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[CodeGenObjCXX] Fix handling of blocks in lambda. 

This fixes a crash that occurs when a block captures a reference that is
captured by its enclosing lambda.

rdar://problem/18586651

Differential Revision: http://reviews.llvm.org/D19536

llvm-svn: 268532
This commit is contained in:
Akira Hatanaka 2016-05-04 18:40:33 +00:00
parent cc9676a821
commit 1cce6e15c1
2 changed files with 46 additions and 25 deletions
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48
clang/lib/CodeGen/CGBlocks.cpp
View File

@ -780,35 +780,34 @@ llvm::Value *CodeGenFunction::EmitBlockLiteral(const CGBlockInfo &blockInfo) {
// Compute the address of the thing we're going to move into the
// block literal.
Address src = Address::invalid();
if (BlockInfo && CI.isNested()) {
// We need to use the capture from the enclosing block.
const CGBlockInfo::Capture &enclosingCapture =
BlockInfo->getCapture(variable);
// This is a [[type]]*, except that a byref entry wil just be an i8**.
src = Builder.CreateStructGEP(LoadBlockStruct(),
enclosingCapture.getIndex(),
enclosingCapture.getOffset(),
"block.capture.addr");
} else if (blockDecl->isConversionFromLambda()) {
if (blockDecl->isConversionFromLambda()) {
// The lambda capture in a lambda's conversion-to-block-pointer is
// special; we'll simply emit it directly.
src = Address::invalid();
} else {
// Just look it up in the locals map, which will give us back a
// [[type]]*. If that doesn't work, do the more elaborate DRE
// emission.
auto it = LocalDeclMap.find(variable);
if (it != LocalDeclMap.end()) {
src = it->second;
} else if (CI.isByRef()) {
if (BlockInfo && CI.isNested()) {
// We need to use the capture from the enclosing block.
const CGBlockInfo::Capture &enclosingCapture =
BlockInfo->getCapture(variable);
// This is a [[type]]*, except that a byref entry wil just be an i8**.
src = Builder.CreateStructGEP(LoadBlockStruct(),
enclosingCapture.getIndex(),
enclosingCapture.getOffset(),
"block.capture.addr");
} else {
DeclRefExpr declRef(
const_cast<VarDecl *>(variable),
/*RefersToEnclosingVariableOrCapture*/ CI.isNested(), type,
VK_LValue, SourceLocation());
src = EmitDeclRefLValue(&declRef).getAddress();
auto I = LocalDeclMap.find(variable);
assert(I != LocalDeclMap.end());
src = I->second;
}
}
} else {
DeclRefExpr declRef(const_cast<VarDecl *>(variable),
/*RefersToEnclosingVariableOrCapture*/ CI.isNested(),
type.getNonReferenceType(), VK_LValue,
SourceLocation());
src = EmitDeclRefLValue(&declRef).getAddress();
};
// For byrefs, we just write the pointer to the byref struct into
// the block field. There's no need to chase the forwarding
@ -842,8 +841,7 @@ llvm::Value *CodeGenFunction::EmitBlockLiteral(const CGBlockInfo &blockInfo) {
// If it's a reference variable, copy the reference into the block field.
} else if (type->isReferenceType()) {
llvm::Value *ref = Builder.CreateLoad(src, "ref.val");
Builder.CreateStore(ref, blockField);
Builder.CreateStore(src.getPointer(), blockField);
// If this is an ARC __strong block-pointer variable, don't do a
// block copy.

23
clang/test/CodeGenObjCXX/block-nested-in-lambda.cpp Normal file
View File

@ -0,0 +1,23 @@
// RUN: %clang_cc1 -triple=x86_64-apple-darwin10 -emit-llvm -std=c++11 -fblocks -o - %s | FileCheck %s
// CHECK: %[[BLOCK_CAPTURED0:.*]] = getelementptr inbounds <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i32*, i32* }>, <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i32*, i32* }>* %[[BLOCK:.*]], i32 0, i32 5
// CHECK: %[[V0:.*]] = getelementptr inbounds %[[LAMBDA_CLASS:.*]], %[[LAMBDA_CLASS]]* %[[THIS:.*]], i32 0, i32 0
// CHECK: %[[V1:.*]] = load i32*, i32** %[[V0]], align 8
// CHECK: store i32* %[[V1]], i32** %[[BLOCK_CAPTURED0]], align 8
// CHECK: %[[BLOCK_CAPTURED1:.*]] = getelementptr inbounds <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i32*, i32* }>, <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i32*, i32* }>* %[[BLOCK]], i32 0, i32 6
// CHECK: %[[V2:.*]] = getelementptr inbounds %[[LAMBDA_CLASS]], %[[LAMBDA_CLASS]]* %[[THIS]], i32 0, i32 1
// CHECK: %[[V3:.*]] = load i32*, i32** %[[V2]], align 8
// CHECK: store i32* %[[V3]], i32** %[[BLOCK_CAPTURED1]], align 8
void foo1(int &, int &);
void block_in_lambda(int &s1, int &s2) {
auto lambda = [&s1, &s2]() {
auto block = ^{
foo1(s1, s2);
};
block();
};
lambda();
}