<rdar://problem/12368093> Extend module maps with a 'conflict' declaration, and warn when a newly-imported module conflicts with an already-imported module.

llvm-svn: 177577
diff --git a/clang/lib/Basic/Module.cpp b/clang/lib/Basic/Module.cpp
index 197c53f..13518cd 100644
--- a/clang/lib/Basic/Module.cpp
+++ b/clang/lib/Basic/Module.cpp
@@ -347,6 +347,24 @@
     OS << "\"";
   }
 
+  for (unsigned I = 0, N = UnresolvedConflicts.size(); I != N; ++I) {
+    OS.indent(Indent + 2);
+    OS << "conflict ";
+    printModuleId(OS, UnresolvedConflicts[I].Id);
+    OS << ", \"";
+    OS.write_escaped(UnresolvedConflicts[I].Message);
+    OS << "\"\n";
+  }
+
+  for (unsigned I = 0, N = Conflicts.size(); I != N; ++I) {
+    OS.indent(Indent + 2);
+    OS << "conflict ";
+    OS << Conflicts[I].Other->getFullModuleName();
+    OS << ", \"";
+    OS.write_escaped(Conflicts[I].Message);
+    OS << "\"\n";
+  }
+
   if (InferSubmodules) {
     OS.indent(Indent + 2);
     if (InferExplicitSubmodules)