[-Wunreachable-code] Correctly expand artificial reachability to pruned '&&' and '||' branches involving configuration values.
llvm-svn: 203194
diff --git a/clang/lib/Analysis/ReachableCode.cpp b/clang/lib/Analysis/ReachableCode.cpp
index fa31dc1..09abcc9 100644
--- a/clang/lib/Analysis/ReachableCode.cpp
+++ b/clang/lib/Analysis/ReachableCode.cpp
@@ -459,9 +459,13 @@
/// Returns true if we should always explore all successors of a block.
static bool shouldTreatSuccessorsAsReachable(const CFGBlock *B) {
- if (const Stmt *Term = B->getTerminator())
+ if (const Stmt *Term = B->getTerminator()) {
if (isa<SwitchStmt>(Term))
return true;
+ // Specially handle '||' and '&&'.
+ if (isa<BinaryOperator>(Term))
+ return isConfigurationValue(Term);
+ }
return isConfigurationValue(B->getTerminatorCondition());
}
@@ -491,9 +495,9 @@
// and that we should forge ahead and explore those branches anyway.
// This allows us to potentially uncover some "always unreachable" code
// within the "sometimes unreachable" code.
- bool TreatAllSuccessorsAsReachable = shouldTreatSuccessorsAsReachable(item);
-
// Look at the successors and mark then reachable.
+ Optional<bool> TreatAllSuccessorsAsReachable;
+
for (CFGBlock::const_succ_iterator I = item->succ_begin(),
E = item->succ_end(); I != E; ++I) {
const CFGBlock *B = *I;
@@ -502,7 +506,11 @@
if (!UB)
break;
- if (TreatAllSuccessorsAsReachable) {
+ if (!TreatAllSuccessorsAsReachable.hasValue())
+ TreatAllSuccessorsAsReachable =
+ shouldTreatSuccessorsAsReachable(item);
+
+ if (TreatAllSuccessorsAsReachable.getValue()) {
B = UB;
break;
}