[FindGMP.cmake]

Complete overwork of GMP test.
Changed variable GMP_PATH to GMP_PREFIX.

Tested without GMP and with GMP 5.0.5, both installed in /usr and using a
user-specified prefix path.

[[Imported from SVN: r7059]]

cmake/modules/FindGMP.cmake

@@ -2,63 +2,100 @@
 # dirs and
 #
 # Variables used by this module which you may want to set:
-# GMP_PATH Path list to search for GMP
+# GMP_PREFIX Path list to search for GMP
 #
 # Sets the following variables:
 # GMP_FOUND True if the GMP library was found.
 #
 
-include(CheckIncludeFileCXX)
-include(CheckCXXSymbolExists)
+# adds GMP flags to the targets
+function(dune_add_gmp_flags _targets)
+  if(GMP_FOUND)
+    foreach(_target ${_targets})
+      target_link_libraries(${_target} ${GMP_LIBRARIES})
+      set_property(TARGET ${_target}
+        APPEND_STRING
+        PROPERTY COMPILE_FLAGS "-DENABLE_GMP=1 ")
+      foreach(_path ${GMP_INCLUDE_DIRS})
+        set_property(TARGET ${_target}
+          APPEND_STRING
+          PROPERTY COMPILE_FLAGS "-I${_path}")
+      endforeach(_path ${GMP_INCLUDE_DIRS})
+    endforeach(_target ${_targets})
+  endif(GMP_FOUND)
+endfunction(dune_add_gmp_flags)
 
-set(GMP_SEARCH_PATH CACHE FILEPATH "User defined list of directories to search for the GNU GMP library")
+# search for location of header gmpxx.h", only at positions given by the user
+find_path(GMP_INCLUDE_DIR
+  NAMES "gmpxx.h"
+  PATHS ${GMP_PREFIX}
+  PATH_SUFFIXES include
+  NO_DEFAULT_PATH)
+# try default paths now
+find_path(GMP_INCLUDE_DIR
+  NAMES "gmpxx.h")
 
-# save old variables
-set(CMAKE_REQUIRED_INCLUDES_SAVE ${CMAKE_REQUIRED_INCLUDES})
-set(CMAKE_REQUIRED_FLAGS_SAVE    ${CMAKE_REQUIRED_FLAGS})
-set(CMAKE_REQUIRED_LIBRARIES_SAVE ${CMAKE_REQUIRED_LIBRARIES})
+# check if header is accepted
+include(CMakePushCheckState)
+cmake_push_check_state()
+set(CMAKE_REQUIRED_INCLUDES ${CMAKE_REQUIRED_INCLUDES} ${GMP_INCLUDE_DIR})
+include(CheckIncludeFileCXX)
+check_include_file_cxx("gmpxx.h" GMP_FOUND)
 
+# look for library gmp, only at positions given by the user
+find_library(GMP_LIB gmp
+  PATHS ${GMP_PREFIX}
+  PATH_SUFFIXES lib lib64
+  NO_DEFAULT_PATH
+  DOC "GNU GMP library")
+# try default paths now
+find_library(GMP_LIB gmp)
 
-# Search for location of header gmpxx.h"
-find_path(GMP_INCLUDE_DIRS "gmpxx.h" PATHS ${GMP_SEARCH_PATH} PATH_SUFFIXES include NO_DEFAULT_PATH)
-#If not found fall back to default locations
-find_path(GMP_INCLUDE_DIRS "gmpxx.h")
+# look for library gmpxx, only at positions given by the user
+find_library(GMPXX_LIB gmpxx
+  PATHS ${GMP_PREFIX}
+  PATH_SUFFIXES lib lib64
+  NO_DEFAULT_PATH
+  DOC "GNU GMPXX library")
+# try default paths now
+find_library(GMPXX_LIB gmpxx)
 
-if(GMP_INCLUDE_DIRS)
-  set(CMAKE_REQUIRED_INCLUDES ${CMAKE_REQUIRED_INCLUDES_SAVE} ${GMP_INCLUDE_DIRS})
-  check_include_files("gmpxx.h" GMP_FOUND)
-  find_library(GMP_LIB gmp  PATHS ${GMP_SEARCH_PATH} PATH_SUFFIXES lib NODEFAULT_PATH DOC "GNU GMP library")
-  find_library(GMP_LIB gmp)
-  find_library(GMPXX_LIB gmpxx  PATHS ${GMP_SEARCH_PATH} NODEFAULT_PATH DOC DOC "GNU GMPXX library")
-  find_library(GMPXX_LIB gmpxx)
+# check if library works
+set(GMP_FOUND "GMP_FOUND-NOTFOUND")
+if(GMP_LIB AND GMPXX_LIB)
+  include(CheckSymbolExists)
+  check_symbol_exists(__gmpz_abs ${GMP_LIB} GMP_FOUND)
+endif(GMP_LIB AND GMPXX_LIB)
+cmake_pop_check_state()
 
-  if(GMP_LIB AND GMPXX_LIB)
-    set(GMP_FOUND "GMP_FOUND-NOTFOUND")
-    check_symbol_exists(__gmpz_abs ${GMP_LIB} GMP_FOUND)
-    if(GMP_FOUND)
-      set(GMP_LIBRARIES ${GMP_LIB} ${GMPXX_LIB} CACHE INTERNAL)
-      set(GMP_COMPILE_FLAGS "-DENABLE_GMP")
-    endif(GMP_FOUND)
-  else()
-    set(GMP_FOUND "GMP_FOUND-NOTFOUND")
-  endif()
-  set(HAVE_GMP GMP_FOUND)
-endif(GMP_INCLUDE_DIRS)
+# behave like a CMake module is supposed to behave
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(
+  "GMP"
+  DEFAULT_MSG
+  GMP_INCLUDE_DIR GMP_LIB GMPXX_LIB GMP_FOUND
+)
 
-# restore values
-set(CMAKE_REQUIRED_INCLUDES ${CMAKE_REQUIRED_INCLUDES_SAVE})
-set(CMAKE_REQUIRED_FLAGS    ${CMAKE_REQUIRED_FLAGS_SAVE})
-set(CMAKE_REQUIRED_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES_SAVE})
-mark_as_advanced(GMP_LIB GMP_LIBXX)
+mark_as_advanced(GMP_LIB GMPXX_LIB GMP_INCLUDE_DIR)
 
-function(dune_add_gmp_flags _targets)
-  if(GMP_FOUND)
-    foreach(_target ${_targets})
-      target_link_libraries(${_target} ${GMP_LIBRARIES})
-      set_property(TARGET ${_target} APPEND_STRING COMPILE_FLAGS "-DENABLE_GMP=1")
-      foreach(_path ${GMP_INCLUDE_DIRS})
-	set_property(TARGET ${_target} APPEND_STRING COMPILE_FLAGS "-I${_path}")
-      endforeach(_path ${GMP_INCLUDE_DIRS})
-    endif(GMP_FOUND)
-endfunction(dune_add_gmp_flags)
+# if both headers and library are found, store results
+if(GMP_FOUND)
+  set(GMP_INCLUDE_DIRS ${GMP_INCLUDE_DIR})
+  set(GMP_LIBRARIES ${GMP_LIB} ${GMPXX_LIB})
+  set(GMP_COMPILE_FLAGS "-DENABLE_GMP=1")
+  # log result
+  file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
+    "Determing location of GMP succeded:\n"
+    "Include directory: ${GMP_INCLUDE_DIRS}\n"
+    "Library directory: ${GMP_LIBRARIES}\n\n")
+else(GMP_FOUND)
+  # log errornous result
+  file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
+    "Determing location of GMP failed:\n"
+    "Include directory: ${GMP_INCLUDE_DIR}\n"
+    "gmp library directory: ${GMP_LIB}\n"
+    "gmpx library directory: ${GMPXX_LIB}\n\n")
+endif(GMP_FOUND)
 
+# set HAVE_GMP for config.h
+set(HAVE_GMP GMP_FOUND)