TRILAB-192 - cleanup edits and match CMake CXX to autotools

4 files changed, 199 insertions, 88 deletions

diff --git a/config/cmake/HDFCXXCompilerFlags.cmake b/config/cmake/HDFCXXCompilerFlags.cmake
index bf22886..6aa8784 100644
--- a/config/cmake/HDFCXXCompilerFlags.cmake
+++ b/config/cmake/HDFCXXCompilerFlags.cmake
@@ -104,6 +104,8 @@ if (NOT MSVC)
       endif()
     elseif (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
       if (CMAKE_COMPILER_IS_GNUCXX AND CMAKE_CXX_COMPILER_LOADED)
+        # autotools always add the C flags with the CXX flags
+        ADD_H5_FLAGS (HDF5_CMAKE_CXX_FLAGS "${HDF5_SOURCE_DIR}/config/gnu-warnings/general")
         ADD_H5_FLAGS (HDF5_CMAKE_CXX_FLAGS "${HDF5_SOURCE_DIR}/config/gnu-warnings/cxx-general")
       endif ()
     elseif (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
@@ -114,47 +116,160 @@ if (NOT MSVC)
     message (STATUS "CMAKE_CXX_FLAGS_GENERAL=${HDF5_CMAKE_CXX_FLAGS}")
   endif ()
 
-    #-----------------------------------------------------------------------------
-    # Option to allow the user to enable developer warnings
-    # Developer warnings (suggestions from gcc, not code problems)
-    #-----------------------------------------------------------------------------
-    #if (HDF5_ENABLE_DEV_WARNINGS)
-    #  message (STATUS "....HDF5 developer group warnings are enabled")
-    #  if (CMAKE_CXX_COMPILER_ID STREQUAL "Intel")
-    #    list (APPEND H5_CXXFLAGS0 "-Winline -Wreorder -Wport -Wstrict-aliasing")
-    #  elseif (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
-    #    ADD_H5_FLAGS (H5_CXXFLAGS0 "${HDF5_SOURCE_DIR}/config/gnu-warnings/developer-general")
-    #  elseif (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
-    #    ADD_H5_FLAGS (H5_CXXFLAGS0 "${HDF5_SOURCE_DIR}/config/clang-warnings/developer-general")
-    #  endif ()
-    #else ()
-    #  if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
-    #    ADD_H5_FLAGS (H5_CXXFLAGS0 "${HDF5_SOURCE_DIR}/config/gnu-warnings/no-developer-general")
-    #  elseif (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
-    #    ADD_H5_FLAGS (H5_CXXFLAGS0 "${HDF5_SOURCE_DIR}/config/clang-warnings/no-developer-general")
-    #  endif ()
-    #endif ()
-
+  #-----------------------------------------------------------------------------
+  # Option to allow the user to enable developer warnings
+  # Developer warnings (suggestions from gcc, not code problems)
+  #-----------------------------------------------------------------------------
+  if (HDF5_ENABLE_DEV_WARNINGS)
+    message (STATUS "....HDF5 developer group warnings are enabled")
+  #  if (CMAKE_CXX_COMPILER_ID STREQUAL "Intel")
+  #    list (APPEND H5_CXXFLAGS0 "-Winline -Wreorder -Wport -Wstrict-aliasing")
+  #  elseif (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+    if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+      # autotools always add the C flags with the CXX flags
+      ADD_H5_FLAGS (H5_CXXFLAGS0 "${HDF5_SOURCE_DIR}/config/gnu-warnings/developer-general")
+  #  elseif (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+  #    ADD_H5_FLAGS (H5_CXXFLAGS0 "${HDF5_SOURCE_DIR}/config/clang-warnings/developer-general")
+    endif ()
+  else ()
+    if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+      # autotools always add the C flags with the CXX flags
+      ADD_H5_FLAGS (H5_CXXFLAGS0 "${HDF5_SOURCE_DIR}/config/gnu-warnings/no-developer-general")
+  #  elseif (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+  #    ADD_H5_FLAGS (H5_CXXFLAGS0 "${HDF5_SOURCE_DIR}/config/clang-warnings/no-developer-general")
+    endif ()
+  endif ()
 
-    #if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
-    #  # Append warning flags that only gcc 4.3+ knows about
-    #  ADD_H5_FLAGS (H5_CXXFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/4.3")
+  if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+    # Append warning flags that only gcc 4.3+ knows about
+    # autotools always add the C flags with the CXX flags
+    ADD_H5_FLAGS (H5_CXXFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/4.3")
+    #
+    # Technically, variable-length arrays are part of the C99 standard, but
+    #   we should approach them a bit cautiously... Only needed for gcc 4.X
+    if (CMAKE_CXX_COMPILER_VERSION VERSION_LESS 5.0)
+      # autotools always add the C flags with the CXX flags
+      ADD_H5_FLAGS (H5_CXXFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/4.2-4.last")
+    endif ()
 
-    #  # Append more extra warning flags that only gcc 4.4+ know about
-    #  if (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.4)
-    #    ADD_H5_FLAGS (H5_CXXFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/4.4")
-    #  endif ()
-    #endif ()
+    # Append more extra warning flags that only gcc 4.4+ know about
+    if (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.4)
+      # autotools always add the C flags with the CXX flags
+      ADD_H5_FLAGS (H5_CXXFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/4.4")
+    endif ()
 
     # Append more extra warning flags that only gcc 4.5+ know about
-    #if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU" AND NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.5)
-    #  ADD_H5_FLAGS (H5_CXXFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/4.5")
-    #  if (HDF5_ENABLE_DEV_WARNINGS)
-    #    ADD_H5_FLAGS (H5_CXXFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/developer-4.5")
-    #  else ()
-    #    ADD_H5_FLAGS (H5_CXXFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/no-developer-4.5")
-    #  endif ()
-    #endif ()
+    if (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.5)
+      # autotools always add the C flags with the CXX flags
+      ADD_H5_FLAGS (H5_CXXFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/4.5")
+      if (HDF5_ENABLE_DEV_WARNINGS)
+        # autotools always add the C flags with the CXX flags
+        ADD_H5_FLAGS (H5_CXXFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/developer-4.5")
+      else ()
+        # autotools always add the C flags with the CXX flags
+        ADD_H5_FLAGS (H5_CXXFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/no-developer-4.5")
+      endif ()
+    endif ()
+
+    # Append more extra warning flags that only gcc 4.6 and less know about
+    if (CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.7)
+      # autotools always add the C flags with the CXX flags
+      ADD_H5_FLAGS (H5_CXXFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/4.2-4.6")
+    endif ()
+
+    # Append more extra warning flags that only gcc 4.5-4.6 know about
+    if (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.5 AND CMAKE_C_COMPILER_VERSION VERSION_LESS 4.7)
+      # autotools always add the C flags with the CXX flags
+      ADD_H5_FLAGS (H5_CXXFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/4.5-4.6")
+    endif ()
+
+    # Append more extra warning flags that only gcc 4.6+ know about
+    if (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.6)
+      # autotools always add the C flags with the CXX flags
+      ADD_H5_FLAGS (H5_CXXFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/4.6")
+      if (HDF5_ENABLE_DEV_WARNINGS)
+        # autotools always add the C flags with the CXX flags
+        ADD_H5_FLAGS (H5_CXXFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/developer-4.6")
+      else ()
+        # autotools always add the C flags with the CXX flags
+        ADD_H5_FLAGS (H5_CXXFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/no-developer-4.6")
+      endif ()
+    endif ()
+
+    # Append more extra warning flags that only gcc 4.7+ know about
+    if (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.7)
+      # autotools always add the C flags with the CXX flags
+      ADD_H5_FLAGS (H5_CXXFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/4.7")
+      if (HDF5_ENABLE_DEV_WARNINGS)
+        # autotools always add the C flags with the CXX flags
+        ADD_H5_FLAGS (H5_CXXFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/developer-4.7")
+      else ()
+        # autotools always add the C flags with the CXX flags
+        ADD_H5_FLAGS (H5_CXXFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/no-developer-4.7")
+      endif ()
+    endif ()
+
+    # Append more extra warning flags that only gcc 4.8+ know about
+    if (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.8)
+      ADD_H5_FLAGS (H5_CXXFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/4.8")
+      if (HDF5_ENABLE_DEV_WARNINGS)
+        ADD_H5_FLAGS (H5_CXXFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/developer-4.8")
+      else ()
+        ADD_H5_FLAGS (H5_CXXFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/no-developer-4.8")
+      endif ()
+    endif ()
+
+    # Append more extra warning flags that only gcc 4.9+ know about
+    if (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.9)
+      # autotools always add the C flags with the CXX flags
+      ADD_H5_FLAGS (H5_CXXFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/4.9")
+      ADD_H5_FLAGS (H5_CXXFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/cxx-4.9")
+    endif ()
+
+    # Append more extra warning flags that only gcc 5.1+ know about
+    if (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 5.0)
+      # autotools always add the C flags with the CXX flags
+      ADD_H5_FLAGS (H5_CXXFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/5")
+      ADD_H5_FLAGS (H5_CXXFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/error-5")
+    endif ()
+
+    # Append more extra warning flags that only gcc 6.x+ know about
+    if (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 6.0)
+      # autotools always add the C flags with the CXX flags
+      ADD_H5_FLAGS (H5_CXXFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/6")
+    endif ()
+
+    # Append more extra warning flags that only gcc 7.x+ know about
+    if (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 7.0)
+      # autotools always add the C flags with the CXX flags
+      ADD_H5_FLAGS (H5_CXxFLAGS2 "${HDF5_SOURCE_DIR}/config/gnu-warnings/7")
+      if (HDF5_ENABLE_DEV_WARNINGS)
+        # autotools always add the C flags with the CXX flags
+        ADD_H5_FLAGS (H5_CXXFLAGS2 "${HDF5_SOURCE_DIR}/config/gnu-warnings/developer-7")
+      #else ()
+      #  ADD_H5_FLAGS (H5_CXXFLAGS2 "${HDF5_SOURCE_DIR}/config/gnu-warnings/no-developer-7")
+      endif ()
+    endif ()
+
+    # Append more extra warning flags that only gcc 8.x+ know about
+    if (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 8.0)
+      # autotools always add the C flags with the CXX flags
+      ADD_H5_FLAGS (H5_CXXFLAGS3 "${HDF5_SOURCE_DIR}/config/gnu-warnings/8")
+      if (HDF5_ENABLE_DEV_WARNINGS)
+        # autotools always add the C flags with the CXX flags
+        ADD_H5_FLAGS (H5_CXXFLAGS3 "${HDF5_SOURCE_DIR}/config/gnu-warnings/developer-8")
+      else ()
+        # autotools always add the C flags with the CXX flags
+        ADD_H5_FLAGS (H5_CXXFLAGS3 "${HDF5_SOURCE_DIR}/config/gnu-warnings/no-developer-8")
+      endif ()
+    endif ()
+
+    # Append more extra warning flags that only gcc 9.x+ know about
+    if (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 9.0)
+      # autotools always add the C flags with the CXX flags
+      ADD_H5_FLAGS (H5_CXXFLAGS4 "${HDF5_SOURCE_DIR}/config/gnu-warnings/9")
+    endif ()
+  endif ()
 else ()
     list (APPEND HDF5_CMAKE_CXX_FLAGS "/EHsc")
 endif ()
diff --git a/config/cmake/HDFCompilerFlags.cmake b/config/cmake/HDFCompilerFlags.cmake
index b255e22..72141c0 100644
--- a/config/cmake/HDFCompilerFlags.cmake
+++ b/config/cmake/HDFCompilerFlags.cmake
@@ -125,47 +125,46 @@ if (NOT MSVC)
     message (STATUS "CMAKE_C_FLAGS_GENERAL=${HDF5_CMAKE_C_FLAGS}")
   endif ()
 
-    #-----------------------------------------------------------------------------
-    # Option to allow the user to enable developer warnings
-    # Developer warnings (suggestions from gcc, not code problems)
-    #-----------------------------------------------------------------------------
-    option (HDF5_ENABLE_DEV_WARNINGS "Enable HDF5 developer group warnings" OFF)
-    if (HDF5_ENABLE_DEV_WARNINGS)
-      message (STATUS "....HDF5 developer group warnings are enabled")
-      if (CMAKE_C_COMPILER_ID STREQUAL "Intel")
-        list (APPEND H5_CFLAGS0 "-Winline -Wreorder -Wport -Wstrict-aliasing")
-      elseif (CMAKE_C_COMPILER_ID STREQUAL "GNU")
-        ADD_H5_FLAGS (H5_CFLAGS0 "${HDF5_SOURCE_DIR}/config/gnu-warnings/developer-general")
-      elseif (CMAKE_C_COMPILER_ID STREQUAL "Clang")
-        ADD_H5_FLAGS (H5_CFLAGS0 "${HDF5_SOURCE_DIR}/config/clang-warnings/developer-general")
-      endif ()
-    else ()
-      if (CMAKE_C_COMPILER_ID STREQUAL "GNU")
-        ADD_H5_FLAGS (H5_CFLAGS0 "${HDF5_SOURCE_DIR}/config/gnu-warnings/no-developer-general")
-      elseif (CMAKE_C_COMPILER_ID STREQUAL "Clang")
-        ADD_H5_FLAGS (H5_CFLAGS0 "${HDF5_SOURCE_DIR}/config/clang-warnings/no-developer-general")
-      endif ()
+  #-----------------------------------------------------------------------------
+  # Option to allow the user to enable developer warnings
+  # Developer warnings (suggestions from gcc, not code problems)
+  #-----------------------------------------------------------------------------
+  option (HDF5_ENABLE_DEV_WARNINGS "Enable HDF5 developer group warnings" OFF)
+  if (HDF5_ENABLE_DEV_WARNINGS)
+    message (STATUS "....HDF5 developer group warnings are enabled")
+    if (CMAKE_C_COMPILER_ID STREQUAL "Intel")
+      list (APPEND H5_CFLAGS0 "-Winline -Wreorder -Wport -Wstrict-aliasing")
+    elseif (CMAKE_C_COMPILER_ID STREQUAL "GNU")
+      ADD_H5_FLAGS (H5_CFLAGS0 "${HDF5_SOURCE_DIR}/config/gnu-warnings/developer-general")
+    elseif (CMAKE_C_COMPILER_ID STREQUAL "Clang")
+      ADD_H5_FLAGS (H5_CFLAGS0 "${HDF5_SOURCE_DIR}/config/clang-warnings/developer-general")
+    endif ()
+  else ()
+    if (CMAKE_C_COMPILER_ID STREQUAL "GNU")
+      ADD_H5_FLAGS (H5_CFLAGS0 "${HDF5_SOURCE_DIR}/config/gnu-warnings/no-developer-general")
+    elseif (CMAKE_C_COMPILER_ID STREQUAL "Clang")
+      ADD_H5_FLAGS (H5_CFLAGS0 "${HDF5_SOURCE_DIR}/config/clang-warnings/no-developer-general")
     endif ()
+  endif ()
 
 
-    if (CMAKE_C_COMPILER_ID STREQUAL "GNU")
-      # Append warning flags that only gcc 4.3+ knows about
-      ADD_H5_FLAGS (H5_CFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/4.3")
-      #
-      # Technically, variable-length arrays are part of the C99 standard, but
-      #   we should approach them a bit cautiously... Only needed for gcc 4.X
-      if (CMAKE_C_COMPILER_VERSION VERSION_LESS 5.0)
-        ADD_H5_FLAGS (H5_CFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/4.2-4.last")
-      endif ()
+  if (CMAKE_C_COMPILER_ID STREQUAL "GNU")
+    # Append warning flags that only gcc 4.3+ knows about
+    ADD_H5_FLAGS (H5_CFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/4.3")
+    #
+    # Technically, variable-length arrays are part of the C99 standard, but
+    #   we should approach them a bit cautiously... Only needed for gcc 4.X
+    if (CMAKE_C_COMPILER_VERSION VERSION_LESS 5.0)
+      ADD_H5_FLAGS (H5_CFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/4.2-4.last")
+    endif ()
 
-      # Append more extra warning flags that only gcc 4.4+ know about
-      if (NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.4)
-        ADD_H5_FLAGS (H5_CFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/4.4")
-      endif ()
+    # Append more extra warning flags that only gcc 4.4+ know about
+    if (NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.4)
+      ADD_H5_FLAGS (H5_CFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/4.4")
     endif ()
 
     # Append more extra warning flags that only gcc 4.5+ know about
-    if (CMAKE_C_COMPILER_ID STREQUAL "GNU" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.5)
+    if (NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.5)
       ADD_H5_FLAGS (H5_CFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/4.5")
       if (HDF5_ENABLE_DEV_WARNINGS)
         ADD_H5_FLAGS (H5_CFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/developer-4.5")
@@ -175,17 +174,17 @@ if (NOT MSVC)
     endif ()
 
     # Append more extra warning flags that only gcc 4.6 and less know about
-    if (CMAKE_C_COMPILER_ID STREQUAL "GNU" AND CMAKE_C_COMPILER_VERSION VERSION_LESS 4.7)
+    if (CMAKE_C_COMPILER_VERSION VERSION_LESS 4.7)
       ADD_H5_FLAGS (H5_CFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/4.2-4.6")
     endif ()
 
     # Append more extra warning flags that only gcc 4.5-4.6 know about
-    if (CMAKE_C_COMPILER_ID STREQUAL "GNU" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.5 AND CMAKE_C_COMPILER_VERSION VERSION_LESS 4.7)
+    if (NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.5 AND CMAKE_C_COMPILER_VERSION VERSION_LESS 4.7)
       ADD_H5_FLAGS (H5_CFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/4.5-4.6")
     endif ()
 
     # Append more extra warning flags that only gcc 4.6+ know about
-    if (CMAKE_C_COMPILER_ID STREQUAL "GNU" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.6)
+    if (NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.6)
       ADD_H5_FLAGS (H5_CFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/4.6")
       if (HDF5_ENABLE_DEV_WARNINGS)
         ADD_H5_FLAGS (H5_CFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/developer-4.6")
@@ -195,7 +194,7 @@ if (NOT MSVC)
     endif ()
 
     # Append more extra warning flags that only gcc 4.7+ know about
-    if (CMAKE_C_COMPILER_ID STREQUAL "GNU" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.7)
+    if (NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.7)
       ADD_H5_FLAGS (H5_CFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/4.7")
       if (HDF5_ENABLE_DEV_WARNINGS)
         ADD_H5_FLAGS (H5_CFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/developer-4.7")
@@ -205,7 +204,7 @@ if (NOT MSVC)
     endif ()
 
     # Append more extra warning flags that only gcc 4.8+ know about
-    if (CMAKE_C_COMPILER_ID STREQUAL "GNU" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.8)
+    if (NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.8)
       ADD_H5_FLAGS (H5_CFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/4.8")
       if (HDF5_ENABLE_DEV_WARNINGS)
         ADD_H5_FLAGS (H5_CFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/developer-4.8")
@@ -215,23 +214,23 @@ if (NOT MSVC)
     endif ()
 
     # Append more extra warning flags that only gcc 4.9+ know about
-    if (CMAKE_C_COMPILER_ID STREQUAL "GNU" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.9)
+    if (NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.9)
       ADD_H5_FLAGS (H5_CFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/4.9")
     endif ()
 
     # Append more extra warning flags that only gcc 5.1+ know about
-    if (CMAKE_C_COMPILER_ID STREQUAL "GNU" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 5.0)
+    if (NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 5.0)
       ADD_H5_FLAGS (H5_CFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/5")
       ADD_H5_FLAGS (H5_CFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/error-5")
     endif ()
 
     # Append more extra warning flags that only gcc 6.x+ know about
-    if (CMAKE_C_COMPILER_ID STREQUAL "GNU" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 6.0)
+    if (NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 6.0)
       ADD_H5_FLAGS (H5_CFLAGS1 "${HDF5_SOURCE_DIR}/config/gnu-warnings/6")
     endif ()
 
     # Append more extra warning flags that only gcc 7.x+ know about
-    if (CMAKE_C_COMPILER_ID STREQUAL "GNU" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 7.0)
+    if (NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 7.0)
       ADD_H5_FLAGS (H5_CFLAGS2 "${HDF5_SOURCE_DIR}/config/gnu-warnings/7")
       if (HDF5_ENABLE_DEV_WARNINGS)
         ADD_H5_FLAGS (H5_CFLAGS2 "${HDF5_SOURCE_DIR}/config/gnu-warnings/developer-7")
@@ -241,7 +240,7 @@ if (NOT MSVC)
     endif ()
 
     # Append more extra warning flags that only gcc 8.x+ know about
-    if (CMAKE_C_COMPILER_ID STREQUAL "GNU" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 8.0)
+    if (NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 8.0)
       ADD_H5_FLAGS (H5_CFLAGS3 "${HDF5_SOURCE_DIR}/config/gnu-warnings/8")
       if (HDF5_ENABLE_DEV_WARNINGS)
         ADD_H5_FLAGS (H5_CFLAGS3 "${HDF5_SOURCE_DIR}/config/gnu-warnings/developer-8")
@@ -251,9 +250,10 @@ if (NOT MSVC)
     endif ()
 
     # Append more extra warning flags that only gcc 9.x+ know about
-    if (CMAKE_C_COMPILER_ID STREQUAL "GNU" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 9.0)
+    if (NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 9.0)
       ADD_H5_FLAGS (H5_CFLAGS4 "${HDF5_SOURCE_DIR}/config/gnu-warnings/9")
     endif ()
+  endif ()
 endif ()
 
 #-----------------------------------------------------------------------------
diff --git a/config/gnu-cxxflags b/config/gnu-cxxflags
index 75ba7c9..e177aef 100644
--- a/config/gnu-cxxflags
+++ b/config/gnu-cxxflags
@@ -266,6 +266,7 @@ if test "X-g++" = "X-$cxx_vendor"; then
     # gcc >= 4.9
     if test $cc_vers_major -ge 5 -o $cc_vers_major -eq 4 -a $cc_vers_minor -ge 9; then
         H5_CXXFLAGS="$H5_CXXFLAGS $(load_gnu_arguments 4.9)"
+        H5_CXXFLAGS="$H5_CXXFLAGS $(load_gnu_arguments cxx-4.9)"
     fi
 
     # gcc >= 5
@@ -304,12 +305,6 @@ if test "X-g++" = "X-$cxx_vendor"; then
     cxx_flags_set=yes
 fi
 
-# Version-specific g++ flags
-
-# This flag was left behind when moving warnings flags to common files for    # both autotools and CMake.
-#    # Append more extra warning flags that only gcc 4.9+ know about
-#    -Wopenmp-simd"
-
 # Clear cxx info if no flags set
 if test "X$cxx_flags_set" = "X"; then
   cxx_vendor=
diff --git a/config/gnu-warnings/cxx-4.9 b/config/gnu-warnings/cxx-4.9
new file mode 100644
index 0000000..046d6db
--- /dev/null
+++ b/config/gnu-warnings/cxx-4.9
@@ -0,0 +1 @@
+-Wopenmp-simd