Further refine -Wunreachable-code groups so that -Wno-unreachable-code-break doesn't turn off all unreachable code warnings.

Also relax unreachable 'break' and 'return' to not check for being
preceded by a call to 'noreturn'.  That turns out to not be so
interesting in practice.

llvm-svn: 204000

1 files changed, 19 insertions, 10 deletions

diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp b/clang/lib/Sema/AnalysisBasedWarnings.cpp
index d49dfd58459..32e40ab2ea9 100644
--- a/clang/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp
@@ -74,7 +74,7 @@ namespace {
           diag = diag::warn_unreachable_break;
           break;
         case reachable_code::UK_TrivialReturn:
-          diag = diag::warn_unreachable_trivial_return;
+          diag = diag::warn_unreachable_return;
           break;
         case reachable_code::UK_Other:
           break;
@@ -1665,6 +1665,11 @@ clang::sema::AnalysisBasedWarnings::Policy::Policy() {
   enableConsumedAnalysis = 0;
 }
 
+static unsigned isEnabled(DiagnosticsEngine &D, unsigned diag) {
+  return (unsigned) D.getDiagnosticLevel(diag, SourceLocation()) !=
+                    DiagnosticsEngine::Ignored;
+}
+
 clang::sema::AnalysisBasedWarnings::AnalysisBasedWarnings(Sema &s)
   : S(s),
     NumFunctionsAnalyzed(0),
@@ -1676,16 +1681,20 @@ clang::sema::AnalysisBasedWarnings::AnalysisBasedWarnings(Sema &s)
     MaxUninitAnalysisVariablesPerFunction(0),
     NumUninitAnalysisBlockVisits(0),
     MaxUninitAnalysisBlockVisitsPerFunction(0) {
+
+  using namespace diag;
   DiagnosticsEngine &D = S.getDiagnostics();
-  DefaultPolicy.enableCheckUnreachable = (unsigned)
-    (D.getDiagnosticLevel(diag::warn_unreachable, SourceLocation()) !=
-        DiagnosticsEngine::Ignored);
-  DefaultPolicy.enableThreadSafetyAnalysis = (unsigned)
-    (D.getDiagnosticLevel(diag::warn_double_lock, SourceLocation()) !=
-     DiagnosticsEngine::Ignored);
-  DefaultPolicy.enableConsumedAnalysis = (unsigned)
-    (D.getDiagnosticLevel(diag::warn_use_in_invalid_state, SourceLocation()) !=
-     DiagnosticsEngine::Ignored);
+
+  DefaultPolicy.enableCheckUnreachable =
+    isEnabled(D, warn_unreachable) ||
+    isEnabled(D, warn_unreachable_break) ||
+    isEnabled(D, warn_unreachable_return);
+
+  DefaultPolicy.enableThreadSafetyAnalysis =
+    isEnabled(D, warn_double_lock);
+
+  DefaultPolicy.enableConsumedAnalysis =
+    isEnabled(D, warn_use_in_invalid_state);
 }
 
 static void flushDiagnostics(Sema &S, sema::FunctionScopeInfo *fscope) {