cmake: check all available compiler features even if BUILD_STRICT_C90

CMakeLists.txt

@@ -75,7 +75,7 @@ include(TestBigEndian)
 test_big_endian(GMIO_HOST_IS_BIG_ENDIAN)
 
 # Adapt C compiler flags to satisfy the GMIO_BUILD_STRICT_C90 option
-#    It must be done before checking of C99 and POSIX features
+#    It must be done before checking non ANSI features(C99, POSIX, ...)
 if(GMIO_BUILD_STRICT_C90)
     if(CMAKE_C_COMPILER_IS_GCC_COMPATIBLE)
         set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -ansi -pedantic-errors")
@@ -97,42 +97,42 @@ endif()
 check_type_size("int" GMIO_SIZEOF_INT)
 check_type_size("long" GMIO_SIZEOF_LONG)
 
-# Check non-ANSI available features
+# Check availability of a 64b integer type
-if(NOT GMIO_BUILD_STRICT_C90)
+if(GMIO_HAVE_STDINT_H)
-    # Check availability of a 64b integer type
-    if(GMIO_HAVE_STDINT_H)
     set(CMAKE_REQUIRED_INCLUDES stdint.h)
-    endif()
+endif()
-    check_type_size("int64_t" GMIO_SIZEOF_INT64_T)
+check_type_size("int64_t" GMIO_SIZEOF_INT64_T)
-    if(NOT HAVE_GMIO_SIZEOF_INT64_T)
+if(NOT HAVE_GMIO_SIZEOF_INT64_T)
     check_type_size("__int64" GMIO_SIZEOF_MSVC_INT64)
     if(NOT HAVE_GMIO_SIZEOF_MSVC_INT64)
         check_type_size("long long" GMIO_SIZEOF_LONG_LONG)
     endif()
-    endif()
+endif()
-    set(CMAKE_REQUIRED_INCLUDES)
+set(CMAKE_REQUIRED_INCLUDES) # Pop changes
 
-    if(HAVE_GMIO_SIZEOF_INT64_T)
+if(HAVE_GMIO_SIZEOF_INT64_T)
     set(GMIO_HAVE_INT64_T ${HAVE_GMIO_SIZEOF_INT64_T})
-    elseif(HAVE_GMIO_SIZEOF_MSVC_INT64)
+elseif(HAVE_GMIO_SIZEOF_MSVC_INT64)
     set(GMIO_HAVE_MSVC_INT64 ${HAVE_GMIO_SIZEOF_MSVC_INT64})
-    elseif(HAVE_GMIO_SIZEOF_LONG_LONG)
+elseif(HAVE_GMIO_SIZEOF_LONG_LONG)
     set(GMIO_HAVE_LONG_LONG ${HAVE_GMIO_SIZEOF_LONG_LONG})
-    endif()
+endif()
 
-    # Check C99 features
+# Check C99 features
+if(NOT GMIO_BUILD_STRICT_C90)
     check_function_exists(strtof GMIO_HAVE_STRTOF_FUNC)
 
     if(CMAKE_C_COMPILER_IS_GCC_COMPATIBLE)
         list(APPEND CMAKE_REQUIRED_LIBRARIES m) # -lm
     endif()
     check_function_exists(powf GMIO_HAVE_POWF_FUNC)
-    set(CMAKE_REQUIRED_LIBRARIES)
+    set(CMAKE_REQUIRED_LIBRARIES) # Pop changes
 
     check_include_files(stdbool.h GMIO_HAVE_STDBOOL_H)
+endif()
 
-    # Check POSIX features
+# Check POSIX features
-    if(UNIX)
+if(UNIX)
     # See:
     #   http://linux.die.net/man/2/fstat64
     #   https://developer.apple.com/library/mac/documentation/Darwin/Reference/ManPages/man2/fstat.2.html
@@ -145,50 +145,50 @@ if(NOT GMIO_BUILD_STRICT_C90)
         list(APPEND CMAKE_REQUIRED_DEFINITIONS
                     -D_FILE_OFFSET_BITS=64 -D_LARGEFILE64_SOURCE=1)
     endif()
-    endif()
+endif()
 
-    set(GMIO_HAVE_SYS_TYPES_H ${HAVE_SYS_TYPES_H})
+set(GMIO_HAVE_SYS_TYPES_H ${HAVE_SYS_TYPES_H})
-    if(NOT DEFINED HAVE_SYS_TYPES_H)
+if(NOT DEFINED HAVE_SYS_TYPES_H)
     check_include_files(sys/types.h GMIO_HAVE_SYS_TYPES_H)
-    endif()
+endif()
 
-    set(GMIO_HAVE_SYS_STAT_H ${HAVE_SYS_STAT_H})
+set(GMIO_HAVE_SYS_STAT_H ${HAVE_SYS_STAT_H})
-    if (NOT DEFINED HAVE_SYS_STAT_H)
+if (NOT DEFINED HAVE_SYS_STAT_H)
     check_include_files(sys/stat.h GMIO_HAVE_SYS_STAT_H)
-    endif()
+endif()
 
-    check_function_exists(fileno GMIO_HAVE_POSIX_FILENO_FUNC)
+check_function_exists(fileno GMIO_HAVE_POSIX_FILENO_FUNC)
 
-    # Have fstat64() ?
+# Have fstat64() ?
-    check_c_source_compiles(
+check_c_source_compiles(
     "#include <sys/stat.h>
      int main() { fstat64(0, NULL); return 0; }"
     GMIO_HAVE_POSIX_FSTAT64_FUNC)
-    if(WIN32)
+if(WIN32)
     check_function_exists(_fstat64 GMIO_HAVE_WIN__FSTAT64_FUNC)
-    endif()
+endif()
 
-    # Check size(in bytes) of stat::st_size
+# Check size(in bytes) of stat::st_size
-    set(CMAKE_EXTRA_INCLUDE_FILES sys/stat.h)
+set(CMAKE_EXTRA_INCLUDE_FILES sys/stat.h)
-    if(GMIO_HAVE_WIN__FSTAT64_FUNC)
+if(GMIO_HAVE_WIN__FSTAT64_FUNC)
     check_type_size("((struct _stat64*)0)->st_size" GMIO_SIZEOF_STRUCT_STAT_ST_SIZE)
-    elseif(GMIO_HAVE_POSIX_FSTAT64_FUNC)
+elseif(GMIO_HAVE_POSIX_FSTAT64_FUNC)
     check_type_size("((struct stat64*)0)->st_size" GMIO_SIZEOF_STRUCT_STAT_ST_SIZE)
-    else()
+else()
     check_type_size("((struct stat*)0)->st_size" GMIO_SIZEOF_STRUCT_STAT_ST_SIZE)
-    endif()
+endif()
-    set(CMAKE_EXTRA_INCLUDE_FILES)
+set(CMAKE_EXTRA_INCLUDE_FILES)
-    set(CMAKE_REQUIRED_DEFINITIONS)
+set(CMAKE_REQUIRED_DEFINITIONS)
 
-    # Verify large file support
+# Verify large file support ?
-    if(GMIO_HAVE_SYS_STAT_H
+if(GMIO_HAVE_SYS_STAT_H
        AND NOT(GMIO_SIZEOF_STRUCT_STAT_ST_SIZE STREQUAL "0") # Not arch-dependent size
        AND NOT(GMIO_SIZEOF_STRUCT_STAT_ST_SIZE EQUAL 8))
     message(WARNING "<sys/stat.h> does not provide 64b variant of fstat(), you may encounter problems with files > 2GB")
-    endif()
+endif()
 
-    # Have builtin byte swap functions ?
+# Have compiler-intrisics bytes wap functions ?
-    if(CMAKE_C_COMPILER_IS_GCC_COMPATIBLE)
+if(CMAKE_C_COMPILER_IS_GCC_COMPATIBLE)
     # __builtin_bswap16() is missing in x86 GCC version prior to v4.7
     # See http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52624
     check_c_source_compiles(
@@ -197,13 +197,12 @@ if(NOT GMIO_BUILD_STRICT_C90)
     check_c_source_compiles(
         "int main() { return (int)__builtin_bswap32(0x11223344); }"
         GMIO_HAVE_GCC_BUILTIN_BSWAP32_FUNC)
-    elseif(MSVC)
+elseif(MSVC)
     check_c_source_compiles(
         "#include <stdlib.h>
          int main() { return (int)_byteswap_ulong(0x11223344); }"
         GMIO_HAVE_MSVC_BUILTIN_BSWAP_FUNC)
-    endif()
+endif()
-endif() # !GMIO_BUILD_STRICT_C90
 
 # Specific flags for GCC-like compilers
 if(CMAKE_C_COMPILER_IS_GCC_COMPATIBLE)
@@ -283,5 +282,5 @@ endif()
 
 # Examples:
 #   cmake -DCMAKE_INSTALL_PREFIX=gcc-linux64 -DCMAKE_BUILD_TYPE=Debug -DCMAKE_DEBUG_POSTFIX=_d
-#   cmake -DCMAKE_INSTALL_PREFIX=gcc-linux64 -DCMAKE_BUILD_TYPE=Release -DCMAKE_RELEASE_POSTFIX=_r
+#   cmake -DCMAKE_INSTALL_PREFIX=gcc-linux64 -DCMAKE_BUILD_TYPE=Release -DCMAKE_RELEASE_POSTFIX=
 # make VERBOSE=1  or  cmake -DCMAKE_VERBOSE_MAKEFILE=TRUE