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[SEH] Fix capture of this in lambda functions 

Commit 1b04bdc2f3 added support for
capturing the 'this' pointer in a SEH context (__finally or __except),
But the case in which the 'this' pointer is part of a lambda capture
was not handled properly

Differential Revision: https://reviews.llvm.org/D97687
This commit is contained in:
Olivier Goffart 2021-03-01 15:17:43 +01:00
parent aeaf705d5e
commit 5baea05601
2 changed files with 41 additions and 2 deletions
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21
clang/lib/CodeGen/CGException.cpp
View File

@ -1879,8 +1879,24 @@ void CodeGenFunction::EmitCapturedLocals(CodeGenFunction &ParentCGF,
setAddrOfLocalVar(VD, Recovered);
if (isa<ImplicitParamDecl>(VD)) {
CXXThisValue = Builder.CreateLoad(Recovered, "this");
CXXABIThisValue = CXXThisValue;
CXXABIThisAlignment = ParentCGF.CXXABIThisAlignment;
CXXThisAlignment = ParentCGF.CXXThisAlignment;
CXXABIThisValue = Builder.CreateLoad(Recovered, "this");
if (ParentCGF.LambdaThisCaptureField) {
LambdaThisCaptureField = ParentCGF.LambdaThisCaptureField;
// We are in a lambda function where "this" is captured so the
// CXXThisValue need to be loaded from the lambda capture
LValue ThisFieldLValue =
EmitLValueForLambdaField(LambdaThisCaptureField);
if (!LambdaThisCaptureField->getType()->isPointerType()) {
CXXThisValue = ThisFieldLValue.getAddress(*this).getPointer();
} else {
CXXThisValue = EmitLoadOfLValue(ThisFieldLValue, SourceLocation())
.getScalarVal();
}
} else {
CXXThisValue = CXXABIThisValue;
}
}
}
@ -1949,6 +1965,7 @@ void CodeGenFunction::startOutlinedSEHHelper(CodeGenFunction &ParentCGF,
StartFunction(GlobalDecl(), RetTy, Fn, FnInfo, Args,
OutlinedStmt->getBeginLoc(), OutlinedStmt->getBeginLoc());
CurSEHParent = ParentCGF.CurSEHParent;
CurCodeDecl = ParentCGF.CurCodeDecl;
CGM.SetInternalFunctionAttributes(GlobalDecl(), CurFn, FnInfo);
EmitCapturedLocals(ParentCGF, OutlinedStmt, IsFilter);

22
clang/test/CodeGenCXX/exceptions-seh-filter-captures.cpp
View File

@ -123,3 +123,25 @@ void test_lambda() {
// CHECK: %[[l1_ref:[^ ]*]] = load i32*, i32** %[[l1_ref_ptr]]
// CHECK: %[[l1:[^ ]*]] = load i32, i32* %[[l1_ref]]
// CHECK: call i32 (i32, ...) @basic_filter(i32 %[[l1]], i32 %[[l2]])
struct U {
void this_in_lambda();
};
void U::this_in_lambda() {
auto lambda = [=]() {
__try {
might_crash();
} __except (basic_filter(0, this)) {
}
};
lambda();
}
// CHECK-LABEL: define internal i32 @"?filt$0@0@?R<lambda_1>@?0??this_in_lambda@U@@QEAAXXZ@"(i8* %exception_pointers, i8* %frame_pointer)
// CHECK: %[[this_i8:[^ ]*]] = call i8* @llvm.localrecover(i8* bitcast (void (%class.anon.0*)* @"??R<lambda_1>@?0??this_in_lambda@U@@QEAAXXZ@QEBA@XZ" to i8*), i8* %[[fp:[^ ]*]], i32 0)
// CHECK: %[[this_ptr:[^ ]*]] = bitcast i8* %[[this_i8]] to %class.anon.0**
// CHECK: %[[this:[^ ]*]] = load %class.anon.0*, %class.anon.0** %[[this_ptr]], align 8
// CHECK: %[[actual_this_ptr:[^ ]*]] = getelementptr inbounds %class.anon.0, %class.anon.0* %[[this]], i32 0, i32 0
// CHECK: %[[actual_this:[^ ]*]] = load %struct.U*, %struct.U** %[[actual_this_ptr]], align 8
// CHECK: call i32 (i32, ...) @basic_filter(i32 0, %struct.U* %[[actual_this]])