[libclang] Fix CXTranslationUnit_KeepGoing

Since
  commit 56f548bbbb7e4387a69708f70724d00e9e076153
  [modules] Round-trip -Werror flag through explicit module build.
the behavior of CXTranslationUnit_KeepGoing changed:
Unresolved #includes are fatal errors again. As a consequence, some
templates are not instantiated and lead to confusing errors.

Revert to the old behavior: With CXTranslationUnit_KeepGoing fatal
errors are mapped to errors.

Patch by Nikolai Kosjar.

Differential Revision: https://reviews.llvm.org/D58501

llvm-svn: 355586

1 files changed, 6 insertions, 1 deletions

diff --git a/clang/lib/Basic/DiagnosticIDs.cpp b/clang/lib/Basic/DiagnosticIDs.cpp
index a7473d8bb5d..e8a99d08a91 100644
--- a/clang/lib/Basic/DiagnosticIDs.cpp
+++ b/clang/lib/Basic/DiagnosticIDs.cpp
@@ -481,6 +481,11 @@ DiagnosticIDs::getDiagnosticSeverity(unsigned DiagID, SourceLocation Loc,
       Result = diag::Severity::Fatal;
   }
 
+  // If explicitly requested, map fatal errors to errors.
+  if (Result == diag::Severity::Fatal &&
+      Diag.CurDiagID != diag::fatal_too_many_errors && Diag.FatalsAsError)
+    Result = diag::Severity::Error;
+
   // Custom diagnostics always are emitted in system headers.
   bool ShowInSystemHeader =
       !GetDiagInfo(DiagID) || GetDiagInfo(DiagID)->WarnShowInSystemHeader;
@@ -660,7 +665,7 @@ bool DiagnosticIDs::ProcessDiag(DiagnosticsEngine &Diag) const {
 
   // If a fatal error has already been emitted, silence all subsequent
   // diagnostics.
-  if (Diag.FatalErrorOccurred && Diag.SuppressAfterFatalError) {
+  if (Diag.FatalErrorOccurred) {
     if (DiagLevel >= DiagnosticIDs::Error &&
         Diag.Client->IncludeInDiagnosticCounts()) {
       ++Diag.NumErrors;