Teach AST merging that variables with incomplete array types can be
merged with variables of constant array types. Also, make sure that we
call DiagnosticClient's BeginSourceFile/EndSourceFile, so that it has
a LangOptions to work with.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@95782 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/ASTImporter.cpp b/lib/AST/ASTImporter.cpp
index 75917cf..9fb695e 100644
--- a/lib/AST/ASTImporter.cpp
+++ b/lib/AST/ASTImporter.cpp
@@ -500,6 +500,33 @@
             break;
           }
 
+          if (const IncompleteArrayType *FoundArray
+                = Importer.getToContext().getAsIncompleteArrayType(
+                                                        FoundVar->getType())) {
+            if (const ConstantArrayType *TArray
+                  = Importer.getToContext().getAsConstantArrayType(T)) {
+              if (Importer.getToContext().typesAreCompatible(
+                                               TArray->getElementType(), 
+                                               FoundArray->getElementType())) {
+                FoundVar->setType(T);
+                MergeWithVar = FoundVar;
+                break;
+              }
+            }
+          } else if (const IncompleteArrayType *TArray
+                        = Importer.getToContext().getAsIncompleteArrayType(T)) {
+            if (const ConstantArrayType *FoundArray
+                   = Importer.getToContext().getAsConstantArrayType(
+                                                         FoundVar->getType())) {
+              if (Importer.getToContext().typesAreCompatible(
+                                               TArray->getElementType(), 
+                                               FoundArray->getElementType())) {
+                MergeWithVar = FoundVar;
+                break;
+              }
+            }
+          }
+
           Importer.ToDiag(Loc, diag::err_odr_variable_type_inconsistent)
             << Name << T << FoundVar->getType();
           Importer.ToDiag(FoundVar->getLocation(), diag::note_odr_value_here)
diff --git a/lib/Frontend/ASTMerge.cpp b/lib/Frontend/ASTMerge.cpp
index d51647b..f2de09a 100644
--- a/lib/Frontend/ASTMerge.cpp
+++ b/lib/Frontend/ASTMerge.cpp
@@ -32,6 +32,8 @@
 
 void ASTMergeAction::ExecuteAction() {
   CompilerInstance &CI = getCompilerInstance();
+  CI.getDiagnostics().getClient()->BeginSourceFile(
+                                         CI.getASTContext().getLangOptions());
   CI.getDiagnostics().SetArgToStringFn(&FormatASTNodeDiagnosticArgument,
                                        &CI.getASTContext());
   for (unsigned I = 0, N = ASTFiles.size(); I != N; ++I) {
@@ -68,8 +70,8 @@
     delete Unit;
   }
 
-
-  return AdaptedAction->ExecuteAction();
+  AdaptedAction->ExecuteAction();
+  CI.getDiagnostics().getClient()->EndSourceFile();
 }
 
 void ASTMergeAction::EndSourceFileAction() {