Remove the LINK_LANGUAGE generator expression.

It accepted an optional argument to test for equality, but no way
to get the linker language of a particular target.

TARGET_PROPERTY provides this flexibility and STREQUAL provides
the necessary API for equality test.

Extend the CompileDefinitions test to cover accessing the
property of another target.

1 files changed, 13 insertions, 65 deletions

diff --git a/Source/cmGeneratorExpressionEvaluator.cxx b/Source/cmGeneratorExpressionEvaluator.cxx
index 381ef7c..c1f53b4 100644
--- a/Source/cmGeneratorExpressionEvaluator.cxx
+++ b/Source/cmGeneratorExpressionEvaluator.cxx
@@ -573,69 +573,6 @@ static const struct ConfigurationTestNode : public cmGeneratorExpressionNode
   }
 } configurationTestNode;
 
-//----------------------------------------------------------------------------
-static const struct LinkLanguageNode : public cmGeneratorExpressionNode
-{
-  LinkLanguageNode() {}
-
-  virtual int NumExpectedParameters() const { return ZeroOrMoreParameters; }
-
-  std::string Evaluate(const std::vector<std::string> &parameters,
-                       cmGeneratorExpressionContext *context,
-                       const GeneratorExpressionContent *content,
-                       cmGeneratorExpressionDAGChecker *dagChecker) const
-  {
-    if (dagChecker && dagChecker->EvaluatingLinkLibraries())
-      {
-      reportError(context, content->GetOriginalExpression(),
-          "$<LINK_LANGUAGE> expression can not be used while evaluating "
-          "link libraries");
-      return std::string();
-      }
-    if (parameters.size() != 0 && parameters.size() != 1)
-      {
-      reportError(context, content->GetOriginalExpression(),
-          "$<LINK_LANGUAGE> expression requires one or two parameters");
-      return std::string();
-      }
-    cmTarget* target = context->HeadTarget;
-    if (!target)
-      {
-      reportError(context, content->GetOriginalExpression(),
-          "$<LINK_LANGUAGE> may only be used with targets.  It may not "
-          "be used with add_custom_command.");
-      return std::string();
-      }
-
-    const char *lang = target->GetLinkerLanguage(context->Config);
-    if (parameters.size() == 0)
-      {
-      return lang ? lang : "";
-      }
-    else
-      {
-      cmsys::RegularExpression langValidator;
-      langValidator.compile("^[A-Za-z0-9_]*$");
-      if (!langValidator.find(parameters.begin()->c_str()))
-        {
-        reportError(context, content->GetOriginalExpression(),
-                    "Expression syntax not recognized.");
-        return std::string();
-        }
-      if (!lang)
-        {
-        return parameters.front().empty() ? "1" : "0";
-        }
-
-      if (strcmp(parameters.begin()->c_str(), lang) == 0)
-        {
-        return "1";
-        }
-      return "0";
-      }
-  }
-} linkLanguageNode;
-
 static const struct JoinNode : public cmGeneratorExpressionNode
 {
   JoinNode() {}
@@ -835,6 +772,19 @@ static const struct TargetPropertyNode : public cmGeneratorExpressionNode
 
     assert(target);
 
+    if (propertyName == "LINKER_LANGUAGE")
+      {
+      if (dagCheckerParent && dagCheckerParent->EvaluatingLinkLibraries())
+        {
+        reportError(context, content->GetOriginalExpression(),
+            "LINKER_LANGUAGE target property can not be used while evaluating "
+            "link libraries");
+        return std::string();
+        }
+      const char *lang = target->GetLinkerLanguage(context->Config);
+      return lang ? lang : "";
+      }
+
     cmGeneratorExpressionDAGChecker dagChecker(context->Backtrace,
                                                target->GetName(),
                                                propertyName,
@@ -1380,8 +1330,6 @@ cmGeneratorExpressionNode* GetNode(const std::string &identifier)
     return &configurationNode;
   else if (identifier == "CONFIG")
     return &configurationTestNode;
-  else if (identifier == "LINK_LANGUAGE")
-    return &linkLanguageNode;
   else if (identifier == "TARGET_FILE")
     return &targetFileNode;
   else if (identifier == "TARGET_LINKER_FILE")