FindPkgConfig: Deprecate PKG_CONFIG_FOUND

Since most of the find modules use the `<PackageName>_FOUND` result
variables, this now also syncs it for the FindPkgConfig module. The
`PkgConfig_FOUND` result variable is available since CMake 3.3 and
contains the same value. There is also `PKGCONFIG_FOUND` result variable
automatically set with the same value but for simplicity isn't
documented. The uppercased `<PACKAGENAME>_FOUND` result variables set by
find modules are also considered legacy variables.

Help/manual/cmake-developer.7.rst

@@ -415,7 +415,7 @@ starting point.
 .. code-block:: cmake
 
   find_package(PkgConfig)
-  if(PKG_CONFIG_FOUND)
+  if(PkgConfig_FOUND)
     pkg_check_modules(PC_Foo QUIET Foo)
   endif()
 

Help/release/dev/find-modules.rst

@@ -77,6 +77,10 @@ Find Modules
   result variable.  The ``PKG_CONFIG_VERSION_STRING`` result variable is
   deprecated.
 
+* The :module:`FindPkgConfig` module's result variable ``PKG_CONFIG_FOUND``
+  is deprecated in favor of ``PkgConfig_FOUND``, which is available since
+  CMake 3.3 and has the same value.
+
 * The :module:`FindPNG` module now provides a ``PNG_VERSION`` result
   variable.  The ``PNG_VERSION_STRING`` result variable is deprecated.
 

Modules/FindBLAS.cmake

@@ -327,7 +327,7 @@ if(BLA_PREFER_PKGCONFIG)
     set(BLA_PKGCONFIG_BLAS "blas")
   endif()
   find_package(PkgConfig QUIET)
-  if(PKG_CONFIG_FOUND)
+  if(PkgConfig_FOUND)
     pkg_check_modules(PKGC_BLAS QUIET ${BLA_PKGCONFIG_BLAS})
     if(PKGC_BLAS_FOUND)
       set(BLAS_FOUND ${PKGC_BLAS_FOUND})

Modules/FindCURL.cmake

@@ -187,7 +187,7 @@ if(NOT CURL_NO_CURL_CMAKE)
 endif()
 
 find_package(PkgConfig QUIET)
-if(PKG_CONFIG_FOUND)
+if(PkgConfig_FOUND)
   pkg_check_modules(PC_CURL QUIET libcurl)
   if(PC_CURL_FOUND)
     pkg_get_variable(CURL_SUPPORTED_PROTOCOLS_STRING libcurl supported_protocols)

Modules/FindCurses.cmake

@@ -322,7 +322,7 @@ set(CURSES_INCLUDE_DIRS ${CURSES_INCLUDE_PATH})
 set(CURSES_INCLUDE_DIR ${CURSES_INCLUDE_PATH}) # compatibility
 
 find_package(PkgConfig QUIET)
-if(PKG_CONFIG_FOUND)
+if(PkgConfig_FOUND)
   pkg_check_modules(NCURSES QUIET ${NCURSES_LIBRARY_NAME})
   set(CURSES_CFLAGS ${NCURSES_CFLAGS_OTHER})
 endif()

Modules/FindEXPAT.cmake

@@ -84,7 +84,7 @@ cmake_policy(PUSH)
 cmake_policy(SET CMP0159 NEW) # file(STRINGS) with REGEX updates CMAKE_MATCH_<n>
 
 find_package(PkgConfig QUIET)
-if(PKG_CONFIG_FOUND)
+if(PkgConfig_FOUND)
   pkg_check_modules(PC_EXPAT QUIET expat)
 endif()
 

Modules/FindFontconfig.cmake

@@ -57,7 +57,7 @@ cmake_policy(SET CMP0159 NEW) # file(STRINGS) with REGEX updates CMAKE_MATCH_<n>
 # use pkg-config to get the directories and then use these values
 # in the find_path() and find_library() calls
 find_package(PkgConfig QUIET)
-if(PKG_CONFIG_FOUND)
+if(PkgConfig_FOUND)
   pkg_check_modules(PKG_FONTCONFIG QUIET fontconfig)
 endif()
 set(Fontconfig_COMPILE_OPTIONS ${PKG_FONTCONFIG_CFLAGS_OTHER})

Modules/FindGLUT.cmake

@@ -77,7 +77,7 @@ include(${CMAKE_CURRENT_LIST_DIR}/SelectLibraryConfigurations.cmake)
 include(FindPackageHandleStandardArgs)
 
 find_package(PkgConfig QUIET)
-if(PKG_CONFIG_FOUND)
+if(PkgConfig_FOUND)
   pkg_check_modules(PC_GLUT QUIET glut)
   if(NOT PC_GLUT_FOUND)
     pkg_check_modules(PC_GLUT QUIET freeglut)

Modules/FindGSL.cmake

@@ -115,7 +115,7 @@ endif()
 # This will return ``GSL_INCLUDEDIR`` and ``GSL_LIBDIR`` used below.
 if( GSL_USE_PKGCONFIG )
   find_package(PkgConfig QUIET)
-  if(PKG_CONFIG_FOUND)
+  if(PkgConfig_FOUND)
     pkg_check_modules( GSL QUIET gsl )
     if( EXISTS "${GSL_INCLUDEDIR}" )
       get_filename_component( GSL_ROOT_DIR "${GSL_INCLUDEDIR}" DIRECTORY CACHE)

Modules/FindGTK2.cmake

@@ -707,7 +707,7 @@ endif()
 # used to compute the arch-specific include prefixes. While at it,
 # also retrieve their INCLUDEDIR, to accommodate non-standard layouts.
 find_package(PkgConfig QUIET)
-if(PKG_CONFIG_FOUND)
+if(PkgConfig_FOUND)
   pkg_check_modules(PC_GTK2 QUIET gtk+-2.0)
   if(PC_GTK2_FOUND)
     pkg_get_variable(PC_GTK2_INCLUDEDIR gtk+-2.0 includedir)

Modules/FindGnuTLS.cmake

@@ -101,7 +101,7 @@ if (NOT WIN32)
   # in the find_path() and find_library() calls
   # also fills in GNUTLS_DEFINITIONS, although that isn't normally useful
   find_package(PkgConfig QUIET)
-  if(PKG_CONFIG_FOUND)
+  if(PkgConfig_FOUND)
     pkg_check_modules(PC_GNUTLS QUIET gnutls)
   endif()
   set(GNUTLS_DEFINITIONS ${PC_GNUTLS_CFLAGS_OTHER})

Modules/FindImageMagick.cmake

@@ -151,7 +151,7 @@ find_package(PkgConfig QUIET)
 function(FIND_IMAGEMAGICK_API component header)
   set(ImageMagick_${component}_FOUND FALSE PARENT_SCOPE)
 
-  if(PKG_CONFIG_FOUND)
+  if(PkgConfig_FOUND)
     pkg_check_modules(PC_${component} QUIET ${component})
   endif()
 

Modules/FindLAPACK.cmake

@@ -327,7 +327,7 @@ if(BLA_PREFER_PKGCONFIG)
     set(BLA_PKGCONFIG_LAPACK "lapack")
   endif()
   find_package(PkgConfig QUIET)
-  if(PKG_CONFIG_FOUND)
+  if(PkgConfig_FOUND)
     pkg_check_modules(PKGC_LAPACK QUIET ${BLA_PKGCONFIG_LAPACK})
     if(PKGC_LAPACK_FOUND)
       set(LAPACK_FOUND TRUE)

Modules/FindLibXml2.cmake

@@ -93,7 +93,7 @@ cmake_policy(SET CMP0159 NEW) # file(STRINGS) with REGEX updates CMAKE_MATCH_<n>
 # use pkg-config to get the directories and then use these values
 # in the find_path() and find_library() calls
 find_package(PkgConfig QUIET)
-if(PKG_CONFIG_FOUND)
+if(PkgConfig_FOUND)
   pkg_check_modules(PC_LIBXML QUIET libxml-2.0)
 endif()
 

Modules/FindLibXslt.cmake

@@ -127,7 +127,7 @@ cmake_policy(SET CMP0159 NEW) # file(STRINGS) with REGEX updates CMAKE_MATCH_<n>
 # use pkg-config to get the directories and then use these values
 # in the find_path() and find_library() calls
 find_package(PkgConfig QUIET)
-if(PKG_CONFIG_FOUND)
+if(PkgConfig_FOUND)
   pkg_check_modules(PC_LIBXSLT QUIET libxslt)
 endif()
 set(LIBXSLT_DEFINITIONS ${PC_LIBXSLT_CFLAGS_OTHER})
@@ -153,7 +153,7 @@ find_library(LIBXSLT_LIBRARY NAMES xslt libxslt
 
 set(LIBXSLT_LIBRARIES ${LIBXSLT_LIBRARY})
 
-if(PKG_CONFIG_FOUND)
+if(PkgConfig_FOUND)
   pkg_check_modules(PC_LIBXSLT_EXSLT QUIET libexslt)
 endif()
 set(LIBXSLT_EXSLT_DEFINITIONS ${PC_LIBXSLT_EXSLT_CFLAGS_OTHER})

Modules/FindLibinput.cmake

@@ -57,7 +57,7 @@ Finding the libinput library and linking it to a project target:
 # Use pkg-config to get the directories and then use these values
 # in the FIND_PATH() and FIND_LIBRARY() calls
 find_package(PkgConfig QUIET)
-if(PKG_CONFIG_FOUND)
+if(PkgConfig_FOUND)
   pkg_check_modules(PKG_Libinput QUIET libinput)
 endif()
 

Modules/FindMPI.cmake

@@ -1758,7 +1758,7 @@ foreach(LANG IN ITEMS C CXX Fortran)
           else()
             set(_MPI_PKG "")
           endif()
-          if(_MPI_PKG AND PKG_CONFIG_FOUND)
+          if(_MPI_PKG AND PkgConfig_FOUND)
             pkg_check_modules("MPI_${LANG}_PKG" "${_MPI_PKG}")
             if(MPI_${LANG}_PKG_FOUND)
               set(MPI_${LANG}_COMPILE_OPTIONS  ${MPI_${LANG}_PKG_CFLAGS}        CACHE STRING "MPI ${LANG} compilation options"       FORCE)

Modules/FindOpenSSL.cmake

@@ -285,7 +285,7 @@ endfunction()
 
 if (UNIX)
   find_package(PkgConfig QUIET)
-  if(PKG_CONFIG_FOUND)
+  if(PkgConfig_FOUND)
     pkg_check_modules(_OPENSSL QUIET openssl)
   endif()
 endif ()

Modules/FindPkgConfig.cmake

@@ -26,7 +26,9 @@ Result Variables
 
 This module defines the following variables:
 
-``PKG_CONFIG_FOUND``
+``PkgConfig_FOUND``
+  .. versionadded:: 3.3
+
   Boolean indicating whether the (requested version of) ``pkg-config``
   executable is found.
 
@@ -335,6 +337,13 @@ Deprecated Variables
 
 The following variables are provided for backward compatibility:
 
+``PKG_CONFIG_FOUND``
+  .. deprecated:: 4.2
+    Use ``PkgConfig_FOUND``, which has the same value.
+
+  Boolean indicating whether the (requested version of) ``pkg-config``
+  executable is found.
+
 ``PKG_CONFIG_VERSION_STRING``
   .. deprecated:: 4.2
     Use ``PkgConfig_VERSION``, which has the same value.
@@ -377,7 +386,7 @@ Checking for any version of glib2.  If found, the output variable
 
   find_package(PkgConfig QUIET)
 
-  if(PKG_CONFIG_FOUND)
+  if(PkgConfig_FOUND)
     pkg_check_modules(GLIB2 glib-2.0)
   endif()
 
@@ -388,7 +397,7 @@ the output variable ``GLIB2_VERSION`` will hold the actual version found:
 
   find_package(PkgConfig QUIET)
 
-  if(PKG_CONFIG_FOUND)
+  if(PkgConfig_FOUND)
     pkg_check_modules(GLIB2 glib-2.0>=2.10)
   endif()
 
@@ -401,7 +410,7 @@ will be set to their respective found module versions.
 
   find_package(PkgConfig QUIET)
 
-  if(PKG_CONFIG_FOUND)
+  if(PkgConfig_FOUND)
     pkg_check_modules(FOO glib-2.0>=2.10 gtk+-2.0)
   endif()
 
@@ -427,7 +436,7 @@ module specifications (``libxml-2.0`` or ``libxml2``):
 
   find_package(PkgConfig QUIET)
 
-  if(PKG_CONFIG_FOUND)
+  if(PkgConfig_FOUND)
     pkg_search_module(BAR libxml-2.0 libxml2 libxml>=2)
   endif()
 
@@ -455,7 +464,7 @@ Gobject:
 
   find_package(PkgConfig QUIET)
 
-  if(PKG_CONFIG_FOUND)
+  if(PkgConfig_FOUND)
     pkg_get_variable(GI_GIRDIR gobject-introspection-1.0 girdir)
   endif()
 
@@ -558,7 +567,7 @@ find_package_handle_standard_args(PkgConfig
 # This is needed because the module name is "PkgConfig" but the name of
 # this variable has always been PKG_CONFIG_FOUND so this isn't automatically
 # handled by FPHSA.
-set(PKG_CONFIG_FOUND "${PKGCONFIG_FOUND}")
+set(PKG_CONFIG_FOUND "${PkgConfig_FOUND}")
 
 # Unsets the given variables
 macro(_pkgconfig_unset var)

Modules/FindSQLite3.cmake

@@ -59,7 +59,7 @@ cmake_policy(PUSH)
 cmake_policy(SET CMP0159 NEW) # file(STRINGS) with REGEX updates CMAKE_MATCH_<n>
 
 find_package(PkgConfig QUIET)
-if(PKG_CONFIG_FOUND)
+if(PkgConfig_FOUND)
   pkg_check_modules(PC_SQLite3 QUIET sqlite3)
 endif()
 

Modules/UsePkgConfig.cmake

@@ -80,7 +80,7 @@ Migrating to the :module:`FindPkgConfig`  would look something like this:
 .. code-block:: cmake
 
   find_package(PkgConfig QUIET)
-  if(PKG_CONFIG_FOUND)
+  if(PkgConfig_FOUND)
     pkg_check_modules(LIBART QUIET libart-2.0)
   endif()
 

Tests/RunCMake/CMakeLists.txt

@@ -880,7 +880,7 @@ if (CMake_TEST_Qt4 AND Qt4_FOUND)
 endif()
 
 find_package(PkgConfig QUIET)
-if(PKG_CONFIG_FOUND)
+if(PkgConfig_FOUND)
   add_RunCMake_test(FindPkgConfig)
 endif()
 

Tests/RunCMake/FindPkgConfig/PkgConfigDoesNotExist-stdout.txt

@@ -2,5 +2,6 @@
     Reason given by package: The command
       "pkg-config-does-not-exist" --version
     failed with output.*
+-- PkgConfig_FOUND='FALSE'
 -- PKG_CONFIG_FOUND='FALSE'
 -- PKG_CONFIG_EXECUTABLE=''

Tests/RunCMake/FindPkgConfig/PkgConfigDoesNotExist.cmake

@@ -1,4 +1,5 @@
 set(PKG_CONFIG_EXECUTABLE "pkg-config-does-not-exist" CACHE FILEPATH "")
 find_package(PkgConfig)
+message(STATUS "PkgConfig_FOUND='${PkgConfig_FOUND}'")
 message(STATUS "PKG_CONFIG_FOUND='${PKG_CONFIG_FOUND}'")
 message(STATUS "PKG_CONFIG_EXECUTABLE='${PKG_CONFIG_EXECUTABLE}'")

Tests/RunCMake/FindPkgConfig/RunCMakeTest.cmake

@@ -28,7 +28,7 @@ endif()
 
 # We need a real pkg-config to run the test for get_variable.
 find_package(PkgConfig)
-if (PKG_CONFIG_FOUND)
+if (PkgConfig_FOUND)
   string(FIND "${CMAKE_CURRENT_BINARY_DIR}" " " IS_SPACES_IN_PATH)
   if(IS_SPACES_IN_PATH GREATER -1)
     string(REPLACE " " "\\ " ESCAPED_ROOT "${CMAKE_CURRENT_BINARY_DIR}")