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-rw-r--r--clang/lib/CodeGen/CGExprAgg.cpp34
-rw-r--r--clang/test/CodeGen/aggregate-assign-call.c101
2 files changed, 129 insertions, 6 deletions
diff --git a/clang/lib/CodeGen/CGExprAgg.cpp b/clang/lib/CodeGen/CGExprAgg.cpp
index 5613f8d9700..371c14cde01 100644
--- a/clang/lib/CodeGen/CGExprAgg.cpp
+++ b/clang/lib/CodeGen/CGExprAgg.cpp
@@ -23,6 +23,7 @@
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/Intrinsics.h"
+#include "llvm/IR/IntrinsicInst.h"
using namespace clang;
using namespace CodeGen;
@@ -48,7 +49,7 @@ class AggExprEmitter : public StmtVisitor<AggExprEmitter> {
// Calls `Fn` with a valid return value slot, potentially creating a temporary
// to do so. If a temporary is created, an appropriate copy into `Dest` will
- // be emitted.
+ // be emitted, as will lifetime markers.
//
// The given function should take a ReturnValueSlot, and return an RValue that
// points to said slot.
@@ -250,16 +251,28 @@ void AggExprEmitter::withReturnValueSlot(
(RequiresDestruction && !Dest.getAddress().isValid());
Address RetAddr = Address::invalid();
+
+ EHScopeStack::stable_iterator LifetimeEndBlock;
+ llvm::Value *LifetimeSizePtr = nullptr;
+ llvm::IntrinsicInst *LifetimeStartInst = nullptr;
if (!UseTemp) {
RetAddr = Dest.getAddress();
} else {
RetAddr = CGF.CreateMemTemp(RetTy);
uint64_t Size =
CGF.CGM.getDataLayout().getTypeAllocSize(CGF.ConvertTypeForMem(RetTy));
- if (llvm::Value *LifetimeSizePtr =
- CGF.EmitLifetimeStart(Size, RetAddr.getPointer()))
+ LifetimeSizePtr = CGF.EmitLifetimeStart(Size, RetAddr.getPointer());
+ if (LifetimeSizePtr) {
+ LifetimeStartInst =
+ cast<llvm::IntrinsicInst>(std::prev(Builder.GetInsertPoint()));
+ assert(LifetimeStartInst->getIntrinsicID() ==
+ llvm::Intrinsic::lifetime_start &&
+ "Last insertion wasn't a lifetime.start?");
+
CGF.pushFullExprCleanup<CodeGenFunction::CallLifetimeEnd>(
NormalEHLifetimeMarker, RetAddr, LifetimeSizePtr);
+ LifetimeEndBlock = CGF.EHStack.stable_begin();
+ }
}
RValue Src =
@@ -268,9 +281,18 @@ void AggExprEmitter::withReturnValueSlot(
if (RequiresDestruction)
CGF.pushDestroy(RetTy.isDestructedType(), Src.getAggregateAddress(), RetTy);
- if (UseTemp) {
- assert(Dest.getPointer() != Src.getAggregatePointer());
- EmitFinalDestCopy(E->getType(), Src);
+ if (!UseTemp)
+ return;
+
+ assert(Dest.getPointer() != Src.getAggregatePointer());
+ EmitFinalDestCopy(E->getType(), Src);
+
+ if (!RequiresDestruction && LifetimeStartInst) {
+ // If there's no dtor to run, the copy was the last use of our temporary.
+ // Since we're not guaranteed to be in an ExprWithCleanups, clean up
+ // eagerly.
+ CGF.DeactivateCleanupBlock(LifetimeEndBlock, LifetimeStartInst);
+ CGF.EmitLifetimeEnd(LifetimeSizePtr, RetAddr.getPointer());
}
}
diff --git a/clang/test/CodeGen/aggregate-assign-call.c b/clang/test/CodeGen/aggregate-assign-call.c
new file mode 100644
index 00000000000..3539223f214
--- /dev/null
+++ b/clang/test/CodeGen/aggregate-assign-call.c
@@ -0,0 +1,101 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -O1 -S -emit-llvm -o - %s | FileCheck %s --check-prefix=O1
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -O0 -S -emit-llvm -o - %s | FileCheck %s --check-prefix=O0
+//
+// Ensure that we place appropriate lifetime markers around indirectly returned
+// temporaries, and that the lifetime.ends appear in a timely manner.
+//
+// -O1 is used so lifetime markers actually get emitted.
+
+struct S {
+ int ns[40];
+};
+
+struct S foo(void);
+
+// CHECK-LABEL: define dso_local void @bar
+struct S bar() {
+ // O0-NOT: @llvm.lifetime.start
+ // O0-NOT: @llvm.lifetime.end
+
+ struct S r;
+ // O1: call void @llvm.lifetime.start.p0i8({{[^,]*}}, i8* nonnull %[[R_TMP:[^)]+]])
+
+ // O1: call void @llvm.lifetime.start.p0i8({{[^,]*}}, i8* nonnull %[[TMP1:[^)]+]])
+ // O1: call void @foo
+ r = foo();
+ // O1: call void @llvm.lifetime.end.p0i8({{[^,]*}}, i8* nonnull %[[TMP1]])
+
+ // O1: call void @llvm.lifetime.start.p0i8({{[^,]*}}, i8* nonnull %[[TMP2:[^)]+]])
+ // O1: call void @foo
+ r = foo();
+ // O1: call void @llvm.lifetime.end.p0i8({{[^,]*}}, i8* nonnull %[[TMP2]])
+
+ // O1: call void @llvm.lifetime.start.p0i8({{[^,]*}}, i8* nonnull %[[TMP3:[^)]+]])
+ // O1: call void @foo
+ r = foo();
+ // O1: call void @llvm.lifetime.end.p0i8({{[^,]*}}, i8* nonnull %[[TMP3]])
+
+ // O1: call void @llvm.lifetime.end.p0i8({{[^,]*}}, i8* nonnull %[[R_TMP]])
+ return r;
+}
+
+struct S foo_int(int);
+
+// Be sure that we're placing the lifetime.end so that all paths go through it.
+// Since this function turns out to be large-ish, optnone to hopefully keep it
+// stable.
+// CHECK-LABEL: define dso_local void @baz
+__attribute__((optnone))
+struct S baz(int i, volatile int *j) {
+ // O0-NOT: @llvm.lifetime.start
+ // O0-NOT: @llvm.lifetime.end
+
+ struct S r;
+ // O1: %[[RESULT_ALLOCA:[^ ]+]] = alloca %struct.S
+ // O1: %[[TMP1_ALLOCA:[^ ]+]] = alloca %struct.S
+ // O1: %[[TMP2_ALLOCA:[^ ]+]] = alloca %struct.S
+ // O1: %[[P:[^ ]+]] = bitcast %struct.S* %[[RESULT_ALLOCA]] to i8*
+ // O1: call void @llvm.lifetime.start.p0i8({{[^,]*}}, i8* %[[P]])
+ // O1: br label %[[DO_BODY:.+]]
+
+ do {
+ // O1: [[DO_BODY]]:
+ // O1: %[[P:[^ ]+]] = bitcast %struct.S* %[[TMP1_ALLOCA]] to i8*
+ // O1: call void @llvm.lifetime.start.p0i8({{[^,]*}}, i8* %[[P]])
+ // O1: br i1 {{[^,]+}}, label %[[IF_THEN:[^,]+]], label %[[IF_END:[^,]+]]
+ //
+ // O1: [[IF_THEN]]:
+ // O1: %[[P:[^ ]+]] = bitcast %struct.S* %[[TMP1_ALLOCA]] to i8*
+ // O1: call void @llvm.lifetime.end.p0i8({{[^,]*}}, i8* %[[P]])
+ // O1: br label %[[DO_END:.*]]
+ //
+ // O1: [[IF_END]]:
+ // O1: call void @foo_int(%struct.S* sret %[[TMP1_ALLOCA]],
+ // O1: call void @llvm.memcpy
+ // O1: %[[P:[^ ]+]] = bitcast %struct.S* %[[TMP1_ALLOCA]] to i8*
+ // O1: call void @llvm.lifetime.end.p0i8({{[^,]*}}, i8* %[[P]])
+ // O1: %[[P:[^ ]+]] = bitcast %struct.S* %[[TMP2_ALLOCA]] to i8*
+ // O1: call void @llvm.lifetime.start.p0i8({{[^,]*}}, i8* %[[P]])
+ // O1: call void @foo_int(%struct.S* sret %[[TMP2_ALLOCA]],
+ // O1: call void @llvm.memcpy
+ // O1: %[[P:[^ ]+]] = bitcast %struct.S* %[[TMP2_ALLOCA]] to i8*
+ // O1: call void @llvm.lifetime.end.p0i8({{[^,]*}}, i8* %[[P]])
+ // O1: br label %[[DO_COND:.*]]
+ //
+ // O1: [[DO_COND]]:
+ // O1: br label %[[DO_BODY]]
+ r = foo_int(({
+ if (*j)
+ break;
+ i++;
+ }));
+
+ r = foo_int(i++);
+ } while (1);
+
+ // O1: [[DO_END]]:
+ // O1: call void @llvm.memcpy
+ // O1: %[[P:[^ ]+]] = bitcast %struct.S* %[[RESULT_ALLOCA]] to i8*
+ // O1: call void @llvm.lifetime.end.p0i8({{[^,]*}}, i8* %[[P]])
+ return r;
+}
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