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Add the alloc_size attribute to clang, attempt 2. 

This is a recommit of r290149, which was reverted in r290169 due to msan
failures. msan was failing because we were calling
`isMostDerivedAnUnsizedArray` on an invalid designator, which caused us
to read uninitialized memory. To fix this, the logic of the caller of
said function was simplified, and we now have a `!Invalid` assert in
`isMostDerivedAnUnsizedArray`, so we can catch this particular bug more
easily in the future.

Fingers crossed that this patch sticks this time. :)

Original commit message:

This patch does three things:
- Gives us the alloc_size attribute in clang, which lets us infer the
  number of bytes handed back to us by malloc/realloc/calloc/any user
  functions that act in a similar manner.
- Teaches our constexpr evaluator that evaluating some `const` variables
  is OK sometimes. This is why we have a change in
  test/SemaCXX/constant-expression-cxx11.cpp and other seemingly
  unrelated tests. Richard Smith okay'ed this idea some time ago in
  person.
- Uniques some Blocks in CodeGen, which was reviewed separately at
  D26410. Lack of uniquing only really shows up as a problem when
  combined with our new eagerness in the face of const.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@290297 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
George Burgess IV 2016-12-22 02:50:20 +00:00
parent a8bebbeb2b
commit aa365cb2fe
16 changed files with 1087 additions and 215 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
include/clang/Basic/Attr.td
View File

@ -780,6 +780,15 @@ def EmptyBases : InheritableAttr, TargetSpecificAttr<TargetMicrosoftCXXABI> {
let Documentation = [EmptyBasesDocs];
}
def AllocSize : InheritableAttr {
let Spellings = [GCC<"alloc_size">];
let Subjects = SubjectList<[HasFunctionProto], WarnDiag,
"ExpectedFunctionWithProtoType">;
let Args = [IntArgument<"ElemSizeParam">, IntArgument<"NumElemsParam", 1>];
let TemplateDependent = 1;
let Documentation = [AllocSizeDocs];
}
def EnableIf : InheritableAttr {
let Spellings = [GNU<"enable_if">];
let Subjects = SubjectList<[Function]>;

38
include/clang/Basic/AttrDocs.td
View File

@ -206,6 +206,44 @@ to enforce the provided alignment assumption.
}];
}
def AllocSizeDocs : Documentation {
let Category = DocCatFunction;
let Content = [{
The ``alloc_size`` attribute can be placed on functions that return pointers in
order to hint to the compiler how many bytes of memory will be available at the
returned poiner. ``alloc_size`` takes one or two arguments.
- ``alloc_size(N)`` implies that argument number N equals the number of
available bytes at the returned pointer.
- ``alloc_size(N, M)`` implies that the product of argument number N and
argument number M equals the number of available bytes at the returned
pointer.
Argument numbers are 1-based.
An example of how to use ``alloc_size``
.. code-block:: c
void *my_malloc(int a) __attribute__((alloc_size(1)));
void *my_calloc(int a, int b) __attribute__((alloc_size(1, 2)));
int main() {
void *const p = my_malloc(100);
assert(__builtin_object_size(p, 0) == 100);
void *const a = my_calloc(20, 5);
assert(__builtin_object_size(a, 0) == 100);
}
.. Note:: This attribute works differently in clang than it does in GCC.
Specifically, clang will only trace ``const`` pointers (as above); we give up
on pointers that are not marked as ``const``. In the vast majority of cases,
this is unimportant, because LLVM has support for the ``alloc_size``
attribute. However, this may cause mildly unintuitive behavior when used with
other attributes, such as ``enable_if``.
}];
}
def EnableIfDocs : Documentation {
let Category = DocCatFunction;
let Content = [{

3
include/clang/Basic/DiagnosticSemaKinds.td
View File

@ -2299,6 +2299,9 @@ def warn_attribute_pointers_only : Warning<
"%0 attribute only applies to%select{| constant}1 pointer arguments">,
InGroup<IgnoredAttributes>;
def err_attribute_pointers_only : Error<warn_attribute_pointers_only.Text>;
def err_attribute_integers_only : Error<
"%0 attribute argument may only refer to a function parameter of integer "
"type">;
def warn_attribute_return_pointers_only : Warning<
"%0 attribute only applies to return values that are pointers">,
InGroup<IgnoredAttributes>;

634
lib/AST/ExprConstant.cpp
View File

@ -109,19 +109,57 @@ namespace {
return getAsBaseOrMember(E).getInt();
}
/// Given a CallExpr, try to get the alloc_size attribute. May return null.
static const AllocSizeAttr *getAllocSizeAttr(const CallExpr *CE) {
const FunctionDecl *Callee = CE->getDirectCallee();
return Callee ? Callee->getAttr<AllocSizeAttr>() : nullptr;
}
/// Attempts to unwrap a CallExpr (with an alloc_size attribute) from an Expr.
/// This will look through a single cast.
///
/// Returns null if we couldn't unwrap a function with alloc_size.
static const CallExpr *tryUnwrapAllocSizeCall(const Expr *E) {
if (!E->getType()->isPointerType())
return nullptr;
E = E->IgnoreParens();
// If we're doing a variable assignment from e.g. malloc(N), there will
// probably be a cast of some kind. Ignore it.
if (const auto *Cast = dyn_cast<CastExpr>(E))
E = Cast->getSubExpr()->IgnoreParens();
if (const auto *CE = dyn_cast<CallExpr>(E))
return getAllocSizeAttr(CE) ? CE : nullptr;
return nullptr;
}
/// Determines whether or not the given Base contains a call to a function
/// with the alloc_size attribute.
static bool isBaseAnAllocSizeCall(APValue::LValueBase Base) {
const auto *E = Base.dyn_cast<const Expr *>();
return E && E->getType()->isPointerType() && tryUnwrapAllocSizeCall(E);
}
/// Determines if an LValue with the given LValueBase will have an unsized
/// array in its designator.
/// Find the path length and type of the most-derived subobject in the given
/// path, and find the size of the containing array, if any.
static
unsigned findMostDerivedSubobject(ASTContext &Ctx, QualType Base,
ArrayRef<APValue::LValuePathEntry> Path,
uint64_t &ArraySize, QualType &Type,
bool &IsArray) {
static unsigned
findMostDerivedSubobject(ASTContext &Ctx, APValue::LValueBase Base,
ArrayRef<APValue::LValuePathEntry> Path,
uint64_t &ArraySize, QualType &Type, bool &IsArray) {
// This only accepts LValueBases from APValues, and APValues don't support
// arrays that lack size info.
assert(!isBaseAnAllocSizeCall(Base) &&
"Unsized arrays shouldn't appear here");
unsigned MostDerivedLength = 0;
Type = Base;
Type = getType(Base);
for (unsigned I = 0, N = Path.size(); I != N; ++I) {
if (Type->isArrayType()) {
const ConstantArrayType *CAT =
cast<ConstantArrayType>(Ctx.getAsArrayType(Type));
cast<ConstantArrayType>(Ctx.getAsArrayType(Type));
Type = CAT->getElementType();
ArraySize = CAT->getSize().getZExtValue();
MostDerivedLength = I + 1;
@ -162,17 +200,23 @@ namespace {
/// Is this a pointer one past the end of an object?
unsigned IsOnePastTheEnd : 1;
/// Indicator of whether the first entry is an unsized array.
unsigned FirstEntryIsAnUnsizedArray : 1;
/// Indicator of whether the most-derived object is an array element.
unsigned MostDerivedIsArrayElement : 1;
/// The length of the path to the most-derived object of which this is a
/// subobject.
unsigned MostDerivedPathLength : 29;
unsigned MostDerivedPathLength : 28;
/// The size of the array of which the most-derived object is an element.
/// This will always be 0 if the most-derived object is not an array
/// element. 0 is not an indicator of whether or not the most-derived object
/// is an array, however, because 0-length arrays are allowed.
///
/// If the current array is an unsized array, the value of this is
/// undefined.
uint64_t MostDerivedArraySize;
/// The type of the most derived object referred to by this address.
@ -187,23 +231,24 @@ namespace {
explicit SubobjectDesignator(QualType T)
: Invalid(false), IsOnePastTheEnd(false),
MostDerivedIsArrayElement(false), MostDerivedPathLength(0),
MostDerivedArraySize(0), MostDerivedType(T) {}
FirstEntryIsAnUnsizedArray(false), MostDerivedIsArrayElement(false),
MostDerivedPathLength(0), MostDerivedArraySize(0),
MostDerivedType(T) {}
SubobjectDesignator(ASTContext &Ctx, const APValue &V)
: Invalid(!V.isLValue() || !V.hasLValuePath()), IsOnePastTheEnd(false),
MostDerivedIsArrayElement(false), MostDerivedPathLength(0),
MostDerivedArraySize(0) {
FirstEntryIsAnUnsizedArray(false), MostDerivedIsArrayElement(false),
MostDerivedPathLength(0), MostDerivedArraySize(0) {
assert(V.isLValue() && "Non-LValue used to make an LValue designator?");
if (!Invalid) {
IsOnePastTheEnd = V.isLValueOnePastTheEnd();
ArrayRef<PathEntry> VEntries = V.getLValuePath();
Entries.insert(Entries.end(), VEntries.begin(), VEntries.end());
if (V.getLValueBase()) {
bool IsArray = false;
MostDerivedPathLength =
findMostDerivedSubobject(Ctx, getType(V.getLValueBase()),
V.getLValuePath(), MostDerivedArraySize,
MostDerivedType, IsArray);
MostDerivedPathLength = findMostDerivedSubobject(
Ctx, V.getLValueBase(), V.getLValuePath(), MostDerivedArraySize,
MostDerivedType, IsArray);
MostDerivedIsArrayElement = IsArray;
}
}
@ -214,12 +259,26 @@ namespace {
Entries.clear();
}
/// Determine whether the most derived subobject is an array without a
/// known bound.
bool isMostDerivedAnUnsizedArray() const {
assert(!Invalid && "Calling this makes no sense on invalid designators");
return Entries.size() == 1 && FirstEntryIsAnUnsizedArray;
}
/// Determine what the most derived array's size is. Results in an assertion
/// failure if the most derived array lacks a size.
uint64_t getMostDerivedArraySize() const {
assert(!isMostDerivedAnUnsizedArray() && "Unsized array has no size");
return MostDerivedArraySize;
}
/// Determine whether this is a one-past-the-end pointer.
bool isOnePastTheEnd() const {
assert(!Invalid);
if (IsOnePastTheEnd)
return true;
if (MostDerivedIsArrayElement &&
if (!isMostDerivedAnUnsizedArray() && MostDerivedIsArrayElement &&
Entries[MostDerivedPathLength - 1].ArrayIndex == MostDerivedArraySize)
return true;
return false;
@ -247,6 +306,21 @@ namespace {
MostDerivedArraySize = CAT->getSize().getZExtValue();
MostDerivedPathLength = Entries.size();
}
/// Update this designator to refer to the first element within the array of
/// elements of type T. This is an array of unknown size.
void addUnsizedArrayUnchecked(QualType ElemTy) {
PathEntry Entry;
Entry.ArrayIndex = 0;
Entries.push_back(Entry);
MostDerivedType = ElemTy;
MostDerivedIsArrayElement = true;
// The value in MostDerivedArraySize is undefined in this case. So, set it
// to an arbitrary value that's likely to loudly break things if it's
// used.
MostDerivedArraySize = std::numeric_limits<uint64_t>::max() / 2;
MostDerivedPathLength = Entries.size();
}
/// Update this designator to refer to the given base or member of this
/// object.
void addDeclUnchecked(const Decl *D, bool Virtual = false) {
@ -280,10 +354,16 @@ namespace {
/// Add N to the address of this subobject.
void adjustIndex(EvalInfo &Info, const Expr *E, uint64_t N) {
if (Invalid) return;
if (isMostDerivedAnUnsizedArray()) {
// Can't verify -- trust that the user is doing the right thing (or if
// not, trust that the caller will catch the bad behavior).
Entries.back().ArrayIndex += N;
return;
}
if (MostDerivedPathLength == Entries.size() &&
MostDerivedIsArrayElement) {
Entries.back().ArrayIndex += N;
if (Entries.back().ArrayIndex > MostDerivedArraySize) {
if (Entries.back().ArrayIndex > getMostDerivedArraySize()) {
diagnosePointerArithmetic(Info, E, Entries.back().ArrayIndex);
setInvalid();
}
@ -524,9 +604,15 @@ namespace {
/// gets a chance to look at it.
EM_PotentialConstantExpressionUnevaluated,
/// Evaluate as a constant expression. Continue evaluating if we find a
/// MemberExpr with a base that can't be evaluated.
EM_DesignatorFold,
/// Evaluate as a constant expression. Continue evaluating if either:
/// - We find a MemberExpr with a base that can't be evaluated.
/// - We find a variable initialized with a call to a function that has
/// the alloc_size attribute on it.
/// In either case, the LValue returned shall have an invalid base; in the
/// former, the base will be the invalid MemberExpr, in the latter, the
/// base will be either the alloc_size CallExpr or a CastExpr wrapping
/// said CallExpr.
EM_OffsetFold,
} EvalMode;
/// Are we checking whether the expression is a potential constant
@ -628,7 +714,7 @@ namespace {
case EM_PotentialConstantExpression:
case EM_ConstantExpressionUnevaluated:
case EM_PotentialConstantExpressionUnevaluated:
case EM_DesignatorFold:
case EM_OffsetFold:
HasActiveDiagnostic = false;
return OptionalDiagnostic();
}
@ -720,7 +806,7 @@ namespace {
case EM_ConstantExpression:
case EM_ConstantExpressionUnevaluated:
case EM_ConstantFold:
case EM_DesignatorFold:
case EM_OffsetFold:
return false;
}
llvm_unreachable("Missed EvalMode case");
@ -739,7 +825,7 @@ namespace {
case EM_EvaluateForOverflow:
case EM_IgnoreSideEffects:
case EM_ConstantFold:
case EM_DesignatorFold:
case EM_OffsetFold:
return true;
case EM_PotentialConstantExpression:
@ -775,7 +861,7 @@ namespace {
case EM_ConstantExpressionUnevaluated:
case EM_ConstantFold:
case EM_IgnoreSideEffects:
case EM_DesignatorFold:
case EM_OffsetFold:
return false;
}
llvm_unreachable("Missed EvalMode case");
@ -805,7 +891,7 @@ namespace {
}
bool allowInvalidBaseExpr() const {
return EvalMode == EM_DesignatorFold;
return EvalMode == EM_OffsetFold;
}
class ArrayInitLoopIndex {
@ -856,11 +942,10 @@ namespace {
struct FoldOffsetRAII {
EvalInfo &Info;
EvalInfo::EvaluationMode OldMode;
explicit FoldOffsetRAII(EvalInfo &Info, bool Subobject)
explicit FoldOffsetRAII(EvalInfo &Info)
: Info(Info), OldMode(Info.EvalMode) {
if (!Info.checkingPotentialConstantExpression())
Info.EvalMode = Subobject ? EvalInfo::EM_DesignatorFold
: EvalInfo::EM_ConstantFold;
Info.EvalMode = EvalInfo::EM_OffsetFold;
}
~FoldOffsetRAII() { Info.EvalMode = OldMode; }
@ -966,10 +1051,12 @@ bool SubobjectDesignator::checkSubobject(EvalInfo &Info, const Expr *E,
void SubobjectDesignator::diagnosePointerArithmetic(EvalInfo &Info,
const Expr *E, uint64_t N) {
// If we're complaining, we must be able to statically determine the size of
// the most derived array.
if (MostDerivedPathLength == Entries.size() && MostDerivedIsArrayElement)
Info.CCEDiag(E, diag::note_constexpr_array_index)
<< static_cast<int>(N) << /*array*/ 0
<< static_cast<unsigned>(MostDerivedArraySize);
<< static_cast<unsigned>(getMostDerivedArraySize());
else
Info.CCEDiag(E, diag::note_constexpr_array_index)
<< static_cast<int>(N) << /*non-array*/ 1;
@ -1102,12 +1189,16 @@ namespace {
if (Designator.Invalid)
V = APValue(Base, Offset, APValue::NoLValuePath(), CallIndex,
IsNullPtr);
else
else {
assert(!InvalidBase && "APValues can't handle invalid LValue bases");
assert(!Designator.FirstEntryIsAnUnsizedArray &&
"Unsized array with a valid base?");
V = APValue(Base, Offset, Designator.Entries,
Designator.IsOnePastTheEnd, CallIndex, IsNullPtr);
}
}
void setFrom(ASTContext &Ctx, const APValue &V) {
assert(V.isLValue());
assert(V.isLValue() && "Setting LValue from a non-LValue?");
Base = V.getLValueBase();
Offset = V.getLValueOffset();
InvalidBase = false;
@ -1118,6 +1209,15 @@ namespace {
void set(APValue::LValueBase B, unsigned I = 0, bool BInvalid = false,
bool IsNullPtr_ = false, uint64_t Offset_ = 0) {
#ifndef NDEBUG
// We only allow a few types of invalid bases. Enforce that here.
if (BInvalid) {
const auto *E = B.get<const Expr *>();
assert((isa<MemberExpr>(E) || tryUnwrapAllocSizeCall(E)) &&
"Unexpected type of invalid base");
}
#endif
Base = B;
Offset = CharUnits::fromQuantity(Offset_);
InvalidBase = BInvalid;
@ -1157,6 +1257,13 @@ namespace {
if (checkSubobject(Info, E, isa<FieldDecl>(D) ? CSK_Field : CSK_Base))
Designator.addDeclUnchecked(D, Virtual);
}
void addUnsizedArray(EvalInfo &Info, QualType ElemTy) {
assert(Designator.Entries.empty() && getType(Base)->isPointerType());
assert(isBaseAnAllocSizeCall(Base) &&
"Only alloc_size bases can have unsized arrays");
Designator.FirstEntryIsAnUnsizedArray = true;
Designator.addUnsizedArrayUnchecked(ElemTy);
}
void addArray(EvalInfo &Info, const Expr *E, const ConstantArrayType *CAT) {
if (checkSubobject(Info, E, CSK_ArrayToPointer))
Designator.addArrayUnchecked(CAT);
@ -2796,7 +2903,7 @@ static CompleteObject findCompleteObject(EvalInfo &Info, const Expr *E,
// All the remaining cases only permit reading.
Info.FFDiag(E, diag::note_constexpr_modify_global);
return CompleteObject();
} else if (VD->isConstexpr()) {
} else if (VD->isConstexpr() || BaseType.isConstQualified()) {
// OK, we can read this variable.
} else if (BaseType->isIntegralOrEnumerationType()) {
// In OpenCL if a variable is in constant address space it is a const value.
@ -5079,6 +5186,105 @@ bool LValueExprEvaluator::VisitBinAssign(const BinaryOperator *E) {
// Pointer Evaluation
//===----------------------------------------------------------------------===//
/// \brief Attempts to compute the number of bytes available at the pointer
/// returned by a function with the alloc_size attribute. Returns true if we
/// were successful. Places an unsigned number into `Result`.
///
/// This expects the given CallExpr to be a call to a function with an
/// alloc_size attribute.
static bool getBytesReturnedByAllocSizeCall(const ASTContext &Ctx,
const CallExpr *Call,
llvm::APInt &Result) {
const AllocSizeAttr *AllocSize = getAllocSizeAttr(Call);
// alloc_size args are 1-indexed, 0 means not present.
assert(AllocSize && AllocSize->getElemSizeParam() != 0);
unsigned SizeArgNo = AllocSize->getElemSizeParam() - 1;
unsigned BitsInSizeT = Ctx.getTypeSize(Ctx.getSizeType());
if (Call->getNumArgs() <= SizeArgNo)
return false;
auto EvaluateAsSizeT = [&](const Expr *E, APSInt &Into) {
if (!E->EvaluateAsInt(Into, Ctx, Expr::SE_AllowSideEffects))
return false;
if (Into.isNegative() || !Into.isIntN(BitsInSizeT))
return false;
Into = Into.zextOrSelf(BitsInSizeT);
return true;
};
APSInt SizeOfElem;
if (!EvaluateAsSizeT(Call->getArg(SizeArgNo), SizeOfElem))
return false;
if (!AllocSize->getNumElemsParam()) {
Result = std::move(SizeOfElem);
return true;
}
APSInt NumberOfElems;
// Argument numbers start at 1
unsigned NumArgNo = AllocSize->getNumElemsParam() - 1;
if (!EvaluateAsSizeT(Call->getArg(NumArgNo), NumberOfElems))
return false;
bool Overflow;
llvm::APInt BytesAvailable = SizeOfElem.umul_ov(NumberOfElems, Overflow);
if (Overflow)
return false;
Result = std::move(BytesAvailable);
return true;
}
/// \brief Convenience function. LVal's base must be a call to an alloc_size
/// function.
static bool getBytesReturnedByAllocSizeCall(const ASTContext &Ctx,
const LValue &LVal,
llvm::APInt &Result) {
assert(isBaseAnAllocSizeCall(LVal.getLValueBase()) &&
"Can't get the size of a non alloc_size function");
const auto *Base = LVal.getLValueBase().get<const Expr *>();
const CallExpr *CE = tryUnwrapAllocSizeCall(Base);
return getBytesReturnedByAllocSizeCall(Ctx, CE, Result);
}
/// \brief Attempts to evaluate the given LValueBase as the result of a call to
/// a function with the alloc_size attribute. If it was possible to do so, this
/// function will return true, make Result's Base point to said function call,
/// and mark Result's Base as invalid.
static bool evaluateLValueAsAllocSize(EvalInfo &Info, APValue::LValueBase Base,
LValue &Result) {
if (!Info.allowInvalidBaseExpr() || Base.isNull())
return false;
// Because we do no form of static analysis, we only support const variables.
//
// Additionally, we can't support parameters, nor can we support static
// variables (in the latter case, use-before-assign isn't UB; in the former,
// we have no clue what they'll be assigned to).
const auto *VD =
dyn_cast_or_null<VarDecl>(Base.dyn_cast<const ValueDecl *>());
if (!VD || !VD->isLocalVarDecl() || !VD->getType().isConstQualified())
return false;
const Expr *Init = VD->getAnyInitializer();
if (!Init)
return false;
const Expr *E = Init->IgnoreParens();
if (!tryUnwrapAllocSizeCall(E))
return false;
// Store E instead of E unwrapped so that the type of the LValue's base is
// what the user wanted.
Result.setInvalid(E);
QualType Pointee = E->getType()->castAs<PointerType>()->getPointeeType();
Result.addUnsizedArray(Info, Pointee);
return true;
}
namespace {
class PointerExprEvaluator
: public ExprEvaluatorBase<PointerExprEvaluator> {
@ -5088,6 +5294,8 @@ class PointerExprEvaluator
Result.set(E);
return true;
}
bool visitNonBuiltinCallExpr(const CallExpr *E);
public:
PointerExprEvaluator(EvalInfo &info, LValue &Result)
@ -5270,6 +5478,19 @@ bool PointerExprEvaluator::VisitCastExpr(const CastExpr* E) {
case CK_FunctionToPointerDecay:
return EvaluateLValue(SubExpr, Result, Info);
case CK_LValueToRValue: {
LValue LVal;
if (!EvaluateLValue(E->getSubExpr(), LVal, Info))
return false;
APValue RVal;
// Note, we use the subexpression's type in order to retain cv-qualifiers.
if (!handleLValueToRValueConversion(Info, E, E->getSubExpr()->getType(),
LVal, RVal))
return evaluateLValueAsAllocSize(Info, LVal.Base, Result);
return Success(RVal, E);
}
}
return ExprEvaluatorBaseTy::VisitCastExpr(E);
@ -5307,6 +5528,20 @@ static CharUnits GetAlignOfExpr(EvalInfo &Info, const Expr *E) {
return GetAlignOfType(Info, E->getType());
}
// To be clear: this happily visits unsupported builtins. Better name welcomed.
bool PointerExprEvaluator::visitNonBuiltinCallExpr(const CallExpr *E) {
if (ExprEvaluatorBaseTy::VisitCallExpr(E))
return true;
if (!(Info.allowInvalidBaseExpr() && getAllocSizeAttr(E)))
return false;
Result.setInvalid(E);
QualType PointeeTy = E->getType()->castAs<PointerType>()->getPointeeType();
Result.addUnsizedArray(Info, PointeeTy);
return true;
}
bool PointerExprEvaluator::VisitCallExpr(const CallExpr *E) {
if (IsStringLiteralCall(E))
return Success(E);
@ -5314,7 +5549,7 @@ bool PointerExprEvaluator::VisitCallExpr(const CallExpr *E) {
if (unsigned BuiltinOp = E->getBuiltinCallee())
return VisitBuiltinCallExpr(E, BuiltinOp);
return ExprEvaluatorBaseTy::VisitCallExpr(E);
return visitNonBuiltinCallExpr(E);
}
bool PointerExprEvaluator::VisitBuiltinCallExpr(const CallExpr *E,
@ -5473,7 +5708,7 @@ bool PointerExprEvaluator::VisitBuiltinCallExpr(const CallExpr *E,
}
default:
return ExprEvaluatorBaseTy::VisitCallExpr(E);
return visitNonBuiltinCallExpr(E);
}
}
@ -6512,8 +6747,6 @@ public:
bool VisitCXXNoexceptExpr(const CXXNoexceptExpr *E);
bool VisitSizeOfPackExpr(const SizeOfPackExpr *E);
private:
bool TryEvaluateBuiltinObjectSize(const CallExpr *E, unsigned Type);
// FIXME: Missing: array subscript of vector, member of vector
};
} // end anonymous namespace
@ -6785,7 +7018,7 @@ static QualType getObjectType(APValue::LValueBase B) {
}
/// A more selective version of E->IgnoreParenCasts for
/// TryEvaluateBuiltinObjectSize. This ignores some casts/parens that serve only
/// tryEvaluateBuiltinObjectSize. This ignores some casts/parens that serve only
/// to change the type of E.
/// Ex. For E = `(short*)((char*)(&foo))`, returns `&foo`
///
@ -6852,165 +7085,132 @@ static bool isDesignatorAtObjectEnd(const ASTContext &Ctx, const LValue &LVal) {
}
}
unsigned I = 0;
QualType BaseType = getType(Base);
for (int I = 0, E = LVal.Designator.Entries.size(); I != E; ++I) {
if (LVal.Designator.FirstEntryIsAnUnsizedArray) {
assert(isBaseAnAllocSizeCall(Base) &&
"Unsized array in non-alloc_size call?");
// If this is an alloc_size base, we should ignore the initial array index
++I;
BaseType = BaseType->castAs<PointerType>()->getPointeeType();
}
for (unsigned E = LVal.Designator.Entries.size(); I != E; ++I) {
const auto &Entry = LVal.Designator.Entries[I];
if (BaseType->isArrayType()) {
// Because __builtin_object_size treats arrays as objects, we can ignore
// the index iff this is the last array in the Designator.
if (I + 1 == E)
return true;
auto *CAT = cast<ConstantArrayType>(Ctx.getAsArrayType(BaseType));
uint64_t Index = LVal.Designator.Entries[I].ArrayIndex;
const auto *CAT = cast<ConstantArrayType>(Ctx.getAsArrayType(BaseType));
uint64_t Index = Entry.ArrayIndex;
if (Index + 1 != CAT->getSize())
return false;
BaseType = CAT->getElementType();
} else if (BaseType->isAnyComplexType()) {
auto *CT = BaseType->castAs<ComplexType>();
uint64_t Index = LVal.Designator.Entries[I].ArrayIndex;
const auto *CT = BaseType->castAs<ComplexType>();
uint64_t Index = Entry.ArrayIndex;
if (Index != 1)
return false;
BaseType = CT->getElementType();
} else if (auto *FD = getAsField(LVal.Designator.Entries[I])) {
} else if (auto *FD = getAsField(Entry)) {
bool Invalid;
if (!IsLastOrInvalidFieldDecl(FD, Invalid))
return Invalid;
BaseType = FD->getType();
} else {
assert(getAsBaseClass(LVal.Designator.Entries[I]) != nullptr &&
"Expecting cast to a base class");
assert(getAsBaseClass(Entry) && "Expecting cast to a base class");
return false;
}
}
return true;
}
/// Tests to see if the LValue has a designator (that isn't necessarily valid).
/// Tests to see if the LValue has a user-specified designator (that isn't
/// necessarily valid). Note that this always returns 'true' if the LValue has
/// an unsized array as its first designator entry, because there's currently no
/// way to tell if the user typed *foo or foo[0].
static bool refersToCompleteObject(const LValue &LVal) {
if (LVal.Designator.Invalid || !LVal.Designator.Entries.empty())
if (LVal.Designator.Invalid)
return false;
if (!LVal.Designator.Entries.empty())
return LVal.Designator.isMostDerivedAnUnsizedArray();
if (!LVal.InvalidBase)
return true;
auto *E = LVal.Base.dyn_cast<const Expr *>();
(void)E;
assert(E != nullptr && isa<MemberExpr>(E));
return false;
// If `E` is a MemberExpr, then the first part of the designator is hiding in
// the LValueBase.
const auto *E = LVal.Base.dyn_cast<const Expr *>();
return !E || !isa<MemberExpr>(E);
}
/// Tries to evaluate the __builtin_object_size for @p E. If successful, returns
/// true and stores the result in @p Size.
/// Attempts to detect a user writing into a piece of memory that's impossible
/// to figure out the size of by just using types.
static bool isUserWritingOffTheEnd(const ASTContext &Ctx, const LValue &LVal) {
const SubobjectDesignator &Designator = LVal.Designator;
// Notes:
// - Users can only write off of the end when we have an invalid base. Invalid
// bases imply we don't know where the memory came from.
// - We used to be a bit more aggressive here; we'd only be conservative if
// the array at the end was flexible, or if it had 0 or 1 elements. This
// broke some common standard library extensions (PR30346), but was
// otherwise seemingly fine. It may be useful to reintroduce this behavior
// with some sort of whitelist. OTOH, it seems that GCC is always
// conservative with the last element in structs (if it's an array), so our
// current behavior is more compatible than a whitelisting approach would
// be.
return LVal.InvalidBase &&
Designator.Entries.size() == Designator.MostDerivedPathLength &&
Designator.MostDerivedIsArrayElement &&
isDesignatorAtObjectEnd(Ctx, LVal);
}
/// Converts the given APInt to CharUnits, assuming the APInt is unsigned.
/// Fails if the conversion would cause loss of precision.
static bool convertUnsignedAPIntToCharUnits(const llvm::APInt &Int,
CharUnits &Result) {
auto CharUnitsMax = std::numeric_limits<CharUnits::QuantityType>::max();
if (Int.ugt(CharUnitsMax))
return false;
Result = CharUnits::fromQuantity(Int.getZExtValue());
return true;
}
/// Helper for tryEvaluateBuiltinObjectSize -- Given an LValue, this will
/// determine how many bytes exist from the beginning of the object to either
/// the end of the current subobject, or the end of the object itself, depending
/// on what the LValue looks like + the value of Type.
///
/// If @p WasError is non-null, this will report whether the failure to evaluate
/// is to be treated as an Error in IntExprEvaluator.
static bool tryEvaluateBuiltinObjectSize(const Expr *E, unsigned Type,
EvalInfo &Info, uint64_t &Size,
bool *WasError = nullptr) {
if (WasError != nullptr)
*WasError = false;
/// If this returns false, the value of Result is undefined.
static bool determineEndOffset(EvalInfo &Info, SourceLocation ExprLoc,
unsigned Type, const LValue &LVal,
CharUnits &EndOffset) {
bool DetermineForCompleteObject = refersToCompleteObject(LVal);
auto Error = [&](const Expr *E) {
if (WasError != nullptr)
*WasError = true;
return false;
};
auto Success = [&](uint64_t S, const Expr *E) {
Size = S;
return true;
};
// Determine the denoted object.
LValue Base;
{
// The operand of __builtin_object_size is never evaluated for side-effects.
// If there are any, but we can determine the pointed-to object anyway, then
// ignore the side-effects.
SpeculativeEvaluationRAII SpeculativeEval(Info);
FoldOffsetRAII Fold(Info, Type & 1);
if (E->isGLValue()) {
// It's possible for us to be given GLValues if we're called via
// Expr::tryEvaluateObjectSize.
APValue RVal;
if (!EvaluateAsRValue(Info, E, RVal))
return false;
Base.setFrom(Info.Ctx, RVal);
} else if (!EvaluatePointer(ignorePointerCastsAndParens(E), Base, Info))
// We want to evaluate the size of the entire object. This is a valid fallback
// for when Type=1 and the designator is invalid, because we're asked for an
// upper-bound.
if (!(Type & 1) || LVal.Designator.Invalid || DetermineForCompleteObject) {
// Type=3 wants a lower bound, so we can't fall back to this.
if (Type == 3 && !DetermineForCompleteObject)
return false;
llvm::APInt APEndOffset;
if (isBaseAnAllocSizeCall(LVal.getLValueBase()) &&
getBytesReturnedByAllocSizeCall(Info.Ctx, LVal, APEndOffset))
return convertUnsignedAPIntToCharUnits(APEndOffset, EndOffset);
if (LVal.InvalidBase)
return false;
QualType BaseTy = getObjectType(LVal.getLValueBase());
return !BaseTy.isNull() && HandleSizeof(Info, ExprLoc, BaseTy, EndOffset);
}
CharUnits BaseOffset = Base.getLValueOffset();
// If we point to before the start of the object, there are no accessible
// bytes.
if (BaseOffset.isNegative())
return Success(0, E);
// In the case where we're not dealing with a subobject, we discard the
// subobject bit.
bool SubobjectOnly = (Type & 1) != 0 && !refersToCompleteObject(Base);
// If Type & 1 is 0, we need to be able to statically guarantee that the bytes
// exist. If we can't verify the base, then we can't do that.
//
// As a special case, we produce a valid object size for an unknown object
// with a known designator if Type & 1 is 1. For instance:
//
// extern struct X { char buff[32]; int a, b, c; } *p;
// int a = __builtin_object_size(p->buff + 4, 3); // returns 28
// int b = __builtin_object_size(p->buff + 4, 2); // returns 0, not 40
//
// This matches GCC's behavior.
if (Base.InvalidBase && !SubobjectOnly)
return Error(E);
// If we're not examining only the subobject, then we reset to a complete
// object designator
//
// If Type is 1 and we've lost track of the subobject, just find the complete
// object instead. (If Type is 3, that's not correct behavior and we should
// return 0 instead.)
LValue End = Base;
if (!SubobjectOnly || (End.Designator.Invalid && Type == 1)) {
QualType T = getObjectType(End.getLValueBase());
if (T.isNull())
End.Designator.setInvalid();
else {
End.Designator = SubobjectDesignator(T);
End.Offset = CharUnits::Zero();
}
}
// If it is not possible to determine which objects ptr points to at compile
// time, __builtin_object_size should return (size_t) -1 for type 0 or 1
// and (size_t) 0 for type 2 or 3.
if (End.Designator.Invalid)
return false;
// According to the GCC documentation, we want the size of the subobject
// denoted by the pointer. But that's not quite right -- what we actually
// want is the size of the immediately-enclosing array, if there is one.
int64_t AmountToAdd = 1;
if (End.Designator.MostDerivedIsArrayElement &&
End.Designator.Entries.size() == End.Designator.MostDerivedPathLength) {
// We got a pointer to an array. Step to its end.
AmountToAdd = End.Designator.MostDerivedArraySize -
End.Designator.Entries.back().ArrayIndex;
} else if (End.Designator.isOnePastTheEnd()) {
// We're already pointing at the end of the object.
AmountToAdd = 0;
}
QualType PointeeType = End.Designator.MostDerivedType;
assert(!PointeeType.isNull());
if (PointeeType->isIncompleteType() || PointeeType->isFunctionType())
return Error(E);
if (!HandleLValueArrayAdjustment(Info, E, End, End.Designator.MostDerivedType,
AmountToAdd))
return false;
auto EndOffset = End.getLValueOffset();
// We want to evaluate the size of a subobject.
const SubobjectDesignator &Designator = LVal.Designator;
// The following is a moderately common idiom in C:
//
@ -7018,39 +7218,88 @@ static bool tryEvaluateBuiltinObjectSize(const Expr *E, unsigned Type,
// struct Foo *F = (struct Foo *)malloc(sizeof(struct Foo) + strlen(Bar));
// strcpy(&F->c[0], Bar);
//
// So, if we see that we're examining an array at the end of a struct with an
// unknown base, we give up instead of breaking code that behaves this way.
// Note that we only do this when Type=1, because Type=3 is a lower bound, so
// answering conservatively is fine.
//
// We used to be a bit more aggressive here; we'd only be conservative if the
// array at the end was flexible, or if it had 0 or 1 elements. This broke
// some common standard library extensions (PR30346), but was otherwise
// seemingly fine. It may be useful to reintroduce this behavior with some
// sort of whitelist. OTOH, it seems that GCC is always conservative with the
// last element in structs (if it's an array), so our current behavior is more
// compatible than a whitelisting approach would be.
if (End.InvalidBase && SubobjectOnly && Type == 1 &&
End.Designator.Entries.size() == End.Designator.MostDerivedPathLength &&
End.Designator.MostDerivedIsArrayElement &&
isDesignatorAtObjectEnd(Info.Ctx, End))
// In order to not break too much legacy code, we need to support it.
if (isUserWritingOffTheEnd(Info.Ctx, LVal)) {
// If we can resolve this to an alloc_size call, we can hand that back,
// because we know for certain how many bytes there are to write to.
llvm::APInt APEndOffset;
if (isBaseAnAllocSizeCall(LVal.getLValueBase()) &&
getBytesReturnedByAllocSizeCall(Info.Ctx, LVal, APEndOffset))
return convertUnsignedAPIntToCharUnits(APEndOffset, EndOffset);
// If we cannot determine the size of the initial allocation, then we can't
// given an accurate upper-bound. However, we are still able to give
// conservative lower-bounds for Type=3.
if (Type == 1)
return false;
}
CharUnits BytesPerElem;
if (!HandleSizeof(Info, ExprLoc, Designator.MostDerivedType, BytesPerElem))
return false;
if (BaseOffset > EndOffset)
return Success(0, E);
// According to the GCC documentation, we want the size of the subobject
// denoted by the pointer. But that's not quite right -- what we actually
// want is the size of the immediately-enclosing array, if there is one.
int64_t ElemsRemaining;
if (Designator.MostDerivedIsArrayElement &&
Designator.Entries.size() == Designator.MostDerivedPathLength) {
uint64_t ArraySize = Designator.getMostDerivedArraySize();
uint64_t ArrayIndex = Designator.Entries.back().ArrayIndex;
ElemsRemaining = ArraySize <= ArrayIndex ? 0 : ArraySize - ArrayIndex;
} else {
ElemsRemaining = Designator.isOnePastTheEnd() ? 0 : 1;
}
return Success((EndOffset - BaseOffset).getQuantity(), E);
EndOffset = LVal.getLValueOffset() + BytesPerElem * ElemsRemaining;
return true;
}
bool IntExprEvaluator::TryEvaluateBuiltinObjectSize(const CallExpr *E,
unsigned Type) {
uint64_t Size;
bool WasError;
if (::tryEvaluateBuiltinObjectSize(E->getArg(0), Type, Info, Size, &WasError))
return Success(Size, E);
if (WasError)
return Error(E);
return false;
/// \brief Tries to evaluate the __builtin_object_size for @p E. If successful,
/// returns true and stores the result in @p Size.
///
/// If @p WasError is non-null, this will report whether the failure to evaluate
/// is to be treated as an Error in IntExprEvaluator.
static bool tryEvaluateBuiltinObjectSize(const Expr *E, unsigned Type,
EvalInfo &Info, uint64_t &Size) {
// Determine the denoted object.
LValue LVal;
{
// The operand of __builtin_object_size is never evaluated for side-effects.
// If there are any, but we can determine the pointed-to object anyway, then
// ignore the side-effects.
SpeculativeEvaluationRAII SpeculativeEval(Info);
FoldOffsetRAII Fold(Info);
if (E->isGLValue()) {
// It's possible for us to be given GLValues if we're called via
// Expr::tryEvaluateObjectSize.
APValue RVal;
if (!EvaluateAsRValue(Info, E, RVal))
return false;
LVal.setFrom(Info.Ctx, RVal);
} else if (!EvaluatePointer(ignorePointerCastsAndParens(E), LVal, Info))
return false;
}
// If we point to before the start of the object, there are no accessible
// bytes.
if (LVal.getLValueOffset().isNegative()) {
Size = 0;
return true;
}
CharUnits EndOffset;
if (!determineEndOffset(Info, E->getExprLoc(), Type, LVal, EndOffset))
return false;
// If we've fallen outside of the end offset, just pretend there's nothing to
// write to/read from.
if (EndOffset <= LVal.getLValueOffset())
Size = 0;
else
Size = (EndOffset - LVal.getLValueOffset()).getQuantity();
return true;
}
bool IntExprEvaluator::VisitCallExpr(const CallExpr *E) {
@ -7072,8 +7321,9 @@ bool IntExprEvaluator::VisitBuiltinCallExpr(const CallExpr *E,
E->getArg(1)->EvaluateKnownConstInt(Info.Ctx).getZExtValue();
assert(Type <= 3 && "unexpected type");
if (TryEvaluateBuiltinObjectSize(E, Type))
return true;
uint64_t Size;
if (tryEvaluateBuiltinObjectSize(E->getArg(0), Type, Info, Size))
return Success(Size, E);
if (E->getArg(0)->HasSideEffects(Info.Ctx))
return Success((Type & 2) ? 0 : -1, E);
@ -7086,7 +7336,7 @@ bool IntExprEvaluator::VisitBuiltinCallExpr(const CallExpr *E,
case EvalInfo::EM_ConstantFold:
case EvalInfo::EM_EvaluateForOverflow:
case EvalInfo::EM_IgnoreSideEffects:
case EvalInfo::EM_DesignatorFold:
case EvalInfo::EM_OffsetFold:
// Leave it to IR generation.
return Error(E);
case EvalInfo::EM_ConstantExpressionUnevaluated:
@ -10189,5 +10439,5 @@ bool Expr::tryEvaluateObjectSize(uint64_t &Result, ASTContext &Ctx,
Expr::EvalStatus Status;
EvalInfo Info(Ctx, Status, EvalInfo::EM_ConstantFold);
return ::tryEvaluateBuiltinObjectSize(this, Type, Info, Result);
return tryEvaluateBuiltinObjectSize(this, Type, Info, Result);
}

24
lib/CodeGen/CGBlocks.cpp
View File

@ -686,6 +686,8 @@ llvm::Value *CodeGenFunction::EmitBlockLiteral(const BlockExpr *blockExpr) {
// If the block has no captures, we won't have a pre-computed
// layout for it.
if (!blockExpr->getBlockDecl()->hasCaptures()) {
if (llvm::Constant *Block = CGM.getAddrOfGlobalBlockIfEmitted(blockExpr))
return Block;
CGBlockInfo blockInfo(blockExpr->getBlockDecl(), CurFn->getName());
computeBlockInfo(CGM, this, blockInfo);
blockInfo.BlockExpression = blockExpr;
@ -1047,9 +1049,19 @@ Address CodeGenFunction::GetAddrOfBlockDecl(const VarDecl *variable,
return addr;
}
void CodeGenModule::setAddrOfGlobalBlock(const BlockExpr *BE,
llvm::Constant *Addr) {
bool Ok = EmittedGlobalBlocks.insert(std::make_pair(BE, Addr)).second;
(void)Ok;
assert(Ok && "Trying to replace an already-existing global block!");
}
llvm::Constant *
CodeGenModule::GetAddrOfGlobalBlock(const BlockExpr *BE,
StringRef Name) {
if (llvm::Constant *Block = getAddrOfGlobalBlockIfEmitted(BE))
return Block;
CGBlockInfo blockInfo(BE->getBlockDecl(), Name);
blockInfo.BlockExpression = BE;
@ -1074,6 +1086,11 @@ static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM,
const CGBlockInfo &blockInfo,
llvm::Constant *blockFn) {
assert(blockInfo.CanBeGlobal);
// Callers should detect this case on their own: calling this function
// generally requires computing layout information, which is a waste of time
// if we've already emitted this block.
assert(!CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression) &&
"Refusing to re-emit a global block.");
// Generate the constants for the block literal initializer.
ConstantInitBuilder builder(CGM);
@ -1103,9 +1120,12 @@ static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM,
/*constant*/ true);
// Return a constant of the appropriately-casted type.
llvm::Type *requiredType =
llvm::Type *RequiredType =
CGM.getTypes().ConvertType(blockInfo.getBlockExpr()->getType());
return llvm::ConstantExpr::getBitCast(literal, requiredType);
llvm::Constant *Result =
llvm::ConstantExpr::getBitCast(literal, RequiredType);
CGM.setAddrOfGlobalBlock(blockInfo.BlockExpression, Result);
return Result;
}
void CodeGenFunction::setBlockContextParameter(const ImplicitParamDecl *D,

8
lib/CodeGen/CGCall.cpp
View File

@ -1683,6 +1683,14 @@ void CodeGenModule::ConstructAttributeList(
HasAnyX86InterruptAttr = TargetDecl->hasAttr<AnyX86InterruptAttr>();
HasOptnone = TargetDecl->hasAttr<OptimizeNoneAttr>();
if (auto *AllocSize = TargetDecl->getAttr<AllocSizeAttr>()) {
Optional<unsigned> NumElemsParam;
// alloc_size args are base-1, 0 means not present.
if (unsigned N = AllocSize->getNumElemsParam())
NumElemsParam = N - 1;
FuncAttrs.addAllocSizeAttr(AllocSize->getElemSizeParam() - 1,
NumElemsParam);
}
}
// OptimizeNoneAttr takes precedence over -Os or -Oz. No warning needed.

4
lib/CodeGen/CodeGenFunction.h
View File

@ -1499,7 +1499,6 @@ public:
//===--------------------------------------------------------------------===//
llvm::Value *EmitBlockLiteral(const BlockExpr *);
llvm::Value *EmitBlockLiteral(const CGBlockInfo &Info);
static void destroyBlockInfos(CGBlockInfo *info);
llvm::Function *GenerateBlockFunction(GlobalDecl GD,
@ -2726,6 +2725,9 @@ public:
OMPPrivateScope &LoopScope);
private:
/// Helpers for blocks
llvm::Value *EmitBlockLiteral(const CGBlockInfo &Info);
/// Helpers for the OpenMP loop directives.
void EmitOMPLoopBody(const OMPLoopDirective &D, JumpDest LoopExit);
void EmitOMPSimdInit(const OMPLoopDirective &D, bool IsMonotonic = false);

14
lib/CodeGen/CodeGenModule.h
View File

@ -455,6 +455,10 @@ private:
bool isTriviallyRecursive(const FunctionDecl *F);
bool shouldEmitFunction(GlobalDecl GD);
/// Map of the global blocks we've emitted, so that we don't have to re-emit
/// them if the constexpr evaluator gets aggressive.
llvm::DenseMap<const BlockExpr *, llvm::Constant *> EmittedGlobalBlocks;
/// @name Cache for Blocks Runtime Globals
/// @{
@ -776,6 +780,16 @@ public:
/// Gets the address of a block which requires no captures.
llvm::Constant *GetAddrOfGlobalBlock(const BlockExpr *BE, StringRef Name);
/// Returns the address of a block which requires no caputres, or null if
/// we've yet to emit the block for BE.
llvm::Constant *getAddrOfGlobalBlockIfEmitted(const BlockExpr *BE) {
return EmittedGlobalBlocks.lookup(BE);
}
/// Notes that BE's global block is available via Addr. Asserts that BE
/// isn't already emitted.
void setAddrOfGlobalBlock(const BlockExpr *BE, llvm::Constant *Addr);
/// Return a pointer to a constant CFString object for the given string.
ConstantAddress GetAddrOfConstantCFString(const StringLiteral *Literal);

88
lib/Sema/SemaDeclAttr.cpp
View File

@ -246,6 +246,28 @@ static bool checkUInt32Argument(Sema &S, const AttributeList &Attr,
return true;
}
/// \brief Wrapper around checkUInt32Argument, with an extra check to be sure
/// that the result will fit into a regular (signed) int. All args have the same
/// purpose as they do in checkUInt32Argument.
static bool checkPositiveIntArgument(Sema &S, const AttributeList &Attr,
const Expr *Expr, int &Val,
unsigned Idx = UINT_MAX) {
uint32_t UVal;
if (!checkUInt32Argument(S, Attr, Expr, UVal, Idx))
return false;
if (UVal > std::numeric_limits<int>::max()) {
llvm::APSInt I(32); // for toString
I = UVal;
S.Diag(Expr->getExprLoc(), diag::err_ice_too_large)
<< I.toString(10, false) << 32 << /* Unsigned */ 0;
return false;
}
Val = UVal;
return true;
}
/// \brief Diagnose mutually exclusive attributes when present on a given
/// declaration. Returns true if diagnosed.
template <typename AttrTy>
@ -730,6 +752,69 @@ static void handleAssertExclusiveLockAttr(Sema &S, Decl *D,
Attr.getAttributeSpellingListIndex()));
}
/// \brief Checks to be sure that the given parameter number is inbounds, and is
/// an some integral type. Will emit appropriate diagnostics if this returns
/// false.
///
/// FuncParamNo is expected to be from the user, so is base-1. AttrArgNo is used
/// to actually retrieve the argument, so it's base-0.
static bool checkParamIsIntegerType(Sema &S, const FunctionDecl *FD,
const AttributeList &Attr,
unsigned FuncParamNo, unsigned AttrArgNo) {
assert(Attr.isArgExpr(AttrArgNo) && "Expected expression argument");
uint64_t Idx;
if (!checkFunctionOrMethodParameterIndex(S, FD, Attr, FuncParamNo,
Attr.getArgAsExpr(AttrArgNo), Idx))
return false;
const ParmVarDecl *Param = FD->getParamDecl(Idx);
if (!Param->getType()->isIntegerType() && !Param->getType()->isCharType()) {
SourceLocation SrcLoc = Attr.getArgAsExpr(AttrArgNo)->getLocStart();
S.Diag(SrcLoc, diag::err_attribute_integers_only)
<< Attr.getName() << Param->getSourceRange();
return false;
}
return true;
}
static void handleAllocSizeAttr(Sema &S, Decl *D, const AttributeList &Attr) {
if (!checkAttributeAtLeastNumArgs(S, Attr, 1) ||
!checkAttributeAtMostNumArgs(S, Attr, 2))
return;
const auto *FD = cast<FunctionDecl>(D);
if (!FD->getReturnType()->isPointerType()) {
S.Diag(Attr.getLoc(), diag::warn_attribute_return_pointers_only)
<< Attr.getName();
return;
}
const Expr *SizeExpr = Attr.getArgAsExpr(0);
int SizeArgNo;
// Paramater indices are 1-indexed, hence Index=1
if (!checkPositiveIntArgument(S, Attr, SizeExpr, SizeArgNo, /*Index=*/1))
return;
if (!checkParamIsIntegerType(S, FD, Attr, SizeArgNo, /*AttrArgNo=*/0))
return;
// Args are 1-indexed, so 0 implies that the arg was not present
int NumberArgNo = 0;
if (Attr.getNumArgs() == 2) {
const Expr *NumberExpr = Attr.getArgAsExpr(1);
// Paramater indices are 1-based, hence Index=2
if (!checkPositiveIntArgument(S, Attr, NumberExpr, NumberArgNo,
/*Index=*/2))
return;
if (!checkParamIsIntegerType(S, FD, Attr, NumberArgNo, /*AttrArgNo=*/1))
return;
}
D->addAttr(::new (S.Context) AllocSizeAttr(
Attr.getRange(), S.Context, SizeArgNo, NumberArgNo,
Attr.getAttributeSpellingListIndex()));
}
static bool checkTryLockFunAttrCommon(Sema &S, Decl *D,
const AttributeList &Attr,
@ -5552,6 +5637,9 @@ static void ProcessDeclAttribute(Sema &S, Scope *scope, Decl *D,
case AttributeList::AT_AlignValue:
handleAlignValueAttr(S, D, Attr);
break;
case AttributeList::AT_AllocSize:
handleAllocSizeAttr(S, D, Attr);
break;
case AttributeList::AT_AlwaysInline:
handleAlwaysInlineAttr(S, D, Attr);
break;

352
test/CodeGen/alloc-size.c Normal file
View File

@ -0,0 +1,352 @@
// RUN: %clang_cc1 -triple x86_64-apple-darwin -emit-llvm %s -o - 2>&1 | FileCheck %s
#define NULL ((void *)0)
int gi;
typedef unsigned long size_t;
// CHECK-DAG-RE: define void @my_malloc({{.*}}) #[[MALLOC_ATTR_NUMBER:[0-9]+]]
// N.B. LLVM's allocsize arguments are base-0, whereas ours are base-1 (for
// compat with GCC)
// CHECK-DAG-RE: attributes #[[MALLOC_ATTR_NUMBER]] = {.*allocsize(0).*}
void *my_malloc(size_t) __attribute__((alloc_size(1)));
// CHECK-DAG-RE: define void @my_calloc({{.*}}) #[[CALLOC_ATTR_NUMBER:[0-9]+]]
// CHECK-DAG-RE: attributes #[[CALLOC_ATTR_NUMBER]] = {.*allocsize(0, 1).*}
void *my_calloc(size_t, size_t) __attribute__((alloc_size(1, 2)));
// CHECK-LABEL: @test1
void test1() {
void *const vp = my_malloc(100);
// CHECK: store i32 100
gi = __builtin_object_size(vp, 0);
// CHECK: store i32 100
gi = __builtin_object_size(vp, 1);
// CHECK: store i32 100
gi = __builtin_object_size(vp, 2);
// CHECK: store i32 100
gi = __builtin_object_size(vp, 3);
void *const arr = my_calloc(100, 5);
// CHECK: store i32 500
gi = __builtin_object_size(arr, 0);
// CHECK: store i32 500
gi = __builtin_object_size(arr, 1);
// CHECK: store i32 500
gi = __builtin_object_size(arr, 2);
// CHECK: store i32 500
gi = __builtin_object_size(arr, 3);
// CHECK: store i32 100
gi = __builtin_object_size(my_malloc(100), 0);
// CHECK: store i32 100
gi = __builtin_object_size(my_malloc(100), 1);
// CHECK: store i32 100
gi = __builtin_object_size(my_malloc(100), 2);
// CHECK: store i32 100
gi = __builtin_object_size(my_malloc(100), 3);
// CHECK: store i32 500
gi = __builtin_object_size(my_calloc(100, 5), 0);
// CHECK: store i32 500
gi = __builtin_object_size(my_calloc(100, 5), 1);
// CHECK: store i32 500
gi = __builtin_object_size(my_calloc(100, 5), 2);
// CHECK: store i32 500
gi = __builtin_object_size(my_calloc(100, 5), 3);
void *const zeroPtr = my_malloc(0);
// CHECK: store i32 0
gi = __builtin_object_size(zeroPtr, 0);
// CHECK: store i32 0
gi = __builtin_object_size(my_malloc(0), 0);
void *const zeroArr1 = my_calloc(0, 1);
void *const zeroArr2 = my_calloc(1, 0);
// CHECK: store i32 0
gi = __builtin_object_size(zeroArr1, 0);
// CHECK: store i32 0
gi = __builtin_object_size(zeroArr2, 0);
// CHECK: store i32 0
gi = __builtin_object_size(my_calloc(1, 0), 0);
// CHECK: store i32 0
gi = __builtin_object_size(my_calloc(0, 1), 0);
}
// CHECK-LABEL: @test2
void test2() {
void *const vp = my_malloc(gi);
// CHECK: @llvm.objectsize
gi = __builtin_object_size(vp, 0);
void *const arr1 = my_calloc(gi, 1);
// CHECK: @llvm.objectsize
gi = __builtin_object_size(arr1, 0);
void *const arr2 = my_calloc(1, gi);
// CHECK: @llvm.objectsize
gi = __builtin_object_size(arr2, 0);
}
// CHECK-LABEL: @test3
void test3() {
char *const buf = (char *)my_calloc(100, 5);
// CHECK: store i32 500
gi = __builtin_object_size(buf, 0);
// CHECK: store i32 500
gi = __builtin_object_size(buf, 1);
// CHECK: store i32 500
gi = __builtin_object_size(buf, 2);
// CHECK: store i32 500
gi = __builtin_object_size(buf, 3);
}
struct Data {
int a;
int t[10];
char pad[3];
char end[1];
};
// CHECK-LABEL: @test5
void test5() {
struct Data *const data = my_malloc(sizeof(*data));
// CHECK: store i32 48
gi = __builtin_object_size(data, 0);
// CHECK: store i32 48
gi = __builtin_object_size(data, 1);
// CHECK: store i32 48
gi = __builtin_object_size(data, 2);
// CHECK: store i32 48
gi = __builtin_object_size(data, 3);
// CHECK: store i32 40
gi = __builtin_object_size(&data->t[1], 0);
// CHECK: store i32 36
gi = __builtin_object_size(&data->t[1], 1);
// CHECK: store i32 40
gi = __builtin_object_size(&data->t[1], 2);
// CHECK: store i32 36
gi = __builtin_object_size(&data->t[1], 3);
struct Data *const arr = my_calloc(sizeof(*data), 2);
// CHECK: store i32 96
gi = __builtin_object_size(arr, 0);
// CHECK: store i32 96
gi = __builtin_object_size(arr, 1);
// CHECK: store i32 96
gi = __builtin_object_size(arr, 2);
// CHECK: store i32 96
gi = __builtin_object_size(arr, 3);
// CHECK: store i32 88
gi = __builtin_object_size(&arr->t[1], 0);
// CHECK: store i32 36
gi = __builtin_object_size(&arr->t[1], 1);
// CHECK: store i32 88
gi = __builtin_object_size(&arr->t[1], 2);
// CHECK: store i32 36
gi = __builtin_object_size(&arr->t[1], 3);
}
// CHECK-LABEL: @test6
void test6() {
// Things that would normally trigger conservative estimates don't need to do
// so when we know the source of the allocation.
struct Data *const data = my_malloc(sizeof(*data) + 10);
// CHECK: store i32 11
gi = __builtin_object_size(data->end, 0);
// CHECK: store i32 11
gi = __builtin_object_size(data->end, 1);
// CHECK: store i32 11
gi = __builtin_object_size(data->end, 2);
// CHECK: store i32 11
gi = __builtin_object_size(data->end, 3);
struct Data *const arr = my_calloc(sizeof(*arr) + 5, 3);
// AFAICT, GCC treats malloc and calloc identically. So, we should do the
// same.
//
// Additionally, GCC ignores the initial array index when determining whether
// we're writing off the end of an alloc_size base. e.g.
// arr[0].end
// arr[1].end
// arr[2].end
// ...Are all considered "writing off the end", because there's no way to tell
// with high accuracy if the user meant "allocate a single N-byte `Data`",
// or "allocate M smaller `Data`s with extra padding".
// CHECK: store i32 112
gi = __builtin_object_size(arr->end, 0);
// CHECK: store i32 112
gi = __builtin_object_size(arr->end, 1);
// CHECK: store i32 112
gi = __builtin_object_size(arr->end, 2);
// CHECK: store i32 112
gi = __builtin_object_size(arr->end, 3);
// CHECK: store i32 112
gi = __builtin_object_size(arr[0].end, 0);
// CHECK: store i32 112
gi = __builtin_object_size(arr[0].end, 1);
// CHECK: store i32 112
gi = __builtin_object_size(arr[0].end, 2);
// CHECK: store i32 112
gi = __builtin_object_size(arr[0].end, 3);
// CHECK: store i32 64
gi = __builtin_object_size(arr[1].end, 0);
// CHECK: store i32 64
gi = __builtin_object_size(arr[1].end, 1);
// CHECK: store i32 64
gi = __builtin_object_size(arr[1].end, 2);
// CHECK: store i32 64
gi = __builtin_object_size(arr[1].end, 3);
// CHECK: store i32 16
gi = __builtin_object_size(arr[2].end, 0);
// CHECK: store i32 16
gi = __builtin_object_size(arr[2].end, 1);
// CHECK: store i32 16
gi = __builtin_object_size(arr[2].end, 2);
// CHECK: store i32 16
gi = __builtin_object_size(arr[2].end, 3);
}
// CHECK-LABEL: @test7
void test7() {
struct Data *const data = my_malloc(sizeof(*data) + 5);
// CHECK: store i32 9
gi = __builtin_object_size(data->pad, 0);
// CHECK: store i32 3
gi = __builtin_object_size(data->pad, 1);
// CHECK: store i32 9
gi = __builtin_object_size(data->pad, 2);
// CHECK: store i32 3
gi = __builtin_object_size(data->pad, 3);
}
// CHECK-LABEL: @test8
void test8() {
// Non-const pointers aren't currently supported.
void *buf = my_calloc(100, 5);
// CHECK: @llvm.objectsize.i64.p0i8(i8* %{{.*}}, i1 false)
gi = __builtin_object_size(buf, 0);
// CHECK: @llvm.objectsize
gi = __builtin_object_size(buf, 1);
// CHECK: @llvm.objectsize
gi = __builtin_object_size(buf, 2);
// CHECK: store i32 0
gi = __builtin_object_size(buf, 3);
}
// CHECK-LABEL: @test9
void test9() {
// Check to be sure that we unwrap things correctly.
short *const buf0 = (my_malloc(100));
short *const buf1 = (short*)(my_malloc(100));
short *const buf2 = ((short*)(my_malloc(100)));
// CHECK: store i32 100
gi = __builtin_object_size(buf0, 0);
// CHECK: store i32 100
gi = __builtin_object_size(buf1, 0);
// CHECK: store i32 100
gi = __builtin_object_size(buf2, 0);
}
// CHECK-LABEL: @test10
void test10() {
// Yay overflow
short *const arr = my_calloc((size_t)-1 / 2 + 1, 2);
// CHECK: @llvm.objectsize
gi = __builtin_object_size(arr, 0);
// CHECK: @llvm.objectsize
gi = __builtin_object_size(arr, 1);
// CHECK: @llvm.objectsize
gi = __builtin_object_size(arr, 2);
// CHECK: store i32 0
gi = __builtin_object_size(arr, 3);
// As an implementation detail, CharUnits can't handle numbers greater than or
// equal to 2**63. Realistically, this shouldn't be a problem, but we should
// be sure we don't emit crazy results for this case.
short *const buf = my_malloc((size_t)-1);
// CHECK: @llvm.objectsize
gi = __builtin_object_size(buf, 0);
// CHECK: @llvm.objectsize
gi = __builtin_object_size(buf, 1);
// CHECK: @llvm.objectsize
gi = __builtin_object_size(buf, 2);
// CHECK: store i32 0
gi = __builtin_object_size(buf, 3);
short *const arr_big = my_calloc((size_t)-1 / 2 - 1, 2);
// CHECK: @llvm.objectsize
gi = __builtin_object_size(arr_big, 0);
// CHECK: @llvm.objectsize
gi = __builtin_object_size(arr_big, 1);
// CHECK: @llvm.objectsize
gi = __builtin_object_size(arr_big, 2);
// CHECK: store i32 0
gi = __builtin_object_size(arr_big, 3);
}
void *my_tiny_malloc(char) __attribute__((alloc_size(1)));
void *my_tiny_calloc(char, char) __attribute__((alloc_size(1, 2)));
// CHECK-LABEL: @test11
void test11() {
void *const vp = my_tiny_malloc(100);
// CHECK: store i32 100
gi = __builtin_object_size(vp, 0);
// CHECK: store i32 100
gi = __builtin_object_size(vp, 1);
// CHECK: store i32 100
gi = __builtin_object_size(vp, 2);
// CHECK: store i32 100
gi = __builtin_object_size(vp, 3);
// N.B. This causes char overflow, but not size_t overflow, so it should be
// supported.
void *const arr = my_tiny_calloc(100, 5);
// CHECK: store i32 500
gi = __builtin_object_size(arr, 0);
// CHECK: store i32 500
gi = __builtin_object_size(arr, 1);
// CHECK: store i32 500
gi = __builtin_object_size(arr, 2);
// CHECK: store i32 500
gi = __builtin_object_size(arr, 3);
}
void *my_signed_malloc(long) __attribute__((alloc_size(1)));
void *my_signed_calloc(long, long) __attribute__((alloc_size(1, 2)));
// CHECK-LABEL: @test12
void test12() {
// CHECK: store i32 100
gi = __builtin_object_size(my_signed_malloc(100), 0);
// CHECK: store i32 500
gi = __builtin_object_size(my_signed_calloc(100, 5), 0);
void *const vp = my_signed_malloc(-2);
// CHECK: @llvm.objectsize
gi = __builtin_object_size(vp, 0);
// N.B. These get lowered to -1 because the function calls may have
// side-effects, and we can't determine the objectsize.
// CHECK: store i32 -1
gi = __builtin_object_size(my_signed_malloc(-2), 0);
void *const arr1 = my_signed_calloc(-2, 1);
void *const arr2 = my_signed_calloc(1, -2);
// CHECK: @llvm.objectsize
gi = __builtin_object_size(arr1, 0);
// CHECK: @llvm.objectsize
gi = __builtin_object_size(arr2, 0);
// CHECK: store i32 -1
gi = __builtin_object_size(my_signed_calloc(1, -2), 0);
// CHECK: store i32 -1
gi = __builtin_object_size(my_signed_calloc(-2, 1), 0);
}

72
test/CodeGenCXX/alloc-size.cpp Normal file
View File

@ -0,0 +1,72 @@
// RUN: %clang_cc1 -triple x86_64-apple-darwin -emit-llvm -O0 %s -o - 2>&1 -std=c++11 | FileCheck %s
namespace templates {
void *my_malloc(int N) __attribute__((alloc_size(1)));
void *my_calloc(int N, int M) __attribute__((alloc_size(1, 2)));
struct MyType {
int arr[4];
};
template <typename T> int callMalloc();
template <typename T, int N> int callCalloc();
// CHECK-LABEL: define i32 @_ZN9templates6testItEv()
int testIt() {
// CHECK: call i32 @_ZN9templates10callMallocINS_6MyTypeEEEiv
// CHECK: call i32 @_ZN9templates10callCallocINS_6MyTypeELi4EEEiv
return callMalloc<MyType>() + callCalloc<MyType, 4>();
}
// CHECK-LABEL: define linkonce_odr i32
// @_ZN9templates10callMallocINS_6MyTypeEEEiv
template <typename T> int callMalloc() {
static_assert(sizeof(T) == 16, "");
// CHECK: ret i32 16
return __builtin_object_size(my_malloc(sizeof(T)), 0);
}
// CHECK-LABEL: define linkonce_odr i32
// @_ZN9templates10callCallocINS_6MyTypeELi4EEEiv
template <typename T, int N> int callCalloc() {
static_assert(sizeof(T) * N == 64, "");
// CHECK: ret i32 64
return __builtin_object_size(my_malloc(sizeof(T) * N), 0);
}
}
namespace templated_alloc_size {
using size_t = unsigned long;
// We don't need bodies for any of these, because they're only used in
// __builtin_object_size, and that shouldn't need anything but a function
// decl with alloc_size on it.
template <typename T>
T *my_malloc(size_t N = sizeof(T)) __attribute__((alloc_size(1)));
template <typename T>
T *my_calloc(size_t M, size_t N = sizeof(T)) __attribute__((alloc_size(2, 1)));
template <size_t N>
void *dependent_malloc(size_t NT = N) __attribute__((alloc_size(1)));
template <size_t N, size_t M>
void *dependent_calloc(size_t NT = N, size_t MT = M)
__attribute__((alloc_size(1, 2)));
template <typename T, size_t M>
void *dependent_calloc2(size_t NT = sizeof(T), size_t MT = M)
__attribute__((alloc_size(1, 2)));
// CHECK-LABEL: define i32 @_ZN20templated_alloc_size6testItEv
int testIt() {
// 122 = 4 + 5*4 + 6 + 7*8 + 4*9
// CHECK: ret i32 122
return __builtin_object_size(my_malloc<int>(), 0) +
__builtin_object_size(my_calloc<int>(5), 0) +
__builtin_object_size(dependent_malloc<6>(), 0) +
__builtin_object_size(dependent_calloc<7, 8>(), 0) +
__builtin_object_size(dependent_calloc2<int, 9>(), 0);
}
}

2
test/CodeGenCXX/block-in-ctor-dtor.cpp
View File

@ -42,7 +42,5 @@ X::~X() {
// CHECK-LABEL: define internal void @___ZN4ZoneD2Ev_block_invoke_
// CHECK-LABEL: define internal void @___ZN1XC2Ev_block_invoke
// CHECK-LABEL: define internal void @___ZN1XC2Ev_block_invoke_
// CHECK-LABEL: define internal void @___ZN1XC1Ev_block_invoke
// CHECK-LABEL: define internal void @___ZN1XC1Ev_block_invoke_
// CHECK-LABEL: define internal void @___ZN1XD2Ev_block_invoke
// CHECK-LABEL: define internal void @___ZN1XD2Ev_block_invoke_

3
test/CodeGenCXX/global-init.cpp
View File

@ -18,9 +18,6 @@ struct D { ~D(); };
// CHECK: @__dso_handle = external global i8
// CHECK: @c = global %struct.C zeroinitializer, align 8
// It's okay if we ever implement the IR-generation optimization to remove this.
// CHECK: @_ZN5test3L3varE = internal constant i8* getelementptr inbounds ([7 x i8], [7 x i8]*
// PR6205: The casts should not require global initializers
// CHECK: @_ZN6PR59741cE = external global %"struct.PR5974::C"
// CHECK: @_ZN6PR59741aE = global %"struct.PR5974::A"* getelementptr inbounds (%"struct.PR5974::C", %"struct.PR5974::C"* @_ZN6PR59741cE, i32 0, i32 0)

24
test/CodeGenOpenCL/cl20-device-side-enqueue.cl
View File

@ -3,6 +3,8 @@
typedef void (^bl_t)(local void *);
// N.B. The check here only exists to set BL_GLOBAL
// COMMON: @block_G = {{.*}}bitcast ([[BL_GLOBAL:[^@]+@__block_literal_global(\.[0-9]+)?]]
const bl_t block_G = (bl_t) ^ (local void *a) {};
kernel void device_side_enqueue(global int *a, global int *b, int i) {
@ -122,28 +124,24 @@ kernel void device_side_enqueue(global int *a, global int *b, int i) {
},
4294967296L);
// The full type of these expressions are long (and repeated elsewhere), so we
// capture it as part of the regex for convenience and clarity.
// COMMON: store void ()* bitcast ([[BL_A:[^@]+@__block_literal_global.[0-9]+]] to void ()*), void ()** %block_A
void (^const block_A)(void) = ^{
return;
};
// COMMON: store void (i8 addrspace(2)*)* bitcast ([[BL_B:[^@]+@__block_literal_global.[0-9]+]] to void (i8 addrspace(2)*)*), void (i8 addrspace(2)*)** %block_B
void (^const block_B)(local void *) = ^(local void *a) {
return;
};
// COMMON: [[BL:%[0-9]+]] = load void ()*, void ()** %block_A
// COMMON: [[BL_I8:%[0-9]+]] = bitcast void ()* [[BL]] to i8*
// COMMON: call i32 @__get_kernel_work_group_size_impl(i8* [[BL_I8]])
// COMMON: call i32 @__get_kernel_work_group_size_impl(i8* bitcast ([[BL_A]] to i8*))
unsigned size = get_kernel_work_group_size(block_A);
// COMMON: [[BL:%[0-9]+]] = load void (i8 addrspace(2)*)*, void (i8 addrspace(2)*)** %block_B
// COMMON: [[BL_I8:%[0-9]+]] = bitcast void (i8 addrspace(2)*)* [[BL]] to i8*
// COMMON: call i32 @__get_kernel_work_group_size_impl(i8* [[BL_I8]])
// COMMON: call i32 @__get_kernel_work_group_size_impl(i8* bitcast ([[BL_B]] to i8*))
size = get_kernel_work_group_size(block_B);
// COMMON: [[BL:%[0-9]+]] = load void ()*, void ()** %block_A
// COMMON: [[BL_I8:%[0-9]+]] = bitcast void ()* [[BL]] to i8*
// COMMON: call i32 @__get_kernel_preferred_work_group_multiple_impl(i8* [[BL_I8]])
// COMMON: call i32 @__get_kernel_preferred_work_group_multiple_impl(i8* bitcast ([[BL_A]] to i8*))
size = get_kernel_preferred_work_group_size_multiple(block_A);
// COMMON: [[BL:%[0-9]+]] = load void (i8 addrspace(2)*)*, void (i8 addrspace(2)*)* addrspace(1)* @block_G
// COMMON: [[BL_I8:%[0-9]+]] = bitcast void (i8 addrspace(2)*)* [[BL]] to i8*
// COMMON: call i32 @__get_kernel_preferred_work_group_multiple_impl(i8* [[BL_I8]])
// COMMON: call i32 @__get_kernel_preferred_work_group_multiple_impl(i8* bitcast ([[BL_GLOBAL]] to i8*))
size = get_kernel_preferred_work_group_size_multiple(block_G);
}

23
test/Sema/alloc-size.c Normal file
View File

@ -0,0 +1,23 @@
// RUN: %clang_cc1 %s -verify
void *fail1(int a) __attribute__((alloc_size)); //expected-error{{'alloc_size' attribute takes at least 1 argument}}
void *fail2(int a) __attribute__((alloc_size())); //expected-error{{'alloc_size' attribute takes at least 1 argument}}
void *fail3(int a) __attribute__((alloc_size(0))); //expected-error{{'alloc_size' attribute parameter 0 is out of bounds}}
void *fail4(int a) __attribute__((alloc_size(2))); //expected-error{{'alloc_size' attribute parameter 2 is out of bounds}}
void *fail5(int a, int b) __attribute__((alloc_size(0, 1))); //expected-error{{'alloc_size' attribute parameter 0 is out of bounds}}
void *fail6(int a, int b) __attribute__((alloc_size(3, 1))); //expected-error{{'alloc_size' attribute parameter 3 is out of bounds}}
void *fail7(int a, int b) __attribute__((alloc_size(1, 0))); //expected-error{{'alloc_size' attribute parameter 0 is out of bounds}}
void *fail8(int a, int b) __attribute__((alloc_size(1, 3))); //expected-error{{'alloc_size' attribute parameter 3 is out of bounds}}
int fail9(int a) __attribute__((alloc_size(1))); //expected-warning{{'alloc_size' attribute only applies to return values that are pointers}}
int fail10 __attribute__((alloc_size(1))); //expected-warning{{'alloc_size' attribute only applies to non-K&R-style functions}}
void *fail11(void *a) __attribute__((alloc_size(1))); //expected-error{{'alloc_size' attribute argument may only refer to a function parameter of integer type}}
void *fail12(int a) __attribute__((alloc_size("abc"))); //expected-error{{'alloc_size' attribute requires parameter 1 to be an integer constant}}
void *fail12(int a) __attribute__((alloc_size(1, "abc"))); //expected-error{{'alloc_size' attribute requires parameter 2 to be an integer constant}}
void *fail13(int a) __attribute__((alloc_size(1U<<31))); //expected-error{{integer constant expression evaluates to value 2147483648 that cannot be represented in a 32-bit signed integer type}}

4
test/SemaCXX/constant-expression-cxx11.cpp
View File

@ -1183,7 +1183,7 @@ constexpr int m1b = const_cast<const int&>(n1); // expected-error {{constant exp
constexpr int m2b = const_cast<const int&>(n2); // expected-error {{constant expression}} expected-note {{read of volatile object 'n2'}}
struct T { int n; };
const T t = { 42 }; // expected-note {{declared here}}
const T t = { 42 };
constexpr int f(volatile int &&r) {
return r; // expected-note {{read of volatile-qualified type 'volatile int'}}
@ -1195,7 +1195,7 @@ struct S {
int j : f(0); // expected-error {{constant expression}} expected-note {{in call to 'f(0)'}}
int k : g(0); // expected-error {{constant expression}} expected-note {{temporary created here}} expected-note {{in call to 'g(0)'}}
int l : n3; // expected-error {{constant expression}} expected-note {{read of non-const variable}}
int m : t.n; // expected-error {{constant expression}} expected-note {{read of non-constexpr variable}}
int m : t.n; // expected-warning{{width of bit-field 'm' (42 bits)}}
};
}