CMake/Source/cmAddLibraryCommand.h
Brad King 51988a4f91 add_library: Document object library portability suggestion
Xcode and VS <= 7.1 will not build targets that have no source files
besides $<TARGET_OBJECTS:...>.  Suggest in the documentation that
projects always add at least one real source file.
2013-01-04 09:38:22 -05:00

149 lines
6.0 KiB
C++

/*============================================================================
CMake - Cross Platform Makefile Generator
Copyright 2000-2009 Kitware, Inc., Insight Software Consortium
Distributed under the OSI-approved BSD License (the "License");
see accompanying file Copyright.txt for details.
This software is distributed WITHOUT ANY WARRANTY; without even the
implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the License for more information.
============================================================================*/
#ifndef cmLibrarysCommand_h
#define cmLibrarysCommand_h
#include "cmCommand.h"
/** \class cmLibrarysCommand
* \brief Defines a list of executables to build.
*
* cmLibrarysCommand defines a list of executable (i.e., test)
* programs to create.
*/
class cmAddLibraryCommand : public cmCommand
{
public:
/**
* This is a virtual constructor for the command.
*/
virtual cmCommand* Clone()
{
return new cmAddLibraryCommand;
}
/**
* This is called when the command is first encountered in
* the CMakeLists.txt file.
*/
virtual bool InitialPass(std::vector<std::string> const& args,
cmExecutionStatus &status);
/**
* The name of the command as specified in CMakeList.txt.
*/
virtual const char* GetName() const { return "add_library";}
/**
* Succinct documentation.
*/
virtual const char* GetTerseDocumentation() const
{
return "Add a library to the project using the specified source files.";
}
/**
* More documentation.
*/
virtual const char* GetFullDocumentation() const
{
return
" add_library(<name> [STATIC | SHARED | MODULE]\n"
" [EXCLUDE_FROM_ALL]\n"
" source1 source2 ... sourceN)\n"
"Adds a library target called <name> to be built from the "
"source files listed in the command invocation. "
"The <name> corresponds to the logical target name and must be "
"globally unique within a project. "
"The actual file name of the library built is constructed based on "
"conventions of the native platform "
"(such as lib<name>.a or <name>.lib)."
"\n"
"STATIC, SHARED, or MODULE may be given to specify the type of library "
"to be created. "
"STATIC libraries are archives of object files for use when linking "
"other targets. "
"SHARED libraries are linked dynamically and loaded at runtime. "
"MODULE libraries are plugins that are not linked into other targets "
"but may be loaded dynamically at runtime using dlopen-like "
"functionality. "
"If no type is given explicitly the type is STATIC or SHARED based "
"on whether the current value of the variable BUILD_SHARED_LIBS is "
"true. "
"For SHARED and MODULE libraries the POSITION_INDEPENDENT_CODE "
"target property is set to TRUE automatically."
"\n"
"By default the library file will be created in the build tree "
"directory corresponding to the source tree directory in which "
"the command was invoked. "
"See documentation of the ARCHIVE_OUTPUT_DIRECTORY, "
"LIBRARY_OUTPUT_DIRECTORY, and RUNTIME_OUTPUT_DIRECTORY "
"target properties to change this location. "
"See documentation of the OUTPUT_NAME target property to change "
"the <name> part of the final file name. "
"\n"
"If EXCLUDE_FROM_ALL is given the corresponding property will be "
"set on the created target. "
"See documentation of the EXCLUDE_FROM_ALL target property for "
"details."
"\n"
"The add_library command can also create IMPORTED library "
"targets using this signature:\n"
" add_library(<name> <SHARED|STATIC|MODULE|UNKNOWN> IMPORTED\n"
" [GLOBAL])\n"
"An IMPORTED library target references a library file located "
"outside the project. "
"No rules are generated to build it. "
"The target name has scope in the directory in which it is created "
"and below, but the GLOBAL option extends visibility. "
"It may be referenced like any target built within the project. "
"IMPORTED libraries are useful for convenient reference from "
"commands like target_link_libraries. "
"Details about the imported library are specified by setting "
"properties whose names begin in \"IMPORTED_\". "
"The most important such property is IMPORTED_LOCATION "
"(and its per-configuration version IMPORTED_LOCATION_<CONFIG>) "
"which specifies the location of the main library file on disk. "
"See documentation of the IMPORTED_* properties for more information."
"\n"
"The signature\n"
" add_library(<name> OBJECT <src>...)\n"
"creates a special \"object library\" target. "
"An object library compiles source files but does not archive or link "
"their object files into a library. "
"Instead other targets created by add_library or add_executable may "
"reference the objects using an expression of the form "
"$<TARGET_OBJECTS:objlib> as a source, where \"objlib\" is the "
"object library name. "
"For example:\n"
" add_library(... $<TARGET_OBJECTS:objlib> ...)\n"
" add_executable(... $<TARGET_OBJECTS:objlib> ...)\n"
"will include objlib's object files in a library and an executable "
"along with those compiled from their own sources. "
"Object libraries may contain only sources (and headers) that compile "
"to object files. "
"They may contain custom commands generating such sources, but not "
"PRE_BUILD, PRE_LINK, or POST_BUILD commands. "
"Object libraries cannot be imported, exported, installed, or linked."
" "
"Some native build systems may not like targets that have only "
"object files, so consider adding at least one real source file "
"to any target that references $<TARGET_OBJECTS:objlib>."
;
}
cmTypeMacro(cmAddLibraryCommand, cmCommand);
};
#endif