ART: Fix simplification of catch blocks in the presence of dead code
Simplification of catch blocks transforms the code so that catch
blocks have only exceptional predecessors. However, it is invoked
before trivially dead code is eliminated which breaks simple
assumptions such as the fact that a catch block cannot start with
move-exception if it has non-exceptional predecessors. This patch
fixes the algorithm to work under these relaxed conditions.
Bug: 25494450
Bug: 25492628
Change-Id: Idc8d010102a4b8b9a6cd918b98d6e11d1838db0c
diff --git a/compiler/optimizing/graph_checker.cc b/compiler/optimizing/graph_checker.cc
index 3de96b5..c32ef51 100644
--- a/compiler/optimizing/graph_checker.cc
+++ b/compiler/optimizing/graph_checker.cc
@@ -188,6 +188,21 @@
VisitInstruction(try_boundary);
}
+void GraphChecker::VisitLoadException(HLoadException* load) {
+ // Ensure that LoadException is the first instruction in a catch block.
+ if (!load->GetBlock()->IsCatchBlock()) {
+ AddError(StringPrintf("%s:%d is in a non-catch block %d.",
+ load->DebugName(),
+ load->GetId(),
+ load->GetBlock()->GetBlockId()));
+ } else if (load->GetBlock()->GetFirstInstruction() != load) {
+ AddError(StringPrintf("%s:%d is not the first instruction in catch block %d.",
+ load->DebugName(),
+ load->GetId(),
+ load->GetBlock()->GetBlockId()));
+ }
+}
+
void GraphChecker::VisitInstruction(HInstruction* instruction) {
if (seen_ids_.IsBitSet(instruction->GetId())) {
AddError(StringPrintf("Instruction id %d is duplicate in graph.",