microsoft
/
clang-1
зеркало из https://github.com/microsoft/clang-1.git
1
0
Форкнуть 0
Код Задачи Пакеты Проекты Релизы Вики Активность
clang-1/lib/AST/Expr.cpp

1829 строки
65 KiB
C++
Исходник Ответственный История

//===--- Expr.cpp - Expression AST Node Implementation --------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the Expr class and subclasses.
//
//===----------------------------------------------------------------------===//
#include "clang/AST/Expr.h"
#include "clang/AST/APValue.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/AST/RecordLayout.h"
#include "clang/AST/StmtVisitor.h"
#include "clang/Basic/TargetInfo.h"
using namespace clang;
//===----------------------------------------------------------------------===//
// Primary Expressions.
//===----------------------------------------------------------------------===//
IntegerLiteral* IntegerLiteral::Clone(ASTContext &C) const {
return new (C) IntegerLiteral(Value, getType(), Loc);
}
/// getValueAsApproximateDouble - This returns the value as an inaccurate
/// double. Note that this may cause loss of precision, but is useful for
/// debugging dumps, etc.
double FloatingLiteral::getValueAsApproximateDouble() const {
llvm::APFloat V = getValue();
bool ignored;
V.convert(llvm::APFloat::IEEEdouble, llvm::APFloat::rmNearestTiesToEven,
&ignored);
return V.convertToDouble();
}
StringLiteral *StringLiteral::Create(ASTContext &C, const char *StrData,
unsigned ByteLength, bool Wide,
QualType Ty,
const SourceLocation *Loc,
unsigned NumStrs) {
// Allocate enough space for the StringLiteral plus an array of locations for
// any concatenated string tokens.
void *Mem = C.Allocate(sizeof(StringLiteral)+
sizeof(SourceLocation)*(NumStrs-1),
llvm::alignof<StringLiteral>());
StringLiteral *SL = new (Mem) StringLiteral(Ty);
// OPTIMIZE: could allocate this appended to the StringLiteral.
char *AStrData = new (C, 1) char[ByteLength];
memcpy(AStrData, StrData, ByteLength);
SL->StrData = AStrData;
SL->ByteLength = ByteLength;
SL->IsWide = Wide;
SL->TokLocs[0] = Loc[0];
SL->NumConcatenated = NumStrs;
if (NumStrs != 1)
memcpy(&SL->TokLocs[1], Loc+1, sizeof(SourceLocation)*(NumStrs-1));
return SL;
}
StringLiteral* StringLiteral::Clone(ASTContext &C) const {
return Create(C, StrData, ByteLength, IsWide, getType(),
TokLocs, NumConcatenated);
}
void StringLiteral::Destroy(ASTContext &C) {
C.Deallocate(const_cast<char*>(StrData));
this->~StringLiteral();
C.Deallocate(this);
}
/// getOpcodeStr - Turn an Opcode enum value into the punctuation char it
/// corresponds to, e.g. "sizeof" or "[pre]++".
const char *UnaryOperator::getOpcodeStr(Opcode Op) {
switch (Op) {
default: assert(0 && "Unknown unary operator");
case PostInc: return "++";
case PostDec: return "--";
case PreInc: return "++";
case PreDec: return "--";
case AddrOf: return "&";
case Deref: return "*";
case Plus: return "+";
case Minus: return "-";
case Not: return "~";
case LNot: return "!";
case Real: return "__real";
case Imag: return "__imag";
case Extension: return "__extension__";
case OffsetOf: return "__builtin_offsetof";
}
}
UnaryOperator::Opcode
UnaryOperator::getOverloadedOpcode(OverloadedOperatorKind OO, bool Postfix) {
switch (OO) {
default: assert(false && "No unary operator for overloaded function");
case OO_PlusPlus: return Postfix ? PostInc : PreInc;
case OO_MinusMinus: return Postfix ? PostDec : PreDec;
case OO_Amp: return AddrOf;
case OO_Star: return Deref;
case OO_Plus: return Plus;
case OO_Minus: return Minus;
case OO_Tilde: return Not;
case OO_Exclaim: return LNot;
}
}
OverloadedOperatorKind UnaryOperator::getOverloadedOperator(Opcode Opc) {
switch (Opc) {
case PostInc: case PreInc: return OO_PlusPlus;
case PostDec: case PreDec: return OO_MinusMinus;
case AddrOf: return OO_Amp;
case Deref: return OO_Star;
case Plus: return OO_Plus;
case Minus: return OO_Minus;
case Not: return OO_Tilde;
case LNot: return OO_Exclaim;
default: return OO_None;
}
}
//===----------------------------------------------------------------------===//
// Postfix Operators.
//===----------------------------------------------------------------------===//
CallExpr::CallExpr(ASTContext& C, StmtClass SC, Expr *fn, Expr **args,
unsigned numargs, QualType t, SourceLocation rparenloc)
: Expr(SC, t,
fn->isTypeDependent() || hasAnyTypeDependentArguments(args, numargs),
fn->isValueDependent() || hasAnyValueDependentArguments(args,numargs)),
NumArgs(numargs) {
SubExprs = new (C) Stmt*[numargs+1];
SubExprs[FN] = fn;
for (unsigned i = 0; i != numargs; ++i)
SubExprs[i+ARGS_START] = args[i];
RParenLoc = rparenloc;
}
CallExpr::CallExpr(ASTContext& C, Expr *fn, Expr **args, unsigned numargs,
QualType t, SourceLocation rparenloc)
: Expr(CallExprClass, t,
fn->isTypeDependent() || hasAnyTypeDependentArguments(args, numargs),
fn->isValueDependent() || hasAnyValueDependentArguments(args,numargs)),
NumArgs(numargs) {
SubExprs = new (C) Stmt*[numargs+1];
SubExprs[FN] = fn;
for (unsigned i = 0; i != numargs; ++i)
SubExprs[i+ARGS_START] = args[i];
RParenLoc = rparenloc;
}
void CallExpr::Destroy(ASTContext& C) {
DestroyChildren(C);
if (SubExprs) C.Deallocate(SubExprs);
this->~CallExpr();
C.Deallocate(this);
}
/// setNumArgs - This changes the number of arguments present in this call.
/// Any orphaned expressions are deleted by this, and any new operands are set
/// to null.
void CallExpr::setNumArgs(ASTContext& C, unsigned NumArgs) {
// No change, just return.
if (NumArgs == getNumArgs()) return;
// If shrinking # arguments, just delete the extras and forgot them.
if (NumArgs < getNumArgs()) {
for (unsigned i = NumArgs, e = getNumArgs(); i != e; ++i)
getArg(i)->Destroy(C);
this->NumArgs = NumArgs;
return;
}
// Otherwise, we are growing the # arguments. New an bigger argument array.
Stmt **NewSubExprs = new Stmt*[NumArgs+1];
// Copy over args.
for (unsigned i = 0; i != getNumArgs()+ARGS_START; ++i)
NewSubExprs[i] = SubExprs[i];
// Null out new args.
for (unsigned i = getNumArgs()+ARGS_START; i != NumArgs+ARGS_START; ++i)
NewSubExprs[i] = 0;
delete [] SubExprs;
SubExprs = NewSubExprs;
this->NumArgs = NumArgs;
}
/// isBuiltinCall - If this is a call to a builtin, return the builtin ID. If
/// not, return 0.
unsigned CallExpr::isBuiltinCall(ASTContext &Context) const {
// All simple function calls (e.g. func()) are implicitly cast to pointer to
// function. As a result, we try and obtain the DeclRefExpr from the
// ImplicitCastExpr.
const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(getCallee());
if (!ICE) // FIXME: deal with more complex calls (e.g. (func)(), (*func)()).
return 0;
const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr());
if (!DRE)
return 0;
const FunctionDecl *FDecl = dyn_cast<FunctionDecl>(DRE->getDecl());
if (!FDecl)
return 0;
if (!FDecl->getIdentifier())
return 0;
return FDecl->getBuiltinID(Context);
}
/// getOpcodeStr - Turn an Opcode enum value into the punctuation char it
/// corresponds to, e.g. "<<=".
const char *BinaryOperator::getOpcodeStr(Opcode Op) {
switch (Op) {
case PtrMemD: return ".*";
case PtrMemI: return "->*";
case Mul: return "*";
case Div: return "/";
case Rem: return "%";
case Add: return "+";
case Sub: return "-";
case Shl: return "<<";
case Shr: return ">>";
case LT: return "<";
case GT: return ">";
case LE: return "<=";
case GE: return ">=";
case EQ: return "==";
case NE: return "!=";
case And: return "&";
case Xor: return "^";
case Or: return "|";
case LAnd: return "&&";
case LOr: return "||";
case Assign: return "=";
case MulAssign: return "*=";
case DivAssign: return "/=";
case RemAssign: return "%=";
case AddAssign: return "+=";
case SubAssign: return "-=";
case ShlAssign: return "<<=";
case ShrAssign: return ">>=";
case AndAssign: return "&=";
case XorAssign: return "^=";
case OrAssign: return "|=";
case Comma: return ",";
}
return "";
}
BinaryOperator::Opcode
BinaryOperator::getOverloadedOpcode(OverloadedOperatorKind OO) {
switch (OO) {
default: assert(false && "Not an overloadable binary operator");
case OO_Plus: return Add;
case OO_Minus: return Sub;
case OO_Star: return Mul;
case OO_Slash: return Div;
case OO_Percent: return Rem;
case OO_Caret: return Xor;
case OO_Amp: return And;
case OO_Pipe: return Or;
case OO_Equal: return Assign;
case OO_Less: return LT;
case OO_Greater: return GT;
case OO_PlusEqual: return AddAssign;
case OO_MinusEqual: return SubAssign;
case OO_StarEqual: return MulAssign;
case OO_SlashEqual: return DivAssign;
case OO_PercentEqual: return RemAssign;
case OO_CaretEqual: return XorAssign;
case OO_AmpEqual: return AndAssign;
case OO_PipeEqual: return OrAssign;
case OO_LessLess: return Shl;
case OO_GreaterGreater: return Shr;
case OO_LessLessEqual: return ShlAssign;
case OO_GreaterGreaterEqual: return ShrAssign;
case OO_EqualEqual: return EQ;
case OO_ExclaimEqual: return NE;
case OO_LessEqual: return LE;
case OO_GreaterEqual: return GE;
case OO_AmpAmp: return LAnd;
case OO_PipePipe: return LOr;
case OO_Comma: return Comma;
case OO_ArrowStar: return PtrMemI;
}
}
OverloadedOperatorKind BinaryOperator::getOverloadedOperator(Opcode Opc) {
static const OverloadedOperatorKind OverOps[] = {
/* .* Cannot be overloaded */OO_None, OO_ArrowStar,
OO_Star, OO_Slash, OO_Percent,
OO_Plus, OO_Minus,
OO_LessLess, OO_GreaterGreater,
OO_Less, OO_Greater, OO_LessEqual, OO_GreaterEqual,
OO_EqualEqual, OO_ExclaimEqual,
OO_Amp,
OO_Caret,
OO_Pipe,
OO_AmpAmp,
OO_PipePipe,
OO_Equal, OO_StarEqual,
OO_SlashEqual, OO_PercentEqual,
OO_PlusEqual, OO_MinusEqual,
OO_LessLessEqual, OO_GreaterGreaterEqual,
OO_AmpEqual, OO_CaretEqual,
OO_PipeEqual,
OO_Comma
};
return OverOps[Opc];
}
InitListExpr::InitListExpr(SourceLocation lbraceloc,
Expr **initExprs, unsigned numInits,
SourceLocation rbraceloc)
: Expr(InitListExprClass, QualType()),
LBraceLoc(lbraceloc), RBraceLoc(rbraceloc), SyntacticForm(0),
UnionFieldInit(0), HadArrayRangeDesignator(false) {
InitExprs.insert(InitExprs.end(), initExprs, initExprs+numInits);
}
void InitListExpr::reserveInits(unsigned NumInits) {
if (NumInits > InitExprs.size())
InitExprs.reserve(NumInits);
}
void InitListExpr::resizeInits(ASTContext &Context, unsigned NumInits) {
for (unsigned Idx = NumInits, LastIdx = InitExprs.size();
Idx < LastIdx; ++Idx)
InitExprs[Idx]->Destroy(Context);
InitExprs.resize(NumInits, 0);
}
Expr *InitListExpr::updateInit(unsigned Init, Expr *expr) {
if (Init >= InitExprs.size()) {
InitExprs.insert(InitExprs.end(), Init - InitExprs.size() + 1, 0);
InitExprs.back() = expr;
return 0;
}
Expr *Result = cast_or_null<Expr>(InitExprs[Init]);
InitExprs[Init] = expr;
return Result;
}
/// getFunctionType - Return the underlying function type for this block.
///
const FunctionType *BlockExpr::getFunctionType() const {
return getType()->getAsBlockPointerType()->
getPointeeType()->getAsFunctionType();
}
SourceLocation BlockExpr::getCaretLocation() const {
return TheBlock->getCaretLocation();
}
const Stmt *BlockExpr::getBody() const { return TheBlock->getBody(); }
Stmt *BlockExpr::getBody() { return TheBlock->getBody(); }
//===----------------------------------------------------------------------===//
// Generic Expression Routines
//===----------------------------------------------------------------------===//
/// isUnusedResultAWarning - Return true if this immediate expression should
/// be warned about if the result is unused. If so, fill in Loc and Ranges
/// with location to warn on and the source range[s] to report with the
/// warning.
bool Expr::isUnusedResultAWarning(SourceLocation &Loc, SourceRange &R1,
SourceRange &R2) const {
switch (getStmtClass()) {
default:
Loc = getExprLoc();
R1 = getSourceRange();
return true;
case ParenExprClass:
return cast<ParenExpr>(this)->getSubExpr()->
isUnusedResultAWarning(Loc, R1, R2);
case UnaryOperatorClass: {
const UnaryOperator *UO = cast<UnaryOperator>(this);
switch (UO->getOpcode()) {
default: break;
case UnaryOperator::PostInc:
case UnaryOperator::PostDec:
case UnaryOperator::PreInc:
case UnaryOperator::PreDec: // ++/--
return false; // Not a warning.
case UnaryOperator::Deref:
// Dereferencing a volatile pointer is a side-effect.
if (getType().isVolatileQualified())
return false;
break;
case UnaryOperator::Real:
case UnaryOperator::Imag:
// accessing a piece of a volatile complex is a side-effect.
if (UO->getSubExpr()->getType().isVolatileQualified())
return false;
break;
case UnaryOperator::Extension:
return UO->getSubExpr()->isUnusedResultAWarning(Loc, R1, R2);
}
Loc = UO->getOperatorLoc();
R1 = UO->getSubExpr()->getSourceRange();
return true;
}
case BinaryOperatorClass: {
const BinaryOperator *BO = cast<BinaryOperator>(this);
// Consider comma to have side effects if the LHS or RHS does.
if (BO->getOpcode() == BinaryOperator::Comma)
return BO->getRHS()->isUnusedResultAWarning(Loc, R1, R2) ||
BO->getLHS()->isUnusedResultAWarning(Loc, R1, R2);
if (BO->isAssignmentOp())
return false;
Loc = BO->getOperatorLoc();
R1 = BO->getLHS()->getSourceRange();
R2 = BO->getRHS()->getSourceRange();
return true;
}
case CompoundAssignOperatorClass:
return false;
case ConditionalOperatorClass: {
// The condition must be evaluated, but if either the LHS or RHS is a
// warning, warn about them.
const ConditionalOperator *Exp = cast<ConditionalOperator>(this);
if (Exp->getLHS() && Exp->getLHS()->isUnusedResultAWarning(Loc, R1, R2))
return true;
return Exp->getRHS()->isUnusedResultAWarning(Loc, R1, R2);
}
case MemberExprClass:
// If the base pointer or element is to a volatile pointer/field, accessing
// it is a side effect.
if (getType().isVolatileQualified())
return false;
Loc = cast<MemberExpr>(this)->getMemberLoc();
R1 = SourceRange(Loc, Loc);
R2 = cast<MemberExpr>(this)->getBase()->getSourceRange();
return true;
case ArraySubscriptExprClass:
// If the base pointer or element is to a volatile pointer/field, accessing
// it is a side effect.
if (getType().isVolatileQualified())
return false;
Loc = cast<ArraySubscriptExpr>(this)->getRBracketLoc();
R1 = cast<ArraySubscriptExpr>(this)->getLHS()->getSourceRange();
R2 = cast<ArraySubscriptExpr>(this)->getRHS()->getSourceRange();
return true;
case CallExprClass:
case CXXOperatorCallExprClass: {
// If this is a direct call, get the callee.
const CallExpr *CE = cast<CallExpr>(this);
const Expr *CalleeExpr = CE->getCallee()->IgnoreParenCasts();
if (const DeclRefExpr *CalleeDRE = dyn_cast<DeclRefExpr>(CalleeExpr)) {
// If the callee has attribute pure, const, or warn_unused_result, warn
// about it. void foo() { strlen("bar"); } should warn.
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CalleeDRE->getDecl()))
if (FD->getAttr<WarnUnusedResultAttr>() ||
FD->getAttr<PureAttr>() || FD->getAttr<ConstAttr>()) {
Loc = CE->getCallee()->getLocStart();
R1 = CE->getCallee()->getSourceRange();
if (unsigned NumArgs = CE->getNumArgs())
R2 = SourceRange(CE->getArg(0)->getLocStart(),
CE->getArg(NumArgs-1)->getLocEnd());
return true;
}
}
return false;
}
case ObjCMessageExprClass:
return false;
case StmtExprClass: {
// Statement exprs don't logically have side effects themselves, but are
// sometimes used in macros in ways that give them a type that is unused.
// For example ({ blah; foo(); }) will end up with a type if foo has a type.
// however, if the result of the stmt expr is dead, we don't want to emit a
// warning.
const CompoundStmt *CS = cast<StmtExpr>(this)->getSubStmt();
if (!CS->body_empty())
if (const Expr *E = dyn_cast<Expr>(CS->body_back()))
return E->isUnusedResultAWarning(Loc, R1, R2);
Loc = cast<StmtExpr>(this)->getLParenLoc();
R1 = getSourceRange();
return true;
}
case CStyleCastExprClass:
// If this is a cast to void, check the operand. Otherwise, the result of
// the cast is unused.
if (getType()->isVoidType())
return cast<CastExpr>(this)->getSubExpr()->isUnusedResultAWarning(Loc,
R1, R2);
Loc = cast<CStyleCastExpr>(this)->getLParenLoc();
R1 = cast<CStyleCastExpr>(this)->getSubExpr()->getSourceRange();
return true;
case CXXFunctionalCastExprClass:
// If this is a cast to void, check the operand. Otherwise, the result of
// the cast is unused.
if (getType()->isVoidType())
return cast<CastExpr>(this)->getSubExpr()->isUnusedResultAWarning(Loc,
R1, R2);
Loc = cast<CXXFunctionalCastExpr>(this)->getTypeBeginLoc();
R1 = cast<CXXFunctionalCastExpr>(this)->getSubExpr()->getSourceRange();
return true;
case ImplicitCastExprClass:
// Check the operand, since implicit casts are inserted by Sema
return cast<ImplicitCastExpr>(this)
->getSubExpr()->isUnusedResultAWarning(Loc, R1, R2);
case CXXDefaultArgExprClass:
return cast<CXXDefaultArgExpr>(this)
->getExpr()->isUnusedResultAWarning(Loc, R1, R2);
case CXXNewExprClass:
// FIXME: In theory, there might be new expressions that don't have side
// effects (e.g. a placement new with an uninitialized POD).
case CXXDeleteExprClass:
return false;
}
}
/// DeclCanBeLvalue - Determine whether the given declaration can be
/// an lvalue. This is a helper routine for isLvalue.
static bool DeclCanBeLvalue(const NamedDecl *Decl, ASTContext &Ctx) {
// C++ [temp.param]p6:
// A non-type non-reference template-parameter is not an lvalue.
if (const NonTypeTemplateParmDecl *NTTParm
= dyn_cast<NonTypeTemplateParmDecl>(Decl))
return NTTParm->getType()->isReferenceType();
return isa<VarDecl>(Decl) || isa<FieldDecl>(Decl) ||
// C++ 3.10p2: An lvalue refers to an object or function.
(Ctx.getLangOptions().CPlusPlus &&
(isa<FunctionDecl>(Decl) || isa<OverloadedFunctionDecl>(Decl)));
}
/// isLvalue - C99 6.3.2.1: an lvalue is an expression with an object type or an
/// incomplete type other than void. Nonarray expressions that can be lvalues:
/// - name, where name must be a variable
/// - e[i]
/// - (e), where e must be an lvalue
/// - e.name, where e must be an lvalue
/// - e->name
/// - *e, the type of e cannot be a function type
/// - string-constant
/// - (__real__ e) and (__imag__ e) where e is an lvalue [GNU extension]
/// - reference type [C++ [expr]]
///
Expr::isLvalueResult Expr::isLvalue(ASTContext &Ctx) const {
// first, check the type (C99 6.3.2.1). Expressions with function
// type in C are not lvalues, but they can be lvalues in C++.
if (!Ctx.getLangOptions().CPlusPlus && TR->isFunctionType())
return LV_NotObjectType;
// Allow qualified void which is an incomplete type other than void (yuck).
if (TR->isVoidType() && !Ctx.getCanonicalType(TR).getCVRQualifiers())
return LV_IncompleteVoidType;
assert(!TR->isReferenceType() && "Expressions can't have reference type.");
// the type looks fine, now check the expression
switch (getStmtClass()) {
case StringLiteralClass: // C99 6.5.1p4
case ObjCEncodeExprClass: // @encode behaves like its string in every way.
return LV_Valid;
case ArraySubscriptExprClass: // C99 6.5.3p4 (e1[e2] == (*((e1)+(e2))))
// For vectors, make sure base is an lvalue (i.e. not a function call).
if (cast<ArraySubscriptExpr>(this)->getBase()->getType()->isVectorType())
return cast<ArraySubscriptExpr>(this)->getBase()->isLvalue(Ctx);
return LV_Valid;
case DeclRefExprClass:
case QualifiedDeclRefExprClass: { // C99 6.5.1p2
const NamedDecl *RefdDecl = cast<DeclRefExpr>(this)->getDecl();
if (DeclCanBeLvalue(RefdDecl, Ctx))
return LV_Valid;
break;
}
case BlockDeclRefExprClass: {
const BlockDeclRefExpr *BDR = cast<BlockDeclRefExpr>(this);
if (isa<VarDecl>(BDR->getDecl()))
return LV_Valid;
break;
}
case MemberExprClass: {
const MemberExpr *m = cast<MemberExpr>(this);
if (Ctx.getLangOptions().CPlusPlus) { // C++ [expr.ref]p4:
NamedDecl *Member = m->getMemberDecl();
// C++ [expr.ref]p4:
// If E2 is declared to have type "reference to T", then E1.E2
// is an lvalue.
if (ValueDecl *Value = dyn_cast<ValueDecl>(Member))
if (Value->getType()->isReferenceType())
return LV_Valid;
// -- If E2 is a static data member [...] then E1.E2 is an lvalue.
if (isa<VarDecl>(Member) && Member->getDeclContext()->isRecord())
return LV_Valid;
// -- If E2 is a non-static data member [...]. If E1 is an
// lvalue, then E1.E2 is an lvalue.
if (isa<FieldDecl>(Member))
return m->isArrow() ? LV_Valid : m->getBase()->isLvalue(Ctx);
// -- If it refers to a static member function [...], then
// E1.E2 is an lvalue.
// -- Otherwise, if E1.E2 refers to a non-static member
// function [...], then E1.E2 is not an lvalue.
if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Member))
return Method->isStatic()? LV_Valid : LV_MemberFunction;
// -- If E2 is a member enumerator [...], the expression E1.E2
// is not an lvalue.
if (isa<EnumConstantDecl>(Member))
return LV_InvalidExpression;
// Not an lvalue.
return LV_InvalidExpression;
}
// C99 6.5.2.3p4
return m->isArrow() ? LV_Valid : m->getBase()->isLvalue(Ctx);
}
case UnaryOperatorClass:
if (cast<UnaryOperator>(this)->getOpcode() == UnaryOperator::Deref)
return LV_Valid; // C99 6.5.3p4
if (cast<UnaryOperator>(this)->getOpcode() == UnaryOperator::Real ||
cast<UnaryOperator>(this)->getOpcode() == UnaryOperator::Imag ||
cast<UnaryOperator>(this)->getOpcode() == UnaryOperator::Extension)
return cast<UnaryOperator>(this)->getSubExpr()->isLvalue(Ctx); // GNU.
if (Ctx.getLangOptions().CPlusPlus && // C++ [expr.pre.incr]p1
(cast<UnaryOperator>(this)->getOpcode() == UnaryOperator::PreInc ||
cast<UnaryOperator>(this)->getOpcode() == UnaryOperator::PreDec))
return LV_Valid;
break;
case ImplicitCastExprClass:
return cast<ImplicitCastExpr>(this)->isLvalueCast()? LV_Valid
: LV_InvalidExpression;
case ParenExprClass: // C99 6.5.1p5
return cast<ParenExpr>(this)->getSubExpr()->isLvalue(Ctx);
case BinaryOperatorClass:
case CompoundAssignOperatorClass: {
const BinaryOperator *BinOp = cast<BinaryOperator>(this);
if (Ctx.getLangOptions().CPlusPlus && // C++ [expr.comma]p1
BinOp->getOpcode() == BinaryOperator::Comma)
return BinOp->getRHS()->isLvalue(Ctx);
// C++ [expr.mptr.oper]p6
if ((BinOp->getOpcode() == BinaryOperator::PtrMemD ||
BinOp->getOpcode() == BinaryOperator::PtrMemI) &&
!BinOp->getType()->isFunctionType())
return BinOp->getLHS()->isLvalue(Ctx);
if (!BinOp->isAssignmentOp())
return LV_InvalidExpression;
if (Ctx.getLangOptions().CPlusPlus)
// C++ [expr.ass]p1:
// The result of an assignment operation [...] is an lvalue.
return LV_Valid;
// C99 6.5.16:
// An assignment expression [...] is not an lvalue.
return LV_InvalidExpression;
}
case CallExprClass:
case CXXOperatorCallExprClass:
case CXXMemberCallExprClass: {
// C++0x [expr.call]p10
// A function call is an lvalue if and only if the result type
// is an lvalue reference.
QualType CalleeType = cast<CallExpr>(this)->getCallee()->getType();
if (const PointerType *FnTypePtr = CalleeType->getAsPointerType())
CalleeType = FnTypePtr->getPointeeType();
if (const FunctionType *FnType = CalleeType->getAsFunctionType())
if (FnType->getResultType()->isLValueReferenceType())
return LV_Valid;
break;
}
case CompoundLiteralExprClass: // C99 6.5.2.5p5
return LV_Valid;
case ChooseExprClass:
// __builtin_choose_expr is an lvalue if the selected operand is.
return cast<ChooseExpr>(this)->getChosenSubExpr(Ctx)->isLvalue(Ctx);
case ExtVectorElementExprClass:
if (cast<ExtVectorElementExpr>(this)->containsDuplicateElements())
return LV_DuplicateVectorComponents;
return LV_Valid;
case ObjCIvarRefExprClass: // ObjC instance variables are lvalues.
return LV_Valid;
case ObjCPropertyRefExprClass: // FIXME: check if read-only property.
return LV_Valid;
case ObjCKVCRefExprClass: // FIXME: check if read-only property.
return LV_Valid;
case PredefinedExprClass:
return LV_Valid;
case VAArgExprClass:
return LV_NotObjectType;
case CXXDefaultArgExprClass:
return cast<CXXDefaultArgExpr>(this)->getExpr()->isLvalue(Ctx);
case CXXConditionDeclExprClass:
return LV_Valid;
case CStyleCastExprClass:
case CXXFunctionalCastExprClass:
case CXXStaticCastExprClass:
case CXXDynamicCastExprClass:
case CXXReinterpretCastExprClass:
case CXXConstCastExprClass:
// The result of an explicit cast is an lvalue if the type we are
// casting to is an lvalue reference type. See C++ [expr.cast]p1,
// C++ [expr.static.cast]p2, C++ [expr.dynamic.cast]p2,
// C++ [expr.reinterpret.cast]p1, C++ [expr.const.cast]p1.
if (cast<ExplicitCastExpr>(this)->getTypeAsWritten()->
isLValueReferenceType())
return LV_Valid;
break;
case CXXTypeidExprClass:
// C++ 5.2.8p1: The result of a typeid expression is an lvalue of ...
return LV_Valid;
default:
break;
}
return LV_InvalidExpression;
}
/// isModifiableLvalue - C99 6.3.2.1: an lvalue that does not have array type,
/// does not have an incomplete type, does not have a const-qualified type, and
/// if it is a structure or union, does not have any member (including,
/// recursively, any member or element of all contained aggregates or unions)
/// with a const-qualified type.
Expr::isModifiableLvalueResult Expr::isModifiableLvalue(ASTContext &Ctx) const {
isLvalueResult lvalResult = isLvalue(Ctx);
switch (lvalResult) {
case LV_Valid:
// C++ 3.10p11: Functions cannot be modified, but pointers to
// functions can be modifiable.
if (Ctx.getLangOptions().CPlusPlus && TR->isFunctionType())
return MLV_NotObjectType;
break;
case LV_NotObjectType: return MLV_NotObjectType;
case LV_IncompleteVoidType: return MLV_IncompleteVoidType;
case LV_DuplicateVectorComponents: return MLV_DuplicateVectorComponents;
case LV_InvalidExpression:
// If the top level is a C-style cast, and the subexpression is a valid
// lvalue, then this is probably a use of the old-school "cast as lvalue"
// GCC extension. We don't support it, but we want to produce good
// diagnostics when it happens so that the user knows why.
if (const CStyleCastExpr *CE = dyn_cast<CStyleCastExpr>(this))
if (CE->getSubExpr()->isLvalue(Ctx) == LV_Valid)
return MLV_LValueCast;
return MLV_InvalidExpression;
case LV_MemberFunction: return MLV_MemberFunction;
}
QualType CT = Ctx.getCanonicalType(getType());
if (CT.isConstQualified())
return MLV_ConstQualified;
if (CT->isArrayType())
return MLV_ArrayType;
if (CT->isIncompleteType())
return MLV_IncompleteType;
if (const RecordType *r = CT->getAsRecordType()) {
if (r->hasConstFields())
return MLV_ConstQualified;
}
// The following is illegal:
// void takeclosure(void (^C)(void));
// void func() { int x = 1; takeclosure(^{ x = 7 }); }
//
if (getStmtClass() == BlockDeclRefExprClass) {
const BlockDeclRefExpr *BDR = cast<BlockDeclRefExpr>(this);
if (!BDR->isByRef() && isa<VarDecl>(BDR->getDecl()))
return MLV_NotBlockQualified;
}
// Assigning to an 'implicit' property?
else if (getStmtClass() == ObjCKVCRefExprClass) {
const ObjCKVCRefExpr* KVCExpr = cast<ObjCKVCRefExpr>(this);
if (KVCExpr->getSetterMethod() == 0)
return MLV_NoSetterProperty;
}
return MLV_Valid;
}
/// hasGlobalStorage - Return true if this expression has static storage
/// duration. This means that the address of this expression is a link-time
/// constant.
bool Expr::hasGlobalStorage() const {
switch (getStmtClass()) {
default:
return false;
case ParenExprClass:
return cast<ParenExpr>(this)->getSubExpr()->hasGlobalStorage();
case ImplicitCastExprClass:
return cast<ImplicitCastExpr>(this)->getSubExpr()->hasGlobalStorage();
case CompoundLiteralExprClass:
return cast<CompoundLiteralExpr>(this)->isFileScope();
case DeclRefExprClass:
case QualifiedDeclRefExprClass: {
const Decl *D = cast<DeclRefExpr>(this)->getDecl();
if (const VarDecl *VD = dyn_cast<VarDecl>(D))
return VD->hasGlobalStorage();
if (isa<FunctionDecl>(D))
return true;
return false;
}
case MemberExprClass: {
const MemberExpr *M = cast<MemberExpr>(this);
return !M->isArrow() && M->getBase()->hasGlobalStorage();
}
case ArraySubscriptExprClass:
return cast<ArraySubscriptExpr>(this)->getBase()->hasGlobalStorage();
case PredefinedExprClass:
return true;
case CXXDefaultArgExprClass:
return cast<CXXDefaultArgExpr>(this)->getExpr()->hasGlobalStorage();
}
}
/// isOBJCGCCandidate - Check if an expression is objc gc'able.
///
bool Expr::isOBJCGCCandidate() const {
switch (getStmtClass()) {
default:
return false;
case ObjCIvarRefExprClass:
return true;
case Expr::UnaryOperatorClass:
return cast<UnaryOperator>(this)->getSubExpr()->isOBJCGCCandidate();
case ParenExprClass:
return cast<ParenExpr>(this)->getSubExpr()->isOBJCGCCandidate();
case ImplicitCastExprClass:
return cast<ImplicitCastExpr>(this)->getSubExpr()->isOBJCGCCandidate();
case DeclRefExprClass:
case QualifiedDeclRefExprClass: {
const Decl *D = cast<DeclRefExpr>(this)->getDecl();
if (const VarDecl *VD = dyn_cast<VarDecl>(D))
return VD->hasGlobalStorage();
return false;
}
case MemberExprClass: {
const MemberExpr *M = cast<MemberExpr>(this);
return !M->isArrow() && M->getBase()->isOBJCGCCandidate();
}
case ArraySubscriptExprClass:
return cast<ArraySubscriptExpr>(this)->getBase()->isOBJCGCCandidate();
}
}
Expr* Expr::IgnoreParens() {
Expr* E = this;
while (ParenExpr* P = dyn_cast<ParenExpr>(E))
E = P->getSubExpr();
return E;
}
/// IgnoreParenCasts - Ignore parentheses and casts. Strip off any ParenExpr
/// or CastExprs or ImplicitCastExprs, returning their operand.
Expr *Expr::IgnoreParenCasts() {
Expr *E = this;
while (true) {
if (ParenExpr *P = dyn_cast<ParenExpr>(E))
E = P->getSubExpr();
else if (CastExpr *P = dyn_cast<CastExpr>(E))
E = P->getSubExpr();
else
return E;
}
}
/// IgnoreParenNoopCasts - Ignore parentheses and casts that do not change the
/// value (including ptr->int casts of the same size). Strip off any
/// ParenExpr or CastExprs, returning their operand.
Expr *Expr::IgnoreParenNoopCasts(ASTContext &Ctx) {
Expr *E = this;
while (true) {
if (ParenExpr *P = dyn_cast<ParenExpr>(E)) {
E = P->getSubExpr();
continue;
}
if (CastExpr *P = dyn_cast<CastExpr>(E)) {
// We ignore integer <-> casts that are of the same width, ptr<->ptr and
// ptr<->int casts of the same width. We also ignore all identify casts.
Expr *SE = P->getSubExpr();
if (Ctx.hasSameUnqualifiedType(E->getType(), SE->getType())) {
E = SE;
continue;
}
if ((E->getType()->isPointerType() || E->getType()->isIntegralType()) &&
(SE->getType()->isPointerType() || SE->getType()->isIntegralType()) &&
Ctx.getTypeSize(E->getType()) == Ctx.getTypeSize(SE->getType())) {
E = SE;
continue;
}
}
return E;
}
}
/// hasAnyTypeDependentArguments - Determines if any of the expressions
/// in Exprs is type-dependent.
bool Expr::hasAnyTypeDependentArguments(Expr** Exprs, unsigned NumExprs) {
for (unsigned I = 0; I < NumExprs; ++I)
if (Exprs[I]->isTypeDependent())
return true;
return false;
}
/// hasAnyValueDependentArguments - Determines if any of the expressions
/// in Exprs is value-dependent.
bool Expr::hasAnyValueDependentArguments(Expr** Exprs, unsigned NumExprs) {
for (unsigned I = 0; I < NumExprs; ++I)
if (Exprs[I]->isValueDependent())
return true;
return false;
}
bool Expr::isConstantInitializer(ASTContext &Ctx) const {
// This function is attempting whether an expression is an initializer
// which can be evaluated at compile-time. isEvaluatable handles most
// of the cases, but it can't deal with some initializer-specific
// expressions, and it can't deal with aggregates; we deal with those here,
// and fall back to isEvaluatable for the other cases.
// FIXME: This function assumes the variable being assigned to
// isn't a reference type!
switch (getStmtClass()) {
default: break;
case StringLiteralClass:
case ObjCEncodeExprClass:
return true;
case CompoundLiteralExprClass: {
// This handles gcc's extension that allows global initializers like
// "struct x {int x;} x = (struct x) {};".
// FIXME: This accepts other cases it shouldn't!
const Expr *Exp = cast<CompoundLiteralExpr>(this)->getInitializer();
return Exp->isConstantInitializer(Ctx);
}
case InitListExprClass: {
// FIXME: This doesn't deal with fields with reference types correctly.
// FIXME: This incorrectly allows pointers cast to integers to be assigned
// to bitfields.
const InitListExpr *Exp = cast<InitListExpr>(this);
unsigned numInits = Exp->getNumInits();
for (unsigned i = 0; i < numInits; i++) {
if (!Exp->getInit(i)->isConstantInitializer(Ctx))
return false;
}
return true;
}
case ImplicitValueInitExprClass:
return true;
case ParenExprClass: {
return cast<ParenExpr>(this)->getSubExpr()->isConstantInitializer(Ctx);
}
case UnaryOperatorClass: {
const UnaryOperator* Exp = cast<UnaryOperator>(this);
if (Exp->getOpcode() == UnaryOperator::Extension)
return Exp->getSubExpr()->isConstantInitializer(Ctx);
break;
}
case CStyleCastExprClass:
// Handle casts with a destination that's a struct or union; this
// deals with both the gcc no-op struct cast extension and the
// cast-to-union extension.
if (getType()->isRecordType())
return cast<CastExpr>(this)->getSubExpr()->isConstantInitializer(Ctx);
break;
}
return isEvaluatable(Ctx);
}
/// isIntegerConstantExpr - this recursive routine will test if an expression is
/// an integer constant expression.
/// FIXME: Pass up a reason why! Invalid operation in i-c-e, division by zero,
/// comma, etc
///
/// FIXME: Handle offsetof. Two things to do: Handle GCC's __builtin_offsetof
/// to support gcc 4.0+ and handle the idiom GCC recognizes with a null pointer
/// cast+dereference.
// CheckICE - This function does the fundamental ICE checking: the returned
// ICEDiag contains a Val of 0, 1, or 2, and a possibly null SourceLocation.
// Note that to reduce code duplication, this helper does no evaluation
// itself; the caller checks whether the expression is evaluatable, and
// in the rare cases where CheckICE actually cares about the evaluated
// value, it calls into Evalute.
//
// Meanings of Val:
// 0: This expression is an ICE if it can be evaluated by Evaluate.
// 1: This expression is not an ICE, but if it isn't evaluated, it's
// a legal subexpression for an ICE. This return value is used to handle
// the comma operator in C99 mode.
// 2: This expression is not an ICE, and is not a legal subexpression for one.
struct ICEDiag {
unsigned Val;
SourceLocation Loc;
public:
ICEDiag(unsigned v, SourceLocation l) : Val(v), Loc(l) {}
ICEDiag() : Val(0) {}
};
ICEDiag NoDiag() { return ICEDiag(); }
static ICEDiag CheckEvalInICE(const Expr* E, ASTContext &Ctx) {
Expr::EvalResult EVResult;
if (!E->Evaluate(EVResult, Ctx) || EVResult.HasSideEffects ||
!EVResult.Val.isInt()) {
return ICEDiag(2, E->getLocStart());
}
return NoDiag();
}
static ICEDiag CheckICE(const Expr* E, ASTContext &Ctx) {
assert(!E->isValueDependent() && "Should not see value dependent exprs!");
if (!E->getType()->isIntegralType()) {
return ICEDiag(2, E->getLocStart());
}
switch (E->getStmtClass()) {
default:
return ICEDiag(2, E->getLocStart());
case Expr::ParenExprClass:
return CheckICE(cast<ParenExpr>(E)->getSubExpr(), Ctx);
case Expr::IntegerLiteralClass:
case Expr::CharacterLiteralClass:
case Expr::CXXBoolLiteralExprClass:
case Expr::CXXZeroInitValueExprClass:
case Expr::TypesCompatibleExprClass:
case Expr::UnaryTypeTraitExprClass:
return NoDiag();
case Expr::CallExprClass:
case Expr::CXXOperatorCallExprClass: {
const CallExpr *CE = cast<CallExpr>(E);
if (CE->isBuiltinCall(Ctx))
return CheckEvalInICE(E, Ctx);
return ICEDiag(2, E->getLocStart());
}
case Expr::DeclRefExprClass:
case Expr::QualifiedDeclRefExprClass:
if (isa<EnumConstantDecl>(cast<DeclRefExpr>(E)->getDecl()))
return NoDiag();
if (Ctx.getLangOptions().CPlusPlus &&
E->getType().getCVRQualifiers() == QualType::Const) {
// C++ 7.1.5.1p2
// A variable of non-volatile const-qualified integral or enumeration
// type initialized by an ICE can be used in ICEs.
if (const VarDecl *Dcl =
dyn_cast<VarDecl>(cast<DeclRefExpr>(E)->getDecl())) {
if (const Expr *Init = Dcl->getInit())
return CheckICE(Init, Ctx);
}
}
return ICEDiag(2, E->getLocStart());
case Expr::UnaryOperatorClass: {
const UnaryOperator *Exp = cast<UnaryOperator>(E);
switch (Exp->getOpcode()) {
default:
return ICEDiag(2, E->getLocStart());
case UnaryOperator::Extension:
case UnaryOperator::LNot:
case UnaryOperator::Plus:
case UnaryOperator::Minus:
case UnaryOperator::Not:
case UnaryOperator::Real:
case UnaryOperator::Imag:
return CheckICE(Exp->getSubExpr(), Ctx);
case UnaryOperator::OffsetOf:
// Note that per C99, offsetof must be an ICE. And AFAIK, using
// Evaluate matches the proposed gcc behavior for cases like
// "offsetof(struct s{int x[4];}, x[!.0])". This doesn't affect
// compliance: we should warn earlier for offsetof expressions with
// array subscripts that aren't ICEs, and if the array subscripts
// are ICEs, the value of the offsetof must be an integer constant.
return CheckEvalInICE(E, Ctx);
}
}
case Expr::SizeOfAlignOfExprClass: {
const SizeOfAlignOfExpr *Exp = cast<SizeOfAlignOfExpr>(E);
if (Exp->isSizeOf() && Exp->getTypeOfArgument()->isVariableArrayType())
return ICEDiag(2, E->getLocStart());
return NoDiag();
}
case Expr::BinaryOperatorClass: {
const BinaryOperator *Exp = cast<BinaryOperator>(E);
switch (Exp->getOpcode()) {
default:
return ICEDiag(2, E->getLocStart());
case BinaryOperator::Mul:
case BinaryOperator::Div:
case BinaryOperator::Rem:
case BinaryOperator::Add:
case BinaryOperator::Sub:
case BinaryOperator::Shl:
case BinaryOperator::Shr:
case BinaryOperator::LT:
case BinaryOperator::GT:
case BinaryOperator::LE:
case BinaryOperator::GE:
case BinaryOperator::EQ:
case BinaryOperator::NE:
case BinaryOperator::And:
case BinaryOperator::Xor:
case BinaryOperator::Or:
case BinaryOperator::Comma: {
ICEDiag LHSResult = CheckICE(Exp->getLHS(), Ctx);
ICEDiag RHSResult = CheckICE(Exp->getRHS(), Ctx);
if (Exp->getOpcode() == BinaryOperator::Div ||
Exp->getOpcode() == BinaryOperator::Rem) {
// Evaluate gives an error for undefined Div/Rem, so make sure
// we don't evaluate one.
if (LHSResult.Val != 2 && RHSResult.Val != 2) {
llvm::APSInt REval = Exp->getRHS()->EvaluateAsInt(Ctx);
if (REval == 0)
return ICEDiag(1, E->getLocStart());
if (REval.isSigned() && REval.isAllOnesValue()) {
llvm::APSInt LEval = Exp->getLHS()->EvaluateAsInt(Ctx);
if (LEval.isMinSignedValue())
return ICEDiag(1, E->getLocStart());
}
}
}
if (Exp->getOpcode() == BinaryOperator::Comma) {
if (Ctx.getLangOptions().C99) {
// C99 6.6p3 introduces a strange edge case: comma can be in an ICE
// if it isn't evaluated.
if (LHSResult.Val == 0 && RHSResult.Val == 0)
return ICEDiag(1, E->getLocStart());
} else {
// In both C89 and C++, commas in ICEs are illegal.
return ICEDiag(2, E->getLocStart());
}
}
if (LHSResult.Val >= RHSResult.Val)
return LHSResult;
return RHSResult;
}
case BinaryOperator::LAnd:
case BinaryOperator::LOr: {
ICEDiag LHSResult = CheckICE(Exp->getLHS(), Ctx);
ICEDiag RHSResult = CheckICE(Exp->getRHS(), Ctx);
if (LHSResult.Val == 0 && RHSResult.Val == 1) {
// Rare case where the RHS has a comma "side-effect"; we need
// to actually check the condition to see whether the side
// with the comma is evaluated.
if ((Exp->getOpcode() == BinaryOperator::LAnd) !=
(Exp->getLHS()->EvaluateAsInt(Ctx) == 0))
return RHSResult;
return NoDiag();
}
if (LHSResult.Val >= RHSResult.Val)
return LHSResult;
return RHSResult;
}
}
}
case Expr::ImplicitCastExprClass:
case Expr::CStyleCastExprClass:
case Expr::CXXFunctionalCastExprClass: {
const Expr *SubExpr = cast<CastExpr>(E)->getSubExpr();
if (SubExpr->getType()->isIntegralType())
return CheckICE(SubExpr, Ctx);
if (isa<FloatingLiteral>(SubExpr->IgnoreParens()))
return NoDiag();
return ICEDiag(2, E->getLocStart());
}
case Expr::ConditionalOperatorClass: {
const ConditionalOperator *Exp = cast<ConditionalOperator>(E);
// If the condition (ignoring parens) is a __builtin_constant_p call,
// then only the true side is actually considered in an integer constant
// expression, and it is fully evaluated. This is an important GNU
// extension. See GCC PR38377 for discussion.
if (const CallExpr *CallCE = dyn_cast<CallExpr>(Exp->getCond()->IgnoreParenCasts()))
if (CallCE->isBuiltinCall(Ctx) == Builtin::BI__builtin_constant_p) {
Expr::EvalResult EVResult;
if (!E->Evaluate(EVResult, Ctx) || EVResult.HasSideEffects ||
!EVResult.Val.isInt()) {
return ICEDiag(2, E->getLocStart());
}
return NoDiag();
}
ICEDiag CondResult = CheckICE(Exp->getCond(), Ctx);
ICEDiag TrueResult = CheckICE(Exp->getTrueExpr(), Ctx);
ICEDiag FalseResult = CheckICE(Exp->getFalseExpr(), Ctx);
if (CondResult.Val == 2)
return CondResult;
if (TrueResult.Val == 2)
return TrueResult;
if (FalseResult.Val == 2)
return FalseResult;
if (CondResult.Val == 1)
return CondResult;
if (TrueResult.Val == 0 && FalseResult.Val == 0)
return NoDiag();
// Rare case where the diagnostics depend on which side is evaluated
// Note that if we get here, CondResult is 0, and at least one of
// TrueResult and FalseResult is non-zero.
if (Exp->getCond()->EvaluateAsInt(Ctx) == 0) {
return FalseResult;
}
return TrueResult;
}
case Expr::CXXDefaultArgExprClass:
return CheckICE(cast<CXXDefaultArgExpr>(E)->getExpr(), Ctx);
case Expr::ChooseExprClass: {
return CheckICE(cast<ChooseExpr>(E)->getChosenSubExpr(Ctx), Ctx);
}
}
}
bool Expr::isIntegerConstantExpr(llvm::APSInt &Result, ASTContext &Ctx,
SourceLocation *Loc, bool isEvaluated) const {
ICEDiag d = CheckICE(this, Ctx);
if (d.Val != 0) {
if (Loc) *Loc = d.Loc;
return false;
}
EvalResult EvalResult;
if (!Evaluate(EvalResult, Ctx))
assert(0 && "ICE cannot be evaluated!");
assert(!EvalResult.HasSideEffects && "ICE with side effects!");
assert(EvalResult.Val.isInt() && "ICE that isn't integer!");
Result = EvalResult.Val.getInt();
return true;
}
/// isNullPointerConstant - C99 6.3.2.3p3 - Return true if this is either an
/// integer constant expression with the value zero, or if this is one that is
/// cast to void*.
bool Expr::isNullPointerConstant(ASTContext &Ctx) const
{
// Strip off a cast to void*, if it exists. Except in C++.
if (const ExplicitCastExpr *CE = dyn_cast<ExplicitCastExpr>(this)) {
if (!Ctx.getLangOptions().CPlusPlus) {
// Check that it is a cast to void*.
if (const PointerType *PT = CE->getType()->getAsPointerType()) {
QualType Pointee = PT->getPointeeType();
if (Pointee.getCVRQualifiers() == 0 &&
Pointee->isVoidType() && // to void*
CE->getSubExpr()->getType()->isIntegerType()) // from int.
return CE->getSubExpr()->isNullPointerConstant(Ctx);
}
}
} else if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(this)) {
// Ignore the ImplicitCastExpr type entirely.
return ICE->getSubExpr()->isNullPointerConstant(Ctx);
} else if (const ParenExpr *PE = dyn_cast<ParenExpr>(this)) {
// Accept ((void*)0) as a null pointer constant, as many other
// implementations do.
return PE->getSubExpr()->isNullPointerConstant(Ctx);
} else if (const CXXDefaultArgExpr *DefaultArg
= dyn_cast<CXXDefaultArgExpr>(this)) {
// See through default argument expressions
return DefaultArg->getExpr()->isNullPointerConstant(Ctx);
} else if (isa<GNUNullExpr>(this)) {
// The GNU __null extension is always a null pointer constant.
return true;
}
// This expression must be an integer type.
if (!getType()->isIntegerType())
return false;
// If we have an integer constant expression, we need to *evaluate* it and
// test for the value 0.
// FIXME: We should probably return false if we're compiling in strict mode
// and Diag is not null (this indicates that the value was foldable but not
// an ICE.
EvalResult Result;
return Evaluate(Result, Ctx) && !Result.HasSideEffects &&
Result.Val.isInt() && Result.Val.getInt() == 0;
}
/// isBitField - Return true if this expression is a bit-field.
bool Expr::isBitField() {
Expr *E = this->IgnoreParenCasts();
if (MemberExpr *MemRef = dyn_cast<MemberExpr>(E))
if (FieldDecl *Field = dyn_cast<FieldDecl>(MemRef->getMemberDecl()))
return Field->isBitField();
return false;
}
/// isArrow - Return true if the base expression is a pointer to vector,
/// return false if the base expression is a vector.
bool ExtVectorElementExpr::isArrow() const {
return getBase()->getType()->isPointerType();
}
unsigned ExtVectorElementExpr::getNumElements() const {
if (const VectorType *VT = getType()->getAsVectorType())
return VT->getNumElements();
return 1;
}
/// containsDuplicateElements - Return true if any element access is repeated.
bool ExtVectorElementExpr::containsDuplicateElements() const {
const char *compStr = Accessor.getName();
unsigned length = Accessor.getLength();
// Halving swizzles do not contain duplicate elements.
if (!strcmp(compStr, "hi") || !strcmp(compStr, "lo") ||
!strcmp(compStr, "even") || !strcmp(compStr, "odd"))
return false;
// Advance past s-char prefix on hex swizzles.
if (*compStr == 's') {
compStr++;
length--;
}
for (unsigned i = 0; i != length-1; i++) {
const char *s = compStr+i;
for (const char c = *s++; *s; s++)
if (c == *s)
return true;
}
return false;
}
/// getEncodedElementAccess - We encode the fields as a llvm ConstantArray.
void ExtVectorElementExpr::getEncodedElementAccess(
llvm::SmallVectorImpl<unsigned> &Elts) const {
const char *compStr = Accessor.getName();
if (*compStr == 's')
compStr++;
bool isHi = !strcmp(compStr, "hi");
bool isLo = !strcmp(compStr, "lo");
bool isEven = !strcmp(compStr, "even");
bool isOdd = !strcmp(compStr, "odd");
for (unsigned i = 0, e = getNumElements(); i != e; ++i) {
uint64_t Index;
if (isHi)
Index = e + i;
else if (isLo)
Index = i;
else if (isEven)
Index = 2 * i;
else if (isOdd)
Index = 2 * i + 1;
else
Index = ExtVectorType::getAccessorIdx(compStr[i]);
Elts.push_back(Index);
}
}
// constructor for instance messages.
ObjCMessageExpr::ObjCMessageExpr(Expr *receiver, Selector selInfo,
QualType retType, ObjCMethodDecl *mproto,
SourceLocation LBrac, SourceLocation RBrac,
Expr **ArgExprs, unsigned nargs)
: Expr(ObjCMessageExprClass, retType), SelName(selInfo),
MethodProto(mproto) {
NumArgs = nargs;
SubExprs = new Stmt*[NumArgs+1];
SubExprs[RECEIVER] = receiver;
if (NumArgs) {
for (unsigned i = 0; i != NumArgs; ++i)
SubExprs[i+ARGS_START] = static_cast<Expr *>(ArgExprs[i]);
}
LBracloc = LBrac;
RBracloc = RBrac;
}
// constructor for class messages.
// FIXME: clsName should be typed to ObjCInterfaceType
ObjCMessageExpr::ObjCMessageExpr(IdentifierInfo *clsName, Selector selInfo,
QualType retType, ObjCMethodDecl *mproto,
SourceLocation LBrac, SourceLocation RBrac,
Expr **ArgExprs, unsigned nargs)
: Expr(ObjCMessageExprClass, retType), SelName(selInfo),
MethodProto(mproto) {
NumArgs = nargs;
SubExprs = new Stmt*[NumArgs+1];
SubExprs[RECEIVER] = (Expr*) ((uintptr_t) clsName | IsClsMethDeclUnknown);
if (NumArgs) {
for (unsigned i = 0; i != NumArgs; ++i)
SubExprs[i+ARGS_START] = static_cast<Expr *>(ArgExprs[i]);
}
LBracloc = LBrac;
RBracloc = RBrac;
}
// constructor for class messages.
ObjCMessageExpr::ObjCMessageExpr(ObjCInterfaceDecl *cls, Selector selInfo,
QualType retType, ObjCMethodDecl *mproto,
SourceLocation LBrac, SourceLocation RBrac,
Expr **ArgExprs, unsigned nargs)
: Expr(ObjCMessageExprClass, retType), SelName(selInfo),
MethodProto(mproto) {
NumArgs = nargs;
SubExprs = new Stmt*[NumArgs+1];
SubExprs[RECEIVER] = (Expr*) ((uintptr_t) cls | IsClsMethDeclKnown);
if (NumArgs) {
for (unsigned i = 0; i != NumArgs; ++i)
SubExprs[i+ARGS_START] = static_cast<Expr *>(ArgExprs[i]);
}
LBracloc = LBrac;
RBracloc = RBrac;
}
ObjCMessageExpr::ClassInfo ObjCMessageExpr::getClassInfo() const {
uintptr_t x = (uintptr_t) SubExprs[RECEIVER];
switch (x & Flags) {
default:
assert(false && "Invalid ObjCMessageExpr.");
case IsInstMeth:
return ClassInfo(0, 0);
case IsClsMethDeclUnknown:
return ClassInfo(0, (IdentifierInfo*) (x & ~Flags));
case IsClsMethDeclKnown: {
ObjCInterfaceDecl* D = (ObjCInterfaceDecl*) (x & ~Flags);
return ClassInfo(D, D->getIdentifier());
}
}
}
bool ChooseExpr::isConditionTrue(ASTContext &C) const {
return getCond()->getIntegerConstantExprValue(C) != 0;
}
void SizeOfAlignOfExpr::Destroy(ASTContext& C) {
// Override default behavior of traversing children. If this has a type
// operand and the type is a variable-length array, the child iteration
// will iterate over the size expression. However, this expression belongs
// to the type, not to this, so we don't want to delete it.
// We still want to delete this expression.
if (isArgumentType()) {
this->~SizeOfAlignOfExpr();
C.Deallocate(this);
}
else
Expr::Destroy(C);
}
//===----------------------------------------------------------------------===//
// DesignatedInitExpr
//===----------------------------------------------------------------------===//
IdentifierInfo *DesignatedInitExpr::Designator::getFieldName() {
assert(Kind == FieldDesignator && "Only valid on a field designator");
if (Field.NameOrField & 0x01)
return reinterpret_cast<IdentifierInfo *>(Field.NameOrField&~0x01);
else
return getField()->getIdentifier();
}
DesignatedInitExpr *
DesignatedInitExpr::Create(ASTContext &C, Designator *Designators,
unsigned NumDesignators,
Expr **IndexExprs, unsigned NumIndexExprs,
SourceLocation ColonOrEqualLoc,
bool UsesColonSyntax, Expr *Init) {
void *Mem = C.Allocate(sizeof(DesignatedInitExpr) +
sizeof(Designator) * NumDesignators +
sizeof(Stmt *) * (NumIndexExprs + 1), 8);
DesignatedInitExpr *DIE
= new (Mem) DesignatedInitExpr(C.VoidTy, NumDesignators,
ColonOrEqualLoc, UsesColonSyntax,
NumIndexExprs + 1);
// Fill in the designators
unsigned ExpectedNumSubExprs = 0;
designators_iterator Desig = DIE->designators_begin();
for (unsigned Idx = 0; Idx < NumDesignators; ++Idx, ++Desig) {
new (static_cast<void*>(Desig)) Designator(Designators[Idx]);
if (Designators[Idx].isArrayDesignator())
++ExpectedNumSubExprs;
else if (Designators[Idx].isArrayRangeDesignator())
ExpectedNumSubExprs += 2;
}
assert(ExpectedNumSubExprs == NumIndexExprs && "Wrong number of indices!");
// Fill in the subexpressions, including the initializer expression.
child_iterator Child = DIE->child_begin();
*Child++ = Init;
for (unsigned Idx = 0; Idx < NumIndexExprs; ++Idx, ++Child)
*Child = IndexExprs[Idx];
return DIE;
}
SourceRange DesignatedInitExpr::getSourceRange() const {
SourceLocation StartLoc;
Designator &First =
*const_cast<DesignatedInitExpr*>(this)->designators_begin();
if (First.isFieldDesignator()) {
if (UsesColonSyntax)
StartLoc = SourceLocation::getFromRawEncoding(First.Field.FieldLoc);
else
StartLoc = SourceLocation::getFromRawEncoding(First.Field.DotLoc);
} else
StartLoc =
SourceLocation::getFromRawEncoding(First.ArrayOrRange.LBracketLoc);
return SourceRange(StartLoc, getInit()->getSourceRange().getEnd());
}
DesignatedInitExpr::designators_iterator
DesignatedInitExpr::designators_begin() {
char* Ptr = static_cast<char*>(static_cast<void *>(this));
Ptr += sizeof(DesignatedInitExpr);
return static_cast<Designator*>(static_cast<void*>(Ptr));
}
DesignatedInitExpr::designators_iterator DesignatedInitExpr::designators_end() {
return designators_begin() + NumDesignators;
}
Expr *DesignatedInitExpr::getArrayIndex(const Designator& D) {
assert(D.Kind == Designator::ArrayDesignator && "Requires array designator");
char* Ptr = static_cast<char*>(static_cast<void *>(this));
Ptr += sizeof(DesignatedInitExpr);
Ptr += sizeof(Designator) * NumDesignators;
Stmt **SubExprs = reinterpret_cast<Stmt**>(reinterpret_cast<void**>(Ptr));
return cast<Expr>(*(SubExprs + D.ArrayOrRange.Index + 1));
}
Expr *DesignatedInitExpr::getArrayRangeStart(const Designator& D) {
assert(D.Kind == Designator::ArrayRangeDesignator &&
"Requires array range designator");
char* Ptr = static_cast<char*>(static_cast<void *>(this));
Ptr += sizeof(DesignatedInitExpr);
Ptr += sizeof(Designator) * NumDesignators;
Stmt **SubExprs = reinterpret_cast<Stmt**>(reinterpret_cast<void**>(Ptr));
return cast<Expr>(*(SubExprs + D.ArrayOrRange.Index + 1));
}
Expr *DesignatedInitExpr::getArrayRangeEnd(const Designator& D) {
assert(D.Kind == Designator::ArrayRangeDesignator &&
"Requires array range designator");
char* Ptr = static_cast<char*>(static_cast<void *>(this));
Ptr += sizeof(DesignatedInitExpr);
Ptr += sizeof(Designator) * NumDesignators;
Stmt **SubExprs = reinterpret_cast<Stmt**>(reinterpret_cast<void**>(Ptr));
return cast<Expr>(*(SubExprs + D.ArrayOrRange.Index + 2));
}
//===----------------------------------------------------------------------===//
// ExprIterator.
//===----------------------------------------------------------------------===//
Expr* ExprIterator::operator[](size_t idx) { return cast<Expr>(I[idx]); }
Expr* ExprIterator::operator*() const { return cast<Expr>(*I); }
Expr* ExprIterator::operator->() const { return cast<Expr>(*I); }
const Expr* ConstExprIterator::operator[](size_t idx) const {
return cast<Expr>(I[idx]);
}
const Expr* ConstExprIterator::operator*() const { return cast<Expr>(*I); }
const Expr* ConstExprIterator::operator->() const { return cast<Expr>(*I); }
//===----------------------------------------------------------------------===//
// Child Iterators for iterating over subexpressions/substatements
//===----------------------------------------------------------------------===//
// DeclRefExpr
Stmt::child_iterator DeclRefExpr::child_begin() { return child_iterator(); }
Stmt::child_iterator DeclRefExpr::child_end() { return child_iterator(); }
// ObjCIvarRefExpr
Stmt::child_iterator ObjCIvarRefExpr::child_begin() { return &Base; }
Stmt::child_iterator ObjCIvarRefExpr::child_end() { return &Base+1; }
// ObjCPropertyRefExpr
Stmt::child_iterator ObjCPropertyRefExpr::child_begin() { return &Base; }
Stmt::child_iterator ObjCPropertyRefExpr::child_end() { return &Base+1; }
// ObjCKVCRefExpr
Stmt::child_iterator ObjCKVCRefExpr::child_begin() { return &Base; }
Stmt::child_iterator ObjCKVCRefExpr::child_end() { return &Base+1; }
// ObjCSuperExpr
Stmt::child_iterator ObjCSuperExpr::child_begin() { return child_iterator(); }
Stmt::child_iterator ObjCSuperExpr::child_end() { return child_iterator(); }
// PredefinedExpr
Stmt::child_iterator PredefinedExpr::child_begin() { return child_iterator(); }
Stmt::child_iterator PredefinedExpr::child_end() { return child_iterator(); }
// IntegerLiteral
Stmt::child_iterator IntegerLiteral::child_begin() { return child_iterator(); }
Stmt::child_iterator IntegerLiteral::child_end() { return child_iterator(); }
// CharacterLiteral
Stmt::child_iterator CharacterLiteral::child_begin() { return child_iterator();}
Stmt::child_iterator CharacterLiteral::child_end() { return child_iterator(); }
// FloatingLiteral
Stmt::child_iterator FloatingLiteral::child_begin() { return child_iterator(); }
Stmt::child_iterator FloatingLiteral::child_end() { return child_iterator(); }
// ImaginaryLiteral
Stmt::child_iterator ImaginaryLiteral::child_begin() { return &Val; }
Stmt::child_iterator ImaginaryLiteral::child_end() { return &Val+1; }
// StringLiteral
Stmt::child_iterator StringLiteral::child_begin() { return child_iterator(); }
Stmt::child_iterator StringLiteral::child_end() { return child_iterator(); }
// ParenExpr
Stmt::child_iterator ParenExpr::child_begin() { return &Val; }
Stmt::child_iterator ParenExpr::child_end() { return &Val+1; }
// UnaryOperator
Stmt::child_iterator UnaryOperator::child_begin() { return &Val; }
Stmt::child_iterator UnaryOperator::child_end() { return &Val+1; }
// SizeOfAlignOfExpr
Stmt::child_iterator SizeOfAlignOfExpr::child_begin() {
// If this is of a type and the type is a VLA type (and not a typedef), the
// size expression of the VLA needs to be treated as an executable expression.
// Why isn't this weirdness documented better in StmtIterator?
if (isArgumentType()) {
if (VariableArrayType* T = dyn_cast<VariableArrayType>(
getArgumentType().getTypePtr()))
return child_iterator(T);
return child_iterator();
}
return child_iterator(&Argument.Ex);
}
Stmt::child_iterator SizeOfAlignOfExpr::child_end() {
if (isArgumentType())
return child_iterator();
return child_iterator(&Argument.Ex + 1);
}
// ArraySubscriptExpr
Stmt::child_iterator ArraySubscriptExpr::child_begin() {
return &SubExprs[0];
}
Stmt::child_iterator ArraySubscriptExpr::child_end() {
return &SubExprs[0]+END_EXPR;
}
// CallExpr
Stmt::child_iterator CallExpr::child_begin() {
return &SubExprs[0];
}
Stmt::child_iterator CallExpr::child_end() {
return &SubExprs[0]+NumArgs+ARGS_START;
}
// MemberExpr
Stmt::child_iterator MemberExpr::child_begin() { return &Base; }
Stmt::child_iterator MemberExpr::child_end() { return &Base+1; }
// ExtVectorElementExpr
Stmt::child_iterator ExtVectorElementExpr::child_begin() { return &Base; }
Stmt::child_iterator ExtVectorElementExpr::child_end() { return &Base+1; }
// CompoundLiteralExpr
Stmt::child_iterator CompoundLiteralExpr::child_begin() { return &Init; }
Stmt::child_iterator CompoundLiteralExpr::child_end() { return &Init+1; }
// CastExpr
Stmt::child_iterator CastExpr::child_begin() { return &Op; }
Stmt::child_iterator CastExpr::child_end() { return &Op+1; }
// BinaryOperator
Stmt::child_iterator BinaryOperator::child_begin() {
return &SubExprs[0];
}
Stmt::child_iterator BinaryOperator::child_end() {
return &SubExprs[0]+END_EXPR;
}
// ConditionalOperator
Stmt::child_iterator ConditionalOperator::child_begin() {
return &SubExprs[0];
}
Stmt::child_iterator ConditionalOperator::child_end() {
return &SubExprs[0]+END_EXPR;
}
// AddrLabelExpr
Stmt::child_iterator AddrLabelExpr::child_begin() { return child_iterator(); }
Stmt::child_iterator AddrLabelExpr::child_end() { return child_iterator(); }
// StmtExpr
Stmt::child_iterator StmtExpr::child_begin() { return &SubStmt; }
Stmt::child_iterator StmtExpr::child_end() { return &SubStmt+1; }
// TypesCompatibleExpr
Stmt::child_iterator TypesCompatibleExpr::child_begin() {
return child_iterator();
}
Stmt::child_iterator TypesCompatibleExpr::child_end() {
return child_iterator();
}
// ChooseExpr
Stmt::child_iterator ChooseExpr::child_begin() { return &SubExprs[0]; }
Stmt::child_iterator ChooseExpr::child_end() { return &SubExprs[0]+END_EXPR; }
// GNUNullExpr
Stmt::child_iterator GNUNullExpr::child_begin() { return child_iterator(); }
Stmt::child_iterator GNUNullExpr::child_end() { return child_iterator(); }
// ShuffleVectorExpr
Stmt::child_iterator ShuffleVectorExpr::child_begin() {
return &SubExprs[0];
}
Stmt::child_iterator ShuffleVectorExpr::child_end() {
return &SubExprs[0]+NumExprs;
}
// VAArgExpr
Stmt::child_iterator VAArgExpr::child_begin() { return &Val; }
Stmt::child_iterator VAArgExpr::child_end() { return &Val+1; }
// InitListExpr
Stmt::child_iterator InitListExpr::child_begin() {
return InitExprs.size() ? &InitExprs[0] : 0;
}
Stmt::child_iterator InitListExpr::child_end() {
return InitExprs.size() ? &InitExprs[0] + InitExprs.size() : 0;
}
// DesignatedInitExpr
Stmt::child_iterator DesignatedInitExpr::child_begin() {
char* Ptr = static_cast<char*>(static_cast<void *>(this));
Ptr += sizeof(DesignatedInitExpr);
Ptr += sizeof(Designator) * NumDesignators;
return reinterpret_cast<Stmt**>(reinterpret_cast<void**>(Ptr));
}
Stmt::child_iterator DesignatedInitExpr::child_end() {
return child_iterator(&*child_begin() + NumSubExprs);
}
// ImplicitValueInitExpr
Stmt::child_iterator ImplicitValueInitExpr::child_begin() {
return child_iterator();
}
Stmt::child_iterator ImplicitValueInitExpr::child_end() {
return child_iterator();
}
// ObjCStringLiteral
Stmt::child_iterator ObjCStringLiteral::child_begin() {
return &String;
}
Stmt::child_iterator ObjCStringLiteral::child_end() {
return &String+1;
}
// ObjCEncodeExpr
Stmt::child_iterator ObjCEncodeExpr::child_begin() { return child_iterator(); }
Stmt::child_iterator ObjCEncodeExpr::child_end() { return child_iterator(); }
// ObjCSelectorExpr
Stmt::child_iterator ObjCSelectorExpr::child_begin() {
return child_iterator();
}
Stmt::child_iterator ObjCSelectorExpr::child_end() {
return child_iterator();
}
// ObjCProtocolExpr
Stmt::child_iterator ObjCProtocolExpr::child_begin() {
return child_iterator();
}
Stmt::child_iterator ObjCProtocolExpr::child_end() {
return child_iterator();
}
// ObjCMessageExpr
Stmt::child_iterator ObjCMessageExpr::child_begin() {
return getReceiver() ? &SubExprs[0] : &SubExprs[0] + ARGS_START;
}
Stmt::child_iterator ObjCMessageExpr::child_end() {
return &SubExprs[0]+ARGS_START+getNumArgs();
}
// Blocks
Stmt::child_iterator BlockExpr::child_begin() { return child_iterator(); }
Stmt::child_iterator BlockExpr::child_end() { return child_iterator(); }
Stmt::child_iterator BlockDeclRefExpr::child_begin() { return child_iterator();}
Stmt::child_iterator BlockDeclRefExpr::child_end() { return child_iterator(); }
Ссылка в новой задаче Показать git blame Копировать постоянную ссылку