Merge topic 'cuda-mixed-cxx-standard'

4b7618d1 CUDA: Fix CUDA_STANDARD selection via cxx_std_11 with CXX_STANDARD
1d2d9c18 cmMakefile: Refactor determining a targets C++ standard level

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !1590

4 files changed, 87 insertions, 73 deletions

diff --git a/Source/cmMakefile.cxx b/Source/cmMakefile.cxx
index a9de3f5..a1e2f63 100644
--- a/Source/cmMakefile.cxx
+++ b/Source/cmMakefile.cxx
@@ -4401,8 +4401,10 @@ bool cmMakefile::HaveCxxStandardAvailable(cmTarget const* target,
     existingCxxStandard = defaultCxxStandard;
   }
 
-  if (std::find_if(cm::cbegin(CXX_STANDARDS), cm::cend(CXX_STANDARDS),
-                   cmStrCmp(existingCxxStandard)) == cm::cend(CXX_STANDARDS)) {
+  const char* const* existingCxxLevel =
+    std::find_if(cm::cbegin(CXX_STANDARDS), cm::cend(CXX_STANDARDS),
+                 cmStrCmp(existingCxxStandard));
+  if (existingCxxLevel == cm::cend(CXX_STANDARDS)) {
     std::ostringstream e;
     e << "The CXX_STANDARD property on target \"" << target->GetName()
       << "\" contained an invalid value: \"" << existingCxxStandard << "\".";
@@ -4410,32 +4412,16 @@ bool cmMakefile::HaveCxxStandardAvailable(cmTarget const* target,
     return false;
   }
 
-  const char* const* existingCxxIt = existingCxxStandard
-    ? std::find_if(cm::cbegin(CXX_STANDARDS), cm::cend(CXX_STANDARDS),
-                   cmStrCmp(existingCxxStandard))
-    : cm::cend(CXX_STANDARDS);
+  /* clang-format off */
+  const char* const* needCxxLevel =
+    needCxx17 ? &CXX_STANDARDS[3]
+    : needCxx14 ? &CXX_STANDARDS[2]
+    : needCxx11 ? &CXX_STANDARDS[1]
+    : needCxx98 ? &CXX_STANDARDS[0]
+    : nullptr;
+  /* clang-format on */
 
-  if (needCxx17 &&
-      existingCxxIt < std::find_if(cm::cbegin(CXX_STANDARDS),
-                                   cm::cend(CXX_STANDARDS), cmStrCmp("17"))) {
-    return false;
-  }
-  if (needCxx14 &&
-      existingCxxIt < std::find_if(cm::cbegin(CXX_STANDARDS),
-                                   cm::cend(CXX_STANDARDS), cmStrCmp("14"))) {
-    return false;
-  }
-  if (needCxx11 &&
-      existingCxxIt < std::find_if(cm::cbegin(CXX_STANDARDS),
-                                   cm::cend(CXX_STANDARDS), cmStrCmp("11"))) {
-    return false;
-  }
-  if (needCxx98 &&
-      existingCxxIt < std::find_if(cm::cbegin(CXX_STANDARDS),
-                                   cm::cend(CXX_STANDARDS), cmStrCmp("98"))) {
-    return false;
-  }
-  return true;
+  return !needCxxLevel || needCxxLevel <= existingCxxLevel;
 }
 
 void cmMakefile::CheckNeededCxxLanguage(const std::string& feature,
@@ -4481,10 +4467,12 @@ bool cmMakefile::AddRequiredTargetCxxFeature(cmTarget* target,
                                needCxx17);
 
   const char* existingCxxStandard = target->GetProperty("CXX_STANDARD");
+  const char* const* existingCxxLevel = nullptr;
   if (existingCxxStandard) {
-    if (std::find_if(cm::cbegin(CXX_STANDARDS), cm::cend(CXX_STANDARDS),
-                     cmStrCmp(existingCxxStandard)) ==
-        cm::cend(CXX_STANDARDS)) {
+    existingCxxLevel =
+      std::find_if(cm::cbegin(CXX_STANDARDS), cm::cend(CXX_STANDARDS),
+                   cmStrCmp(existingCxxStandard));
+    if (existingCxxLevel == cm::cend(CXX_STANDARDS)) {
       std::ostringstream e;
       e << "The CXX_STANDARD property on target \"" << target->GetName()
         << "\" contained an invalid value: \"" << existingCxxStandard << "\".";
@@ -4497,50 +4485,51 @@ bool cmMakefile::AddRequiredTargetCxxFeature(cmTarget* target,
       return false;
     }
   }
-  const char* const* existingCxxIt = existingCxxStandard
-    ? std::find_if(cm::cbegin(CXX_STANDARDS), cm::cend(CXX_STANDARDS),
-                   cmStrCmp(existingCxxStandard))
-    : cm::cend(CXX_STANDARDS);
-
-  bool setCxx98 = needCxx98 && !existingCxxStandard;
-  bool setCxx11 = needCxx11 && !existingCxxStandard;
-  bool setCxx14 = needCxx14 && !existingCxxStandard;
-  bool setCxx17 = needCxx17 && !existingCxxStandard;
-
-  if (needCxx17 && existingCxxStandard &&
-      existingCxxIt < std::find_if(cm::cbegin(CXX_STANDARDS),
-                                   cm::cend(CXX_STANDARDS), cmStrCmp("17"))) {
-    setCxx17 = true;
-  } else if (needCxx14 && existingCxxStandard &&
-             existingCxxIt < std::find_if(cm::cbegin(CXX_STANDARDS),
-                                          cm::cend(CXX_STANDARDS),
-                                          cmStrCmp("14"))) {
-    setCxx14 = true;
-  } else if (needCxx11 && existingCxxStandard &&
-             existingCxxIt < std::find_if(cm::cbegin(CXX_STANDARDS),
-                                          cm::cend(CXX_STANDARDS),
-                                          cmStrCmp("11"))) {
-    setCxx11 = true;
-  } else if (needCxx98 && existingCxxStandard &&
-             existingCxxIt < std::find_if(cm::cbegin(CXX_STANDARDS),
-                                          cm::cend(CXX_STANDARDS),
-                                          cmStrCmp("98"))) {
-    setCxx98 = true;
-  }
-
-  if (setCxx17) {
-    target->SetProperty("CXX_STANDARD", "17");
-    target->SetProperty("CUDA_STANDARD", "17");
-  } else if (setCxx14) {
-    target->SetProperty("CXX_STANDARD", "14");
-    target->SetProperty("CUDA_STANDARD", "14");
-  } else if (setCxx11) {
-    target->SetProperty("CXX_STANDARD", "11");
-    target->SetProperty("CUDA_STANDARD", "11");
-  } else if (setCxx98) {
-    target->SetProperty("CXX_STANDARD", "98");
-    target->SetProperty("CUDA_STANDARD", "98");
+
+  const char* existingCudaStandard = target->GetProperty("CUDA_STANDARD");
+  const char* const* existingCudaLevel = nullptr;
+  if (existingCudaStandard) {
+    existingCudaLevel =
+      std::find_if(cm::cbegin(CXX_STANDARDS), cm::cend(CXX_STANDARDS),
+                   cmStrCmp(existingCudaStandard));
+    if (existingCudaLevel == cm::cend(CXX_STANDARDS)) {
+      std::ostringstream e;
+      e << "The CUDA_STANDARD property on target \"" << target->GetName()
+        << "\" contained an invalid value: \"" << existingCudaStandard
+        << "\".";
+      if (error) {
+        *error = e.str();
+      } else {
+        this->GetCMakeInstance()->IssueMessage(cmake::FATAL_ERROR, e.str(),
+                                               this->Backtrace);
+      }
+      return false;
+    }
+  }
+
+  /* clang-format off */
+  const char* const* needCxxLevel =
+    needCxx17 ? &CXX_STANDARDS[3]
+    : needCxx14 ? &CXX_STANDARDS[2]
+    : needCxx11 ? &CXX_STANDARDS[1]
+    : needCxx98 ? &CXX_STANDARDS[0]
+    : nullptr;
+  /* clang-format on */
+
+  if (needCxxLevel) {
+    // Ensure the C++ language level is high enough to support
+    // the needed C++ features.
+    if (!existingCxxLevel || existingCxxLevel < needCxxLevel) {
+      target->SetProperty("CXX_STANDARD", *needCxxLevel);
+    }
+
+    // Ensure the CUDA language level is high enough to support
+    // the needed C++ features.
+    if (!existingCudaLevel || existingCudaLevel < needCxxLevel) {
+      target->SetProperty("CUDA_STANDARD", *needCxxLevel);
+    }
   }
+
   return true;
 }
 
diff --git a/Tests/Cuda/CMakeLists.txt b/Tests/Cuda/CMakeLists.txt
index de48501..8a43df5 100644
--- a/Tests/Cuda/CMakeLists.txt
+++ b/Tests/Cuda/CMakeLists.txt
@@ -2,6 +2,7 @@
 ADD_TEST_MACRO(Cuda.Complex CudaComplex)
 ADD_TEST_MACRO(Cuda.ConsumeCompileFeatures CudaConsumeCompileFeatures)
 ADD_TEST_MACRO(Cuda.ObjectLibrary CudaObjectLibrary)
+ADD_TEST_MACRO(Cuda.MixedStandardLevels MixedStandardLevels)
 ADD_TEST_MACRO(Cuda.ToolkitInclude CudaToolkitInclude)
 ADD_TEST_MACRO(Cuda.ProperLinkFlags ProperLinkFlags)
 ADD_TEST_MACRO(Cuda.WithC CudaWithC)
diff --git a/Tests/Cuda/MixedStandardLevels/CMakeLists.txt b/Tests/Cuda/MixedStandardLevels/CMakeLists.txt
new file mode 100644
index 0000000..683abe7
--- /dev/null
+++ b/Tests/Cuda/MixedStandardLevels/CMakeLists.txt
@@ -0,0 +1,14 @@
+cmake_minimum_required(VERSION 3.7)
+project(CudaComplex CXX CUDA)
+
+string(APPEND CMAKE_CUDA_FLAGS " -gencode arch=compute_30,code=compute_30")
+
+set(CMAKE_CXX_STANDARD 11)
+
+add_executable(MixedStandardLevels main.cu)
+target_compile_features(MixedStandardLevels PUBLIC cxx_std_11)
+
+if(APPLE)
+  # Help the static cuda runtime find the driver (libcuda.dyllib) at runtime.
+  set_property(TARGET MixedStandardLevels PROPERTY BUILD_RPATH ${CMAKE_CUDA_IMPLICIT_LINK_DIRECTORIES})
+endif()
diff --git a/Tests/Cuda/MixedStandardLevels/main.cu b/Tests/Cuda/MixedStandardLevels/main.cu
new file mode 100644
index 0000000..d57c05a
--- /dev/null
+++ b/Tests/Cuda/MixedStandardLevels/main.cu
@@ -0,0 +1,10 @@
+
+#include <type_traits>
+
+int main(int argc, char** argv)
+{
+  // Verify that issue #17519 Setting CXX_STANDARD breaks CUDA_STANDARD
+  // selection via cxx_std_11 has been corrected
+  using returnv = std::integral_constant<int, 0>;
+  return returnv::value;
+}