Skip compilation when falling-through out of method code.
Bug: 19988134
Change-Id: I68638ce9551848a67af587595f264b51f976df11
diff --git a/compiler/optimizing/builder.cc b/compiler/optimizing/builder.cc
index 0f44af0..a5c6f23 100644
--- a/compiler/optimizing/builder.cc
+++ b/compiler/optimizing/builder.cc
@@ -282,7 +282,10 @@
// To avoid splitting blocks, we compute ahead of time the instructions that
// start a new block, and create these blocks.
- ComputeBranchTargets(code_ptr, code_end, &number_of_branches);
+ if (!ComputeBranchTargets(code_ptr, code_end, &number_of_branches)) {
+ MaybeRecordStat(MethodCompilationStat::kNotCompiledBranchOutsideMethodCode);
+ return false;
+ }
// Note that the compiler driver is null when unit testing.
if ((compiler_driver_ != nullptr) && SkipCompilation(code_item, number_of_branches)) {
@@ -349,7 +352,7 @@
current_block_ = block;
}
-void HGraphBuilder::ComputeBranchTargets(const uint16_t* code_ptr,
+bool HGraphBuilder::ComputeBranchTargets(const uint16_t* code_ptr,
const uint16_t* code_end,
size_t* number_of_branches) {
branch_targets_.SetSize(code_end - code_ptr);
@@ -374,7 +377,14 @@
}
dex_pc += instruction.SizeInCodeUnits();
code_ptr += instruction.SizeInCodeUnits();
- if ((code_ptr < code_end) && (FindBlockStartingAt(dex_pc) == nullptr)) {
+
+ if (code_ptr >= code_end) {
+ if (instruction.CanFlowThrough()) {
+ // In the normal case we should never hit this but someone can artificially forge a dex
+ // file to fall-through out the method code. In this case we bail out compilation.
+ return false;
+ }
+ } else if (FindBlockStartingAt(dex_pc) == nullptr) {
block = new (arena_) HBasicBlock(graph_, dex_pc);
branch_targets_.Put(dex_pc, block);
}
@@ -406,7 +416,12 @@
// Fall-through. Add a block if there is more code afterwards.
dex_pc += instruction.SizeInCodeUnits();
code_ptr += instruction.SizeInCodeUnits();
- if ((code_ptr < code_end) && (FindBlockStartingAt(dex_pc) == nullptr)) {
+ if (code_ptr >= code_end) {
+ // In the normal case we should never hit this but someone can artificially forge a dex
+ // file to fall-through out the method code. In this case we bail out compilation.
+ // (A switch can fall-through so we don't need to check CanFlowThrough().)
+ return false;
+ } else if (FindBlockStartingAt(dex_pc) == nullptr) {
block = new (arena_) HBasicBlock(graph_, dex_pc);
branch_targets_.Put(dex_pc, block);
}
@@ -415,6 +430,7 @@
dex_pc += instruction.SizeInCodeUnits();
}
}
+ return true;
}
HBasicBlock* HGraphBuilder::FindBlockStartingAt(int32_t index) const {