Tests/CompileFeatures: Cover c_std_## and cxx_std_## meta-features

Tests/CompileFeatures/CMakeLists.txt

@@ -6,6 +6,18 @@ project(CompileFeatures)
 
 set(ext_C c)
 set(ext_CXX cpp)
+set(std_C 90 99 11 17 23)
+set(std_CXX 98 11 14 17 20 23)
+
+foreach(lang C CXX)
+  foreach(std IN LISTS std_${lang})
+    string(TOLOWER "${lang}_std_${std}" feature)
+    if(CMAKE_${lang}${std}_STANDARD_COMPILE_OPTION)
+      add_library(test_${feature} OBJECT ${feature}.${ext_${lang}})
+      target_compile_features(test_${feature} PRIVATE ${feature})
+    endif()
+  endforeach()
+endforeach()
 
 macro(run_test feature lang)
   if (${feature} IN_LIST CMAKE_${lang}_COMPILE_FEATURES)

Tests/CompileFeatures/c_std_11.c

@@ -0,0 +1,5 @@
+#include "c_std.h"
+#if defined(C_STD) && C_STD <= C_STD_99 &&                                    \
+  !(defined(__SUNPRO_C) && __SUNPRO_C < 0x5140 && C_STD == C_STD_99)
+#  error "c_std_11 not honored"
+#endif

Tests/CompileFeatures/c_std_17.c

@@ -0,0 +1,4 @@
+#include "c_std.h"
+#if defined(C_STD) && C_STD <= C_STD_11
+#  error "c_std_17 not honored"
+#endif

Tests/CompileFeatures/c_std_23.c

@@ -0,0 +1,6 @@
+#include "c_std.h"
+#if defined(C_STD) && C_STD <= C_STD_17 &&                                    \
+  !(C_STD == C_STD_17 && defined(__apple_build_version__) &&                  \
+    defined(__clang_major__) && __clang_major__ < 14)
+#  error "c_std_23 not honored"
+#endif

Tests/CompileFeatures/c_std_99.c

@@ -0,0 +1,4 @@
+#include "c_std.h"
+#if defined(C_STD) && C_STD < C_STD_99
+#  error "c_std_99 not honored"
+#endif

Tests/CompileFeatures/cxx_std_11.cpp

@@ -0,0 +1,6 @@
+#include "cxx_std.h"
+#if defined(CXX_STD) && CXX_STD < CXX_STD_11 &&                               \
+  !(CXX_STD == CXX_STD_98 &&                                                  \
+    (defined(__IBMCPP__) && defined(_AIX) && __IBMCPP__ == 1610))
+#  error "cxx_std_11 not honored"
+#endif

Tests/CompileFeatures/cxx_std_14.cpp

@@ -0,0 +1,9 @@
+#include "cxx_std.h"
+#if defined(CXX_STD) && CXX_STD <= CXX_STD_11 &&                              \
+  !(CXX_STD == CXX_STD_11 &&                                                  \
+    ((defined(__GNUC__) && defined(__GNUC_MINOR__) && __GNUC__ == 4 &&        \
+      __GNUC_MINOR__ <= 8 && !defined(__clang__) &&                           \
+      !defined(__INTEL_COMPILER) && !defined(__PGI)) ||                       \
+     (defined(__SUNPRO_CC) && __SUNPRO_CC < 0x5150)))
+#  error "cxx_std_14 not honored"
+#endif

Tests/CompileFeatures/cxx_std_17.cpp

@@ -0,0 +1,4 @@
+#include "cxx_std.h"
+#if defined(CXX_STD) && CXX_STD <= CXX_STD_14
+#  error "cxx_std_17 not honored"
+#endif

Tests/CompileFeatures/cxx_std_20.cpp

@@ -0,0 +1,4 @@
+#include "cxx_std.h"
+#if defined(CXX_STD) && CXX_STD <= CXX_STD_17
+#  error "cxx_std_20 not honored"
+#endif

Tests/CompileFeatures/cxx_std_23.cpp

@@ -0,0 +1,4 @@
+#include "cxx_std.h"
+#if defined(CXX_STD) && CXX_STD <= CXX_STD_20
+#  error "cxx_std_23 not honored"
+#endif