[llvm] r273779 - Revert "[SimplifyCFG] Stop inserting calls to llvm.trap for UB"
David Majnemer via llvm-commits
llvm-commits at lists.llvm.org
Sat Jun 25 01:19:55 PDT 2016
Author: majnemer
Date: Sat Jun 25 03:19:55 2016
New Revision: 273779
URL: http://llvm.org/viewvc/llvm-project?rev=273779&view=rev
Log:
Revert "[SimplifyCFG] Stop inserting calls to llvm.trap for UB"
This reverts commit r273778, it seems to break UBSan :/
Added:
llvm/trunk/test/Transforms/SimplifyCFG/trap-debugloc.ll
Modified:
llvm/trunk/include/llvm/Transforms/Utils/Local.h
llvm/trunk/lib/CodeGen/WinEHPrepare.cpp
llvm/trunk/lib/Transforms/IPO/PruneEH.cpp
llvm/trunk/lib/Transforms/Scalar/SCCP.cpp
llvm/trunk/lib/Transforms/Utils/InlineFunction.cpp
llvm/trunk/lib/Transforms/Utils/Local.cpp
llvm/trunk/lib/Transforms/Utils/LoopSimplify.cpp
llvm/trunk/test/Transforms/SimplifyCFG/invoke.ll
llvm/trunk/test/Transforms/SimplifyCFG/trapping-load-unreachable.ll
Modified: llvm/trunk/include/llvm/Transforms/Utils/Local.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/Utils/Local.h?rev=273779&r1=273778&r2=273779&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Transforms/Utils/Local.h (original)
+++ llvm/trunk/include/llvm/Transforms/Utils/Local.h Sat Jun 25 03:19:55 2016
@@ -296,7 +296,7 @@ unsigned removeAllNonTerminatorAndEHPadI
/// Insert an unreachable instruction before the specified
/// instruction, making it and the rest of the code in the block dead.
-unsigned changeToUnreachable(Instruction *I);
+unsigned changeToUnreachable(Instruction *I, bool UseLLVMTrap);
/// Replace 'BB's terminator with one that does not have an unwind successor
/// block. Rewrites `invoke` to `call`, etc. Updates any PHIs in unwind
Modified: llvm/trunk/lib/CodeGen/WinEHPrepare.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/WinEHPrepare.cpp?rev=273779&r1=273778&r2=273779&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/WinEHPrepare.cpp (original)
+++ llvm/trunk/lib/CodeGen/WinEHPrepare.cpp Sat Jun 25 03:19:55 2016
@@ -963,9 +963,9 @@ void WinEHPrepare::removeImplausibleInst
BasicBlock::iterator CallI =
std::prev(BB->getTerminator()->getIterator());
auto *CI = cast<CallInst>(&*CallI);
- changeToUnreachable(CI);
+ changeToUnreachable(CI, /*UseLLVMTrap=*/false);
} else {
- changeToUnreachable(&I);
+ changeToUnreachable(&I, /*UseLLVMTrap=*/false);
}
// There are no more instructions in the block (except for unreachable),
@@ -986,7 +986,7 @@ void WinEHPrepare::removeImplausibleInst
IsUnreachableCleanupret = CRI->getCleanupPad() != CleanupPad;
if (IsUnreachableRet || IsUnreachableCatchret ||
IsUnreachableCleanupret) {
- changeToUnreachable(TI);
+ changeToUnreachable(TI, /*UseLLVMTrap=*/false);
} else if (isa<InvokeInst>(TI)) {
if (Personality == EHPersonality::MSVC_CXX && CleanupPad) {
// Invokes within a cleanuppad for the MSVC++ personality never
Modified: llvm/trunk/lib/Transforms/IPO/PruneEH.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/IPO/PruneEH.cpp?rev=273779&r1=273778&r2=273779&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/IPO/PruneEH.cpp (original)
+++ llvm/trunk/lib/Transforms/IPO/PruneEH.cpp Sat Jun 25 03:19:55 2016
@@ -258,7 +258,7 @@ void PruneEH::DeleteBasicBlock(BasicBloc
if (TokenInst) {
if (!isa<TerminatorInst>(TokenInst))
- changeToUnreachable(TokenInst->getNextNode());
+ changeToUnreachable(TokenInst->getNextNode(), /*UseLLVMTrap=*/false);
} else {
// Get the list of successors of this block.
std::vector<BasicBlock *> Succs(succ_begin(BB), succ_end(BB));
Modified: llvm/trunk/lib/Transforms/Scalar/SCCP.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/SCCP.cpp?rev=273779&r1=273778&r2=273779&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/SCCP.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/SCCP.cpp Sat Jun 25 03:19:55 2016
@@ -1802,7 +1802,8 @@ static bool runIPSCCP(Module &M, const D
DEBUG(dbgs() << " BasicBlock Dead:" << *BB);
++NumDeadBlocks;
- NumInstRemoved += changeToUnreachable(BB->getFirstNonPHI());
+ NumInstRemoved +=
+ changeToUnreachable(BB->getFirstNonPHI(), /*UseLLVMTrap=*/false);
MadeChanges = true;
Modified: llvm/trunk/lib/Transforms/Utils/InlineFunction.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/InlineFunction.cpp?rev=273779&r1=273778&r2=273779&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/InlineFunction.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/InlineFunction.cpp Sat Jun 25 03:19:55 2016
@@ -1833,7 +1833,7 @@ bool llvm::InlineFunction(CallSite CS, I
// As such, we replace the cleanupret with unreachable.
if (auto *CleanupRet = dyn_cast<CleanupReturnInst>(BB->getTerminator()))
if (CleanupRet->unwindsToCaller() && EHPadForCallUnwindsLocally)
- changeToUnreachable(CleanupRet);
+ changeToUnreachable(CleanupRet, /*UseLLVMTrap=*/false);
Instruction *I = BB->getFirstNonPHI();
if (!I->isEHPad())
Modified: llvm/trunk/lib/Transforms/Utils/Local.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/Local.cpp?rev=273779&r1=273778&r2=273779&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/Local.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/Local.cpp Sat Jun 25 03:19:55 2016
@@ -42,13 +42,11 @@
#include "llvm/IR/MDBuilder.h"
#include "llvm/IR/Metadata.h"
#include "llvm/IR/Operator.h"
-#include "llvm/IR/PatternMatch.h"
#include "llvm/IR/ValueHandle.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
-using namespace llvm::PatternMatch;
#define DEBUG_TYPE "local"
@@ -1312,13 +1310,21 @@ unsigned llvm::removeAllNonTerminatorAnd
return NumDeadInst;
}
-unsigned llvm::changeToUnreachable(Instruction *I) {
+unsigned llvm::changeToUnreachable(Instruction *I, bool UseLLVMTrap) {
BasicBlock *BB = I->getParent();
// Loop over all of the successors, removing BB's entry from any PHI
// nodes.
- for (BasicBlock *Succ : successors(BB))
- Succ->removePredecessor(BB);
+ for (succ_iterator SI = succ_begin(BB), SE = succ_end(BB); SI != SE; ++SI)
+ (*SI)->removePredecessor(BB);
+ // Insert a call to llvm.trap right before this. This turns the undefined
+ // behavior into a hard fail instead of falling through into random code.
+ if (UseLLVMTrap) {
+ Function *TrapFn =
+ Intrinsic::getDeclaration(BB->getParent()->getParent(), Intrinsic::trap);
+ CallInst *CallTrap = CallInst::Create(TrapFn, "", I);
+ CallTrap->setDebugLoc(I->getDebugLoc());
+ }
new UnreachableInst(I->getContext(), I);
// All instructions after this are dead.
@@ -1368,14 +1374,22 @@ static bool markAliveBlocks(Function &F,
// Do a quick scan of the basic block, turning any obviously unreachable
// instructions into LLVM unreachable insts. The instruction combining pass
// canonicalizes unreachable insts into stores to null or undef.
- for (Instruction &I : *BB) {
+ for (BasicBlock::iterator BBI = BB->begin(), E = BB->end(); BBI != E;++BBI){
// Assumptions that are known to be false are equivalent to unreachable.
// Also, if the condition is undefined, then we make the choice most
// beneficial to the optimizer, and choose that to also be unreachable.
- if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(&I)) {
+ if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(BBI)) {
if (II->getIntrinsicID() == Intrinsic::assume) {
- if (match(II->getArgOperand(0), m_CombineOr(m_Zero(), m_Undef()))) {
- changeToUnreachable(II);
+ bool MakeUnreachable = false;
+ if (isa<UndefValue>(II->getArgOperand(0)))
+ MakeUnreachable = true;
+ else if (ConstantInt *Cond =
+ dyn_cast<ConstantInt>(II->getArgOperand(0)))
+ MakeUnreachable = Cond->isZero();
+
+ if (MakeUnreachable) {
+ // Don't insert a call to llvm.trap right before the unreachable.
+ changeToUnreachable(&*BBI, false);
Changed = true;
break;
}
@@ -1390,19 +1404,19 @@ static bool markAliveBlocks(Function &F,
// Note: unlike in llvm.assume, it is not "obviously profitable" for
// guards to treat `undef` as `false` since a guard on `undef` can
// still be useful for widening.
- if (match(II->getArgOperand(0), m_Zero()))
- if (!isa<UnreachableInst>(II->getNextNode())) {
- changeToUnreachable(II->getNextNode());
+ if (auto *CI = dyn_cast<ConstantInt>(II->getArgOperand(0)))
+ if (CI->isZero() && !isa<UnreachableInst>(II->getNextNode())) {
+ changeToUnreachable(II->getNextNode(), /*UseLLVMTrap=*/ false);
Changed = true;
break;
}
}
}
- if (auto *CI = dyn_cast<CallInst>(&I)) {
+ if (CallInst *CI = dyn_cast<CallInst>(BBI)) {
Value *Callee = CI->getCalledValue();
if (isa<ConstantPointerNull>(Callee) || isa<UndefValue>(Callee)) {
- changeToUnreachable(CI);
+ changeToUnreachable(CI, /*UseLLVMTrap=*/false);
Changed = true;
break;
}
@@ -1410,8 +1424,10 @@ static bool markAliveBlocks(Function &F,
// If we found a call to a no-return function, insert an unreachable
// instruction after it. Make sure there isn't *already* one there
// though.
- if (!isa<UnreachableInst>(CI->getNextNode())) {
- changeToUnreachable(CI->getNextNode());
+ ++BBI;
+ if (!isa<UnreachableInst>(BBI)) {
+ // Don't insert a call to llvm.trap right before the unreachable.
+ changeToUnreachable(&*BBI, false);
Changed = true;
}
break;
@@ -1421,7 +1437,7 @@ static bool markAliveBlocks(Function &F,
// Store to undef and store to null are undefined and used to signal that
// they should be changed to unreachable by passes that can't modify the
// CFG.
- if (auto *SI = dyn_cast<StoreInst>(&I)) {
+ if (StoreInst *SI = dyn_cast<StoreInst>(BBI)) {
// Don't touch volatile stores.
if (SI->isVolatile()) continue;
@@ -1430,7 +1446,7 @@ static bool markAliveBlocks(Function &F,
if (isa<UndefValue>(Ptr) ||
(isa<ConstantPointerNull>(Ptr) &&
SI->getPointerAddressSpace() == 0)) {
- changeToUnreachable(SI);
+ changeToUnreachable(SI, true);
Changed = true;
break;
}
@@ -1442,7 +1458,7 @@ static bool markAliveBlocks(Function &F,
// Turn invokes that call 'nounwind' functions into ordinary calls.
Value *Callee = II->getCalledValue();
if (isa<ConstantPointerNull>(Callee) || isa<UndefValue>(Callee)) {
- changeToUnreachable(II);
+ changeToUnreachable(II, true);
Changed = true;
} else if (II->doesNotThrow() && canSimplifyInvokeNoUnwind(&F)) {
if (II->use_empty() && II->onlyReadsMemory()) {
@@ -1495,9 +1511,9 @@ static bool markAliveBlocks(Function &F,
}
Changed |= ConstantFoldTerminator(BB, true);
- for (BasicBlock *Succ : successors(BB))
- if (Reachable.insert(Succ).second)
- Worklist.push_back(Succ);
+ for (succ_iterator SI = succ_begin(BB), SE = succ_end(BB); SI != SE; ++SI)
+ if (Reachable.insert(*SI).second)
+ Worklist.push_back(*SI);
} while (!Worklist.empty());
return Changed;
}
Modified: llvm/trunk/lib/Transforms/Utils/LoopSimplify.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/LoopSimplify.cpp?rev=273779&r1=273778&r2=273779&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/LoopSimplify.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/LoopSimplify.cpp Sat Jun 25 03:19:55 2016
@@ -491,7 +491,7 @@ ReprocessLoop:
// Zap the dead pred's terminator and replace it with unreachable.
TerminatorInst *TI = P->getTerminator();
- changeToUnreachable(TI);
+ changeToUnreachable(TI, /*UseLLVMTrap=*/false);
Changed = true;
}
}
Modified: llvm/trunk/test/Transforms/SimplifyCFG/invoke.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SimplifyCFG/invoke.ll?rev=273779&r1=273778&r2=273779&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/SimplifyCFG/invoke.ll (original)
+++ llvm/trunk/test/Transforms/SimplifyCFG/invoke.ll Sat Jun 25 03:19:55 2016
@@ -12,6 +12,7 @@ declare i32 @fn()
; CHECK-LABEL: @f1(
define i8* @f1() nounwind uwtable ssp personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) {
entry:
+; CHECK: call void @llvm.trap()
; CHECK: unreachable
%call = invoke noalias i8* undef()
to label %invoke.cont unwind label %lpad
@@ -30,6 +31,7 @@ lpad:
; CHECK-LABEL: @f2(
define i8* @f2() nounwind uwtable ssp personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) {
entry:
+; CHECK: call void @llvm.trap()
; CHECK: unreachable
%call = invoke noalias i8* null()
to label %invoke.cont unwind label %lpad
Added: llvm/trunk/test/Transforms/SimplifyCFG/trap-debugloc.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SimplifyCFG/trap-debugloc.ll?rev=273779&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/SimplifyCFG/trap-debugloc.ll (added)
+++ llvm/trunk/test/Transforms/SimplifyCFG/trap-debugloc.ll Sat Jun 25 03:19:55 2016
@@ -0,0 +1,22 @@
+; RUN: opt -S -simplifycfg < %s | FileCheck %s
+; Radar 9342286
+; Assign DebugLoc to trap instruction.
+define void @foo() nounwind ssp !dbg !0 {
+; CHECK: call void @llvm.trap(), !dbg
+ store i32 42, i32* null, !dbg !5
+ ret void, !dbg !7
+}
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!10}
+
+!0 = distinct !DISubprogram(name: "foo", line: 3, isLocal: false, isDefinition: true, virtualIndex: 6, isOptimized: false, unit: !2, file: !8, scope: !1, type: !3)
+!1 = !DIFile(filename: "foo.c", directory: "/private/tmp")
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "Apple clang version 3.0 (tags/Apple/clang-206.1) (based on LLVM 3.0svn)", isOptimized: true, emissionKind: FullDebug, file: !8, enums: !{}, retainedTypes: !{})
+!3 = !DISubroutineType(types: !4)
+!4 = !{null}
+!5 = !DILocation(line: 4, column: 2, scope: !6)
+!6 = distinct !DILexicalBlock(line: 3, column: 12, file: !8, scope: !0)
+!7 = !DILocation(line: 5, column: 1, scope: !6)
+!8 = !DIFile(filename: "foo.c", directory: "/private/tmp")
+!10 = !{i32 1, !"Debug Info Version", i32 3}
Modified: llvm/trunk/test/Transforms/SimplifyCFG/trapping-load-unreachable.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SimplifyCFG/trapping-load-unreachable.ll?rev=273779&r1=273778&r2=273779&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/SimplifyCFG/trapping-load-unreachable.ll (original)
+++ llvm/trunk/test/Transforms/SimplifyCFG/trapping-load-unreachable.ll Sat Jun 25 03:19:55 2016
@@ -28,6 +28,7 @@ entry:
ret void
; CHECK-LABEL: @test2(
+; CHECK: call void @llvm.trap
; CHECK: unreachable
}
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