\myLib\myLib.lib")

Data Types: char | string | cell

Since R2020b

C/C++ source files, specified as a string array, character vector, or cell array of character vectors. Use with the SupportingSourceFiles name-value argument. Supported file extensions are .c, .cpp, and .cxx. If not in the current folder or on your MATLAB path, then the argument includes the full or relative path to the file. A supporting source file must contain C/C++ code.

For more information, see "Files in Your Library" in Tips.

For information about building C source files, see CLinkage.

If the library is completely defined by header and C++ source files, then compiled library files are not required.

Example: "sample.cpp"

Data Types: char | string | cell

Folders for included header files, specified as a string array, character vector, or cell array of character vectors. Each value inIncludePath must be the full pathname to folders to include during compilation of the header files.

If the main header file contains #include statements for header files in different folders, then use the IncludePath argument to specify these paths.

Data Types: char | string | cell

Since R2024a

Starting pathname for publishers who plan to share library definition files, specified as a scalar dictionary, where key is a variable name chosen by the publisher and value is a relative pathname. The dictionary entries are specified as string scalars or character vectors. For example, on your computer, the starting pathname to the library files isc:\user1\libname. Another publisher has the same library version located in folder c:\user2\libname. Choose a key variable name and pass that name to the other publisher, who uses it to identify their local folder in theclibgen.generateLibraryDefinition function.

Identify the local path to files specified in these arguments, and put the path in a RootPaths dictionary argument:

Then replace the local path in any of these argument names with theRootPaths key by using the< and > tags. This enables another publisher to specify their own local path in theRootPaths key-value argument which MATLAB uses to identify the path in these arguments. For example, these statements create a library definition file nameddefinemyLib.m. The dictionary key isrootpath, and the library files are located on your computer in C:\user1\libname.

startpaths = dictionary; startpaths("rootpath") = "C:\user1\libname"; clibgen.generateLibraryDefinition( ... ["\src\header1.hpp" "\include\header2.hpp"], ... IncludePath="\include", ... Libraries="\lib\libname.lib", ... OutputFolder="\MATLAB", ... RootPaths=startpaths, ... InterfaceName="myLib");

If another publisher has the same version of the library in the same file structure, but under a root folder namedC:\user2\libname, then you can give the publisher your definemyLib.m andmyLibData.xml files with these instructions for building the interface.

libdef = definemyLib; %myPath = location of files that define library in local folder libdef.RootPaths("rootpath") = myPath; libdef.build

Configuration

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Since R2024a

Generated interface namespace, specified as a string scalar or a character vector. For interfaces created from a single header file, the default value is the name of the header. For multiple header files,InterfaceName must be a valid MATLAB name.

For example, this statement creates definemylib.m in the current folder.

clibgen.generateLibraryDefinition(["h1.hpp","h2.hpp"],InterfaceName="mylib")

Use the InterfaceName to call the library from MATLAB. For example, to call function myfunc in library interface libname, type:

For more information, see Call Functions in C++ Compiled Library.

Data Types: char | string | cell

Folder name for the generated definition file, specified as a string scalar or a character vector. Verify that the folder is on your MATLAB path before calling the build function. This statement createsdefinemyHeader.m inC:\work.

clibgen.generateLibraryDefinition("myHeader.hpp",OutputFolder="C:\work")

Data Types: char | string | cell

Since R2021b

Option to overwrite library definition files, specified as a numeric or logical 1 (true) or0 (false). A definition file is of the formdefine_`libName`_.m ordefine_`libname`_.m. Set OverwriteExistingDefinitionFiles totrue to overwrite the existing files. Use this option to regenerate the definition file.

Caution

When you use this option, the function deletes the files, including edits you might have made to the files.

Data Types: logical

Option to display generation messages, specified as a numeric or logical 1 (true) or0 (false). IfVerbose is true, then the function displays generation messages to the command window while creating the definition file and for the build command. This statement createsdefineh1.m and displays messages to the command window.

clibgen.generateLibraryDefinition("h1.hpp",Verbose=true)

For more information, see Messages About Unsupported Types.

Data Types: logical

C++ Library Settings

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Since R2022a

Option to specify how to parse and build .h header files, specified as a numeric or logical 1 (true) or0 (false).

If CLinkage is true, then the function treats.h header files in theInterfaceGenerationFiles argument as C header files. C header files are included with extern "C" blocks in the generated interface code, which avoids name mangling issues when linking against C source files or a C library.

Set CLinkage to true when creating an interface for a library defined by:

If CLinkage is false, then the function treats.h header files as C++ files. Use the default (CLinkage is false) when creating an interface from C++ files with C dependencies. In this case, the C file is specified by one of these arguments:

For examples showing how to use C files inclibgen.generateLibraryDefinition arguments, see "Files in Your Library" in Tips and search forCLinkage.

Data Types: logical

List of macro definitions to use while parsing header files, specified as empty, a scalar string, or a row vector of scalar strings. The macro name contains characters 1–9, a–z, A–Z, and '_' and cannot begin with a numeral.

Data Types: string

List of macro cancellations to use while parsing header files, specified as empty, a scalar string, or a row vector of scalar strings. The macro name contains characters 1–9, a–z, A–Z, and '_' and cannot begin with a numeral.

Data Types: string

Since R2022a

List of compiler flags, specified as a string array, character vector, or cell array of character vectors, to append to the compiler flags used to build the interface. The function passes the flags directly to the compiler without validation.

For more information, see Build C++ Library Interface and Review Contents.

Example: clibgen.generateLibraryDefinition("A.hpp","AdditionalCompilerFlags","-std=c++20")

Data Types: char | string | cell

Since R2022a

List of linker flags, specified as a string array, character vector, or cell array of character vector, to append to the linker flags used to build the interface. The function passes the flags directly to the linker without validation.

For more information, see Build C++ Library Interface and Review Contents.

Data Types: char | string | cell

Definition Configurations

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Shape specifier for object pointers, specified as a numeric or logical1 (true) or0 (false). IfTreatObjectPointerAsScalar istrue, then the function treats all object pointers in the library as scalars by specifying SHAPE as1. Otherwise, the shape of the object pointer is unknown.

Introduced in R2019b.

Data Types: logical

Shape and MATLAB type specifier for const character pointers, specified as a numeric or logical 1 (true) or0 (false). IfTreatConstCharPointerAsCString is true, then the function treats all const character pointers in the library as null-terminated C strings by specifying MLTYPE asstring and SHAPE asnullTerminated. Otherwise, MATLAB type and the shape of const character pointers are unknown. Supported pointer types are:

Data Types: logical

Option specifying how to return non-object C++ arrays, specified as a numeric or logical 1 (true) or 0 (false). IfReturnCArrays is true, then the function converts C++ arrays to the MATLAB clib array type (clib.array.*). Iffalse, then the function converts C++ arrays to native MATLAB arrays.

Data Types: logical

Option to generate documentation from C++ files, specified as a numeric or logical1 (true) or 0 (false). IfGenerateDocumentationFromHeaderFiles is true, then the function generates documentation from comments in C++ files for display using the MATLABdoc command. If false, then the function ignores C++ comments and only generates documentation of MATLAB and C++ type mappings.

For more information, see Publish Help Text for MATLAB Interface to C++ Library.

Data Types: logical

Limitations

Tips

Alternative Functionality

Version History

Introduced in R2019a

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You can share a MATLAB interface to a C++ library, for example by uploading the library definition files to GitHub®. If another publisher has the same C++ library version and file structure as you, then they can download the definition files and build the interface.

The files used to generate the interface, such as theInterfaceGenerationFiles argument to theclibgen.generateLibraryDefinition function, contain file specifications based on the folder structure of your computer. Starting in R2024a, you can specify file paths relative to an absolute path using the RootPaths name-value argument. Then another publisher can build the interface by specifying the RootPaths argument based on the folder structure on their computer. The other publisher must have the same C++ library version and file structure as you have.

For an example, see Define Pathnames to Share Library Definition Files.

The name of the PackageName name-value argument is nowInterfaceName. The behavior of the argument remains the same. There are no plans to remove support for existing references to the argument.

The clibgen.generateLibraryDefinition function creates a library definition file with a .m file extension. The function no longer creates a file with the .mlx file extension. You can continue to modify and build existing library definition files with the.mlx file extension.

To create interfaces for libraries with C files built with C compilers, use theCLinkage name-value argument.

You can specify static libraries with .a file extensions. For more information, see Libraries.

You can specify libraries with .dll file extensions forMicrosoft Visual Studio compilers. For more information, see Libraries.

You can build a MATLAB interface to a C++ library or algorithm from source files that contain complete implementations for the library. For more information, seeSupportingSourceFiles.

If a library creates an object,​ then the library is responsible for releasing the memory. Likewise, if MATLAB creates the object,​ then MATLAB is responsible for releasing the memory. To overwrite this default behavior, use the ReleaseOnCall and DeleteFcn name-value arguments.

To specify the shape for object pointer types as scalar for all functions in a library, use the TreatObjectPointerAsScalar name-value argument.