[GlobalMerge] Handle non-landingpad EH pads

This code crashed on funclet-style EH instructions such as catchpad,
catchswitch, and cleanuppad. Just treat all EH pad instructions
equivalently and avoid merging the globals they reference through any
use.

llvm-svn: 284633
This commit is contained in:
Reid Kleckner 2016-10-19 19:56:22 +00:00
parent 5c6ef75485
commit f8d1d12fef
2 changed files with 57 additions and 13 deletions

View File

@ -502,24 +502,20 @@ void GlobalMerge::collectUsedGlobalVariables(Module &M) {
void GlobalMerge::setMustKeepGlobalVariables(Module &M) {
collectUsedGlobalVariables(M);
for (Module::iterator IFn = M.begin(), IEndFn = M.end(); IFn != IEndFn;
++IFn) {
for (Function::iterator IBB = IFn->begin(), IEndBB = IFn->end();
IBB != IEndBB; ++IBB) {
// Follow the invoke link to find the landing pad instruction
const InvokeInst *II = dyn_cast<InvokeInst>(IBB->getTerminator());
if (!II) continue;
for (Function &F : M) {
for (BasicBlock &BB : F) {
Instruction *Pad = BB.getFirstNonPHI();
if (!Pad->isEHPad())
continue;
const LandingPadInst *LPInst = II->getUnwindDest()->getLandingPadInst();
// Look for globals in the clauses of the landing pad instruction
for (unsigned Idx = 0, NumClauses = LPInst->getNumClauses();
Idx != NumClauses; ++Idx)
// Keep globals used by landingpads and catchpads.
for (const Use &U : Pad->operands()) {
if (const GlobalVariable *GV =
dyn_cast<GlobalVariable>(LPInst->getClause(Idx)
->stripPointerCasts()))
dyn_cast<GlobalVariable>(U->stripPointerCasts()))
MustKeepGlobalVariables.insert(GV);
}
}
}
}
bool GlobalMerge::doInitialization(Module &M) {

View File

@ -0,0 +1,48 @@
; RUN: llc < %s | FileCheck %s
; CHECK: "??1field@@AAA@XZ":
; CHECK: bl free
; C++ source:
; class field { ~field(); };
; extern "C" void free(void *ptr);
; field::~field() { free((void *)0); }
; ModuleID = 't.cpp'
source_filename = "t.cpp"
target datalayout = "e-m:w-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
target triple = "thumbv7--windows-msvc19.0.24210"
%class.field = type { i8 }
; Function Attrs: nounwind
define arm_aapcs_vfpcc void @"\01??1field@@AAA@XZ"(%class.field* nocapture readnone %this) unnamed_addr #0 align 2 personality i8* bitcast (i32 (...)* @__CxxFrameHandler3 to i8*) {
entry:
invoke arm_aapcs_vfpcc void @free(i8* null)
to label %invoke.cont unwind label %terminate
invoke.cont: ; preds = %entry
ret void
terminate: ; preds = %entry
%0 = cleanuppad within none []
tail call arm_aapcs_vfpcc void @__std_terminate() #2 [ "funclet"(token %0) ]
unreachable
}
declare arm_aapcs_vfpcc void @free(i8*) local_unnamed_addr #1
declare arm_aapcs_vfpcc i32 @__CxxFrameHandler3(...)
declare arm_aapcs_vfpcc void @__std_terminate() local_unnamed_addr
attributes #0 = { nounwind "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="cortex-a9" "target-features"="+dsp,+fp16,+neon,+strict-align,+vfp3" "unsafe-fp-math"="false" "use-soft-float"="false" }
attributes #1 = { "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="cortex-a9" "target-features"="+dsp,+fp16,+neon,+strict-align,+vfp3" "unsafe-fp-math"="false" "use-soft-float"="false" }
attributes #2 = { noreturn nounwind }
!llvm.module.flags = !{!0, !1}
!llvm.ident = !{!2}
!0 = !{i32 1, !"wchar_size", i32 2}
!1 = !{i32 1, !"min_enum_size", i32 4}
!2 = !{!"clang version 4.0.0 (trunk 284595) (llvm/trunk 284597)"}