Merge topic 'vs-mixed-lang-std'

b325484928 VS: Fix C language standard in target with C++ sources

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !5295

4 files changed, 49 insertions, 0 deletions

diff --git a/Source/cmVisualStudio10TargetGenerator.cxx b/Source/cmVisualStudio10TargetGenerator.cxx
index ae4a5be..a7b90b4 100644
--- a/Source/cmVisualStudio10TargetGenerator.cxx
+++ b/Source/cmVisualStudio10TargetGenerator.cxx
@@ -2868,6 +2868,23 @@ bool cmVisualStudio10TargetGenerator::ComputeClOptions(
       this->Makefile->IsOn("CMAKE_VERBOSE_MAKEFILE"));
   }
 
+  // Add C-specific flags expressible in a ClCompile meant for C++.
+  if (langForClCompile == "CXX") {
+    std::set<std::string> languages;
+    this->GeneratorTarget->GetLanguages(languages, configName);
+    if (languages.count("C")) {
+      std::string flagsC;
+      this->LocalGenerator->AddCompileOptions(flagsC, this->GeneratorTarget,
+                                              "C", configName);
+      Options optC(this->LocalGenerator, Options::Compiler,
+                   gg->GetClFlagTable());
+      optC.Parse(flagsC);
+      if (const char* stdC = optC.GetFlag("LanguageStandard_C")) {
+        clOptions.AddFlag("LanguageStandard_C", stdC);
+      }
+    }
+  }
+
   // Add a definition for the configuration name.
   std::string configDefine = cmStrCat("CMAKE_INTDIR=\"", configName, '"');
   clOptions.AddDefine(configDefine);
diff --git a/Tests/RunCMake/VS10Project/LanguageStandard-check.cmake b/Tests/RunCMake/VS10Project/LanguageStandard-check.cmake
new file mode 100644
index 0000000..85e2858
--- /dev/null
+++ b/Tests/RunCMake/VS10Project/LanguageStandard-check.cmake
@@ -0,0 +1,23 @@
+set(vcProjectFile "${RunCMake_TEST_BINARY_DIR}/foo.vcxproj")
+if(NOT EXISTS "${vcProjectFile}")
+  set(RunCMake_TEST_FAILED "Project file ${vcProjectFile} does not exist.")
+  return()
+endif()
+
+set(found_LanguageStandard_stdcpp17 0)
+set(found_LanguageStandard_C_stdc11 0)
+file(STRINGS "${vcProjectFile}" lines)
+foreach(line IN LISTS lines)
+  if(line MATCHES "<LanguageStandard>stdcpp17</LanguageStandard>")
+    set(found_LanguageStandard_stdcpp17 1)
+  endif()
+  if(line MATCHES "<LanguageStandard_C>stdc11</LanguageStandard_C>")
+    set(found_LanguageStandard_C_stdc11 1)
+  endif()
+endforeach()
+if(NOT found_LanguageStandard_stdcpp17)
+  string(APPEND RunCMake_TEST_FAILED "LanguageStandard stdcpp17 not found in\n  ${vcProjectFile}\n")
+endif()
+if(NOT found_LanguageStandard_C_stdc11)
+  string(APPEND RunCMake_TEST_FAILED "LanguageStandard_C stdc11 not found in\n  ${vcProjectFile}\n")
+endif()
diff --git a/Tests/RunCMake/VS10Project/LanguageStandard.cmake b/Tests/RunCMake/VS10Project/LanguageStandard.cmake
new file mode 100644
index 0000000..f8b62e2
--- /dev/null
+++ b/Tests/RunCMake/VS10Project/LanguageStandard.cmake
@@ -0,0 +1,5 @@
+enable_language(C)
+enable_language(CXX)
+
+add_library(foo empty.c empty.cxx)
+target_compile_features(foo PRIVATE c_std_11 cxx_std_17)
diff --git a/Tests/RunCMake/VS10Project/RunCMakeTest.cmake b/Tests/RunCMake/VS10Project/RunCMakeTest.cmake
index e9f251a..8e56e1b 100644
--- a/Tests/RunCMake/VS10Project/RunCMakeTest.cmake
+++ b/Tests/RunCMake/VS10Project/RunCMakeTest.cmake
@@ -3,6 +3,10 @@ cmake_policy(SET CMP0057 NEW)
 include(RunCMake)
 cmake_policy(SET CMP0054 NEW)
 
+if(CMAKE_C_COMPILER_ID STREQUAL "MSVC" AND CMAKE_C_COMPILER_VERSION VERSION_GREATER_EQUAL 19.27)
+  run_cmake(LanguageStandard)
+endif()
+
 run_cmake(VsCsharpSourceGroup)
 run_cmake(VsCSharpCompilerOpts)
 run_cmake(ExplicitCMakeLists)