Merge pull request #1764 in HDFFV/hdf5 from ~KOZIOL/hdf5:feature/update_gcc_flags to develop

Updated CMake bulids, too.

* commit '17ae90917856e4cbab5a2f1c597197ee98802fc7':
  Update GCC 6 & 7 flags for CMake builds
  Move -Wnormalized down into GCC 6.x flags
  Add support for GCC 7.x warnings, update warnhist script to account for them, clean up warnings.

2 files changed, 54 insertions, 5 deletions

diff --git a/config/cmake/HDFCompilerFlags.cmake b/config/cmake/HDFCompilerFlags.cmake
index 0a39568..4712f50 100644
--- a/config/cmake/HDFCompilerFlags.cmake
+++ b/config/cmake/HDFCompilerFlags.cmake
@@ -195,7 +195,12 @@ if (NOT MSVC AND CMAKE_COMPILER_IS_GNUCC)
 
     # 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)
-      set (H5_CFLAGS4 "${H5_CFLAGS4} -Wnull-dereference -Wunused-const-variable -Wduplicated-cond -Whsa")
+      set (H5_CFLAGS4 "${H5_CFLAGS4} -Wnull-dereference -Wunused-const-variable -Wduplicated-cond -Whsa -Wnormalized")
+    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)
+      set (H5_CFLAGS4 "${H5_CFLAGS4} -Walloc-zero -Walloca -Wduplicated-branches -Wformat-overflow=2 -Wformat-truncation=2 -Wimplicit-fallthrough=5 -Wrestrict")
     endif ()
 
 endif ()
diff --git a/config/gnu-flags b/config/gnu-flags
index 7df72c7..c55391d 100644
--- a/config/gnu-flags
+++ b/config/gnu-flags
@@ -117,7 +117,7 @@ case "$cc_vendor-$cc_version" in
     H5_CFLAGS="$H5_CFLAGS -Wcast-qual -Wconversion -Wdeclaration-after-statement -Wdisabled-optimization -Wfloat-equal"
     H5_CFLAGS="$H5_CFLAGS -Wformat=2 -Winit-self -Winvalid-pch -Wmissing-declarations -Wmissing-include-dirs"
     H5_CFLAGS="$H5_CFLAGS -Wmissing-prototypes -Wnested-externs -Wold-style-definition -Wpacked -Wpointer-arith"
-    H5_CFLAGS="$H5_CFLAGS -Wredundant-decls -Wshadow -Wstrict-prototypes -Wswitch-default -Wswitch-enum"
+    H5_CFLAGS="$H5_CFLAGS -Wredundant-decls -Wshadow -Wstrict-prototypes -Wswitch-enum -Wswitch-default"
     H5_CFLAGS="$H5_CFLAGS -Wundef -Wunused-macros -Wunsafe-loop-optimizations -Wwrite-strings"
 
     # Production
@@ -187,10 +187,10 @@ esac
 # the information from the previous version and adding modifications to that.
 case "$cc_vendor-$cc_version" in
 
-# When the gcc 7.x release is out, we should check for additional flags to
+# When the gcc 8.x release is out, we should check for additional flags to
 # include and break it out into it's own section, like the other versions
 # below. -QAK
-  gcc-[6789].*)
+  gcc-[789].*)
     # Append warning flags that only gcc 4.2+ knows about
     # (none, or incorporated in -Wall / -Wextra now)
 
@@ -227,7 +227,51 @@ case "$cc_vendor-$cc_version" in
     H5_CFLAGS="$H5_CFLAGS -Warray-bounds=2 -Wc99-c11-compat"
 
     # Append warning flags that only gcc 6.x+ knows about
-    H5_CFLAGS="$H5_CFLAGS -Wnull-dereference -Wunused-const-variable -Wduplicated-cond -Whsa"
+    H5_CFLAGS="$H5_CFLAGS -Wnull-dereference -Wunused-const-variable -Wduplicated-cond -Whsa -Wnormalized"
+
+    # Append warning flags that only gcc 7.x+ knows about
+    DEVELOPER_WARNING_CFLAGS="$DEVELOPER_WARNING_CFLAGS -Wstringop-overflow=2"
+    H5_CFLAGS="$H5_CFLAGS -Walloc-zero -Walloca -Wduplicated-branches -Wformat-overflow=2 -Wformat-truncation=2 -Wimplicit-fallthrough=5 -Wrestrict"
+    ;;
+
+  gcc-6*)
+    # Append warning flags that only gcc 4.2+ knows about
+    # (none, or incorporated in -Wall / -Wextra now)
+
+    # Append warning flags that only gcc 4.3+ knows about
+    #
+    # Technically, variable-length arrays are part of the C99 standard, but
+    #   we should approach them a bit cautiously... -QAK
+    H5_CFLAGS="$H5_CFLAGS -Wlogical-op -Wlarger-than=2048 -Wvla"
+
+    # Append warning flags that only gcc 4.4+ knows about
+    H5_CFLAGS="$H5_CFLAGS -Wsync-nand -Wframe-larger-than=16384 -Wpacked-bitfield-compat"
+
+    # Append warning flags that only gcc 4.5+ knows about
+    H5_CFLAGS="$H5_CFLAGS -Wstrict-overflow=5 -Wjump-misses-init -Wunsuffixed-float-constants"
+
+    # Append warning flags that only gcc 4.6+ knows about
+    H5_CFLAGS="$H5_CFLAGS -Wdouble-promotion -Wtrampolines"
+    DEVELOPER_WARNING_CFLAGS="$DEVELOPER_WARNING_CFLAGS -Wsuggest-attribute=const"
+    NO_DEVELOPER_WARNING_CFLAGS="$NO_DEVELOPER_WARNING_CFLAGS -Wno-suggest-attribute=const"
+
+    # Append warning flags that only gcc 4.7+ knows about
+    H5_CFLAGS="$H5_CFLAGS -Wstack-usage=8192 -Wvector-operation-performance"
+    DEVELOPER_WARNING_CFLAGS="$DEVELOPER_WARNING_CFLAGS -Wsuggest-attribute=pure -Wsuggest-attribute=noreturn"
+    NO_DEVELOPER_WARNING_CFLAGS="$NO_DEVELOPER_WARNING_CFLAGS -Wno-suggest-attribute=pure -Wno-suggest-attribute=noreturn"
+
+    # Append warning flags that only gcc 4.8+ knows about
+    DEVELOPER_WARNING_CFLAGS="$DEVELOPER_WARNING_CFLAGS -Wsuggest-attribute=format"
+    NO_DEVELOPER_WARNING_CFLAGS="$NO_DEVELOPER_WARNING_CFLAGS -Wno-suggest-attribute=format"
+
+    # Append warning flags that only gcc 4.9+ knows about
+    H5_CFLAGS="$H5_CFLAGS -Wdate-time"
+
+    # Append warning flags that only gcc 5.x+ knows about
+    H5_CFLAGS="$H5_CFLAGS -Warray-bounds=2 -Wc99-c11-compat"
+
+    # Append warning flags that only gcc 6.x+ knows about
+    H5_CFLAGS="$H5_CFLAGS -Wnull-dereference -Wunused-const-variable -Wduplicated-cond -Whsa -Wnormalized"
     ;;
 
   gcc-5*)