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llvm-project/clang/AST/Expr.cpp

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//===--- Expr.cpp - Expression AST Node Implementation --------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by Chris Lattner and 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/ASTContext.h"
#include "clang/AST/StmtVisitor.h"
#include "clang/Lex/IdentifierTable.h"
using namespace clang;
//===----------------------------------------------------------------------===//
// Primary Expressions.
//===----------------------------------------------------------------------===//
StringLiteral::StringLiteral(const char *strData, unsigned byteLength,
bool Wide, QualType t, SourceLocation firstLoc,
SourceLocation lastLoc) :
Expr(StringLiteralClass, t) {
// OPTIMIZE: could allocate this appended to the StringLiteral.
char *AStrData = new char[byteLength];
memcpy(AStrData, strData, byteLength);
StrData = AStrData;
ByteLength = byteLength;
IsWide = Wide;
firstTokLoc = firstLoc;
lastTokLoc = lastLoc;
}
StringLiteral::~StringLiteral() {
delete[] StrData;
}
bool UnaryOperator::isPostfix(Opcode Op) {
switch (Op) {
case PostInc:
case PostDec:
return true;
default:
return false;
}
}
/// 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 SizeOf: return "sizeof";
case AlignOf: return "alignof";
case Extension: return "__extension__";
case OffsetOf: return "__builtin_offsetof";
}
}
//===----------------------------------------------------------------------===//
// Postfix Operators.
//===----------------------------------------------------------------------===//
CallExpr::CallExpr(Expr *fn, Expr **args, unsigned numargs, QualType t,
SourceLocation rparenloc)
: Expr(CallExprClass, t), NumArgs(numargs) {
SubExprs = new Expr*[numargs+1];
SubExprs[FN] = fn;
for (unsigned i = 0; i != numargs; ++i)
SubExprs[i+ARGS_START] = args[i];
RParenLoc = rparenloc;
}
bool CallExpr::isBuiltinClassifyType(llvm::APSInt &Result) const {
// The following enum mimics gcc's internal "typeclass.h" file.
enum gcc_type_class {
no_type_class = -1,
void_type_class, integer_type_class, char_type_class,
enumeral_type_class, boolean_type_class,
pointer_type_class, reference_type_class, offset_type_class,
real_type_class, complex_type_class,
function_type_class, method_type_class,
record_type_class, union_type_class,
array_type_class, string_type_class,
lang_type_class
};
Result.setIsSigned(true);
// 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 false;
const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr());
if (!DRE)
return false;
// We have a DeclRefExpr.
if (strcmp(DRE->getDecl()->getName(), "__builtin_classify_type") == 0) {
// If no argument was supplied, default to "no_type_class". This isn't
// ideal, however it's what gcc does.
Result = static_cast<uint64_t>(no_type_class);
if (NumArgs >= 1) {
QualType argType = getArg(0)->getType();
if (argType->isVoidType())
Result = void_type_class;
else if (argType->isEnumeralType())
Result = enumeral_type_class;
else if (argType->isBooleanType())
Result = boolean_type_class;
else if (argType->isCharType())
Result = string_type_class; // gcc doesn't appear to use char_type_class
else if (argType->isIntegerType())
Result = integer_type_class;
else if (argType->isPointerType())
Result = pointer_type_class;
else if (argType->isReferenceType())
Result = reference_type_class;
else if (argType->isRealType())
Result = real_type_class;
else if (argType->isComplexType())
Result = complex_type_class;
else if (argType->isFunctionType())
Result = function_type_class;
else if (argType->isStructureType())
Result = record_type_class;
else if (argType->isUnionType())
Result = union_type_class;
else if (argType->isArrayType())
Result = array_type_class;
else if (argType->isUnionType())
Result = union_type_class;
else // FIXME: offset_type_class, method_type_class, & lang_type_class?
assert(1 && "CallExpr::isBuiltinClassifyType(): unimplemented type");
}
return true;
}
return false;
}
/// getOpcodeStr - Turn an Opcode enum value into the punctuation char it
/// corresponds to, e.g. "<<=".
const char *BinaryOperator::getOpcodeStr(Opcode Op) {
switch (Op) {
default: assert(0 && "Unknown binary operator");
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 ",";
}
}
InitListExpr::InitListExpr(SourceLocation lbraceloc,
Expr **initexprs, unsigned numinits,
SourceLocation rbraceloc)
: Expr(InitListExprClass, QualType())
, NumInits(numinits)
, LBraceLoc(lbraceloc)
, RBraceLoc(rbraceloc)
{
InitExprs = new Expr*[numinits];
for (unsigned i = 0; i != numinits; i++)
InitExprs[i] = initexprs[i];
}
//===----------------------------------------------------------------------===//
// Generic Expression Routines
//===----------------------------------------------------------------------===//
/// hasLocalSideEffect - Return true if this immediate expression has side
/// effects, not counting any sub-expressions.
bool Expr::hasLocalSideEffect() const {
switch (getStmtClass()) {
default:
return false;
case ParenExprClass:
return cast<ParenExpr>(this)->getSubExpr()->hasLocalSideEffect();
case UnaryOperatorClass: {
const UnaryOperator *UO = cast<UnaryOperator>(this);
switch (UO->getOpcode()) {
default: return false;
case UnaryOperator::PostInc:
case UnaryOperator::PostDec:
case UnaryOperator::PreInc:
case UnaryOperator::PreDec:
return true; // ++/--
case UnaryOperator::Deref:
// Dereferencing a volatile pointer is a side-effect.
return getType().isVolatileQualified();
case UnaryOperator::Real:
case UnaryOperator::Imag:
// accessing a piece of a volatile complex is a side-effect.
return UO->getSubExpr()->getType().isVolatileQualified();
case UnaryOperator::Extension:
return UO->getSubExpr()->hasLocalSideEffect();
}
}
case BinaryOperatorClass:
return cast<BinaryOperator>(this)->isAssignmentOp();
case CompoundAssignOperatorClass:
return true;
case MemberExprClass:
case ArraySubscriptExprClass:
// If the base pointer or element is to a volatile pointer/field, accessing
// if is a side effect.
return getType().isVolatileQualified();
case CallExprClass:
// TODO: check attributes for pure/const. "void foo() { strlen("bar"); }"
// should warn.
return true;
case CastExprClass:
// 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()->hasLocalSideEffect();
return false;
}
}
/// 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
/// - reference type [C++ [expr]]
///
Expr::isLvalueResult Expr::isLvalue() const {
// first, check the type (C99 6.3.2.1)
if (TR->isFunctionType()) // from isObjectType()
return LV_NotObjectType;
if (TR->isVoidType())
return LV_IncompleteVoidType;
if (TR->isReferenceType()) // C++ [expr]
return LV_Valid;
// the type looks fine, now check the expression
switch (getStmtClass()) {
case StringLiteralClass: // C99 6.5.1p4
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();
return LV_Valid;
case DeclRefExprClass: // C99 6.5.1p2
if (isa<VarDecl>(cast<DeclRefExpr>(this)->getDecl()))
return LV_Valid;
break;
case MemberExprClass: { // C99 6.5.2.3p4
const MemberExpr *m = cast<MemberExpr>(this);
return m->isArrow() ? LV_Valid : m->getBase()->isLvalue();
}
case UnaryOperatorClass: // C99 6.5.3p4
if (cast<UnaryOperator>(this)->getOpcode() == UnaryOperator::Deref)
return LV_Valid;
break;
case ParenExprClass: // C99 6.5.1p5
return cast<ParenExpr>(this)->getSubExpr()->isLvalue();
case OCUVectorElementExprClass:
if (cast<OCUVectorElementExpr>(this)->containsDuplicateElements())
return LV_DuplicateVectorComponents;
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() const {
isLvalueResult lvalResult = isLvalue();
switch (lvalResult) {
case LV_Valid: break;
case LV_NotObjectType: return MLV_NotObjectType;
case LV_IncompleteVoidType: return MLV_IncompleteVoidType;
case LV_DuplicateVectorComponents: return MLV_DuplicateVectorComponents;
case LV_InvalidExpression: return MLV_InvalidExpression;
}
if (TR.isConstQualified())
return MLV_ConstQualified;
if (TR->isArrayType())
return MLV_ArrayType;
if (TR->isIncompleteType())
return MLV_IncompleteType;
if (const RecordType *r = dyn_cast<RecordType>(TR.getCanonicalType())) {
if (r->hasConstFields())
return MLV_ConstQualified;
}
return MLV_Valid;
}
bool Expr::isConstantExpr(ASTContext &Ctx, SourceLocation *Loc) const {
switch (getStmtClass()) {
default:
if (Loc) *Loc = getLocStart();
return false;
case ParenExprClass:
return cast<ParenExpr>(this)->getSubExpr()->isConstantExpr(Ctx, Loc);
case StringLiteralClass:
case FloatingLiteralClass:
case IntegerLiteralClass:
case CharacterLiteralClass:
case ImaginaryLiteralClass:
case TypesCompatibleExprClass:
break;
case CallExprClass: {
const CallExpr *CE = cast<CallExpr>(this);
llvm::APSInt Result(32);
Result.zextOrTrunc(
static_cast<uint32_t>(Ctx.getTypeSize(getType(), CE->getLocStart())));
if (CE->isBuiltinClassifyType(Result))
break;
if (Loc) *Loc = getLocStart();
return false;
}
case DeclRefExprClass:
if (isa<EnumConstantDecl>(cast<DeclRefExpr>(this)->getDecl()))
break;
if (Loc) *Loc = getLocStart();
return false;
case UnaryOperatorClass: {
const UnaryOperator *Exp = cast<UnaryOperator>(this);
// Get the operand value. If this is sizeof/alignof, do not evalute the
// operand. This affects C99 6.6p3.
if (!Exp->isSizeOfAlignOfOp() &&
!Exp->getSubExpr()->isConstantExpr(Ctx, Loc))
return false;
switch (Exp->getOpcode()) {
// Address, indirect, pre/post inc/dec, etc are not valid constant exprs.
// See C99 6.6p3.
default:
if (Loc) *Loc = Exp->getOperatorLoc();
return false;
case UnaryOperator::Extension:
return true; // FIXME: this is wrong.
case UnaryOperator::SizeOf:
case UnaryOperator::AlignOf:
// sizeof(vla) is not a constantexpr: C99 6.5.3.4p2.
if (!Exp->getSubExpr()->getType()->isConstantSizeType(Ctx, Loc))
return false;
break;
case UnaryOperator::LNot:
case UnaryOperator::Plus:
case UnaryOperator::Minus:
case UnaryOperator::Not:
break;
}
break;
}
case SizeOfAlignOfTypeExprClass: {
const SizeOfAlignOfTypeExpr *Exp = cast<SizeOfAlignOfTypeExpr>(this);
// alignof always evaluates to a constant.
if (Exp->isSizeOf() && !Exp->getArgumentType()->isConstantSizeType(Ctx,Loc))
return false;
break;
}
case BinaryOperatorClass: {
const BinaryOperator *Exp = cast<BinaryOperator>(this);
// The LHS of a constant expr is always evaluated and needed.
if (!Exp->getLHS()->isConstantExpr(Ctx, Loc))
return false;
if (!Exp->getRHS()->isConstantExpr(Ctx, Loc))
return false;
break;
}
case ImplicitCastExprClass:
case CastExprClass: {
const Expr *SubExpr;
SourceLocation CastLoc;
if (const CastExpr *C = dyn_cast<CastExpr>(this)) {
SubExpr = C->getSubExpr();
CastLoc = C->getLParenLoc();
} else {
SubExpr = cast<ImplicitCastExpr>(this)->getSubExpr();
CastLoc = getLocStart();
}
if (!SubExpr->isConstantExpr(Ctx, Loc)) {
if (Loc) *Loc = SubExpr->getLocStart();
return false;
}
break;
}
case ConditionalOperatorClass: {
const ConditionalOperator *Exp = cast<ConditionalOperator>(this);
if (!Exp->getCond()->isConstantExpr(Ctx, Loc))
return false;
if (!Exp->getLHS()->isConstantExpr(Ctx, Loc))
return false;
if (!Exp->getRHS()->isConstantExpr(Ctx, Loc))
return false;
break;
}
}
return true;
}
/// isIntegerConstantExpr - this recursive routine will test if an expression is
/// an integer constant expression. Note: With the introduction of VLA's in
/// C99 the result of the sizeof operator is no longer always a constant
/// expression. The generalization of the wording to include any subexpression
/// that is not evaluated (C99 6.6p3) means that nonconstant subexpressions
/// can appear as operands to other operators (e.g. &&, ||, ?:). For instance,
/// "0 || f()" can be treated as a constant expression. In C90 this expression,
/// occurring in a context requiring a constant, would have been a constraint
/// violation. FIXME: This routine currently implements C90 semantics.
/// To properly implement C99 semantics this routine will need to evaluate
/// expressions involving operators previously mentioned.
/// FIXME: Pass up a reason why! Invalid operation in i-c-e, division by zero,
/// comma, etc
///
/// FIXME: This should ext-warn on overflow during evaluation! ISO C does not
/// permit this.
///
/// 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.
bool Expr::isIntegerConstantExpr(llvm::APSInt &Result, ASTContext &Ctx,
SourceLocation *Loc, bool isEvaluated) const {
switch (getStmtClass()) {
default:
if (Loc) *Loc = getLocStart();
return false;
case ParenExprClass:
return cast<ParenExpr>(this)->getSubExpr()->
isIntegerConstantExpr(Result, Ctx, Loc, isEvaluated);
case IntegerLiteralClass:
Result = cast<IntegerLiteral>(this)->getValue();
break;
case CharacterLiteralClass: {
const CharacterLiteral *CL = cast<CharacterLiteral>(this);
Result.zextOrTrunc(
static_cast<uint32_t>(Ctx.getTypeSize(getType(), CL->getLoc())));
Result = CL->getValue();
Result.setIsUnsigned(!getType()->isSignedIntegerType());
break;
}
case TypesCompatibleExprClass: {
const TypesCompatibleExpr *TCE = cast<TypesCompatibleExpr>(this);
Result.zextOrTrunc(
static_cast<uint32_t>(Ctx.getTypeSize(getType(), TCE->getLocStart())));
Result = TCE->typesAreCompatible();
break;
}
case CallExprClass: {
const CallExpr *CE = cast<CallExpr>(this);
Result.zextOrTrunc(
static_cast<uint32_t>(Ctx.getTypeSize(getType(), CE->getLocStart())));
if (CE->isBuiltinClassifyType(Result))
break;
if (Loc) *Loc = getLocStart();
return false;
}
case DeclRefExprClass:
if (const EnumConstantDecl *D =
dyn_cast<EnumConstantDecl>(cast<DeclRefExpr>(this)->getDecl())) {
Result = D->getInitVal();
break;
}
if (Loc) *Loc = getLocStart();
return false;
case UnaryOperatorClass: {
const UnaryOperator *Exp = cast<UnaryOperator>(this);
// Get the operand value. If this is sizeof/alignof, do not evalute the
// operand. This affects C99 6.6p3.
if (!Exp->isSizeOfAlignOfOp() &&
!Exp->getSubExpr()->isIntegerConstantExpr(Result, Ctx, Loc,isEvaluated))
return false;
switch (Exp->getOpcode()) {
// Address, indirect, pre/post inc/dec, etc are not valid constant exprs.
// See C99 6.6p3.
default:
if (Loc) *Loc = Exp->getOperatorLoc();
return false;
case UnaryOperator::Extension:
return true; // FIXME: this is wrong.
case UnaryOperator::SizeOf:
case UnaryOperator::AlignOf:
// sizeof(vla) is not a constantexpr: C99 6.5.3.4p2.
if (!Exp->getSubExpr()->getType()->isConstantSizeType(Ctx, Loc))
return false;
// Return the result in the right width.
Result.zextOrTrunc(
static_cast<uint32_t>(Ctx.getTypeSize(getType(), Exp->getOperatorLoc())));
// Get information about the size or align.
if (Exp->getOpcode() == UnaryOperator::SizeOf)
Result = Ctx.getTypeSize(Exp->getSubExpr()->getType(),
Exp->getOperatorLoc());
else
Result = Ctx.getTypeAlign(Exp->getSubExpr()->getType(),
Exp->getOperatorLoc());
break;
case UnaryOperator::LNot: {
bool Val = Result != 0;
Result.zextOrTrunc(
static_cast<uint32_t>(Ctx.getTypeSize(getType(), Exp->getOperatorLoc())));
Result = Val;
break;
}
case UnaryOperator::Plus:
break;
case UnaryOperator::Minus:
Result = -Result;
break;
case UnaryOperator::Not:
Result = ~Result;
break;
}
break;
}
case SizeOfAlignOfTypeExprClass: {
const SizeOfAlignOfTypeExpr *Exp = cast<SizeOfAlignOfTypeExpr>(this);
// alignof always evaluates to a constant.
if (Exp->isSizeOf() && !Exp->getArgumentType()->isConstantSizeType(Ctx,Loc))
return false;
// Return the result in the right width.
Result.zextOrTrunc(
static_cast<uint32_t>(Ctx.getTypeSize(getType(), Exp->getOperatorLoc())));
// Get information about the size or align.
if (Exp->isSizeOf())
Result = Ctx.getTypeSize(Exp->getArgumentType(), Exp->getOperatorLoc());
else
Result = Ctx.getTypeAlign(Exp->getArgumentType(), Exp->getOperatorLoc());
break;
}
case BinaryOperatorClass: {
const BinaryOperator *Exp = cast<BinaryOperator>(this);
// The LHS of a constant expr is always evaluated and needed.
if (!Exp->getLHS()->isIntegerConstantExpr(Result, Ctx, Loc, isEvaluated))
return false;
llvm::APSInt RHS(Result);
// The short-circuiting &&/|| operators don't necessarily evaluate their
// RHS. Make sure to pass isEvaluated down correctly.
if (Exp->isLogicalOp()) {
bool RHSEval;
if (Exp->getOpcode() == BinaryOperator::LAnd)
RHSEval = Result != 0;
else {
assert(Exp->getOpcode() == BinaryOperator::LOr &&"Unexpected logical");
RHSEval = Result == 0;
}
if (!Exp->getRHS()->isIntegerConstantExpr(RHS, Ctx, Loc,
isEvaluated & RHSEval))
return false;
} else {
if (!Exp->getRHS()->isIntegerConstantExpr(RHS, Ctx, Loc, isEvaluated))
return false;
}
switch (Exp->getOpcode()) {
default:
if (Loc) *Loc = getLocStart();
return false;
case BinaryOperator::Mul:
Result *= RHS;
break;
case BinaryOperator::Div:
if (RHS == 0) {
if (!isEvaluated) break;
if (Loc) *Loc = getLocStart();
return false;
}
Result /= RHS;
break;
case BinaryOperator::Rem:
if (RHS == 0) {
if (!isEvaluated) break;
if (Loc) *Loc = getLocStart();
return false;
}
Result %= RHS;
break;
case BinaryOperator::Add: Result += RHS; break;
case BinaryOperator::Sub: Result -= RHS; break;
case BinaryOperator::Shl:
Result <<=
static_cast<uint32_t>(RHS.getLimitedValue(Result.getBitWidth()-1));
break;
case BinaryOperator::Shr:
Result >>=
static_cast<uint32_t>(RHS.getLimitedValue(Result.getBitWidth()-1));
break;
case BinaryOperator::LT: Result = Result < RHS; break;
case BinaryOperator::GT: Result = Result > RHS; break;
case BinaryOperator::LE: Result = Result <= RHS; break;
case BinaryOperator::GE: Result = Result >= RHS; break;
case BinaryOperator::EQ: Result = Result == RHS; break;
case BinaryOperator::NE: Result = Result != RHS; break;
case BinaryOperator::And: Result &= RHS; break;
case BinaryOperator::Xor: Result ^= RHS; break;
case BinaryOperator::Or: Result |= RHS; break;
case BinaryOperator::LAnd:
Result = Result != 0 && RHS != 0;
break;
case BinaryOperator::LOr:
Result = Result != 0 || RHS != 0;
break;
case BinaryOperator::Comma:
// C99 6.6p3: "shall not contain assignment, ..., or comma operators,
// *except* when they are contained within a subexpression that is not
// evaluated". Note that Assignment can never happen due to constraints
// on the LHS subexpr, so we don't need to check it here.
if (isEvaluated) {
if (Loc) *Loc = getLocStart();
return false;
}
// The result of the constant expr is the RHS.
Result = RHS;
return true;
}
assert(!Exp->isAssignmentOp() && "LHS can't be a constant expr!");
break;
}
case ImplicitCastExprClass:
case CastExprClass: {
const Expr *SubExpr;
SourceLocation CastLoc;
if (const CastExpr *C = dyn_cast<CastExpr>(this)) {
SubExpr = C->getSubExpr();
CastLoc = C->getLParenLoc();
} else {
SubExpr = cast<ImplicitCastExpr>(this)->getSubExpr();
CastLoc = getLocStart();
}
// C99 6.6p6: shall only convert arithmetic types to integer types.
if (!SubExpr->getType()->isArithmeticType() ||
!getType()->isIntegerType()) {
if (Loc) *Loc = SubExpr->getLocStart();
return false;
}
// Handle simple integer->integer casts.
if (SubExpr->getType()->isIntegerType()) {
if (!SubExpr->isIntegerConstantExpr(Result, Ctx, Loc, isEvaluated))
return false;
// Figure out if this is a truncate, extend or noop cast.
unsigned DestWidth =
static_cast<uint32_t>(Ctx.getTypeSize(getType(), CastLoc));
// If the input is signed, do a sign extend, noop, or truncate.
if (SubExpr->getType()->isSignedIntegerType())
Result.sextOrTrunc(DestWidth);
else // If the input is unsigned, do a zero extend, noop, or truncate.
Result.zextOrTrunc(DestWidth);
break;
}
// Allow floating constants that are the immediate operands of casts or that
// are parenthesized.
const Expr *Operand = SubExpr;
while (const ParenExpr *PE = dyn_cast<ParenExpr>(Operand))
Operand = PE->getSubExpr();
if (const FloatingLiteral *FL = dyn_cast<FloatingLiteral>(Operand)) {
// FIXME: Evaluate this correctly!
Result = (int)FL->getValue();
break;
}
if (Loc) *Loc = Operand->getLocStart();
return false;
}
case ConditionalOperatorClass: {
const ConditionalOperator *Exp = cast<ConditionalOperator>(this);
if (!Exp->getCond()->isIntegerConstantExpr(Result, Ctx, Loc, isEvaluated))
return false;
const Expr *TrueExp = Exp->getLHS();
const Expr *FalseExp = Exp->getRHS();
if (Result == 0) std::swap(TrueExp, FalseExp);
// Evaluate the false one first, discard the result.
if (!FalseExp->isIntegerConstantExpr(Result, Ctx, Loc, false))
return false;
// Evalute the true one, capture the result.
if (!TrueExp->isIntegerConstantExpr(Result, Ctx, Loc, isEvaluated))
return false;
break;
}
}
// Cases that are valid constant exprs fall through to here.
Result.setIsUnsigned(getType()->isUnsignedIntegerType());
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.
if (const CastExpr *CE = dyn_cast<CastExpr>(this)) {
// Check that it is a cast to void*.
if (const PointerType *PT = dyn_cast<PointerType>(CE->getType())) {
QualType Pointee = PT->getPointeeType();
if (Pointee.getQualifiers() == 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);
}
// 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.
llvm::APSInt Val(32);
return isIntegerConstantExpr(Val, Ctx, 0, true) && Val == 0;
}
unsigned OCUVectorElementExpr::getNumElements() const {
return strlen(Accessor.getName());
}
/// getComponentType - Determine whether the components of this access are
/// "point" "color" or "texture" elements.
OCUVectorElementExpr::ElementType
OCUVectorElementExpr::getElementType() const {
// derive the component type, no need to waste space.
const char *compStr = Accessor.getName();
if (OCUVectorType::getPointAccessorIdx(*compStr) != -1) return Point;
if (OCUVectorType::getColorAccessorIdx(*compStr) != -1) return Color;
assert(OCUVectorType::getTextureAccessorIdx(*compStr) != -1 &&
"getComponentType(): Illegal accessor");
return Texture;
}
/// containsDuplicateElements - Return true if any element access is
/// repeated.
bool OCUVectorElementExpr::containsDuplicateElements() const {
const char *compStr = Accessor.getName();
unsigned length = strlen(compStr);
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 fields with two bits per component.
unsigned OCUVectorElementExpr::getEncodedElementAccess() const {
const char *compStr = Accessor.getName();
unsigned length = getNumElements();
unsigned Result = 0;
while (length--) {
Result <<= 2;
int Idx = OCUVectorType::getAccessorIdx(compStr[length]);
assert(Idx != -1 && "Invalid accessor letter");
Result |= Idx;
}
return Result;
}
//===----------------------------------------------------------------------===//
// Child Iterators for iterating over subexpressions/substatements
//===----------------------------------------------------------------------===//
// DeclRefExpr
Stmt::child_iterator DeclRefExpr::child_begin() { return NULL; }
Stmt::child_iterator DeclRefExpr::child_end() { return NULL; }
// PreDefinedExpr
Stmt::child_iterator PreDefinedExpr::child_begin() { return NULL; }
Stmt::child_iterator PreDefinedExpr::child_end() { return NULL; }
// IntegerLiteral
Stmt::child_iterator IntegerLiteral::child_begin() { return NULL; }
Stmt::child_iterator IntegerLiteral::child_end() { return NULL; }
// CharacterLiteral
Stmt::child_iterator CharacterLiteral::child_begin() { return NULL; }
Stmt::child_iterator CharacterLiteral::child_end() { return NULL; }
// FloatingLiteral
Stmt::child_iterator FloatingLiteral::child_begin() { return NULL; }
Stmt::child_iterator FloatingLiteral::child_end() { return NULL; }
// ImaginaryLiteral
Stmt::child_iterator ImaginaryLiteral::child_begin() {
return reinterpret_cast<Stmt**>(&Val);
}
Stmt::child_iterator ImaginaryLiteral::child_end() {
return reinterpret_cast<Stmt**>(&Val)+1;
}
// StringLiteral
Stmt::child_iterator StringLiteral::child_begin() { return NULL; }
Stmt::child_iterator StringLiteral::child_end() { return NULL; }
// ParenExpr
Stmt::child_iterator ParenExpr::child_begin() {
return reinterpret_cast<Stmt**>(&Val);
}
Stmt::child_iterator ParenExpr::child_end() {
return reinterpret_cast<Stmt**>(&Val)+1;
}
// UnaryOperator
Stmt::child_iterator UnaryOperator::child_begin() {
return reinterpret_cast<Stmt**>(&Val);
}
Stmt::child_iterator UnaryOperator::child_end() {
return reinterpret_cast<Stmt**>(&Val)+1;
}
// SizeOfAlignOfTypeExpr
Stmt::child_iterator SizeOfAlignOfTypeExpr::child_begin() { return NULL; }
Stmt::child_iterator SizeOfAlignOfTypeExpr::child_end() { return NULL; }
// ArraySubscriptExpr
Stmt::child_iterator ArraySubscriptExpr::child_begin() {
return reinterpret_cast<Stmt**>(&SubExprs);
}
Stmt::child_iterator ArraySubscriptExpr::child_end() {
return reinterpret_cast<Stmt**>(&SubExprs)+END_EXPR;
}
// CallExpr
Stmt::child_iterator CallExpr::child_begin() {
return reinterpret_cast<Stmt**>(&SubExprs[0]);
}
Stmt::child_iterator CallExpr::child_end() {
return reinterpret_cast<Stmt**>(&SubExprs[NumArgs+ARGS_START]);
}
// MemberExpr
Stmt::child_iterator MemberExpr::child_begin() {
return reinterpret_cast<Stmt**>(&Base);
}
Stmt::child_iterator MemberExpr::child_end() {
return reinterpret_cast<Stmt**>(&Base)+1;
}
// OCUVectorElementExpr
Stmt::child_iterator OCUVectorElementExpr::child_begin() {
return reinterpret_cast<Stmt**>(&Base);
}
Stmt::child_iterator OCUVectorElementExpr::child_end() {
return reinterpret_cast<Stmt**>(&Base)+1;
}
// CompoundLiteralExpr
Stmt::child_iterator CompoundLiteralExpr::child_begin() {
return reinterpret_cast<Stmt**>(&Init);
}
Stmt::child_iterator CompoundLiteralExpr::child_end() {
return reinterpret_cast<Stmt**>(&Init)+1;
}
// ImplicitCastExpr
Stmt::child_iterator ImplicitCastExpr::child_begin() {
return reinterpret_cast<Stmt**>(&Op);
}
Stmt::child_iterator ImplicitCastExpr::child_end() {
return reinterpret_cast<Stmt**>(&Op)+1;
}
// CastExpr
Stmt::child_iterator CastExpr::child_begin() {
return reinterpret_cast<Stmt**>(&Op);
}
Stmt::child_iterator CastExpr::child_end() {
return reinterpret_cast<Stmt**>(&Op)+1;
}
// BinaryOperator
Stmt::child_iterator BinaryOperator::child_begin() {
return reinterpret_cast<Stmt**>(&SubExprs);
}
Stmt::child_iterator BinaryOperator::child_end() {
return reinterpret_cast<Stmt**>(&SubExprs)+END_EXPR;
}
// ConditionalOperator
Stmt::child_iterator ConditionalOperator::child_begin() {
return reinterpret_cast<Stmt**>(&SubExprs);
}
Stmt::child_iterator ConditionalOperator::child_end() {
return reinterpret_cast<Stmt**>(&SubExprs)+END_EXPR;
}
// AddrLabelExpr
Stmt::child_iterator AddrLabelExpr::child_begin() { return NULL; }
Stmt::child_iterator AddrLabelExpr::child_end() { return NULL; }
// StmtExpr
Stmt::child_iterator StmtExpr::child_begin() {
return reinterpret_cast<Stmt**>(&SubStmt);
}
Stmt::child_iterator StmtExpr::child_end() {
return reinterpret_cast<Stmt**>(&SubStmt)+1;
}
// TypesCompatibleExpr
Stmt::child_iterator TypesCompatibleExpr::child_begin() { return NULL; }
Stmt::child_iterator TypesCompatibleExpr::child_end() { return NULL; }
// ChooseExpr
Stmt::child_iterator ChooseExpr::child_begin() {
return reinterpret_cast<Stmt**>(&SubExprs);
}
Stmt::child_iterator ChooseExpr::child_end() {
return reinterpret_cast<Stmt**>(&SubExprs)+END_EXPR;
}
// InitListExpr
Stmt::child_iterator InitListExpr::child_begin() {
return reinterpret_cast<Stmt**>(&InitExprs[0]);
}
Stmt::child_iterator InitListExpr::child_end() {
return reinterpret_cast<Stmt**>(&InitExprs[NumInits]);
}
// ObjCStringLiteral
Stmt::child_iterator ObjCStringLiteral::child_begin() { return NULL; }
Stmt::child_iterator ObjCStringLiteral::child_end() { return NULL; }
// ObjCEncodeExpr
Stmt::child_iterator ObjCEncodeExpr::child_begin() { return NULL; }
Stmt::child_iterator ObjCEncodeExpr::child_end() { return NULL; }
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