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llvm-project/clang/Sema/SemaExpr.cpp

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//===--- SemaExpr.cpp - Semantic Analysis for Expressions -----------------===//
//
// 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 semantic analysis for expressions.
//
//===----------------------------------------------------------------------===//
#include "Sema.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Decl.h"
#include "clang/AST/Expr.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/Lex/LiteralSupport.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/LangOptions.h"
#include "clang/Basic/TargetInfo.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringExtras.h"
using namespace llvm;
using namespace clang;
// Sema.h avoids including Expr.h. As a result, all the Check* functions take
// an unsigned which is really an enum. These typedefs provide a short hand
// notiation for casting (to keep the lines within 80 columns:-)
typedef BinaryOperator::Opcode BOP;
typedef UnaryOperator::Opcode UOP;
/// ParseStringLiteral - The specified tokens were lexed as pasted string
/// fragments (e.g. "foo" "bar" L"baz"). The result string has to handle string
/// concatenation ([C99 5.1.1.2, translation phase #6]), so it may come from
/// multiple tokens. However, the common case is that StringToks points to one
/// string.
///
Action::ExprResult
Sema::ParseStringLiteral(const LexerToken *StringToks, unsigned NumStringToks) {
assert(NumStringToks && "Must have at least one string!");
StringLiteralParser Literal(StringToks, NumStringToks, PP, Context.Target);
if (Literal.hadError)
return ExprResult(true);
SmallVector<SourceLocation, 4> StringTokLocs;
for (unsigned i = 0; i != NumStringToks; ++i)
StringTokLocs.push_back(StringToks[i].getLocation());
// FIXME: handle wchar_t
QualType t = Context.getPointerType(Context.CharTy);
// FIXME: use factory.
// Pass &StringTokLocs[0], StringTokLocs.size() to factory!
return new StringLiteral(Literal.GetString(), Literal.GetStringLength(),
Literal.AnyWide, t);
}
/// ParseIdentifierExpr - The parser read an identifier in expression context,
/// validate it per-C99 6.5.1. HasTrailingLParen indicates whether this
/// identifier is used in an function call context.
Sema::ExprResult Sema::ParseIdentifierExpr(Scope *S, SourceLocation Loc,
IdentifierInfo &II,
bool HasTrailingLParen) {
// Could be enum-constant or decl.
Decl *D = LookupScopedDecl(&II, Decl::IDNS_Ordinary, Loc, S);
if (D == 0) {
// Otherwise, this could be an implicitly declared function reference (legal
// in C90, extension in C99).
if (HasTrailingLParen &&
// Not in C++.
!getLangOptions().CPlusPlus)
D = ImplicitlyDefineFunction(Loc, II, S);
else {
// If this name wasn't predeclared and if this is not a function call,
// diagnose the problem.
return Diag(Loc, diag::err_undeclared_var_use, II.getName());
}
}
if (ValueDecl *VD = dyn_cast<ValueDecl>(D))
return new DeclRefExpr(VD, VD->getType());
if (isa<TypedefDecl>(D))
return Diag(Loc, diag::err_unexpected_typedef, II.getName());
assert(0 && "Invalid decl");
}
Sema::ExprResult Sema::ParseSimplePrimaryExpr(SourceLocation Loc,
tok::TokenKind Kind) {
switch (Kind) {
default:
assert(0 && "Unknown simple primary expr!");
// TODO: MOVE this to be some other callback.
case tok::kw___func__: // primary-expression: __func__ [C99 6.4.2.2]
case tok::kw___FUNCTION__: // primary-expression: __FUNCTION__ [GNU]
case tok::kw___PRETTY_FUNCTION__: // primary-expression: __P..Y_F..N__ [GNU]
return 0;
}
}
Sema::ExprResult Sema::ParseCharacterConstant(const LexerToken &Tok) {
SmallString<16> CharBuffer;
CharBuffer.resize(Tok.getLength());
const char *ThisTokBegin = &CharBuffer[0];
unsigned ActualLength = PP.getSpelling(Tok, ThisTokBegin);
CharLiteralParser Literal(ThisTokBegin, ThisTokBegin+ActualLength,
Tok.getLocation(), PP);
if (Literal.hadError())
return ExprResult(true);
return new CharacterLiteral(Literal.getValue(), Context.IntTy);
}
Action::ExprResult Sema::ParseNumericConstant(const LexerToken &Tok) {
// fast path for a single digit (which is quite common). A single digit
// cannot have a trigraph, escaped newline, radix prefix, or type suffix.
if (Tok.getLength() == 1) {
const char *t = PP.getSourceManager().getCharacterData(Tok.getLocation());
return ExprResult(new IntegerLiteral(*t-'0', Context.IntTy));
}
SmallString<512> IntegerBuffer;
IntegerBuffer.resize(Tok.getLength());
const char *ThisTokBegin = &IntegerBuffer[0];
// Get the spelling of the token, which eliminates trigraphs, etc. Notes:
// - We know that ThisTokBuf points to a buffer that is big enough for the
// whole token and 'spelled' tokens can only shrink.
// - In practice, the local buffer is only used when the spelling doesn't
// match the original token (which is rare). The common case simply returns
// a pointer to a *constant* buffer (avoiding a copy).
unsigned ActualLength = PP.getSpelling(Tok, ThisTokBegin);
NumericLiteralParser Literal(ThisTokBegin, ThisTokBegin+ActualLength,
Tok.getLocation(), PP);
if (Literal.hadError)
return ExprResult(true);
if (Literal.isIntegerLiteral()) {
QualType t;
if (Literal.hasSuffix()) {
if (Literal.isLong)
t = Literal.isUnsigned ? Context.UnsignedLongTy : Context.LongTy;
else if (Literal.isLongLong)
t = Literal.isUnsigned ? Context.UnsignedLongLongTy : Context.LongLongTy;
else
t = Context.UnsignedIntTy;
} else {
t = Context.IntTy; // implicit type is "int"
}
uintmax_t val;
if (Literal.GetIntegerValue(val)) {
return new IntegerLiteral(val, t);
}
} else if (Literal.isFloatingLiteral()) {
// FIXME: fill in the value and compute the real type...
return new FloatingLiteral(7.7, Context.FloatTy);
}
return ExprResult(true);
}
Action::ExprResult Sema::ParseParenExpr(SourceLocation L, SourceLocation R,
ExprTy *Val) {
Expr *e = (Expr *)Val;
assert((e != 0) && "ParseParenExpr() missing expr");
return e;
}
// Unary Operators. 'Tok' is the token for the operator.
Action::ExprResult Sema::ParseUnaryOp(SourceLocation OpLoc, tok::TokenKind Op,
ExprTy *Input) {
UnaryOperator::Opcode Opc;
switch (Op) {
default: assert(0 && "Unknown unary op!");
case tok::plusplus: Opc = UnaryOperator::PreInc; break;
case tok::minusminus: Opc = UnaryOperator::PreDec; break;
case tok::amp: Opc = UnaryOperator::AddrOf; break;
case tok::star: Opc = UnaryOperator::Deref; break;
case tok::plus: Opc = UnaryOperator::Plus; break;
case tok::minus: Opc = UnaryOperator::Minus; break;
case tok::tilde: Opc = UnaryOperator::Not; break;
case tok::exclaim: Opc = UnaryOperator::LNot; break;
case tok::kw_sizeof: Opc = UnaryOperator::SizeOf; break;
case tok::kw___alignof: Opc = UnaryOperator::AlignOf; break;
case tok::kw___real: Opc = UnaryOperator::Real; break;
case tok::kw___imag: Opc = UnaryOperator::Imag; break;
case tok::ampamp: Opc = UnaryOperator::AddrLabel; break;
case tok::kw___extension__:
return Input;
//Opc = UnaryOperator::Extension;
//break;
}
if (Opc == UnaryOperator::PreInc || Opc == UnaryOperator::PreDec)
return CheckIncrementDecrementOperand((Expr *)Input, OpLoc, Opc);
else if (Opc == UnaryOperator::AddrOf)
return CheckAddressOfOperand((Expr *)Input, OpLoc);
else if (Opc == UnaryOperator::Deref)
return CheckIndirectionOperand((Expr *)Input, OpLoc);
else if (UnaryOperator::isArithmeticOp(Opc))
return CheckArithmeticOperand((Expr *)Input, OpLoc, Opc);
// will go away when all cases are handled...
return new UnaryOperator((Expr *)Input, Opc, QualType());
}
Action::ExprResult Sema::
ParseSizeOfAlignOfTypeExpr(SourceLocation OpLoc, bool isSizeof,
SourceLocation LParenLoc, TypeTy *Ty,
SourceLocation RParenLoc) {
// If error parsing type, ignore.
if (Ty == 0) return true;
// Verify that this is a valid expression.
QualType ArgTy = QualType::getFromOpaquePtr(Ty);
if (isa<FunctionType>(ArgTy) && isSizeof) {
// alignof(function) is allowed.
Diag(OpLoc, diag::ext_sizeof_function_type);
return new IntegerLiteral(1, Context.IntTy);
} else if (ArgTy->isVoidType()) {
Diag(OpLoc, diag::ext_sizeof_void_type, isSizeof ? "sizeof" : "__alignof");
} else if (ArgTy->isIncompleteType()) {
std::string TypeName;
ArgTy->getAsString(TypeName);
Diag(OpLoc, isSizeof ? diag::err_sizeof_incomplete_type :
diag::err_alignof_incomplete_type, TypeName);
return new IntegerLiteral(0, Context.IntTy);
}
// C99 6.5.3.4p4: the type (an unsigned integer type) is size_t.
return new SizeOfAlignOfTypeExpr(isSizeof, ArgTy, Context.getSizeType());
}
Action::ExprResult Sema::ParsePostfixUnaryOp(SourceLocation OpLoc,
tok::TokenKind Kind,
ExprTy *Input) {
UnaryOperator::Opcode Opc;
switch (Kind) {
default: assert(0 && "Unknown unary op!");
case tok::plusplus: Opc = UnaryOperator::PostInc; break;
case tok::minusminus: Opc = UnaryOperator::PostDec; break;
}
return CheckIncrementDecrementOperand((Expr *)Input, OpLoc, Opc);
}
Action::ExprResult Sema::
ParseArraySubscriptExpr(ExprTy *Base, SourceLocation LLoc,
ExprTy *Idx, SourceLocation RLoc) {
QualType t1 = ((Expr *)Base)->getType();
QualType t2 = ((Expr *)Idx)->getType();
assert(!t1.isNull() && "no type for array base expression");
assert(!t2.isNull() && "no type for array index expression");
QualType canonT1 = t1.getCanonicalType();
QualType canonT2 = t2.getCanonicalType();
// C99 6.5.2.1p2: the expression e1[e2] is by definition precisely equivalent
// to the expression *((e1)+(e2)). This means the array "Base" may actually be
// in the subscript position. As a result, we need to derive the array base
// and index from the expression types.
QualType baseType, indexType;
if (isa<ArrayType>(canonT1) || isa<PointerType>(canonT1)) {
baseType = canonT1;
indexType = canonT2;
} else if (isa<ArrayType>(canonT2) || isa<PointerType>(canonT2)) { // uncommon
baseType = canonT2;
indexType = canonT1;
} else
return Diag(LLoc, diag::err_typecheck_subscript_value);
// C99 6.5.2.1p1
if (!indexType->isIntegerType())
return Diag(LLoc, diag::err_typecheck_subscript);
// FIXME: need to deal with const...
QualType resultType;
if (ArrayType *ary = dyn_cast<ArrayType>(baseType)) {
resultType = ary->getElementType();
} else if (PointerType *ary = dyn_cast<PointerType>(baseType)) {
resultType = ary->getPointeeType();
// in practice, the following check catches trying to index a pointer
// to a function (e.g. void (*)(int)). Functions are not objects in c99.
if (!resultType->isObjectType())
return Diag(LLoc, diag::err_typecheck_subscript_not_object, baseType);
}
return new ArraySubscriptExpr((Expr*)Base, (Expr*)Idx, resultType);
}
Action::ExprResult Sema::
ParseMemberReferenceExpr(ExprTy *Base, SourceLocation OpLoc,
tok::TokenKind OpKind, SourceLocation MemberLoc,
IdentifierInfo &Member) {
QualType qualifiedType = ((Expr *)Base)->getType();
assert(!qualifiedType.isNull() && "no type for member expression");
QualType canonType = qualifiedType.getCanonicalType();
if (OpKind == tok::arrow) {
if (PointerType *PT = dyn_cast<PointerType>(canonType)) {
qualifiedType = PT->getPointeeType();
canonType = qualifiedType.getCanonicalType();
} else
return Diag(OpLoc, diag::err_typecheck_member_reference_arrow);
}
if (!isa<RecordType>(canonType))
return Diag(OpLoc, diag::err_typecheck_member_reference_structUnion);
// get the struct/union definition from the type.
RecordDecl *RD = cast<RecordType>(canonType)->getDecl();
if (canonType->isIncompleteType())
return Diag(OpLoc, diag::err_typecheck_incomplete_tag, RD->getName());
FieldDecl *MemberDecl = RD->getMember(&Member);
if (!MemberDecl)
return Diag(OpLoc, diag::err_typecheck_no_member, Member.getName());
return new MemberExpr((Expr*)Base, OpKind == tok::arrow, MemberDecl);
}
/// ParseCallExpr - Handle a call to Fn with the specified array of arguments.
/// This provides the location of the left/right parens and a list of comma
/// locations.
Action::ExprResult Sema::
ParseCallExpr(ExprTy *Fn, SourceLocation LParenLoc,
ExprTy **Args, unsigned NumArgs,
SourceLocation *CommaLocs, SourceLocation RParenLoc) {
QualType qType = ((Expr *)Fn)->getType();
assert(!qType.isNull() && "no type for function call expression");
const FunctionType *funcT = dyn_cast<FunctionType>(qType.getCanonicalType());
assert(funcT && "ParseCallExpr(): not a function type");
// If a prototype isn't declared, the parser implicitly defines a func decl
QualType resultType = funcT->getResultType();
if (const FunctionTypeProto *proto = dyn_cast<FunctionTypeProto>(funcT)) {
// C99 6.5.2.2p7 - the arguments are implicitly converted, as if by
// assignment, to the types of the corresponding parameter, ...
unsigned NumArgsInProto = proto->getNumArgs();
unsigned n = NumArgs;
if (NumArgs < NumArgsInProto)
Diag(LParenLoc, diag::ext_typecheck_call_too_few_args);
else if (NumArgs > NumArgsInProto) { // FIXME: check isVariadic()...
Diag(LParenLoc, diag::ext_typecheck_call_too_many_args);
n = NumArgsInProto;
}
// Continue to check argument types (even if we have too few/many args).
for (unsigned i = 0; i < n; i++) {
QualType lhsType = proto->getArgType(i);
QualType rhsType = ((Expr **)Args)[i]->getType();
if (lhsType == rhsType) // common case, fast path...
continue;
AssignmentConversionResult result;
UsualAssignmentConversions(lhsType, ((Expr **)Args)[i], result);
SourceLocation l = (i == 0) ? LParenLoc : CommaLocs[i-1];
// decode the result (notice that AST's are still created for extensions).
// FIXME: consider fancier error diagnostics (since this is quite common).
// #1: emit the actual prototype arg...requires adding source loc info.
// #2: pass Diag the offending argument type...requires hacking Diag.
switch (result) {
case Compatible:
break;
case PointerFromInt:
Diag(l, diag::ext_typecheck_passing_pointer_from_int, utostr(i+1));
break;
case IntFromPointer:
Diag(l, diag::ext_typecheck_passing_int_from_pointer, utostr(i+1));
break;
case IncompatiblePointer:
Diag(l, diag::ext_typecheck_passing_incompatible_pointer, utostr(i+1));
break;
case Incompatible:
return Diag(l, diag::err_typecheck_passing_incompatible, utostr(i+1));
}
}
}
return new CallExpr((Expr*)Fn, (Expr**)Args, NumArgs, resultType);
}
Action::ExprResult Sema::
ParseCastExpr(SourceLocation LParenLoc, TypeTy *Ty,
SourceLocation RParenLoc, ExprTy *Op) {
// If error parsing type, ignore.
assert((Ty != 0) && "ParseCastExpr(): missing type");
return new CastExpr(QualType::getFromOpaquePtr(Ty), (Expr*)Op);
}
// Binary Operators. 'Tok' is the token for the operator.
Action::ExprResult Sema::ParseBinOp(SourceLocation TokLoc, tok::TokenKind Kind,
ExprTy *LHS, ExprTy *RHS) {
BinaryOperator::Opcode Opc;
switch (Kind) {
default: assert(0 && "Unknown binop!");
case tok::star: Opc = BinaryOperator::Mul; break;
case tok::slash: Opc = BinaryOperator::Div; break;
case tok::percent: Opc = BinaryOperator::Rem; break;
case tok::plus: Opc = BinaryOperator::Add; break;
case tok::minus: Opc = BinaryOperator::Sub; break;
case tok::lessless: Opc = BinaryOperator::Shl; break;
case tok::greatergreater: Opc = BinaryOperator::Shr; break;
case tok::lessequal: Opc = BinaryOperator::LE; break;
case tok::less: Opc = BinaryOperator::LT; break;
case tok::greaterequal: Opc = BinaryOperator::GE; break;
case tok::greater: Opc = BinaryOperator::GT; break;
case tok::exclaimequal: Opc = BinaryOperator::NE; break;
case tok::equalequal: Opc = BinaryOperator::EQ; break;
case tok::amp: Opc = BinaryOperator::And; break;
case tok::caret: Opc = BinaryOperator::Xor; break;
case tok::pipe: Opc = BinaryOperator::Or; break;
case tok::ampamp: Opc = BinaryOperator::LAnd; break;
case tok::pipepipe: Opc = BinaryOperator::LOr; break;
case tok::equal: Opc = BinaryOperator::Assign; break;
case tok::starequal: Opc = BinaryOperator::MulAssign; break;
case tok::slashequal: Opc = BinaryOperator::DivAssign; break;
case tok::percentequal: Opc = BinaryOperator::RemAssign; break;
case tok::plusequal: Opc = BinaryOperator::AddAssign; break;
case tok::minusequal: Opc = BinaryOperator::SubAssign; break;
case tok::lesslessequal: Opc = BinaryOperator::ShlAssign; break;
case tok::greatergreaterequal: Opc = BinaryOperator::ShrAssign; break;
case tok::ampequal: Opc = BinaryOperator::AndAssign; break;
case tok::caretequal: Opc = BinaryOperator::XorAssign; break;
case tok::pipeequal: Opc = BinaryOperator::OrAssign; break;
case tok::comma: Opc = BinaryOperator::Comma; break;
}
Expr *lhs = (Expr *)LHS, *rhs = (Expr*)RHS;
assert((lhs != 0) && "ParseBinOp(): missing left expression");
assert((rhs != 0) && "ParseBinOp(): missing right expression");
if (BinaryOperator::isMultiplicativeOp(Opc))
return CheckMultiplicativeOperands(lhs, rhs, TokLoc, Opc);
else if (BinaryOperator::isAdditiveOp(Opc))
return CheckAdditiveOperands(lhs, rhs, TokLoc, Opc);
else if (BinaryOperator::isShiftOp(Opc))
return CheckShiftOperands(lhs, rhs, TokLoc, Opc);
else if (BinaryOperator::isRelationalOp(Opc))
return CheckRelationalOperands(lhs, rhs, TokLoc, Opc);
else if (BinaryOperator::isEqualityOp(Opc))
return CheckEqualityOperands(lhs, rhs, TokLoc, Opc);
else if (BinaryOperator::isBitwiseOp(Opc))
return CheckBitwiseOperands(lhs, rhs, TokLoc, Opc);
else if (BinaryOperator::isLogicalOp(Opc))
return CheckLogicalOperands(lhs, rhs, TokLoc, Opc);
else if (BinaryOperator::isAssignmentOp(Opc))
return CheckAssignmentOperands(lhs, rhs, TokLoc, Opc);
else if (Opc == BinaryOperator::Comma)
return CheckCommaOperands(lhs, rhs, TokLoc);
assert(0 && "ParseBinOp(): illegal binary op");
}
/// ParseConditionalOp - Parse a ?: operation. Note that 'LHS' may be null
/// in the case of a the GNU conditional expr extension.
Action::ExprResult Sema::ParseConditionalOp(SourceLocation QuestionLoc,
SourceLocation ColonLoc,
ExprTy *Cond, ExprTy *LHS,
ExprTy *RHS) {
QualType lhs = ((Expr *)LHS)->getType();
QualType rhs = ((Expr *)RHS)->getType();
assert(!lhs.isNull() && "ParseConditionalOp(): no lhs type");
assert(!rhs.isNull() && "ParseConditionalOp(): no rhs type");
QualType canonType = rhs.getCanonicalType(); // FIXME
return new ConditionalOperator((Expr*)Cond, (Expr*)LHS, (Expr*)RHS, canonType);
}
/// UsualUnaryConversion - Performs various conversions that are common to most
/// operators (C99 6.3). The conversions of array and function types are
/// sometimes surpressed. For example, the array->pointer conversion doesn't
/// apply if the array is an argument to the sizeof or address (&) operators.
/// In these instances, this routine should *not* be called.
QualType Sema::UsualUnaryConversion(QualType t) {
assert(!t.isNull() && "UsualUnaryConversion - missing type");
if (t->isPromotableIntegerType()) // C99 6.3.1.1p2
return Context.IntTy;
else if (t->isFunctionType()) // C99 6.3.2.1p4
return Context.getPointerType(t);
else if (t->isArrayType()) // C99 6.3.2.1p3
return Context.getPointerType(cast<ArrayType>(t)->getElementType());
return t;
}
/// UsualArithmeticConversions - Performs various conversions that are common to
/// binary operators (C99 6.3.1.8). If both operands aren't arithmetic, this
/// routine returns the first non-arithmetic type found. The client is
/// responsible for emitting appropriate error diagnostics.
QualType Sema::UsualArithmeticConversions(QualType t1, QualType t2) {
QualType lhs = UsualUnaryConversion(t1);
QualType rhs = UsualUnaryConversion(t2);
// if either operand is not of arithmetic type, no conversion is possible.
if (!lhs->isArithmeticType())
return lhs;
if (!rhs->isArithmeticType())
return rhs;
// if both arithmetic types are identical, no conversion is needed.
if (lhs == rhs)
return lhs;
// at this point, we have two different arithmetic types.
// Handle complex types first (C99 6.3.1.8p1).
if (lhs->isComplexType() || rhs->isComplexType()) {
// if we have an integer operand, the result is the complex type.
if (rhs->isIntegerType())
return lhs;
if (lhs->isIntegerType())
return rhs;
return Context.maxComplexType(lhs, rhs);
}
// Now handle "real" floating types (i.e. float, double, long double).
if (lhs->isRealFloatingType() || rhs->isRealFloatingType()) {
// if we have an integer operand, the result is the real floating type.
if (rhs->isIntegerType())
return lhs;
if (lhs->isIntegerType())
return rhs;
// we have two real floating types, float/complex combos were handled above.
return Context.maxFloatingType(lhs, rhs);
}
return Context.maxIntegerType(lhs, rhs);
}
/// UsualAssignmentConversions (C99 6.5.16) - This routine currently
/// has code to accommodate several GCC extensions when type checking
/// pointers. Here are some objectionable examples that GCC considers warnings:
///
/// int a, *pint;
/// short *pshort;
/// struct foo *pfoo;
///
/// pint = pshort; // warning: assignment from incompatible pointer type
/// a = pint; // warning: assignment makes integer from pointer without a cast
/// pint = a; // warning: assignment makes pointer from integer without a cast
/// pint = pfoo; // warning: assignment from incompatible pointer type
///
/// As a result, the code for dealing with pointers is more complex than the
/// C99 spec dictates.
/// Note: the warning above turn into errors when -pedantic-errors is enabled.
///
QualType Sema::UsualAssignmentConversions(QualType lhsType, Expr *rex,
AssignmentConversionResult &r) {
QualType rhsType = rex->getType();
// this check seems unnatural, however it necessary to insure the proper
// conversion of functions/arrays. If the conversion where done for all
// DeclExpr's (created by ParseIdentifierExpr), it would mess up the
// unary expressions that surpress this implicit conversion (&, sizeof).
if (rhsType->isFunctionType() || rhsType->isArrayType())
rhsType = UsualUnaryConversion(rhsType);
r = Compatible;
if (lhsType->isArithmeticType() && rhsType->isArithmeticType())
return lhsType;
else if (lhsType->isPointerType()) {
if (rhsType->isIntegerType()) {
// check for null pointer constant (C99 6.3.2.3p3)
const IntegerLiteral *constant = dyn_cast<IntegerLiteral>(rex);
if (!constant || constant->getValue() != 0)
r = PointerFromInt;
return rhsType;
}
// FIXME: make sure the qualifier are matching
if (rhsType->isPointerType()) {
if (!Type::pointerTypesAreCompatible(lhsType, rhsType))
r = IncompatiblePointer;
return rhsType;
}
} else if (rhsType->isPointerType()) {
if (lhsType->isIntegerType()) {
// C99 6.5.16.1p1: the left operand is _Bool and the right is a pointer.
if (lhsType != Context.BoolTy)
r = IntFromPointer;
return rhsType;
}
// - both operands are pointers to qualified or unqualified versions of
// compatible types, and the type pointed to by the left has *all* the
// qualifiers of the type pointed to by the right;
if (lhsType->isPointerType()) {
if (!Type::pointerTypesAreCompatible(lhsType, rhsType))
r = IncompatiblePointer;
return rhsType;
}
} else if (lhsType->isStructureType() && rhsType->isStructureType()) {
if (Type::structureTypesAreCompatible(lhsType, rhsType))
return rhsType;
} else if (lhsType->isUnionType() && rhsType->isUnionType()) {
if (Type::unionTypesAreCompatible(lhsType, rhsType))
return rhsType;
}
r = Incompatible;
return QualType();
}
Action::ExprResult Sema::CheckMultiplicativeOperands(
Expr *lex, Expr *rex, SourceLocation loc, unsigned code)
{
QualType resType = UsualArithmeticConversions(lex->getType(), rex->getType());
if ((BOP)code == BinaryOperator::Rem) {
if (!resType->isIntegerType())
return Diag(loc, diag::err_typecheck_invalid_operands);
} else { // *, /
if (!resType->isArithmeticType())
return Diag(loc, diag::err_typecheck_invalid_operands);
}
return new BinaryOperator(lex, rex, (BOP)code, resType);
}
Action::ExprResult Sema::CheckAdditiveOperands( // C99 6.5.6
Expr *lex, Expr *rex, SourceLocation loc, unsigned code)
{
QualType lhsType = lex->getType(), rhsType = rex->getType();
QualType resType = UsualArithmeticConversions(lhsType, rhsType);
// handle the common case first (both operands are arithmetic).
if (resType->isArithmeticType())
return new BinaryOperator(lex, rex, (BOP)code, resType);
else {
if ((BOP)code == BinaryOperator::Add) {
if ((lhsType->isPointerType() && rhsType->isIntegerType()) ||
(lhsType->isIntegerType() && rhsType->isPointerType()))
return new BinaryOperator(lex, rex, (BOP)code, resType);
} else { // -
if ((lhsType->isPointerType() && rhsType->isIntegerType()) ||
(lhsType->isPointerType() && rhsType->isPointerType()))
return new BinaryOperator(lex, rex, (BOP)code, resType);
}
}
return Diag(loc, diag::err_typecheck_invalid_operands);
}
Action::ExprResult Sema::CheckShiftOperands( // C99 6.5.7
Expr *lex, Expr *rex, SourceLocation loc, unsigned code)
{
QualType resType = UsualArithmeticConversions(lex->getType(), rex->getType());
if (!resType->isIntegerType())
return Diag(loc, diag::err_typecheck_invalid_operands);
return new BinaryOperator(lex, rex, (BOP)code, resType);
}
Action::ExprResult Sema::CheckRelationalOperands( // C99 6.5.8
Expr *lex, Expr *rex, SourceLocation loc, unsigned code)
{
QualType lType = lex->getType(), rType = rex->getType();
if (lType->isRealType() && rType->isRealType())
return new BinaryOperator(lex, rex, (BOP)code, Context.IntTy);
if (lType->isPointerType() && rType->isPointerType())
return new BinaryOperator(lex, rex, (BOP)code, Context.IntTy);
if (lType->isIntegerType() || rType->isIntegerType()) // GCC extension.
return Diag(loc, diag::ext_typecheck_comparison_of_pointer_integer);
return Diag(loc, diag::err_typecheck_invalid_operands);
}
Action::ExprResult Sema::CheckEqualityOperands( // C99 6.5.9
Expr *lex, Expr *rex, SourceLocation loc, unsigned code)
{
QualType lType = lex->getType(), rType = rex->getType();
if (lType->isArithmeticType() && rType->isArithmeticType())
return new BinaryOperator(lex, rex, (BOP)code, Context.IntTy);
if (lType->isPointerType() && rType->isPointerType())
return new BinaryOperator(lex, rex, (BOP)code, Context.IntTy);
if (lType->isIntegerType() || rType->isIntegerType()) // GCC extension.
return Diag(loc, diag::ext_typecheck_comparison_of_pointer_integer);
return Diag(loc, diag::err_typecheck_invalid_operands);
}
Action::ExprResult Sema::CheckBitwiseOperands(
Expr *lex, Expr *rex, SourceLocation loc, unsigned code)
{
QualType resType = UsualArithmeticConversions(lex->getType(), rex->getType());
if (!resType->isIntegerType())
return Diag(loc, diag::err_typecheck_invalid_operands);
return new BinaryOperator(lex, rex, (BOP)code, resType);
}
Action::ExprResult Sema::CheckLogicalOperands( // C99 6.5.[13,14]
Expr *lex, Expr *rex, SourceLocation loc, unsigned code)
{
QualType lhsType = UsualUnaryConversion(lex->getType());
QualType rhsType = UsualUnaryConversion(rex->getType());
if (!lhsType->isScalarType() || !rhsType->isScalarType())
return Diag(loc, diag::err_typecheck_invalid_operands);
return new BinaryOperator(lex, rex, (BOP)code, Context.IntTy);
}
Action::ExprResult Sema::CheckAssignmentOperands(
Expr *lex, Expr *rex, SourceLocation loc, unsigned code)
{
QualType lhsType = lex->getType();
QualType rhsType = rex->getType();
if ((BOP)code == BinaryOperator::Assign) { // C99 6.5.16.1
// FIXME: consider hacking isModifiableLvalue to return an enum that
// communicates why the expression/type wasn't a modifiableLvalue.
// this check is done first to give a more precise diagnostic.
if (lhsType.isConstQualified())
return Diag(loc, diag::err_typecheck_assign_const);
if (!lex->isModifiableLvalue()) // this includes checking for "const"
return Diag(loc, diag::ext_typecheck_assign_non_lvalue);
if (lhsType == rhsType) // common case, fast path...
return new BinaryOperator(lex, rex, (BOP)code, lhsType);
AssignmentConversionResult result;
QualType resType = UsualAssignmentConversions(lhsType, rex, result);
// decode the result (notice that AST's are still created for extensions).
switch (result) {
case Compatible:
break;
case PointerFromInt:
Diag(loc, diag::ext_typecheck_assign_pointer_from_int);
break;
case IntFromPointer:
Diag(loc, diag::ext_typecheck_assign_int_from_pointer);
break;
case IncompatiblePointer:
Diag(loc, diag::ext_typecheck_assign_incompatible_pointer);
break;
case Incompatible:
return Diag(loc, diag::err_typecheck_assign_incompatible);
}
return new BinaryOperator(lex, rex, (BOP)code, resType);
}
// FIXME: type check compound assignments...
return new BinaryOperator(lex, rex, (BOP)code, Context.IntTy);
}
Action::ExprResult Sema::CheckCommaOperands( // C99 6.5.17
Expr *lex, Expr *rex, SourceLocation loc)
{
QualType rhsType = UsualUnaryConversion(rex->getType());
return new BinaryOperator(lex, rex, BinaryOperator::Comma, rhsType);
}
Action::ExprResult
Sema::CheckIncrementDecrementOperand(Expr *op, SourceLocation OpLoc,
unsigned OpCode) {
QualType qType = op->getType();
assert(!qType.isNull() && "no type for increment/decrement expression");
QualType canonType = qType.getCanonicalType();
// C99 6.5.2.4p1
if (const PointerType *pt = dyn_cast<PointerType>(canonType)) {
if (!pt->getPointeeType()->isObjectType()) // C99 6.5.2.4p2, 6.5.6p2
return Diag(OpLoc, diag::err_typecheck_arithmetic_incomplete_type, qType);
} else if (!canonType->isRealType()) {
// FIXME: Allow Complex as a GCC extension.
return Diag(OpLoc, diag::err_typecheck_illegal_increment_decrement, qType);
}
// At this point, we know we have a real or pointer type. As a result, the
// following predicate is overkill (i.e. it will check for types we know we
// don't have in this context). Nevertheless, we model the C99 spec closely.
if (!canonType.isModifiableLvalue())
return Diag(OpLoc, diag::err_typecheck_not_modifiable, qType);
return new UnaryOperator(op, (UOP)OpCode, qType);
}
/// getPrimaryDeclaration - Helper function for CheckAddressOfOperand().
/// This routine allows us to typecheck complex/recursive expressions
/// where the declaration is needed for type checking. Here are some
/// examples: &s.xx, &s.zz[1].yy, &(1+2), &(XX), &"123"[2].
static Decl *getPrimaryDeclaration(Expr *e) {
switch (e->getStmtClass()) {
case Stmt::DeclRefExprClass:
return cast<DeclRefExpr>(e)->getDecl();
case Stmt::MemberExprClass:
return getPrimaryDeclaration(cast<MemberExpr>(e)->getBase());
case Stmt::ArraySubscriptExprClass:
return getPrimaryDeclaration(cast<ArraySubscriptExpr>(e)->getBase());
case Stmt::CallExprClass:
return getPrimaryDeclaration(cast<CallExpr>(e)->getCallee());
case Stmt::UnaryOperatorClass:
return getPrimaryDeclaration(cast<UnaryOperator>(e)->getSubExpr());
case Stmt::ParenExprClass:
return getPrimaryDeclaration(cast<ParenExpr>(e)->getSubExpr());
default:
return 0;
}
}
/// CheckAddressOfOperand - The operand of & must be either a function
/// designator or an lvalue designating an object. If it is an lvalue, the
/// object cannot be declared with storage class register or be a bit field.
/// Note: The usual conversions are *not* applied to the operand of the &
/// operator, and its result is never an lvalue.
Action::ExprResult
Sema::CheckAddressOfOperand(Expr *op, SourceLocation OpLoc) {
Decl *dcl = getPrimaryDeclaration(op);
if (!op->isModifiableLvalue()) {
if (dcl && isa<FunctionDecl>(dcl))
; // C99 6.5.3.2p1: Allow function designators.
else
return Diag(OpLoc, diag::err_typecheck_invalid_lvalue_addrof);
} else if (dcl) {
// We have an lvalue with a decl. Make sure the decl is not declared
// with the register storage-class specifier.
if (const VarDecl *vd = dyn_cast<VarDecl>(dcl)) {
if (vd->getStorageClass() == VarDecl::Register)
return Diag(OpLoc, diag::err_typecheck_address_of_register);
} else
assert(0 && "Unknown/unexpected decl type");
// FIXME: add check for bitfields!
}
// If the operand has type "type", the result has type "pointer to type".
return new UnaryOperator(op, UnaryOperator::AddrOf,
Context.getPointerType(op->getType()));
}
Action::ExprResult
Sema::CheckIndirectionOperand(Expr *op, SourceLocation OpLoc) {
QualType qType = op->getType();
assert(!qType.isNull() && "no type for * expression");
QualType canonType = qType.getCanonicalType();
// FIXME: add type checking and fix result type
return new UnaryOperator(op, UnaryOperator::Deref, Context.IntTy);
}
/// CheckArithmeticOperand - Check the arithmetic unary operators (C99 6.5.3.3).
Action::ExprResult
Sema::CheckArithmeticOperand(Expr *op, SourceLocation OpLoc, unsigned Opc) {
QualType resultType = UsualUnaryConversion(op->getType());
switch (Opc) {
case UnaryOperator::Plus:
case UnaryOperator::Minus:
if (!resultType->isArithmeticType()) // C99 6.5.3.3p1
return Diag(OpLoc, diag::err_typecheck_unary_expr, resultType);
break;
case UnaryOperator::Not: // bitwise complement
if (!resultType->isIntegerType()) // C99 6.5.3.3p1
return Diag(OpLoc, diag::err_typecheck_unary_expr, resultType);
break;
case UnaryOperator::LNot: // logical negation
if (!resultType->isScalarType()) // C99 6.5.3.3p1
return Diag(OpLoc, diag::err_typecheck_unary_expr, resultType);
break;
}
return new UnaryOperator(op, (UOP)Opc, resultType);
}
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