Ninja: Fix module .def file path conversion

Refactoring in commit a2514f15 (Simplify cmNinjaTargetGenerator using
cmGeneratorTarget, 2012-03-13) accidentally removed mapping of .def file
paths through ConvertToNinjaPath (via GetSourceFilePath).  Take the
ModuleDefinitionFile value from cmGeneratorTarget and map it correctly
through ConvertToNinjaPath.

In addition to generating cleaner paths in the ninja build files this
correctly links up references to a generated .def file with the custom
command output that produces it.

Source/cmNinjaTargetGenerator.cxx

@@ -234,9 +234,9 @@ cmNinjaDeps cmNinjaTargetGenerator::ComputeLinkDeps() const
   std::transform(deps.begin(), deps.end(), result.begin(), MapToNinjaPath());
 
   // Add a dependency on the link definitions file, if any.
-  if(!this->GeneratorTarget->ModuleDefinitionFile.empty())
+  if(!this->ModuleDefinitionFile.empty())
     {
-    result.push_back(this->GeneratorTarget->ModuleDefinitionFile);
+    result.push_back(this->ModuleDefinitionFile);
     }
 
   return result;
@@ -400,6 +400,11 @@ cmNinjaTargetGenerator
     {
     this->WriteObjectBuildStatement(*si);
     }
+  if(!this->GeneratorTarget->ModuleDefinitionFile.empty())
+    {
+    this->ModuleDefinitionFile = this->ConvertToNinjaPath(
+      this->GeneratorTarget->ModuleDefinitionFile.c_str());
+    }
 
   this->GetBuildFileStream() << "\n";
 }
@@ -478,7 +483,7 @@ void
 cmNinjaTargetGenerator
 ::AddModuleDefinitionFlag(std::string& flags)
 {
-  if(this->GeneratorTarget->ModuleDefinitionFile.empty())
+  if(this->ModuleDefinitionFile.empty())
     {
     return;
     }
@@ -495,6 +500,6 @@ cmNinjaTargetGenerator
   // vs6's "cl -link" pass it to the linker.
   std::string flag = defFileFlag;
   flag += (this->LocalGenerator->ConvertToLinkReference(
-             this->GeneratorTarget->ModuleDefinitionFile.c_str()));
+             this->ModuleDefinitionFile.c_str()));
   this->LocalGenerator->AppendFlags(flags, flag.c_str());
 }

Source/cmNinjaTargetGenerator.h

@@ -118,6 +118,9 @@ private:
   cmLocalNinjaGenerator* LocalGenerator;
   /// List of object files for this target.
   cmNinjaDeps Objects;
+
+  // The windows module definition source file (.def), if any.
+  std::string ModuleDefinitionFile;
 };
 
 #endif // ! cmNinjaTargetGenerator_h