Optionally demote fatal errors to non-fatal errors.

This behavior is enabled when the new CXTranslationUnit_KeepGoing
option is passed to clang_parseTranslationUnit{,2}. It is geared
towards use by IDEs and similar consumers of the clang-c API where
fatal errors may arise when parsing incomplete code mid-edit, or
when include paths are not properly configured yet. In such situations
one still wants to get as much information as possible about a TU.
Previously, the semantic analysis would not instantiate templates
or report additional fatal errors after the first fatal error was
encountered.

Fixes PR24268.

Patch by Milian Wolff.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@262318 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 23 insertions, 0 deletions

diff --git a/unittests/Basic/DiagnosticTest.cpp b/unittests/Basic/DiagnosticTest.cpp
index fa2b56e083..4ffa0837bd 100644
--- a/unittests/Basic/DiagnosticTest.cpp
+++ b/unittests/Basic/DiagnosticTest.cpp
@@ -46,4 +46,27 @@ TEST(DiagnosticTest, suppressAndTrap) {
   EXPECT_FALSE(Diags.hasUnrecoverableErrorOccurred());
 }
 
+// Check that FatalsAsErrors works as intended
+TEST(DiagnosticTest, fatalsAsErrors) {
+  DiagnosticsEngine Diags(new DiagnosticIDs(),
+                          new DiagnosticOptions,
+                          new IgnoringDiagConsumer());
+  Diags.setFatalsAsError(true);
+
+  // Diag that would set UncompilableErrorOccurred and ErrorOccurred.
+  Diags.Report(diag::err_target_unknown_triple) << "unknown";
+
+  // Diag that would set UnrecoverableErrorOccurred and ErrorOccurred.
+  Diags.Report(diag::err_cannot_open_file) << "file" << "error";
+
+  // Diag that would set FatalErrorOccurred
+  // (via non-note following a fatal error).
+  Diags.Report(diag::warn_mt_message) << "warning";
+
+  EXPECT_TRUE(Diags.hasErrorOccurred());
+  EXPECT_FALSE(Diags.hasFatalErrorOccurred());
+  EXPECT_TRUE(Diags.hasUncompilableErrorOccurred());
+  EXPECT_TRUE(Diags.hasUnrecoverableErrorOccurred());
+}
+
 }