Genex: Add a COMPILE_LANGUAGE generator expression.

Source/cmGeneratorExpression.cxx

@@ -52,14 +52,16 @@ cmGeneratorExpression::~cmGeneratorExpression()
 const char *cmCompiledGeneratorExpression::Evaluate(
   cmMakefile* mf, const std::string& config, bool quiet,
   cmTarget const* headTarget,
-  cmGeneratorExpressionDAGChecker *dagChecker) const
+  cmGeneratorExpressionDAGChecker *dagChecker,
+                       std::string const& language) const
 {
   return this->Evaluate(mf,
                         config,
                         quiet,
                         headTarget,
                         headTarget,
-                        dagChecker);
+                        dagChecker,
+                        language);
 }
 
 //----------------------------------------------------------------------------
@@ -67,7 +69,8 @@ const char *cmCompiledGeneratorExpression::Evaluate(
   cmMakefile* mf, const std::string& config, bool quiet,
   cmTarget const* headTarget,
   cmTarget const* currentTarget,
-  cmGeneratorExpressionDAGChecker *dagChecker) const
+  cmGeneratorExpressionDAGChecker *dagChecker,
+  std::string const& language) const
 {
   if (!this->NeedsEvaluation)
     {
@@ -93,6 +96,7 @@ const char *cmCompiledGeneratorExpression::Evaluate(
   context.EvaluateForBuildsystem = this->EvaluateForBuildsystem;
   context.CurrentTarget = currentTarget ? currentTarget : headTarget;
   context.Backtrace = this->Backtrace;
+  context.Language = language;
 
   for ( ; it != end; ++it)
     {

Source/cmGeneratorExpression.h

@@ -80,11 +80,13 @@ public:
                        bool quiet = false,
                        cmTarget const* headTarget = 0,
                        cmTarget const* currentTarget = 0,
-                       cmGeneratorExpressionDAGChecker *dagChecker = 0) const;
+                       cmGeneratorExpressionDAGChecker *dagChecker = 0,
+                       std::string const& language = std::string()) const;
   const char* Evaluate(cmMakefile* mf, const std::string& config,
                        bool quiet,
                        cmTarget const* headTarget,
-                       cmGeneratorExpressionDAGChecker *dagChecker) const;
+                       cmGeneratorExpressionDAGChecker *dagChecker,
+                       std::string const& language = std::string()) const;
 
   /** Get set of targets found during evaluations.  */
   std::set<cmTarget*> const& GetTargets() const

Source/cmGeneratorExpressionEvaluator.cxx

@@ -16,6 +16,7 @@
 #include "cmGeneratorExpressionDAGChecker.h"
 #include "cmGeneratorExpression.h"
 #include "cmLocalGenerator.h"
+#include "cmGlobalGenerator.h"
 #include "cmSourceFile.h"
 
 #include <cmsys/String.h>
@@ -89,7 +90,8 @@ std::string cmGeneratorExpressionNode::EvaluateDependentExpression(
                         context->Quiet,
                         headTarget,
                         currentTarget,
-                        dagChecker);
+                        dagChecker,
+                        context->Language);
   if (cge->GetHadContextSensitiveCondition())
     {
     context->HadContextSensitiveCondition = true;
@@ -806,6 +808,33 @@ static const struct JoinNode : public cmGeneratorExpressionNode
   }
 } joinNode;
 
+static const struct CompileLanguageNode : public cmGeneratorExpressionNode
+{
+  CompileLanguageNode() {}
+
+  virtual int NumExpectedParameters() const { return OneOrZeroParameters; }
+
+  std::string Evaluate(const std::vector<std::string> &parameters,
+                       cmGeneratorExpressionContext *context,
+                       const GeneratorExpressionContent *content,
+                       cmGeneratorExpressionDAGChecker *) const
+  {
+    if(context->Language.empty())
+      {
+      reportError(context, content->GetOriginalExpression(),
+          "$<COMPILE_LANGUAGE:...> may only be used to specify include "
+          "directories compile definitions, compile options and to evaluate "
+          "components of the file(GENERATE) command.");
+      return std::string();
+      }
+    if (parameters.empty())
+      {
+      return context->Language;
+      }
+    return context->Language == parameters.front() ? "1" : "0";
+  }
+} languageNode;
+
 #define TRANSITIVE_PROPERTY_NAME(PROPERTY) \
   , "INTERFACE_" #PROPERTY
 
@@ -1829,6 +1858,7 @@ cmGeneratorExpressionNode* GetNode(const std::string &identifier)
     nodeMap["INSTALL_PREFIX"] = &installPrefixNode;
     nodeMap["JOIN"] = &joinNode;
     nodeMap["LINK_ONLY"] = &linkOnlyNode;
+    nodeMap["COMPILE_LANGUAGE"] = &languageNode;
     }
   NodeMap::const_iterator i = nodeMap.find(identifier);
   if (i == nodeMap.end())

Source/cmGeneratorExpressionEvaluator.h

@@ -36,6 +36,7 @@ struct cmGeneratorExpressionContext
                                                           MaxLanguageStandard;
   cmMakefile *Makefile;
   std::string Config;
+  std::string Language;
   cmTarget const* HeadTarget; // The target whose property is being evaluated.
   cmTarget const* CurrentTarget; // The dependent of HeadTarget which appears
                                  // directly or indirectly in the property.

Tests/RunCMake/GeneratorExpression/COMPILE_LANGUAGE-add_custom_command-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/GeneratorExpression/COMPILE_LANGUAGE-add_custom_command-stderr.txt

@@ -0,0 +1,10 @@
+CMake Error at COMPILE_LANGUAGE-add_custom_command.cmake:6 \(add_custom_command\):
+  Error evaluating generator expression:
+
+    \$<COMPILE_LANGUAGE>
+
+  \$<COMPILE_LANGUAGE:...> may only be used to specify include directories
+  compile definitions, compile options and to evaluate components of the
+  file\(GENERATE\) command.
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)

Tests/RunCMake/GeneratorExpression/COMPILE_LANGUAGE-add_custom_command.cmake

@@ -0,0 +1,8 @@
+
+enable_language(C)
+
+add_library(empty empty.c)
+
+add_custom_command(TARGET empty PRE_BUILD
+  COMMAND ${CMAKE_COMMAND} -E echo $<COMPILE_LANGUAGE>
+)

Tests/RunCMake/GeneratorExpression/COMPILE_LANGUAGE-add_custom_target-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/GeneratorExpression/COMPILE_LANGUAGE-add_custom_target-stderr.txt

@@ -0,0 +1,10 @@
+CMake Error at COMPILE_LANGUAGE-add_custom_target.cmake:4 \(add_custom_target\):
+  Error evaluating generator expression:
+
+    \$<COMPILE_LANGUAGE>
+
+  \$<COMPILE_LANGUAGE:...> may only be used to specify include directories
+  compile definitions, compile options and to evaluate components of the
+  file\(GENERATE\) command.
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)

Tests/RunCMake/GeneratorExpression/COMPILE_LANGUAGE-add_custom_target.cmake

@@ -0,0 +1,6 @@
+
+enable_language(C)
+
+add_custom_target(empty
+  COMMAND ${CMAKE_COMMAND} -E echo $<COMPILE_LANGUAGE>
+)

Tests/RunCMake/GeneratorExpression/COMPILE_LANGUAGE-add_executable-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/GeneratorExpression/COMPILE_LANGUAGE-add_executable-stderr.txt

@@ -0,0 +1,10 @@
+CMake Error at COMPILE_LANGUAGE-add_executable.cmake:4 \(add_executable\):
+  Error evaluating generator expression:
+
+    \$<COMPILE_LANGUAGE>
+
+  \$<COMPILE_LANGUAGE:...> may only be used to specify include directories
+  compile definitions, compile options and to evaluate components of the
+  file\(GENERATE\) command.
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)

Tests/RunCMake/GeneratorExpression/COMPILE_LANGUAGE-add_executable.cmake

@@ -0,0 +1,4 @@
+
+enable_language(C)
+
+add_executable(empty empty.$<COMPILE_LANGUAGE>)

Tests/RunCMake/GeneratorExpression/COMPILE_LANGUAGE-add_library-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/GeneratorExpression/COMPILE_LANGUAGE-add_library-stderr.txt

@@ -0,0 +1,10 @@
+CMake Error at COMPILE_LANGUAGE-add_library.cmake:4 \(add_library\):
+  Error evaluating generator expression:
+
+    \$<COMPILE_LANGUAGE>
+
+  \$<COMPILE_LANGUAGE:...> may only be used to specify include directories
+  compile definitions, compile options and to evaluate components of the
+  file\(GENERATE\) command.
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)

Tests/RunCMake/GeneratorExpression/COMPILE_LANGUAGE-add_library.cmake

@@ -0,0 +1,4 @@
+
+enable_language(C)
+
+add_library(empty empty.$<COMPILE_LANGUAGE>)

Tests/RunCMake/GeneratorExpression/COMPILE_LANGUAGE-add_test-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/GeneratorExpression/COMPILE_LANGUAGE-add_test-stderr.txt

@@ -0,0 +1,10 @@
+CMake Error at COMPILE_LANGUAGE-add_test.cmake:5 \(add_test\):
+  Error evaluating generator expression:
+
+    \$<COMPILE_LANGUAGE>
+
+  \$<COMPILE_LANGUAGE:...> may only be used to specify include directories
+  compile definitions, compile options and to evaluate components of the
+  file\(GENERATE\) command.
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)

Tests/RunCMake/GeneratorExpression/COMPILE_LANGUAGE-add_test.cmake

@@ -0,0 +1,5 @@
+
+include(CTest)
+enable_testing()
+
+add_test(NAME dummy COMMAND ${CMAKE_COMMAND} -E echo $<COMPILE_LANGUAGE>)

Tests/RunCMake/GeneratorExpression/COMPILE_LANGUAGE-install-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/GeneratorExpression/COMPILE_LANGUAGE-install-stderr.txt

@@ -0,0 +1,8 @@
+CMake Error:
+  Error evaluating generator expression:
+
+    \$<COMPILE_LANGUAGE>
+
+  \$<COMPILE_LANGUAGE:...> may only be used to specify include directories
+  compile definitions, compile options and to evaluate components of the
+  file\(GENERATE\) command.

Tests/RunCMake/GeneratorExpression/COMPILE_LANGUAGE-install.cmake

@@ -0,0 +1,5 @@
+
+install(FILES
+  empty.$<COMPILE_LANGUAGE>
+  DESTINATION src
+)

Tests/RunCMake/GeneratorExpression/COMPILE_LANGUAGE-target_sources-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/GeneratorExpression/COMPILE_LANGUAGE-target_sources-stderr.txt

@@ -0,0 +1,10 @@
+CMake Error at COMPILE_LANGUAGE-target_sources.cmake:5 \(target_sources\):
+  Error evaluating generator expression:
+
+    \$<COMPILE_LANGUAGE>
+
+  \$<COMPILE_LANGUAGE:...> may only be used to specify include directories
+  compile definitions, compile options and to evaluate components of the
+  file\(GENERATE\) command.
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)

Tests/RunCMake/GeneratorExpression/COMPILE_LANGUAGE-target_sources.cmake

@@ -0,0 +1,5 @@
+
+enable_language(C)
+
+add_library(empty empty.c)
+target_sources(empty PRIVATE empty.$<COMPILE_LANGUAGE>)

Tests/RunCMake/GeneratorExpression/RunCMakeTest.cmake

@@ -16,6 +16,13 @@ run_cmake(NonValidTarget-C_COMPILER_VERSION)
 run_cmake(NonValidTarget-CXX_COMPILER_VERSION)
 run_cmake(NonValidTarget-TARGET_PROPERTY)
 run_cmake(NonValidTarget-TARGET_POLICY)
+run_cmake(COMPILE_LANGUAGE-add_custom_target)
+run_cmake(COMPILE_LANGUAGE-add_custom_command)
+run_cmake(COMPILE_LANGUAGE-install)
+run_cmake(COMPILE_LANGUAGE-target_sources)
+run_cmake(COMPILE_LANGUAGE-add_executable)
+run_cmake(COMPILE_LANGUAGE-add_library)
+run_cmake(COMPILE_LANGUAGE-add_test)
 
 if(LINKER_SUPPORTS_PDB)
   run_cmake(NonValidTarget-TARGET_PDB_FILE)