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Factor duplicated implicit memcpy call generation code out of copy/move 

assignment generation. This incidentally avoids reusing the same Expr* across
multiple statements in the same object; that was generating slightly broken
ASTs, but I couldn't trigger any observable bad behavior, so no test.

llvm-svn: 167779
This commit is contained in:
Richard Smith 2012-11-12 23:33:00 +00:00
parent 8defc464d5
commit 11d1959ff2
1 changed files with 69 additions and 200 deletions
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269
clang/lib/Sema/SemaDeclCXX.cpp
View File

@ -7439,10 +7439,72 @@ void Sema::AdjustDestructorExceptionSpec(CXXRecordDecl *ClassDecl,
///
/// \returns A statement or a loop that copies the expressions.
static StmtResult
BuildSingleCopyAssign(Sema &S, SourceLocation Loc, QualType T,
BuildSingleCopyAssign(Sema &S, SourceLocation Loc, QualType T,
Expr *To, Expr *From,
bool CopyingBaseSubobject, bool Copying,
unsigned Depth = 0) {
// If the field should be copied with __builtin_memcpy rather than via
// explicit assignments, do so. This optimization only applies for arrays
// of scalars and arrays of class type with trivial copy-assignment
// operators.
QualType BaseType = S.Context.getBaseElementType(T);
if (T->isArrayType() && !T.isVolatileQualified()
&& BaseType.hasTrivialAssignment(S.Context, Copying)) {
// Compute the size of the memory buffer to be copied.
QualType SizeType = S.Context.getSizeType();
llvm::APInt Size(S.Context.getTypeSize(SizeType),
S.Context.getTypeSizeInChars(BaseType).getQuantity());
for (const ConstantArrayType *Array
= S.Context.getAsConstantArrayType(T);
Array;
Array = S.Context.getAsConstantArrayType(Array->getElementType())) {
llvm::APInt ArraySize
= Array->getSize().zextOrTrunc(Size.getBitWidth());
Size *= ArraySize;
}
// Take the address of the field references for "from" and "to". We
// directly construct UnaryOperators here because semantic analysis
// does not permit us to take the address of an xvalue.
From = new (S.Context) UnaryOperator(From, UO_AddrOf,
S.Context.getPointerType(From->getType()),
VK_RValue, OK_Ordinary, Loc);
To = new (S.Context) UnaryOperator(To, UO_AddrOf,
S.Context.getPointerType(To->getType()),
VK_RValue, OK_Ordinary, Loc);
bool NeedsCollectableMemCpy =
(BaseType->isRecordType() &&
BaseType->getAs<RecordType>()->getDecl()->hasObjectMember());
// Create a reference to the __builtin_objc_memmove_collectable function
StringRef MemCpyName = NeedsCollectableMemCpy ?
"__builtin_objc_memmove_collectable" :
"__builtin_memcpy";
LookupResult R(S, &S.Context.Idents.get(MemCpyName), Loc,
Sema::LookupOrdinaryName);
S.LookupName(R, S.TUScope, true);
FunctionDecl *MemCpy = R.getAsSingle<FunctionDecl>();
if (!MemCpy)
// Something went horribly wrong earlier, and we will have complained
// about it.
return StmtError();
ExprResult MemCpyRef = S.BuildDeclRefExpr(MemCpy, S.Context.BuiltinFnTy,
VK_RValue, Loc, 0);
assert(MemCpyRef.isUsable() && "Builtin reference cannot fail");
Expr *CallArgs[] = {
To, From, IntegerLiteral::Create(S.Context, Size, SizeType, Loc)
};
ExprResult Call = S.ActOnCallExpr(/*Scope=*/0, MemCpyRef.take(),
Loc, CallArgs, Loc);
assert(!Call.isInvalid() && "Call to __builtin_memcpy cannot fail!");
return S.Owned(Call.takeAs<Stmt>());
}
// C++0x [class.copy]p28:
// Each subobject is assigned in the manner appropriate to its type:
//
@ -7461,6 +7523,8 @@ BuildSingleCopyAssign(Sema &S, SourceLocation Loc, QualType T,
S.LookupQualifiedName(OpLookup, ClassDecl, false);
// Filter out any result that isn't a copy/move-assignment operator.
// FIXME: This is wrong in C++11. We should perform overload resolution
// instead here.
LookupResult::Filter F = OpLookup.makeFilter();
while (F.hasNext()) {
NamedDecl *D = F.next();
@ -7521,6 +7585,7 @@ BuildSingleCopyAssign(Sema &S, SourceLocation Loc, QualType T,
if (Call.isInvalid())
return StmtError();
// FIXME: ActOnFinishFullExpr, ActOnExprStmt.
return S.Owned(Call.takeAs<Stmt>());
}
@ -7907,11 +7972,6 @@ void Sema::DefineImplicitCopyAssignment(SourceLocation CurrentLocation,
Statements.push_back(Copy.takeAs<Expr>());
}
// \brief Reference to the __builtin_memcpy function.
Expr *BuiltinMemCpyRef = 0;
// \brief Reference to the __builtin_objc_memmove_collectable function.
Expr *CollectableMemCpyRef = 0;
// Assign non-static members.
for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
FieldEnd = ClassDecl->field_end();
@ -7969,99 +8029,9 @@ void Sema::DefineImplicitCopyAssignment(SourceLocation CurrentLocation,
MemberLookup, 0);
assert(!From.isInvalid() && "Implicit field reference cannot fail");
assert(!To.isInvalid() && "Implicit field reference cannot fail");
// If the field should be copied with __builtin_memcpy rather than via
// explicit assignments, do so. This optimization only applies for arrays
// of scalars and arrays of class type with trivial copy-assignment
// operators.
if (FieldType->isArrayType() && !FieldType.isVolatileQualified()
&& BaseType.hasTrivialAssignment(Context, /*Copying=*/true)) {
// Compute the size of the memory buffer to be copied.
QualType SizeType = Context.getSizeType();
llvm::APInt Size(Context.getTypeSize(SizeType),
Context.getTypeSizeInChars(BaseType).getQuantity());
for (const ConstantArrayType *Array
= Context.getAsConstantArrayType(FieldType);
Array;
Array = Context.getAsConstantArrayType(Array->getElementType())) {
llvm::APInt ArraySize
= Array->getSize().zextOrTrunc(Size.getBitWidth());
Size *= ArraySize;
}
// Take the address of the field references for "from" and "to".
From = CreateBuiltinUnaryOp(Loc, UO_AddrOf, From.get());
To = CreateBuiltinUnaryOp(Loc, UO_AddrOf, To.get());
bool NeedsCollectableMemCpy =
(BaseType->isRecordType() &&
BaseType->getAs<RecordType>()->getDecl()->hasObjectMember());
if (NeedsCollectableMemCpy) {
if (!CollectableMemCpyRef) {
// Create a reference to the __builtin_objc_memmove_collectable function.
LookupResult R(*this,
&Context.Idents.get("__builtin_objc_memmove_collectable"),
Loc, LookupOrdinaryName);
LookupName(R, TUScope, true);
FunctionDecl *CollectableMemCpy = R.getAsSingle<FunctionDecl>();
if (!CollectableMemCpy) {
// Something went horribly wrong earlier, and we will have
// complained about it.
Invalid = true;
continue;
}
CollectableMemCpyRef = BuildDeclRefExpr(CollectableMemCpy,
Context.BuiltinFnTy,
VK_RValue, Loc, 0).take();
assert(CollectableMemCpyRef && "Builtin reference cannot fail");
}
}
// Create a reference to the __builtin_memcpy builtin function.
else if (!BuiltinMemCpyRef) {
LookupResult R(*this, &Context.Idents.get("__builtin_memcpy"), Loc,
LookupOrdinaryName);
LookupName(R, TUScope, true);
FunctionDecl *BuiltinMemCpy = R.getAsSingle<FunctionDecl>();
if (!BuiltinMemCpy) {
// Something went horribly wrong earlier, and we will have complained
// about it.
Invalid = true;
continue;
}
BuiltinMemCpyRef = BuildDeclRefExpr(BuiltinMemCpy,
Context.BuiltinFnTy,
VK_RValue, Loc, 0).take();
assert(BuiltinMemCpyRef && "Builtin reference cannot fail");
}
SmallVector<Expr*, 8> CallArgs;
CallArgs.push_back(To.takeAs<Expr>());
CallArgs.push_back(From.takeAs<Expr>());
CallArgs.push_back(IntegerLiteral::Create(Context, Size, SizeType, Loc));
ExprResult Call = ExprError();
if (NeedsCollectableMemCpy)
Call = ActOnCallExpr(/*Scope=*/0,
CollectableMemCpyRef,
Loc, CallArgs,
Loc);
else
Call = ActOnCallExpr(/*Scope=*/0,
BuiltinMemCpyRef,
Loc, CallArgs,
Loc);
assert(!Call.isInvalid() && "Call to __builtin_memcpy cannot fail!");
Statements.push_back(Call.takeAs<Expr>());
continue;
}
// Build the copy of this field.
StmtResult Copy = BuildSingleCopyAssign(*this, Loc, FieldType,
StmtResult Copy = BuildSingleCopyAssign(*this, Loc, FieldType,
To.get(), From.get(),
/*CopyingBaseSubobject=*/false,
/*Copying=*/true);
@ -8446,11 +8416,6 @@ void Sema::DefineImplicitMoveAssignment(SourceLocation CurrentLocation,
Statements.push_back(Move.takeAs<Expr>());
}
// \brief Reference to the __builtin_memcpy function.
Expr *BuiltinMemCpyRef = 0;
// \brief Reference to the __builtin_objc_memmove_collectable function.
Expr *CollectableMemCpyRef = 0;
// Assign non-static members.
for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
FieldEnd = ClassDecl->field_end();
@ -8513,104 +8478,8 @@ void Sema::DefineImplicitMoveAssignment(SourceLocation CurrentLocation,
"Member reference with rvalue base must be rvalue except for reference "
"members, which aren't allowed for move assignment.");
// If the field should be copied with __builtin_memcpy rather than via
// explicit assignments, do so. This optimization only applies for arrays
// of scalars and arrays of class type with trivial move-assignment
// operators.
if (FieldType->isArrayType() && !FieldType.isVolatileQualified()
&& BaseType.hasTrivialAssignment(Context, /*Copying=*/false)) {
// Compute the size of the memory buffer to be copied.
QualType SizeType = Context.getSizeType();
llvm::APInt Size(Context.getTypeSize(SizeType),
Context.getTypeSizeInChars(BaseType).getQuantity());
for (const ConstantArrayType *Array
= Context.getAsConstantArrayType(FieldType);
Array;
Array = Context.getAsConstantArrayType(Array->getElementType())) {
llvm::APInt ArraySize
= Array->getSize().zextOrTrunc(Size.getBitWidth());
Size *= ArraySize;
}
// Take the address of the field references for "from" and "to". We
// directly construct UnaryOperators here because semantic analysis
// does not permit us to take the address of an xvalue.
From = new (Context) UnaryOperator(From.get(), UO_AddrOf,
Context.getPointerType(From.get()->getType()),
VK_RValue, OK_Ordinary, Loc);
To = new (Context) UnaryOperator(To.get(), UO_AddrOf,
Context.getPointerType(To.get()->getType()),
VK_RValue, OK_Ordinary, Loc);
bool NeedsCollectableMemCpy =
(BaseType->isRecordType() &&
BaseType->getAs<RecordType>()->getDecl()->hasObjectMember());
if (NeedsCollectableMemCpy) {
if (!CollectableMemCpyRef) {
// Create a reference to the __builtin_objc_memmove_collectable function.
LookupResult R(*this,
&Context.Idents.get("__builtin_objc_memmove_collectable"),
Loc, LookupOrdinaryName);
LookupName(R, TUScope, true);
FunctionDecl *CollectableMemCpy = R.getAsSingle<FunctionDecl>();
if (!CollectableMemCpy) {
// Something went horribly wrong earlier, and we will have
// complained about it.
Invalid = true;
continue;
}
CollectableMemCpyRef = BuildDeclRefExpr(CollectableMemCpy,
Context.BuiltinFnTy,
VK_RValue, Loc, 0).take();
assert(CollectableMemCpyRef && "Builtin reference cannot fail");
}
}
// Create a reference to the __builtin_memcpy builtin function.
else if (!BuiltinMemCpyRef) {
LookupResult R(*this, &Context.Idents.get("__builtin_memcpy"), Loc,
LookupOrdinaryName);
LookupName(R, TUScope, true);
FunctionDecl *BuiltinMemCpy = R.getAsSingle<FunctionDecl>();
if (!BuiltinMemCpy) {
// Something went horribly wrong earlier, and we will have complained
// about it.
Invalid = true;
continue;
}
BuiltinMemCpyRef = BuildDeclRefExpr(BuiltinMemCpy,
Context.BuiltinFnTy,
VK_RValue, Loc, 0).take();
assert(BuiltinMemCpyRef && "Builtin reference cannot fail");
}
SmallVector<Expr*, 8> CallArgs;
CallArgs.push_back(To.takeAs<Expr>());
CallArgs.push_back(From.takeAs<Expr>());
CallArgs.push_back(IntegerLiteral::Create(Context, Size, SizeType, Loc));
ExprResult Call = ExprError();
if (NeedsCollectableMemCpy)
Call = ActOnCallExpr(/*Scope=*/0,
CollectableMemCpyRef,
Loc, CallArgs,
Loc);
else
Call = ActOnCallExpr(/*Scope=*/0,
BuiltinMemCpyRef,
Loc, CallArgs,
Loc);
assert(!Call.isInvalid() && "Call to __builtin_memcpy cannot fail!");
Statements.push_back(Call.takeAs<Expr>());
continue;
}
// Build the move of this field.
StmtResult Move = BuildSingleCopyAssign(*this, Loc, FieldType,
StmtResult Move = BuildSingleCopyAssign(*this, Loc, FieldType,
To.get(), From.get(),
/*CopyingBaseSubobject=*/false,
/*Copying=*/false);
@ -8620,7 +8489,7 @@ void Sema::DefineImplicitMoveAssignment(SourceLocation CurrentLocation,
MoveAssignOperator->setInvalidDecl();
return;
}
// Success! Record the copy.
Statements.push_back(Move.takeAs<Stmt>());
}