shylie/llvm-project
1
0
Fork 0
Code Issues Pull Requests Actions 6 Packages Projects Releases Wiki Activity

When creating a this-adjustment thunk where the return value is of C++

Browse Source 
class type (that uses a return slot), pass the return slot to the
callee directly rather than allocating new storage and trying to copy
the object. This appears to have been the cause of the remaining two
Boost.Interprocess failures.

llvm-svn: 104215
This commit is contained in:
Douglas Gregor 2010-05-20 05:54:35 +00:00
parent c53cc4f8bf
commit aa2ac80eaa
2 changed files with 54 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
clang/lib/CodeGen/CGVTables.cpp
View File

@ -2657,8 +2657,15 @@ void CodeGenFunction::GenerateThunk(llvm::Function *Fn, GlobalDecl GD,
CGM.getTypes().getFunctionInfo(ResultType, CallArgs,
FPT->getExtInfo());
// Determine whether we have a return value slot to use.
ReturnValueSlot Slot;
if (!ResultType->isVoidType() &&
FnInfo.getReturnInfo().getKind() == ABIArgInfo::Indirect &&
hasAggregateLLVMType(CurFnInfo->getReturnType()))
Slot = ReturnValueSlot(ReturnValue, ResultType.isVolatileQualified());
// Now emit our call.
RValue RV = EmitCall(FnInfo, Callee, ReturnValueSlot(), CallArgs, MD);
RValue RV = EmitCall(FnInfo, Callee, Slot, CallArgs, MD);
if (!Thunk.Return.isEmpty()) {
// Emit the return adjustment.
@ -2701,7 +2708,7 @@ void CodeGenFunction::GenerateThunk(llvm::Function *Fn, GlobalDecl GD,
RV = RValue::get(ReturnValue);
}
if (!ResultType->isVoidType())
if (!ResultType->isVoidType() && Slot.isNull())
EmitReturnOfRValue(RV, ResultType);
FinishFunction();

49
clang/test/CodeGenCXX/thunks.cpp
View File

@ -86,10 +86,6 @@ void C::f() { }
}
// This is from Test5:
// CHECK: define linkonce_odr void @_ZTv0_n24_N5Test51B1fEv
// CHECK: define internal void @_ZThn8_N12_GLOBAL__N_11C1fEv(
// Check that the thunk gets internal linkage.
namespace {
@ -134,4 +130,49 @@ void f(B b) {
}
}
namespace Test6 {
struct X {
X();
X(const X&);
X &operator=(const X&);
~X();
};
struct P {
P();
P(const P&);
~P();
X first;
X second;
};
P getP();
struct Base1 {
int i;
virtual X f() { return X(); }
};
struct Base2 {
float real;
virtual X f() { return X(); }
};
struct Thunks : Base1, Base2 {
long l;
virtual X f();
};
// CHECK: define void @_ZThn16_N5Test66Thunks1fEv
// CHECK-NOT: memcpy
// CHECK: {{call void @_ZN5Test66Thunks1fEv.*sret}}
// CHECK: ret void
X Thunks::f() { return X(); }
}
// This is from Test5:
// CHECK: define linkonce_odr void @_ZTv0_n24_N5Test51B1fEv
// CHECK: define internal void @_ZThn8_N12_GLOBAL__N_11C1fEv(