build: set C/C++ standard before checking compiler flags

Otherwise CMake would try to detect compiler features/support without the required language standard - this may impact results.
MegEngine · Apr 12, 2019 · a1c5b34 · a1c5b34
1 parent f2cef86
commit a1c5b34
Show file tree

Hide file tree

Showing 2 changed files with 6 additions and 2 deletions.
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -68,6 +68,11 @@ set(CMAKE_SRC_CCXX_FLAGS) # SRC specifics
 set(CMAKE_EXAMPLE_CCXX_FLAGS) # EXAMPLE specifics
 set(CMAKE_TEST_CCXX_FLAGS) # TESTS specifics
 
+if(UNIX OR MINGW)
+ set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=c99")
+ set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
+endif()
+
 include(GNUInstallDirs)
 include(CMakePackageConfigHelpers)
 

diff --git a/cmake/platform.cmake b/cmake/platform.cmake
@@ -68,8 +68,7 @@ elseif(UNIX OR MINGW)
  append(CMAKE_CCXX_FLAGS "-Wall -Wno-unknown-pragmas")
  append_if(MKLDNN_WERROR CMAKE_CCXX_FLAGS "-Werror")
  append(CMAKE_CCXX_FLAGS "-fvisibility=internal")
- append(CMAKE_C_FLAGS "-std=c99")
- append(CMAKE_CXX_FLAGS "-std=c++11 -fvisibility-inlines-hidden")
+ append(CMAKE_CXX_FLAGS "-fvisibility-inlines-hidden")
  # compiler specific settings
  if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
  # Clang cannot vectorize some loops with #pragma omp simd and gets