Add option to control gcc 10 warnings diagnostics (#321)

* OESS-98 convert plugin option to FetchContent, add tests

* Fixes for pkcfg files because of plugin option

* OESS-98 fix tools test for plugins

* Keep doxygen comments under 100 chars long - format hint

* Whitespace

* HDFFV-11144 - Reclassify CMake messages

* HDFFV-11099/11100 added help text

* Reworked switch statement to compare string instead

* Fix typo

* Update CDash mode

* Correct name of threadsafe

* Correct option name

* Undo accidental commit

* Note LLVM 10 to 11 format default changes

* Update format plugin

* Undo clang-format version 11 changes

* One more correction

* Update supported platforms

* Revert whitespace changes

* Correct whitespace

* Changes from PR#3

* HDFFV-11213 added option to control gcc10 warnings diagnostics

8 files changed, 121 insertions, 0 deletions

diff --git a/config/cmake/HDFCXXCompilerFlags.cmake b/config/cmake/HDFCXXCompilerFlags.cmake
index 4f2eabe..ebda39f 100644
--- a/config/cmake/HDFCXXCompilerFlags.cmake
+++ b/config/cmake/HDFCXXCompilerFlags.cmake
@@ -30,6 +30,14 @@ if (CMAKE_COMPILER_IS_GNUCXX AND CMAKE_CXX_COMPILER_LOADED)
     if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU" AND NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 5.0)
       set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fstdarg-opt")
     endif ()
+    if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU" AND NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 10.0)
+      if (HDF5_ENABLE_BUILD_DIAGS)
+        message (STATUS "... default color and URL extended diagnostic messages enabled")
+      else ()
+        message (STATUS "... disable color and URL extended diagnostic messages")
+        set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fdiagnostics-urls=never -fno-diagnostics-color")
+      endif ()
+    endif ()
   endif ()
 endif ()
 
diff --git a/config/cmake/HDFCompilerFlags.cmake b/config/cmake/HDFCompilerFlags.cmake
index fb527d5..3d3cc6a 100644
--- a/config/cmake/HDFCompilerFlags.cmake
+++ b/config/cmake/HDFCompilerFlags.cmake
@@ -31,6 +31,20 @@ if (CMAKE_COMPILER_IS_GNUCC)
     if (CMAKE_C_COMPILER_ID STREQUAL "GNU" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 5.0)
       set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fstdarg-opt")
     endif ()
+    if (CMAKE_C_COMPILER_ID STREQUAL "GNU" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 10.0)
+      #-----------------------------------------------------------------------------
+      # Option to allow the user to enable build extended diagnostics
+      #
+      # This should NOT be on by default as it can cause process issues.
+      #-----------------------------------------------------------------------------
+      option (HDF5_ENABLE_BUILD_DIAGS "Enable color and URL extended diagnostic messages" OFF)
+      if (HDF5_ENABLE_BUILD_DIAGS)
+        message (STATUS "... default color and URL extended diagnostic messages enabled")
+      else ()
+        message (STATUS "... disable color and URL extended diagnostic messages")
+        set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fdiagnostics-urls=never -fno-diagnostics-color")
+      endif ()
+    endif ()
   endif ()
 endif ()
 
diff --git a/config/cmake/HDFFortranCompilerFlags.cmake b/config/cmake/HDFFortranCompilerFlags.cmake
index c7f085c..5521f6d 100644
--- a/config/cmake/HDFFortranCompilerFlags.cmake
+++ b/config/cmake/HDFFortranCompilerFlags.cmake
@@ -45,6 +45,14 @@ endif ()
 #-----------------------------------------------------------------------------
 # HDF5 library compile options
 #-----------------------------------------------------------------------------
+if (CMAKE_Fortran_COMPILER_ID STREQUAL "GNU" AND NOT CMAKE_Fortran_COMPILER_VERSION VERSION_LESS 10.0)
+  if (HDF5_ENABLE_BUILD_DIAGS)
+    message (STATUS "... default color and URL extended diagnostic messages enabled")
+  else ()
+    message (STATUS "... disable color and URL extended diagnostic messages")
+    set (CMAKE_Fortran_FLAGS "${CMAKE_Fortran_FLAGS} -fdiagnostics-urls=never -fno-diagnostics-color")
+  endif ()
+endif ()
 
 #-----------------------------------------------------------------------------
 # CDash is configured to only allow 3000 warnings, so
diff --git a/config/gnu-cxxflags b/config/gnu-cxxflags
index 0b48bdf..6189db6 100644
--- a/config/gnu-cxxflags
+++ b/config/gnu-cxxflags
@@ -144,6 +144,15 @@ if test "X-g++" = "X-$cxx_vendor"; then
         DEBUG_CXXFLAGS="-ftrapv -fno-common"
     fi
 
+    ########################
+    # Enhanced Diagnostics #
+    ########################
+
+    if test $cc_vers_major -ge 10; then
+        NO_DIAGS_CXXFLAGS="-fdiagnostics-urls=never -fno-diagnostics-color"
+    fi
+    DIAGS_CXXFLAGS=
+
     ###########
     # Symbols #
     ###########
diff --git a/config/gnu-fflags b/config/gnu-fflags
index 105a990..32e5a28 100644
--- a/config/gnu-fflags
+++ b/config/gnu-fflags
@@ -105,6 +105,15 @@ if test "X-gfortran" = "X-$f9x_vendor"; then
         DEBUG_FCFLAGS="-fbounds-check"
     fi
 
+    ########################
+    # Enhanced Diagnostics #
+    ########################
+
+    if test $cc_vers_major -ge 10; then
+        NO_DIAGS_FCFLAGS="-fdiagnostics-urls=never -fno-diagnostics-color"
+    fi
+    DIAGS_FCFLAGS=
+
     ###########
     # Symbols #
     ###########
diff --git a/config/gnu-flags b/config/gnu-flags
index 538fd53..6f7aea6 100644
--- a/config/gnu-flags
+++ b/config/gnu-flags
@@ -158,6 +158,15 @@ if test "X-gcc" = "X-$cc_vendor"; then
         DEBUG_CFLAGS="-ftrapv -fno-common"
     fi
 
+    ########################
+    # Enhanced Diagnostics #
+    ########################
+
+    if test $cc_vers_major -ge 10; then
+        NO_DIAGS_CFLAGS="-fdiagnostics-urls=never -fno-diagnostics-color"
+    fi
+    DIAGS_CFLAGS=
+
     ###########
     # Symbols #
     ###########
diff --git a/configure.ac b/configure.ac
index 131bd27..2ff8519 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2158,6 +2158,51 @@ AC_ARG_ENABLE([production],
 
 
 ## ----------------------------------------------------------------------
+## Check if the compiler should include build diagnostics
+##
+AC_MSG_CHECKING([enable build diagnostics])
+AC_ARG_ENABLE([diags],
+              [AS_HELP_STRING([--enable-diags=(yes|no|<custom>)],
+                              [Allow default enhanced diagnostics to the build.
+                               This is independent of the build mode and optimization
+                               level.
+                               [default=no]
+                               ])],
+              [DIAGS=$enableval])
+
+## Set default
+if test "X-$DIAGS" = X- ; then
+  DIAGS=no
+fi
+
+## Allow this variable to be substituted in
+## other files (src/libhdf5.settings.in, etc.)
+AC_SUBST([DIAGS])
+
+case "X-$DIAGS" in
+  X-yes)
+    H5_CFLAGS="$H5_CFLAGS $DIAGS_CFLAGS"
+    H5_CXXFLAGS="$H5_CXXFLAGS $DIAGS_CXXFLAGS"
+    H5_FCFLAGS="$H5_FCFLAGS $DIAGS_FCFLAGS"
+    AC_MSG_RESULT([yes])
+    ;;
+  X-no)
+    H5_CFLAGS="$H5_CFLAGS $NO_DIAGS_CFLAGS"
+    H5_CXXFLAGS="$H5_CXXFLAGS $NO_DIAGS_CXXFLAGS"
+    H5_FCFLAGS="$H5_FCFLAGS $NO_DIAGS_FCFLAGS"
+    AC_MSG_RESULT([no])
+    ;;
+  *)
+    H5_CFLAGS="$H5_CFLAGS $DIAGS"
+    H5_CXXFLAGS="$H5_CXXFLAGS $DIAGS"
+    H5_FCFLAGS="$H5_FCFLAGS $DIAGS"
+    DIAGS="custom ($DIAGS)"
+    AC_MSG_RESULT([$DIAGS])
+    ;;
+esac
+
+
+## ----------------------------------------------------------------------
 ## Check if the compiler should include symbols
 ##
 AC_MSG_CHECKING([enable debugging symbols])
diff --git a/release_docs/RELEASE.txt b/release_docs/RELEASE.txt
index 1d7e6da..c844b82 100644
--- a/release_docs/RELEASE.txt
+++ b/release_docs/RELEASE.txt
@@ -55,6 +55,25 @@ New Features
 
       (SAM - 2021/02/07, https://github.com/HDFGroup/hdf5/issues/311)
 
+    - Added a configure-time option to control certain compiler warnings
+      diagnostics
+
+      A new configure-time option was added that allows some compiler warnings
+      diagnostics to have the default operation. This is mainly intended for
+      library developers and currently only works for gcc 10 and above. The
+      diagnostics flags apply to C, C++ and Fortran compilers and will appear
+      in "H5 C Flags", H5 C++ Flags" and H5 Fortran Flags, respectively. They
+      will NOT be exported to h5cc, etc.
+
+      The default is OFF, which will disable the warnings URL and color attributes
+      for the warnings output. ON will not add the flags and allow default behavior.
+
+      Autotools:    --enable-diags
+
+      CMake:        HDF5_ENABLE_BUILD_DIAGS
+
+      (ADB - 2021/02/05, HDFFV-11213)
+
     - CMake option to build the HDF filter plugins project as an external project
 
         The HDF filter plugins project is a collection of registered compression