Merge topic 'dag-LINKER_LANGUAGE'

ff015ee Genex: Report error if a target file is needed to evaluate link libraries.
b58aff9 Genex: Extend EvaluatingLinkLibraries to also check the top target name.
b1c19ce Genex: Make LINK_LANGUAGE report an error when evaluating link libraries.
0e1cb07 Add missing return after error report.

Source/cmGeneratorExpressionDAGChecker.cxx

@@ -139,7 +139,7 @@ cmGeneratorExpressionDAGChecker::checkGraph() const
 }
 
 //----------------------------------------------------------------------------
-bool cmGeneratorExpressionDAGChecker::EvaluatingLinkLibraries()
+bool cmGeneratorExpressionDAGChecker::EvaluatingLinkLibraries(const char *tgt)
 {
   const cmGeneratorExpressionDAGChecker *top = this;
   const cmGeneratorExpressionDAGChecker *parent = this->Parent;
@@ -150,6 +150,12 @@ bool cmGeneratorExpressionDAGChecker::EvaluatingLinkLibraries()
     }
 
   const char *prop = top->Property.c_str();
+
+  if (tgt)
+    {
+    return top->Target == tgt && strcmp(prop, "LINK_LIBRARIES") == 0;
+    }
+
   return (strcmp(prop, "LINK_LIBRARIES") == 0
        || strcmp(prop, "LINK_INTERFACE_LIBRARIES") == 0
        || strcmp(prop, "IMPORTED_LINK_INTERFACE_LIBRARIES") == 0

Source/cmGeneratorExpressionDAGChecker.h

@@ -47,7 +47,7 @@ struct cmGeneratorExpressionDAGChecker
   void reportError(cmGeneratorExpressionContext *context,
                    const std::string &expr);
 
-  bool EvaluatingLinkLibraries();
+  bool EvaluatingLinkLibraries(const char *tgt = 0);
 
 #define DECLARE_TRANSITIVE_PROPERTY_METHOD(METHOD) \
   bool METHOD () const;

Source/cmGeneratorExpressionEvaluator.cxx

@@ -469,8 +469,15 @@ static const struct LinkLanguageNode : public cmGeneratorExpressionNode
   std::string Evaluate(const std::vector<std::string> &parameters,
                        cmGeneratorExpressionContext *context,
                        const GeneratorExpressionContent *content,
-                       cmGeneratorExpressionDAGChecker *) const
+                       cmGeneratorExpressionDAGChecker *dagChecker) const
   {
+    if (dagChecker && dagChecker->EvaluatingLinkLibraries())
+      {
+      reportError(context, content->GetOriginalExpression(),
+          "$<LINK_LANGUAGE> expression can not be used while evaluating "
+          "link libraries");
+      return std::string();
+      }
     if (parameters.size() != 0 && parameters.size() != 1)
       {
       reportError(context, content->GetOriginalExpression(),
@@ -483,6 +490,7 @@ static const struct LinkLanguageNode : public cmGeneratorExpressionNode
       reportError(context, content->GetOriginalExpression(),
           "$<LINK_LANGUAGE> may only be used with targets.  It may not "
           "be used with add_custom_command.");
+      return std::string();
       }
 
     const char *lang = target->GetLinkerLanguage(context->Config);
@@ -1146,7 +1154,7 @@ struct TargetFilesystemArtifact : public cmGeneratorExpressionNode
   std::string Evaluate(const std::vector<std::string> &parameters,
                        cmGeneratorExpressionContext *context,
                        const GeneratorExpressionContent *content,
-                       cmGeneratorExpressionDAGChecker *) const
+                       cmGeneratorExpressionDAGChecker *dagChecker) const
   {
     // Lookup the referenced target.
     std::string name = *parameters.begin();
@@ -1171,6 +1179,13 @@ struct TargetFilesystemArtifact : public cmGeneratorExpressionNode
                   "Target \"" + name + "\" is not an executable or library.");
       return std::string();
       }
+    if (dagChecker && dagChecker->EvaluatingLinkLibraries(name.c_str()))
+      {
+      ::reportError(context, content->GetOriginalExpression(),
+                    "Expressions which require the linker language may not "
+                    "be used while evaluating link libraries");
+      return std::string();
+      }
     context->DependTargets.insert(target);
     context->AllTargets.insert(target);
 

Tests/RunCMake/Languages/LINK_LANGUAGE-genex-result.txt

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

Tests/RunCMake/Languages/LINK_LANGUAGE-genex-stderr.txt

@@ -0,0 +1,6 @@
+CMake Error:
+  Error evaluating generator expression:
+
+    \$<LINK_LANGUAGE>
+
+  \$<LINK_LANGUAGE> expression can not be used while evaluating link libraries

Tests/RunCMake/Languages/LINK_LANGUAGE-genex.cmake

@@ -0,0 +1,4 @@
+
+add_library(foo SHARED empty.cpp)
+add_library(bar SHARED empty.cpp)
+target_link_libraries(foo $<$<STREQUAL:$<LINK_LANGUAGE>,anything>:bar>)

Tests/RunCMake/Languages/RunCMakeTest.cmake

@@ -1,3 +1,6 @@
 include(RunCMake)
 
 run_cmake(NoLangSHARED)
+run_cmake(LINK_LANGUAGE-genex)
+run_cmake(link-libraries-TARGET_FILE-genex)
+run_cmake(link-libraries-TARGET_FILE-genex-ok)

Tests/RunCMake/Languages/empty.cpp

@@ -0,0 +1,7 @@
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int empty(void)
+{
+  return 0;
+}

Tests/RunCMake/Languages/link-libraries-TARGET_FILE-genex-ok-result.txt

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

Tests/RunCMake/Languages/link-libraries-TARGET_FILE-genex-ok.cmake

@@ -0,0 +1,6 @@
+
+enable_language(CXX)
+
+add_library(foo SHARED empty.cpp)
+add_library(bar SHARED empty.cpp)
+target_link_libraries(foo $<$<STREQUAL:$<TARGET_FILE:bar>,anything>:bar>)

Tests/RunCMake/Languages/link-libraries-TARGET_FILE-genex-result.txt

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

Tests/RunCMake/Languages/link-libraries-TARGET_FILE-genex-stderr.txt

@@ -0,0 +1,7 @@
+CMake Error:
+  Error evaluating generator expression:
+
+    \$<TARGET_FILE:foo>
+
+  Expressions which require the linker language may not be used while
+  evaluating link libraries

Tests/RunCMake/Languages/link-libraries-TARGET_FILE-genex.cmake

@@ -0,0 +1,4 @@
+
+add_library(foo SHARED empty.cpp)
+add_library(bar SHARED empty.cpp)
+target_link_libraries(foo $<$<STREQUAL:$<TARGET_FILE:foo>,anything>:bar>)