Merge branch 'add_c_standard_input_flag' (TriBITSPub#239)

This is needed for trilinos/Trilinos#1974.

Build/Test Cases Summary
Enabled Packages:
Enabled all Packages
0) MPI_DEBUG => passed: passed=263,notpassed=0 (0.74 min)
1) SERIAL_RELEASE => passed: passed=263,notpassed=0 (0.62 min)
2) MPI_DEBUG_CMAKE-3.6.2 => passed: passed=284,notpassed=0 (0.62 min)
3) SERIAL_RELEASE_CMAKE-3.6.2 => passed: passed=284,notpassed=0 (0.53 min)
Other local commits for this build/test group: 6e3d7d2, f22a20e, 09cc5c4

test/core/CMakeLists.txt

@@ -62,7 +62,7 @@ TRIBITS_ADD_ADVANCED_TEST( CompilerOptions_UnitTests
       -D${PROJECT_NAME}_TRIBITS_DIR=${${PROJECT_NAME}_TRIBITS_DIR}
       -P "${CMAKE_CURRENT_SOURCE_DIR}/CompilerOptions_UnitTests.cmake"
     PASS_REGULAR_EXPRESSION_ALL
-      "Final UnitTests Result: num_run = 198"
+      "Final UnitTests Result: num_run = 207"
       "Final UnitTests Result: PASSED"
   )
 

test/core/CompilerOptions_UnitTests.cmake

@@ -111,6 +111,32 @@ FUNCTION(UNITEST_GCC_BASE_OPTIONS)
 ENDFUNCTION()
 
 
+FUNCTION(UNITEST_GCC_STD_OVERRIDE_OPTIONS)
+
+  MESSAGE("\n***")
+  MESSAGE("*** Testing GCC compiler options with override of c standard to c34")
+  MESSAGE("***\n")
+
+  TRIBITS_SET_ALL_COMPILER_ID(GNU)
+  SET(${PROJECT_NAME}_C_Standard "c34" )
+
+  TRIBITS_COMPILE_OPTIONS_COMMON_ACTIONS()
+
+  UNITTEST_COMPARE_CONST( CMAKE_C_FLAGS
+    " -pedantic -Wall -Wno-long-long -std=c34" )
+  UNITTEST_COMPARE_CONST( CMAKE_CXX_FLAGS
+    " -pedantic -Wall -Wno-long-long -std=c++98 -Wwrite-strings" )
+  UNITTEST_COMPARE_CONST( CMAKE_Fortran_FLAGS "" )
+  UNITTEST_COMPARE_CONST( CMAKE_C_FLAGS_DEBUG "-g -O0" )
+  UNITTEST_COMPARE_CONST( CMAKE_CXX_FLAGS_DEBUG "-g -O0" )
+  UNITTEST_COMPARE_CONST( CMAKE_Fortran_FLAGS_DEBUG "-g -O0" )
+  UNITTEST_COMPARE_CONST( CMAKE_C_FLAGS_RELEASE "-O3 -DNDEBUG" )
+  UNITTEST_COMPARE_CONST( CMAKE_CXX_FLAGS_RELEASE "-O3 -DNDEBUG" )
+  UNITTEST_COMPARE_CONST( CMAKE_Fortran_FLAGS_RELEASE "-O3" )
+
+ENDFUNCTION()
+
+
 FUNCTION(UNITEST_GCC_ENABLE_CXX11_OPTIONS)
 
   MESSAGE("\n***")
@@ -819,6 +845,7 @@ SET(CMAKE_BUILD_TYPE DEBUG)
 
 UNITEST_GCC_ENABLE_CXX11_OPTIONS()
 UNITEST_GCC_BASE_OPTIONS()
+UNITEST_GCC_STD_OVERRIDE_OPTIONS()
 UNITEST_GCC_PROJECT_DEFINED_STRONG_C_OPTIONS()
 UNITEST_GCC_PROJECT_DEFINED_STRONG_CXX_OPTIONS()
 UNITEST_GCC_PROJECT_DEFINED_STRONG_C_CXX_OPTIONS()
@@ -842,4 +869,4 @@ UNITEST_OTHER_BASE_OPTIONS()
 UNITEST_OTHER_WITH_SHADOW_CLEANED_CHECKED_STL_COVERAGE_OPTIONS()
 
 # Pass in the number of expected tests that must pass!
-UNITTEST_FINAL_RESULT(198)
+UNITTEST_FINAL_RESULT(207)

tribits/core/package_arch/TribitsDefineStandardCompileVars.cmake

@@ -94,9 +94,14 @@ MACRO(TRIBITS_DEFINE_STANDARD_COMPILE_FLAGS_VARS  ENABLE_SHADOWING_WARNINGS)
   IF (${PROJECT_NAME}_C_STRONG_COMPILE_WARNING_FLAGS)
     SET(C_STRONG_COMPILE_WARNING_FLAGS ${${PROJECT_NAME}_C_STRONG_COMPILE_WARNING_FLAGS})
   ELSE()
+    IF ("${${PROJECT_NAME}_C_Standard}" STREQUAL "")
+      SET(${PROJECT_NAME}_C_Standard_USED c99)
+    ELSE()
+      SET(${PROJECT_NAME}_C_Standard_USED ${${PROJECT_NAME}_C_Standard})
+    ENDIF()
     MULTILINE_SET(C_STRONG_COMPILE_WARNING_FLAGS
       ${COMMON_STRONG_COMPILE_WARNING_FLAGS}
-      " -std=c99" # Check for C99
+      " -std=${${PROJECT_NAME}_C_Standard_USED}"
       )
   ENDIF()
 

tribits/core/package_arch/TribitsGlobalMacros.cmake

@@ -222,6 +222,14 @@ MACRO(TRIBITS_DEFINE_GLOBAL_OPTIONS_AND_DEFINE_EXTRA_REPOS)
     "Enable the C compiler and related code"
     ${${PROJECT_NAME}_ENABLE_C_DEFAULT} )
 
+  IF ("${${PROJECT_NAME}_C_Standard_DEFAULT}" STREQUAL "")
+    SET(${PROJECT_NAME}_C_Standard_DEFAULT c99)
+  ENDIF()
+  ADVANCED_SET(${PROJECT_NAME}_C_Standard
+    ${${PROJECT_NAME}_C_Standard_DEFAULT}
+    CACHE STRING
+    "The standard <cstd> to use in --std=<cstd> for GCC compilers." )
+
   IF ("${${PROJECT_NAME}_ENABLE_CXX_DEFAULT}" STREQUAL "")
     SET(${PROJECT_NAME}_ENABLE_CXX_DEFAULT ON)
   ENDIF()

tribits/doc/developers_guide/TribitsDevelopersGuide.rst

@@ -7811,6 +7811,7 @@ be documented in `TribitsBuildReference`_.
 The global project-level TriBITS options for which defaults can be provided by
 a given TriBITS project are:
 
+* `${PROJECT_NAME}_C_Standard`_
 * `${PROJECT_NAME}_CHECK_FOR_UNPARSED_ARGUMENTS`_
 * `${PROJECT_NAME}_CONFIGURE_OPTIONS_FILE_APPEND`_
 * `${PROJECT_NAME}_CPACK_SOURCE_GENERATOR`_
@@ -7842,9 +7843,19 @@ a given TriBITS project are:
 * `MPI_EXEC_MAX_NUMPROCS`_
 * `PythonInterp_FIND_VERSION`_
 
-
 These options are described below.
 
+.. _${PROJECT_NAME}_C_Standard:
+
+**${PROJECT_NAME}_C_Standard**
+
+  The variable ``${PROJECT_NAME}_C_Standard`` is used define the C standard
+  pass to the compiler in ``--std=<cstd>`` for GCC builds of the project.
+  TriBITS sets the default as ``c99`` but the project can set a new default in
+  the project's base `<projectDir>/CMakeLists.txt`_ file with, for example::
+
+    SET(${PROJECT_NAME}_C_Standard_DEFAULT c11)
+
 .. _${PROJECT_NAME}_CHECK_FOR_UNPARSED_ARGUMENTS:
 
 **${PROJECT_NAME}_CHECK_FOR_UNPARSED_ARGUMENTS**