UnreachableCodeChecker cleanup and improvements
- Fixed some iterator style issues
- Don't process blocks that have been visited already
- Fixed a case where a unreachable block cycle was not reported
- Minor test case changes
- Added one test case from flow-sensitive version of the check. More coming.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@115861 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Checker/UnreachableCodeChecker.cpp b/lib/Checker/UnreachableCodeChecker.cpp
index 52fb0ca..6854219 100644
--- a/lib/Checker/UnreachableCodeChecker.cpp
+++ b/lib/Checker/UnreachableCodeChecker.cpp
@@ -91,7 +91,7 @@
ASTContext &Ctx = B.getContext();
// Find CFGBlocks that were not covered by any node
- for (CFG::const_iterator I = C->begin(); I != C->end(); ++I) {
+ for (CFG::const_iterator I = C->begin(), E = C->end(); I != E; ++I) {
const CFGBlock *CB = *I;
// Check if the block is unreachable
if (reachable.count(CB->getBlockID()))
@@ -102,7 +102,8 @@
continue;
// Find the entry points for this block
- FindUnreachableEntryPoints(CB);
+ if (!visited.count(CB->getBlockID()))
+ FindUnreachableEntryPoints(CB);
// This block may have been pruned; check if we still want to report it
if (reachable.count(CB->getBlockID()))
@@ -149,28 +150,19 @@
// Recursively finds the entry point(s) for this dead CFGBlock.
void UnreachableCodeChecker::FindUnreachableEntryPoints(const CFGBlock *CB) {
- bool allPredecessorsReachable = true;
-
visited.insert(CB->getBlockID());
- for (CFGBlock::const_pred_iterator I = CB->pred_begin(); I != CB->pred_end();
- ++I) {
- // Recurse over all unreachable blocks
+ for (CFGBlock::const_pred_iterator I = CB->pred_begin(), E = CB->pred_end();
+ I != E; ++I) {
if (!reachable.count((*I)->getBlockID())) {
- // At least one predeccessor was unreachable
- allPredecessorsReachable = false;
-
- // Only visit the block once
+ // If we find an unreachable predecessor, mark this block as reachable so
+ // we don't report this block
+ reachable.insert(CB->getBlockID());
if (!visited.count((*I)->getBlockID()))
+ // If we haven't previously visited the unreachable predecessor, recurse
FindUnreachableEntryPoints(*I);
}
}
-
- // If at least one predecessor is unreachable, mark this block as reachable
- // so we don't report this block.
- if (!allPredecessorsReachable) {
- reachable.insert(CB->getBlockID());
- }
}
// Find the Stmt* in a CFGBlock for reporting a warning