[backported/clang-9][libclang] Fix CXTranslationUnit_KeepGoingrelease_70-based

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

Subscribers: arphaman, cfe-commits

Tags: #clang

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

Fixes: QTCREATORBUG-21892
Change-Id: I6b5c2490922a798fcc9080fa73fa1fdaecf7bddd
Reviewed-by: Ivan Donchevskii <[email protected]>

1 files changed, 6 insertions, 1 deletions

diff --git a/lib/Basic/DiagnosticIDs.cpp b/lib/Basic/DiagnosticIDs.cpp
index c50da06d3b..93d13849ba 100644
--- a/lib/Basic/DiagnosticIDs.cpp
+++ b/lib/Basic/DiagnosticIDs.cpp
@@ -485,6 +485,11 @@ DiagnosticIDs::getDiagnosticSeverity(unsigned DiagID, SourceLocation Loc,
     return diag::Severity::Ignored;
   }
 
+  // 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;
@@ -664,7 +669,7 @@ 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;