Ensure inlined static calls perform clinit checks in Optimizing.
Calls to static methods have implicit class initialization
(clinit) checks of the method's declaring class in
Optimizing. However, when such a static call is inlined,
the implicit clinit check vanishes, possibly leading to an
incorrect behavior.
To ensure that inlining static methods does not change the
behavior of a program, add explicit class initialization
checks (art::HClinitCheck) as well as load class
instructions (art::HLoadClass) as last input of static
calls (art::HInvokeStaticOrDirect) in Optimizing' control
flow graphs, when the declaring class is reachable and not
known to be already initialized. Then when considering the
inlining of a static method call, proceed only if the method
has no implicit clinit check requirement.
The added explicit clinit checks are already removed by the
art::PrepareForRegisterAllocation visitor. This CL also
extends this visitor to turn explicit clinit checks from
static invokes into implicit ones after the inlining step,
by removing the added art::HLoadClass nodes mentioned
hereinbefore.
Change-Id: I9ba452b8bd09ae1fdd9a3797ef556e3e7e19c651
diff --git a/compiler/optimizing/code_generator_x86_64.cc b/compiler/optimizing/code_generator_x86_64.cc
index d8d2ae3..e996e46 100644
--- a/compiler/optimizing/code_generator_x86_64.cc
+++ b/compiler/optimizing/code_generator_x86_64.cc
@@ -1270,6 +1270,10 @@
}
void LocationsBuilderX86_64::VisitInvokeStaticOrDirect(HInvokeStaticOrDirect* invoke) {
+ // Explicit clinit checks triggered by static invokes must have been
+ // pruned by art::PrepareForRegisterAllocation.
+ DCHECK(!invoke->IsStaticWithExplicitClinitCheck());
+
IntrinsicLocationsBuilderX86_64 intrinsic(codegen_);
if (intrinsic.TryDispatch(invoke)) {
return;
@@ -1288,6 +1292,10 @@
}
void InstructionCodeGeneratorX86_64::VisitInvokeStaticOrDirect(HInvokeStaticOrDirect* invoke) {
+ // Explicit clinit checks triggered by static invokes must have been
+ // pruned by art::PrepareForRegisterAllocation.
+ DCHECK(!invoke->IsStaticWithExplicitClinitCheck());
+
if (TryGenerateIntrinsicCode(invoke, codegen_)) {
return;
}