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CodeGen: __uuidof should work even with an incomplete _GUID type

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Summary:
We would crash in CodeGen::CodeGenModule::EmitUuidofInitializer
because our attempt to enter CodeGen::CodeGenModule::EmitConstantValue
will be foiled: the type of the constant value is incomplete.

Instead, create an unnamed type with the proper layout on all platforms.
Punt the problem of wrongly defined struct _GUID types to the user.
(It's impossible because the TU may never get to see the type and thus
we can't verify that it is suitable.)

This fixes PR16856.

Reviewers: rsmith, rnk, thakis

Reviewed By: rnk

CC: cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D1375

llvm-svn: 188481
This commit is contained in:
David Majnemer
2013-08-15 19:59:14 +00:00
parent 313ae7009e
commit bbecd09658
4 changed files with 81 additions and 76 deletions
Download Patch File Download Diff File Expand all files Collapse all files

53
clang/lib/CodeGen/CodeGenModule.cpp
View File

@@ -1057,22 +1057,9 @@ llvm::Constant *CodeGenModule::GetAddrOfUuidDescriptor(
llvm::Constant *Init = EmitUuidofInitializer(Uuid, E->getType());
assert(Init && "failed to initialize as constant");
// GUIDs are assumed to be 16 bytes, spread over 4-2-2-8 bytes. However, the
// first field is declared as "long", which for many targets is 8 bytes.
// Those architectures are not supported. (With the MS abi, long is always 4
// bytes.)
llvm::Type *GuidType = getTypes().ConvertType(E->getType());
if (Init->getType() != GuidType) {
DiagnosticsEngine &Diags = getDiags();
unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
"__uuidof codegen is not supported on this architecture");
Diags.Report(E->getExprLoc(), DiagID) << E->getSourceRange();
Init = llvm::UndefValue::get(GuidType);
}
llvm::GlobalVariable *GV = new llvm::GlobalVariable(getModule(), GuidType,
llvm::GlobalVariable *GV = new llvm::GlobalVariable(
getModule(), Init->getType(),
/*isConstant=*/true, llvm::GlobalValue::ExternalLinkage, Init, Name);
GV->setUnnamedAddr(true);
return GV;
}
@@ -3077,26 +3064,24 @@ llvm::Constant *CodeGenModule::EmitUuidofInitializer(StringRef Uuid,
// Sema has checked that all uuid strings are of the form
// "12345678-1234-1234-1234-1234567890ab".
assert(Uuid.size() == 36);
const char *Uuidstr = Uuid.data();
for (int i = 0; i < 36; ++i) {
if (i == 8 || i == 13 || i == 18 || i == 23) assert(Uuidstr[i] == '-');
else assert(isHexDigit(Uuidstr[i]));
for (unsigned i = 0; i < 36; ++i) {
if (i == 8 || i == 13 || i == 18 || i == 23) assert(Uuid[i] == '-');
else assert(isHexDigit(Uuid[i]));
}
llvm::APInt Field0(32, StringRef(Uuidstr , 8), 16);
llvm::APInt Field1(16, StringRef(Uuidstr + 9, 4), 16);
llvm::APInt Field2(16, StringRef(Uuidstr + 14, 4), 16);
static const int Field3ValueOffsets[] = { 19, 21, 24, 26, 28, 30, 32, 34 };
APValue InitStruct(APValue::UninitStruct(), /*NumBases=*/0, /*NumFields=*/4);
InitStruct.getStructField(0) = APValue(llvm::APSInt(Field0));
InitStruct.getStructField(1) = APValue(llvm::APSInt(Field1));
InitStruct.getStructField(2) = APValue(llvm::APSInt(Field2));
APValue& Arr = InitStruct.getStructField(3);
Arr = APValue(APValue::UninitArray(), 8, 8);
for (int t = 0; t < 8; ++t)
Arr.getArrayInitializedElt(t) = APValue(llvm::APSInt(
llvm::APInt(8, StringRef(Uuidstr + Field3ValueOffsets[t], 2), 16)));
const unsigned Field3ValueOffsets[8] = { 19, 21, 24, 26, 28, 30, 32, 34 };
return EmitConstantValue(InitStruct, GuidType);
llvm::Constant *Field3[8];
for (unsigned Idx = 0; Idx < 8; ++Idx)
Field3[Idx] = llvm::ConstantInt::get(
Int8Ty, Uuid.substr(Field3ValueOffsets[Idx], 2), 16);
llvm::Constant *Fields[4] = {
llvm::ConstantInt::get(Int32Ty, Uuid.substr(0, 8), 16),
llvm::ConstantInt::get(Int16Ty, Uuid.substr(9, 4), 16),
llvm::ConstantInt::get(Int16Ty, Uuid.substr(14, 4), 16),
llvm::ConstantArray::get(llvm::ArrayType::get(Int8Ty, 8), Field3)
};
return llvm::ConstantStruct::getAnon(Fields);
}