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-rw-r--r--lib/AST/ExprConstant.cpp94
1 files changed, 57 insertions, 37 deletions
diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index 6a6baf96ad37..2c0fce91844c 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -604,10 +604,12 @@ namespace {
/// gets a chance to look at it.
EM_PotentialConstantExpressionUnevaluated,
- /// 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.
+ /// Evaluate as a constant expression. In certain scenarios, if:
+ /// - we find a MemberExpr with a base that can't be evaluated, or
+ /// - we find a variable initialized with a call to a function that has
+ /// the alloc_size attribute on it
+ /// then we may consider evaluation to have succeeded.
+ ///
/// 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
@@ -890,10 +892,6 @@ namespace {
return KeepGoing;
}
- bool allowInvalidBaseExpr() const {
- return EvalMode == EM_OffsetFold;
- }
-
class ArrayInitLoopIndex {
EvalInfo &Info;
uint64_t OuterIndex;
@@ -1394,8 +1392,10 @@ static bool Evaluate(APValue &Result, EvalInfo &Info, const Expr *E);
static bool EvaluateInPlace(APValue &Result, EvalInfo &Info,
const LValue &This, const Expr *E,
bool AllowNonLiteralTypes = false);
-static bool EvaluateLValue(const Expr *E, LValue &Result, EvalInfo &Info);
-static bool EvaluatePointer(const Expr *E, LValue &Result, EvalInfo &Info);
+static bool EvaluateLValue(const Expr *E, LValue &Result, EvalInfo &Info,
+ bool InvalidBaseOK = false);
+static bool EvaluatePointer(const Expr *E, LValue &Result, EvalInfo &Info,
+ bool InvalidBaseOK = false);
static bool EvaluateMemberPointer(const Expr *E, MemberPtr &Result,
EvalInfo &Info);
static bool EvaluateTemporary(const Expr *E, LValue &Result, EvalInfo &Info);
@@ -4803,6 +4803,7 @@ class LValueExprEvaluatorBase
: public ExprEvaluatorBase<Derived> {
protected:
LValue &Result;
+ bool InvalidBaseOK;
typedef LValueExprEvaluatorBase LValueExprEvaluatorBaseTy;
typedef ExprEvaluatorBase<Derived> ExprEvaluatorBaseTy;
@@ -4811,9 +4812,14 @@ protected:
return true;
}
+ bool evaluatePointer(const Expr *E, LValue &Result) {
+ return EvaluatePointer(E, Result, this->Info, InvalidBaseOK);
+ }
+
public:
- LValueExprEvaluatorBase(EvalInfo &Info, LValue &Result) :
- ExprEvaluatorBaseTy(Info), Result(Result) {}
+ LValueExprEvaluatorBase(EvalInfo &Info, LValue &Result, bool InvalidBaseOK)
+ : ExprEvaluatorBaseTy(Info), Result(Result),
+ InvalidBaseOK(InvalidBaseOK) {}
bool Success(const APValue &V, const Expr *E) {
Result.setFrom(this->Info.Ctx, V);
@@ -4825,7 +4831,7 @@ public:
QualType BaseTy;
bool EvalOK;
if (E->isArrow()) {
- EvalOK = EvaluatePointer(E->getBase(), Result, this->Info);
+ EvalOK = evaluatePointer(E->getBase(), Result);
BaseTy = E->getBase()->getType()->castAs<PointerType>()->getPointeeType();
} else if (E->getBase()->isRValue()) {
assert(E->getBase()->getType()->isRecordType());
@@ -4836,7 +4842,7 @@ public:
BaseTy = E->getBase()->getType();
}
if (!EvalOK) {
- if (!this->Info.allowInvalidBaseExpr())
+ if (!InvalidBaseOK)
return false;
Result.setInvalid(E);
return true;
@@ -4930,8 +4936,8 @@ namespace {
class LValueExprEvaluator
: public LValueExprEvaluatorBase<LValueExprEvaluator> {
public:
- LValueExprEvaluator(EvalInfo &Info, LValue &Result) :
- LValueExprEvaluatorBaseTy(Info, Result) {}
+ LValueExprEvaluator(EvalInfo &Info, LValue &Result, bool InvalidBaseOK) :
+ LValueExprEvaluatorBaseTy(Info, Result, InvalidBaseOK) {}
bool VisitVarDecl(const Expr *E, const VarDecl *VD);
bool VisitUnaryPreIncDec(const UnaryOperator *UO);
@@ -4984,10 +4990,11 @@ public:
/// * function designators in C, and
/// * "extern void" objects
/// * @selector() expressions in Objective-C
-static bool EvaluateLValue(const Expr *E, LValue &Result, EvalInfo &Info) {
+static bool EvaluateLValue(const Expr *E, LValue &Result, EvalInfo &Info,
+ bool InvalidBaseOK) {
assert(E->isGLValue() || E->getType()->isFunctionType() ||
E->getType()->isVoidType() || isa<ObjCSelectorExpr>(E));
- return LValueExprEvaluator(Info, Result).Visit(E);
+ return LValueExprEvaluator(Info, Result, InvalidBaseOK).Visit(E);
}
bool LValueExprEvaluator::VisitDeclRefExpr(const DeclRefExpr *E) {
@@ -5148,7 +5155,7 @@ bool LValueExprEvaluator::VisitArraySubscriptExpr(const ArraySubscriptExpr *E) {
if (E->getBase()->getType()->isVectorType())
return Error(E);
- if (!EvaluatePointer(E->getBase(), Result, Info))
+ if (!evaluatePointer(E->getBase(), Result))
return false;
APSInt Index;
@@ -5160,7 +5167,7 @@ bool LValueExprEvaluator::VisitArraySubscriptExpr(const ArraySubscriptExpr *E) {
}
bool LValueExprEvaluator::VisitUnaryDeref(const UnaryOperator *E) {
- return EvaluatePointer(E->getSubExpr(), Result, Info);
+ return evaluatePointer(E->getSubExpr(), Result);
}
bool LValueExprEvaluator::VisitUnaryReal(const UnaryOperator *E) {
@@ -5308,7 +5315,7 @@ static bool getBytesReturnedByAllocSizeCall(const ASTContext &Ctx,
/// and mark Result's Base as invalid.
static bool evaluateLValueAsAllocSize(EvalInfo &Info, APValue::LValueBase Base,
LValue &Result) {
- if (!Info.allowInvalidBaseExpr() || Base.isNull())
+ if (Base.isNull())
return false;
// Because we do no form of static analysis, we only support const variables.
@@ -5342,17 +5349,27 @@ namespace {
class PointerExprEvaluator
: public ExprEvaluatorBase<PointerExprEvaluator> {
LValue &Result;
+ bool InvalidBaseOK;
bool Success(const Expr *E) {
Result.set(E);
return true;
}
+ bool evaluateLValue(const Expr *E, LValue &Result) {
+ return EvaluateLValue(E, Result, Info, InvalidBaseOK);
+ }
+
+ bool evaluatePointer(const Expr *E, LValue &Result) {
+ return EvaluatePointer(E, Result, Info, InvalidBaseOK);
+ }
+
bool visitNonBuiltinCallExpr(const CallExpr *E);
public:
- PointerExprEvaluator(EvalInfo &info, LValue &Result)
- : ExprEvaluatorBaseTy(info), Result(Result) {}
+ PointerExprEvaluator(EvalInfo &info, LValue &Result, bool InvalidBaseOK)
+ : ExprEvaluatorBaseTy(info), Result(Result),
+ InvalidBaseOK(InvalidBaseOK) {}
bool Success(const APValue &V, const Expr *E) {
Result.setFrom(Info.Ctx, V);
@@ -5399,9 +5416,10 @@ public:
};
} // end anonymous namespace
-static bool EvaluatePointer(const Expr* E, LValue& Result, EvalInfo &Info) {
+static bool EvaluatePointer(const Expr* E, LValue& Result, EvalInfo &Info,
+ bool InvalidBaseOK) {
assert(E->isRValue() && E->getType()->hasPointerRepresentation());
- return PointerExprEvaluator(Info, Result).Visit(E);
+ return PointerExprEvaluator(Info, Result, InvalidBaseOK).Visit(E);
}
bool PointerExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
@@ -5414,7 +5432,7 @@ bool PointerExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
if (IExp->getType()->isPointerType())
std::swap(PExp, IExp);
- bool EvalPtrOK = EvaluatePointer(PExp, Result, Info);
+ bool EvalPtrOK = evaluatePointer(PExp, Result);
if (!EvalPtrOK && !Info.noteFailure())
return false;
@@ -5432,7 +5450,7 @@ bool PointerExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
}
bool PointerExprEvaluator::VisitUnaryAddrOf(const UnaryOperator *E) {
- return EvaluateLValue(E->getSubExpr(), Result, Info);
+ return evaluateLValue(E->getSubExpr(), Result);
}
bool PointerExprEvaluator::VisitCastExpr(const CastExpr* E) {
@@ -5466,7 +5484,7 @@ bool PointerExprEvaluator::VisitCastExpr(const CastExpr* E) {
case CK_DerivedToBase:
case CK_UncheckedDerivedToBase:
- if (!EvaluatePointer(E->getSubExpr(), Result, Info))
+ if (!evaluatePointer(E->getSubExpr(), Result))
return false;
if (!Result.Base && Result.Offset.isZero())
return true;
@@ -5513,7 +5531,7 @@ bool PointerExprEvaluator::VisitCastExpr(const CastExpr* E) {
}
case CK_ArrayToPointerDecay:
if (SubExpr->isGLValue()) {
- if (!EvaluateLValue(SubExpr, Result, Info))
+ if (!evaluateLValue(SubExpr, Result))
return false;
} else {
Result.set(SubExpr, Info.CurrentCall->Index);
@@ -5530,18 +5548,19 @@ bool PointerExprEvaluator::VisitCastExpr(const CastExpr* E) {
return true;
case CK_FunctionToPointerDecay:
- return EvaluateLValue(SubExpr, Result, Info);
+ return evaluateLValue(SubExpr, Result);
case CK_LValueToRValue: {
LValue LVal;
- if (!EvaluateLValue(E->getSubExpr(), LVal, Info))
+ if (!evaluateLValue(E->getSubExpr(), LVal))
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 InvalidBaseOK &&
+ evaluateLValueAsAllocSize(Info, LVal.Base, Result);
return Success(RVal, E);
}
}
@@ -5586,7 +5605,7 @@ bool PointerExprEvaluator::visitNonBuiltinCallExpr(const CallExpr *E) {
if (ExprEvaluatorBaseTy::VisitCallExpr(E))
return true;
- if (!(Info.allowInvalidBaseExpr() && getAllocSizeAttr(E)))
+ if (!(InvalidBaseOK && getAllocSizeAttr(E)))
return false;
Result.setInvalid(E);
@@ -5609,12 +5628,12 @@ bool PointerExprEvaluator::VisitBuiltinCallExpr(const CallExpr *E,
unsigned BuiltinOp) {
switch (BuiltinOp) {
case Builtin::BI__builtin_addressof:
- return EvaluateLValue(E->getArg(0), Result, Info);
+ return evaluateLValue(E->getArg(0), Result);
case Builtin::BI__builtin_assume_aligned: {
// We need to be very careful here because: if the pointer does not have the
// asserted alignment, then the behavior is undefined, and undefined
// behavior is non-constant.
- if (!EvaluatePointer(E->getArg(0), Result, Info))
+ if (!evaluatePointer(E->getArg(0), Result))
return false;
LValue OffsetResult(Result);
@@ -6255,7 +6274,7 @@ class TemporaryExprEvaluator
: public LValueExprEvaluatorBase<TemporaryExprEvaluator> {
public:
TemporaryExprEvaluator(EvalInfo &Info, LValue &Result) :
- LValueExprEvaluatorBaseTy(Info, Result) {}
+ LValueExprEvaluatorBaseTy(Info, Result, false) {}
/// Visit an expression which constructs the value of this temporary.
bool VisitConstructExpr(const Expr *E) {
@@ -7358,7 +7377,8 @@ static bool tryEvaluateBuiltinObjectSize(const Expr *E, unsigned Type,
if (!EvaluateAsRValue(Info, E, RVal))
return false;
LVal.setFrom(Info.Ctx, RVal);
- } else if (!EvaluatePointer(ignorePointerCastsAndParens(E), LVal, Info))
+ } else if (!EvaluatePointer(ignorePointerCastsAndParens(E), LVal, Info,
+ /*InvalidBaseOK=*/true))
return false;
}