StephenFan updated this revision to Diff 445420.
StephenFan added a comment.
Herald added a project: LLVM.
Herald added a subscriber: llvm-commits.
1. Rebase.
2. Add a test case of goto_bypass.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D129448/new/
https://reviews.llvm.org/D129448
Files:
clang/lib/CodeGen/CGDecl.cpp
clang/lib/CodeGen/CGStmt.cpp
clang/lib/CodeGen/CodeGenFunction.cpp
clang/lib/CodeGen/CodeGenFunction.h
clang/test/CodeGen/lifetime2.c
llvm/test/Instrumentation/MemorySanitizer/alloca.ll
Index: llvm/test/Instrumentation/MemorySanitizer/alloca.ll
===================================================================
--- llvm/test/Instrumentation/MemorySanitizer/alloca.ll
+++ llvm/test/Instrumentation/MemorySanitizer/alloca.ll
@@ -209,7 +209,42 @@
; KMSAN-NOT: call void @__msan_poison_alloca(i8* {{.*}}, i64 4,
; CHECK: call void @llvm.lifetime.end
+define void @goto_bypass() sanitize_memory {
+entry:
+ %x = alloca i8, align 1
+ call void @llvm.lifetime.start.p0i8(i64 1, i8* %x)
+ br label %l1
+
+l1:
+ call void @llvm.lifetime.start.p0i8(i64 1, i8* %x)
+ call void @bar(i8* noundef %x, i32 noundef 1)
+ %0 = load i8, i8* %x
+ %tobool = icmp ne i8 %0, 0
+ br i1 %tobool, label %if.then, label %if.end
+
+if.then:
+ br label %l1
+
+if.end:
+ call void @llvm.lifetime.end.p0i8(i64 1, i8* %x)
+ br label %l1
+}
-
+; CHECK-LABEL: define void @goto_bypass(
+; CHECK-LABEL: entry:
+; CHECK: %x = alloca i8
+; INLINE: call void @llvm.memset.p0i8.i64(i8* align 1 {{.*}}, i8 -1, i64 1, i1 false)
+; CALL: call void @__msan_poison_stack(i8* {{.*}}, i64 1)
+; ORIGIN: call void @__msan_set_alloca_origin4(i8* {{.*}}, i64 1,
+; KMSAN: call void @__msan_poison_alloca(i8* {{.*}}, i64 1,
+
+; FIXME: It is invalid to instrument here Since variable x may be initialized by callee bar.
+; CHECK-LABEL: l1:
+; INLINE: call void @llvm.memset.p0i8.i64(i8* align 1 {{.*}}, i8 -1, i64 1, i1 false)
+; CALL: call void @__msan_poison_stack(i8* {{.*}}, i64 1)
+; ORIGIN: call void @__msan_set_alloca_origin4(i8* {{.*}}, i64 1,
+; KMSAN: call void @__msan_poison_alloca(i8* {{.*}}, i64 1,
+
+declare void @bar(i8* noundef, i32 noundef)
declare void @llvm.lifetime.start.p0i8(i64 immarg, i8* nocapture)
declare void @llvm.lifetime.end.p0i8(i64 immarg, i8* nocapture)
Index: clang/test/CodeGen/lifetime2.c
===================================================================
--- clang/test/CodeGen/lifetime2.c
+++ clang/test/CodeGen/lifetime2.c
@@ -35,8 +35,11 @@
void goto_bypass(void) {
{
char x;
+ // O2: @llvm.lifetime.start.p0i8(i64 1
l1:
+ // O2: @llvm.lifetime.start.p0i8(i64 1
bar(&x, 1);
+ // O2: @llvm.lifetime.end.p0i8(i64 1
}
goto l1;
}
@@ -67,21 +70,30 @@
case 1:
n = n;
char x;
+ // O2: @llvm.lifetime.start.p0i8(i64 1
bar(&x, 1);
break;
case 2:
+ // O2: @llvm.lifetime.start.p0i8(i64 1
bar(&x, 1);
break;
+ // O2: @llvm.lifetime.end.p0i8(i64 1
}
}
// CHECK-LABEL: @indirect_jump
void indirect_jump(int n) {
char x;
+ // O2: @llvm.lifetime.start.p0i8(i64 1
void *T[] = {&&L};
+ // O2: @llvm.lifetime.start.p0i8(i64 8
goto *T[n];
L:
+ // O2: @llvm.lifetime.start.p0i8(i64 1
+ // O2: @llvm.lifetime.start.p0i8(i64 8
bar(&x, 1);
+ // O2: @llvm.lifetime.end.p0i8(i64 8
+ // O2: @llvm.lifetime.end.p0i8(i64 1
}
extern void foo2(int p);
Index: clang/lib/CodeGen/CodeGenFunction.h
===================================================================
--- clang/lib/CodeGen/CodeGenFunction.h
+++ clang/lib/CodeGen/CodeGenFunction.h
@@ -38,6 +38,7 @@
#include "llvm/ADT/MapVector.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Frontend/OpenMP/OMPIRBuilder.h"
+#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/ValueHandle.h"
#include "llvm/Support/Debug.h"
#include "llvm/Transforms/Utils/SanitizerStats.h"
@@ -1926,6 +1927,14 @@
/// The current lexical scope.
LexicalScope *CurLexicalScope = nullptr;
+ /// Map from lexical socpe to vector of bypassed lifetime start markers.
+ /// NOTE: If a lifetime start marker isn't defined in any lexical scope(
+ /// defining while CurLexicalScope is nullptr), its key is nullptr;
+ std::map<const LexicalScope *, llvm::SmallVector<llvm::CallInst *, 8>>
+ BypassedLifetimeStartMarkers;
+
+ void restartBypassedVariable();
+
/// The current source location that should be used for exception
/// handling code.
SourceLocation CurEHLocation;
@@ -2922,7 +2931,8 @@
void EmitSehTryScopeBegin();
void EmitSehTryScopeEnd();
- llvm::Value *EmitLifetimeStart(llvm::TypeSize Size, llvm::Value *Addr);
+ llvm::Value *EmitLifetimeStart(llvm::TypeSize Size, llvm::Value *Addr,
+ bool isBypassed = false);
void EmitLifetimeEnd(llvm::Value *Size, llvm::Value *Addr);
llvm::Value *EmitCXXNewExpr(const CXXNewExpr *E);
Index: clang/lib/CodeGen/CodeGenFunction.cpp
===================================================================
--- clang/lib/CodeGen/CodeGenFunction.cpp
+++ clang/lib/CodeGen/CodeGenFunction.cpp
@@ -1247,6 +1247,8 @@
EmitBranch(SkipCountBB);
}
EmitBlock(BB);
+ restartBypassedVariable();
+
uint64_t CurrentCount = getCurrentProfileCount();
incrementProfileCounter(S);
setCurrentProfileCount(getCurrentProfileCount() + CurrentCount);
@@ -1313,6 +1315,14 @@
return ResTy;
}
+void CodeGenFunction::restartBypassedVariable() {
+ if (BypassedLifetimeStartMarkers.count(CurLexicalScope))
+ llvm::for_each(BypassedLifetimeStartMarkers[CurLexicalScope],
+ [this](const llvm::CallInst *LifetimeStartMarker) {
+ Builder.Insert(LifetimeStartMarker->clone());
+ });
+}
+
void CodeGenFunction::GenerateCode(GlobalDecl GD, llvm::Function *Fn,
const CGFunctionInfo &FnInfo) {
assert(Fn && "generating code for null Function");
@@ -1468,6 +1478,8 @@
// a quick pass now to see if we can.
if (!CurFn->doesNotThrow())
TryMarkNoThrow(CurFn);
+
+ BypassedLifetimeStartMarkers.clear();
}
/// ContainsLabel - Return true if the statement contains a label in it. If
Index: clang/lib/CodeGen/CGStmt.cpp
===================================================================
--- clang/lib/CodeGen/CGStmt.cpp
+++ clang/lib/CodeGen/CGStmt.cpp
@@ -646,6 +646,7 @@
}
EmitBlock(Dest.getBlock());
+ restartBypassedVariable();
// Emit debug info for labels.
if (CGDebugInfo *DI = getDebugInfo()) {
Index: clang/lib/CodeGen/CGDecl.cpp
===================================================================
--- clang/lib/CodeGen/CGDecl.cpp
+++ clang/lib/CodeGen/CGDecl.cpp
@@ -1330,7 +1330,8 @@
/// \return a pointer to the temporary size Value if a marker was emitted, null
/// otherwise
llvm::Value *CodeGenFunction::EmitLifetimeStart(llvm::TypeSize Size,
- llvm::Value *Addr) {
+ llvm::Value *Addr,
+ bool isBypassed) {
if (!ShouldEmitLifetimeMarkers)
return nullptr;
@@ -1342,6 +1343,8 @@
Addr = Builder.CreateBitCast(Addr, AllocaInt8PtrTy);
llvm::CallInst *C =
Builder.CreateCall(CGM.getLLVMLifetimeStartFn(), {SizeV, Addr});
+ if (isBypassed)
+ BypassedLifetimeStartMarkers[CurLexicalScope].push_back(C);
C->setDoesNotThrow();
return SizeV;
}
@@ -1551,24 +1554,10 @@
// Emit a lifetime intrinsic if meaningful. There's no point in doing this
// if we don't have a valid insertion point (?).
if (HaveInsertPoint() && !IsMSCatchParam) {
- // If there's a jump into the lifetime of this variable, its lifetime
- // gets broken up into several regions in IR, which requires more work
- // to handle correctly. For now, just omit the intrinsics; this is a
- // rare case, and it's better to just be conservatively correct.
- // PR28267.
- //
- // We have to do this in all language modes if there's a jump past the
- // declaration. We also have to do it in C if there's a jump to an
- // earlier point in the current block because non-VLA lifetimes begin as
- // soon as the containing block is entered, not when its variables
- // actually come into scope; suppressing the lifetime annotations
- // completely in this case is unnecessarily pessimistic, but again, this
- // is rare.
- if (!Bypasses.IsBypassed(&D) &&
- !(!getLangOpts().CPlusPlus && hasLabelBeenSeenInCurrentScope())) {
+ if (!(!getLangOpts().CPlusPlus && hasLabelBeenSeenInCurrentScope())) {
llvm::TypeSize Size = CGM.getDataLayout().getTypeAllocSize(allocaTy);
- emission.SizeForLifetimeMarkers =
- EmitLifetimeStart(Size, AllocaAddr.getPointer());
+ emission.SizeForLifetimeMarkers = EmitLifetimeStart(
+ Size, AllocaAddr.getPointer(), Bypasses.IsBypassed(&D));
}
} else {
assert(!emission.useLifetimeMarkers());
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