CMake/Source/cmAddLibraryCommand.h

/*============================================================================
  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>."
      "\n"
      "The signature\n"
      "  add_library(<name> ALIAS <target>)\n"
      "creates an alias, such that <name> can be used to refer to <target> "
      "in subsequent commands.  The <name> does not appear in the generated "
      "buildsystem as a make target.  The <target> may not be an IMPORTED "
      "target or an ALIAS.  Alias targets can be used as linkable targets, "
      "targets to read properties from.  They can also be tested for "
      "existance with the "
      "regular if(TARGET) subcommand.  The <name> may not be used to modify "
      "properties of <target>, that is, it may not be used as the operand of "
      "set_property, set_target_properties, target_link_libraries etc.  An "
      "ALIAS target may not be installed of exported."
      "\n"
      "The signature\n"
      "  add_library(<name> INTERFACE)\n"
      "creates an interface target. An interface target does not directly "
      "create build output, though it may have properties set on it and it "
      "may be installed, exported and imported.  Typically the INTERFACE_* "
      "properties are populated on the interface target using the "
      "set_property(), target_link_libraries(), target_include_directories() "
      "and target_compile_defintions() commands, and then it is used as an "
      "argument to target_link_libraries() like any other target."
      ;
    }

  cmTypeMacro(cmAddLibraryCommand, cmCommand);
};


#endif