Add a cc1 "dump-coverage-mapping" for testing coverage mapping.

Differential Revision: http://reviews.llvm.org/D4799

llvm-svn: 215258
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 5040965..1f0dd73 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -3198,10 +3198,20 @@
 }
 
 void CodeGenModule::EmitDeferredUnusedCoverageMappings() {
+  std::vector<const Decl *> DeferredDecls;
   for (const auto I : DeferredEmptyCoverageMappingDecls) {
     if (!I.second)
       continue;
-    const auto *D = I.first;
+    DeferredDecls.push_back(I.first);
+  }
+  // Sort the declarations by their location to make sure that the tests get a
+  // predictable order for the coverage mapping for the unused declarations.
+  if (CodeGenOpts.DumpCoverageMapping)
+    std::sort(DeferredDecls.begin(), DeferredDecls.end(),
+              [] (const Decl *LHS, const Decl *RHS) {
+      return LHS->getLocStart() < RHS->getLocStart();
+    });
+  for (const auto *D : DeferredDecls) {
     switch (D->getKind()) {
     case Decl::CXXConversion:
     case Decl::CXXMethod: