Genex: Report error if a target file is needed to evaluate link libraries.

Constructs such as

 target_link_libraries(foo $<$<STREQUAL:$<TARGET_FILE:foo>,foo.so>:bar>)

segfault before this patch.

1 files changed, 8 insertions, 1 deletions

diff --git a/Source/cmGeneratorExpressionEvaluator.cxx b/Source/cmGeneratorExpressionEvaluator.cxx
index cd0d26b..f57e683 100644
--- a/Source/cmGeneratorExpressionEvaluator.cxx
+++ b/Source/cmGeneratorExpressionEvaluator.cxx
@@ -1100,7 +1100,7 @@ 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();
@@ -1125,6 +1125,13 @@ 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);