| //===--- PPExpressions.cpp - Preprocessor Expression Evaluation -----------===// |
| // |
| // 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 Preprocessor::EvaluateDirectiveExpression method, |
| // which parses and evaluates integer constant expressions for #if directives. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // FIXME: implement testing for #assert's. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "clang/Lex/Preprocessor.h" |
| #include "clang/Lex/MacroInfo.h" |
| #include "clang/Lex/LiteralSupport.h" |
| #include "clang/Basic/TargetInfo.h" |
| #include "clang/Basic/TokenKinds.h" |
| #include "clang/Basic/Diagnostic.h" |
| #include "llvm/ADT/APSInt.h" |
| #include "llvm/ADT/SmallString.h" |
| using namespace clang; |
| |
| static bool EvaluateDirectiveSubExpr(llvm::APSInt &LHS, unsigned MinPrec, |
| Token &PeekTok, bool ValueLive, |
| Preprocessor &PP); |
| |
| /// DefinedTracker - This struct is used while parsing expressions to keep track |
| /// of whether !defined(X) has been seen. |
| /// |
| /// With this simple scheme, we handle the basic forms: |
| /// !defined(X) and !defined X |
| /// but we also trivially handle (silly) stuff like: |
| /// !!!defined(X) and +!defined(X) and !+!+!defined(X) and !(defined(X)). |
| struct DefinedTracker { |
| /// Each time a Value is evaluated, it returns information about whether the |
| /// parsed value is of the form defined(X), !defined(X) or is something else. |
| enum TrackerState { |
| DefinedMacro, // defined(X) |
| NotDefinedMacro, // !defined(X) |
| Unknown // Something else. |
| } State; |
| /// TheMacro - When the state is DefinedMacro or NotDefinedMacro, this |
| /// indicates the macro that was checked. |
| IdentifierInfo *TheMacro; |
| }; |
| |
| |
| |
| /// EvaluateValue - Evaluate the token PeekTok (and any others needed) and |
| /// return the computed value in Result. Return true if there was an error |
| /// parsing. This function also returns information about the form of the |
| /// expression in DT. See above for information on what DT means. |
| /// |
| /// If ValueLive is false, then this value is being evaluated in a context where |
| /// the result is not used. As such, avoid diagnostics that relate to |
| /// evaluation. |
| static bool EvaluateValue(llvm::APSInt &Result, Token &PeekTok, |
| DefinedTracker &DT, bool ValueLive, |
| Preprocessor &PP) { |
| Result = 0; |
| DT.State = DefinedTracker::Unknown; |
| |
| // If this token's spelling is a pp-identifier, check to see if it is |
| // 'defined' or if it is a macro. Note that we check here because many |
| // keywords are pp-identifiers, so we can't check the kind. |
| if (IdentifierInfo *II = PeekTok.getIdentifierInfo()) { |
| // If this identifier isn't 'defined' and it wasn't macro expanded, it turns |
| // into a simple 0, unless it is the C++ keyword "true", in which case it |
| // turns into "1". |
| if (II->getPPKeywordID() != tok::pp_defined) { |
| Result = II->getTokenID() == tok::kw_true; |
| Result.setIsUnsigned(false); // "0" is signed intmax_t 0. |
| PP.LexNonComment(PeekTok); |
| return false; |
| } |
| |
| // Handle "defined X" and "defined(X)". |
| |
| // Get the next token, don't expand it. |
| PP.LexUnexpandedToken(PeekTok); |
| |
| // Two options, it can either be a pp-identifier or a (. |
| bool InParens = false; |
| if (PeekTok.is(tok::l_paren)) { |
| // Found a paren, remember we saw it and skip it. |
| InParens = true; |
| PP.LexUnexpandedToken(PeekTok); |
| } |
| |
| // If we don't have a pp-identifier now, this is an error. |
| if ((II = PeekTok.getIdentifierInfo()) == 0) { |
| PP.Diag(PeekTok, diag::err_pp_defined_requires_identifier); |
| return true; |
| } |
| |
| // Otherwise, we got an identifier, is it defined to something? |
| Result = II->hasMacroDefinition(); |
| Result.setIsUnsigned(false); // Result is signed intmax_t. |
| |
| // If there is a macro, mark it used. |
| if (Result != 0 && ValueLive) { |
| MacroInfo *Macro = PP.getMacroInfo(II); |
| Macro->setIsUsed(true); |
| |
| // If this is the first use of a target-specific macro, warn about it. |
| if (Macro->isTargetSpecific()) { |
| // Don't warn on second use. |
| Macro->setIsTargetSpecific(false); |
| PP.getTargetInfo().DiagnoseNonPortability(PeekTok.getLocation(), |
| diag::port_target_macro_use); |
| } |
| } else if (ValueLive) { |
| // Use of a target-specific macro for some other target? If so, warn. |
| if (II->isOtherTargetMacro()) { |
| II->setIsOtherTargetMacro(false); // Don't warn on second use. |
| PP.getTargetInfo().DiagnoseNonPortability(PeekTok.getLocation(), |
| diag::port_target_macro_use); |
| } |
| } |
| |
| // Consume identifier. |
| PP.LexNonComment(PeekTok); |
| |
| // If we are in parens, ensure we have a trailing ). |
| if (InParens) { |
| if (PeekTok.isNot(tok::r_paren)) { |
| PP.Diag(PeekTok, diag::err_pp_missing_rparen); |
| return true; |
| } |
| // Consume the ). |
| PP.LexNonComment(PeekTok); |
| } |
| |
| // Success, remember that we saw defined(X). |
| DT.State = DefinedTracker::DefinedMacro; |
| DT.TheMacro = II; |
| return false; |
| } |
| |
| switch (PeekTok.getKind()) { |
| default: // Non-value token. |
| PP.Diag(PeekTok, diag::err_pp_expr_bad_token); |
| return true; |
| case tok::eom: |
| case tok::r_paren: |
| // If there is no expression, report and exit. |
| PP.Diag(PeekTok, diag::err_pp_expected_value_in_expr); |
| return true; |
| case tok::numeric_constant: { |
| llvm::SmallString<64> IntegerBuffer; |
| IntegerBuffer.resize(PeekTok.getLength()); |
| const char *ThisTokBegin = &IntegerBuffer[0]; |
| unsigned ActualLength = PP.getSpelling(PeekTok, ThisTokBegin); |
| NumericLiteralParser Literal(ThisTokBegin, ThisTokBegin+ActualLength, |
| PeekTok.getLocation(), PP); |
| if (Literal.hadError) |
| return true; // a diagnostic was already reported. |
| |
| if (Literal.isFloatingLiteral() || Literal.isImaginary) { |
| PP.Diag(PeekTok, diag::err_pp_illegal_floating_literal); |
| return true; |
| } |
| assert(Literal.isIntegerLiteral() && "Unknown ppnumber"); |
| |
| // long long is a C99 feature. |
| if (!PP.getLangOptions().C99 && !PP.getLangOptions().CPlusPlus0x |
| && Literal.isLongLong) |
| PP.Diag(PeekTok, diag::ext_longlong); |
| |
| // Parse the integer literal into Result. |
| if (Literal.GetIntegerValue(Result)) { |
| // Overflow parsing integer literal. |
| if (ValueLive) PP.Diag(PeekTok, diag::warn_integer_too_large); |
| Result.setIsUnsigned(true); |
| } else { |
| // Set the signedness of the result to match whether there was a U suffix |
| // or not. |
| Result.setIsUnsigned(Literal.isUnsigned); |
| |
| // Detect overflow based on whether the value is signed. If signed |
| // and if the value is too large, emit a warning "integer constant is so |
| // large that it is unsigned" e.g. on 12345678901234567890 where intmax_t |
| // is 64-bits. |
| if (!Literal.isUnsigned && Result.isNegative()) { |
| if (ValueLive)PP.Diag(PeekTok, diag::warn_integer_too_large_for_signed); |
| Result.setIsUnsigned(true); |
| } |
| } |
| |
| // Consume the token. |
| PP.LexNonComment(PeekTok); |
| return false; |
| } |
| case tok::char_constant: { // 'x' |
| llvm::SmallString<32> CharBuffer; |
| CharBuffer.resize(PeekTok.getLength()); |
| const char *ThisTokBegin = &CharBuffer[0]; |
| unsigned ActualLength = PP.getSpelling(PeekTok, ThisTokBegin); |
| CharLiteralParser Literal(ThisTokBegin, ThisTokBegin+ActualLength, |
| PeekTok.getLocation(), PP); |
| if (Literal.hadError()) |
| return true; // A diagnostic was already emitted. |
| |
| // Character literals are always int or wchar_t, expand to intmax_t. |
| TargetInfo &TI = PP.getTargetInfo(); |
| unsigned NumBits; |
| if (Literal.isWide()) |
| NumBits = TI.getWCharWidth(PeekTok.getLocation()); |
| else |
| NumBits = TI.getCharWidth(PeekTok.getLocation()); |
| |
| // Set the width. |
| llvm::APSInt Val(NumBits); |
| // Set the value. |
| Val = Literal.getValue(); |
| // Set the signedness. |
| Val.setIsUnsigned(!TI.isCharSigned(PeekTok.getLocation())); |
| |
| if (Result.getBitWidth() > Val.getBitWidth()) { |
| if (Val.isSigned()) |
| Result = Val.sext(Result.getBitWidth()); |
| else |
| Result = Val.zext(Result.getBitWidth()); |
| Result.setIsUnsigned(Val.isUnsigned()); |
| } else { |
| assert(Result.getBitWidth() == Val.getBitWidth() && |
| "intmax_t smaller than char/wchar_t?"); |
| Result = Val; |
| } |
| |
| // Consume the token. |
| PP.LexNonComment(PeekTok); |
| return false; |
| } |
| case tok::l_paren: |
| PP.LexNonComment(PeekTok); // Eat the (. |
| // Parse the value and if there are any binary operators involved, parse |
| // them. |
| if (EvaluateValue(Result, PeekTok, DT, ValueLive, PP)) return true; |
| |
| // If this is a silly value like (X), which doesn't need parens, check for |
| // !(defined X). |
| if (PeekTok.is(tok::r_paren)) { |
| // Just use DT unmodified as our result. |
| } else { |
| if (EvaluateDirectiveSubExpr(Result, 1, PeekTok, ValueLive, PP)) |
| return true; |
| |
| if (PeekTok.isNot(tok::r_paren)) { |
| PP.Diag(PeekTok, diag::err_pp_expected_rparen); |
| return true; |
| } |
| DT.State = DefinedTracker::Unknown; |
| } |
| PP.LexNonComment(PeekTok); // Eat the ). |
| return false; |
| |
| case tok::plus: |
| // Unary plus doesn't modify the value. |
| PP.LexNonComment(PeekTok); |
| return EvaluateValue(Result, PeekTok, DT, ValueLive, PP); |
| case tok::minus: { |
| SourceLocation Loc = PeekTok.getLocation(); |
| PP.LexNonComment(PeekTok); |
| if (EvaluateValue(Result, PeekTok, DT, ValueLive, PP)) return true; |
| // C99 6.5.3.3p3: The sign of the result matches the sign of the operand. |
| Result = -Result; |
| |
| bool Overflow = false; |
| if (Result.isUnsigned()) |
| Overflow = !Result.isPositive(); |
| else if (Result.isMinSignedValue()) |
| Overflow = true; // -MININT is the only thing that overflows. |
| |
| // If this operator is live and overflowed, report the issue. |
| if (Overflow && ValueLive) |
| PP.Diag(Loc, diag::warn_pp_expr_overflow); |
| |
| DT.State = DefinedTracker::Unknown; |
| return false; |
| } |
| |
| case tok::tilde: |
| PP.LexNonComment(PeekTok); |
| if (EvaluateValue(Result, PeekTok, DT, ValueLive, PP)) return true; |
| // C99 6.5.3.3p4: The sign of the result matches the sign of the operand. |
| Result = ~Result; |
| DT.State = DefinedTracker::Unknown; |
| return false; |
| |
| case tok::exclaim: |
| PP.LexNonComment(PeekTok); |
| if (EvaluateValue(Result, PeekTok, DT, ValueLive, PP)) return true; |
| Result = !Result; |
| // C99 6.5.3.3p5: The sign of the result is 'int', aka it is signed. |
| Result.setIsUnsigned(false); |
| |
| if (DT.State == DefinedTracker::DefinedMacro) |
| DT.State = DefinedTracker::NotDefinedMacro; |
| else if (DT.State == DefinedTracker::NotDefinedMacro) |
| DT.State = DefinedTracker::DefinedMacro; |
| return false; |
| |
| // FIXME: Handle #assert |
| } |
| } |
| |
| |
| |
| /// getPrecedence - Return the precedence of the specified binary operator |
| /// token. This returns: |
| /// ~0 - Invalid token. |
| /// 14 - *,/,% |
| /// 13 - -,+ |
| /// 12 - <<,>> |
| /// 11 - >=, <=, >, < |
| /// 10 - ==, != |
| /// 9 - & |
| /// 8 - ^ |
| /// 7 - | |
| /// 6 - && |
| /// 5 - || |
| /// 4 - ? |
| /// 3 - : |
| /// 0 - eom, ) |
| static unsigned getPrecedence(tok::TokenKind Kind) { |
| switch (Kind) { |
| default: return ~0U; |
| case tok::percent: |
| case tok::slash: |
| case tok::star: return 14; |
| case tok::plus: |
| case tok::minus: return 13; |
| case tok::lessless: |
| case tok::greatergreater: return 12; |
| case tok::lessequal: |
| case tok::less: |
| case tok::greaterequal: |
| case tok::greater: return 11; |
| case tok::exclaimequal: |
| case tok::equalequal: return 10; |
| case tok::amp: return 9; |
| case tok::caret: return 8; |
| case tok::pipe: return 7; |
| case tok::ampamp: return 6; |
| case tok::pipepipe: return 5; |
| case tok::question: return 4; |
| case tok::colon: return 3; |
| case tok::comma: return 2; |
| case tok::r_paren: return 0; // Lowest priority, end of expr. |
| case tok::eom: return 0; // Lowest priority, end of macro. |
| } |
| } |
| |
| |
| /// EvaluateDirectiveSubExpr - Evaluate the subexpression whose first token is |
| /// PeekTok, and whose precedence is PeekPrec. |
| /// |
| /// If ValueLive is false, then this value is being evaluated in a context where |
| /// the result is not used. As such, avoid diagnostics that relate to |
| /// evaluation. |
| static bool EvaluateDirectiveSubExpr(llvm::APSInt &LHS, unsigned MinPrec, |
| Token &PeekTok, bool ValueLive, |
| Preprocessor &PP) { |
| unsigned PeekPrec = getPrecedence(PeekTok.getKind()); |
| // If this token isn't valid, report the error. |
| if (PeekPrec == ~0U) { |
| PP.Diag(PeekTok, diag::err_pp_expr_bad_token); |
| return true; |
| } |
| |
| while (1) { |
| // If this token has a lower precedence than we are allowed to parse, return |
| // it so that higher levels of the recursion can parse it. |
| if (PeekPrec < MinPrec) |
| return false; |
| |
| tok::TokenKind Operator = PeekTok.getKind(); |
| |
| // If this is a short-circuiting operator, see if the RHS of the operator is |
| // dead. Note that this cannot just clobber ValueLive. Consider |
| // "0 && 1 ? 4 : 1 / 0", which is parsed as "(0 && 1) ? 4 : (1 / 0)". In |
| // this example, the RHS of the && being dead does not make the rest of the |
| // expr dead. |
| bool RHSIsLive; |
| if (Operator == tok::ampamp && LHS == 0) |
| RHSIsLive = false; // RHS of "0 && x" is dead. |
| else if (Operator == tok::pipepipe && LHS != 0) |
| RHSIsLive = false; // RHS of "1 || x" is dead. |
| else if (Operator == tok::question && LHS == 0) |
| RHSIsLive = false; // RHS (x) of "0 ? x : y" is dead. |
| else |
| RHSIsLive = ValueLive; |
| |
| // Consume the operator, saving the operator token for error reporting. |
| Token OpToken = PeekTok; |
| PP.LexNonComment(PeekTok); |
| |
| llvm::APSInt RHS(LHS.getBitWidth()); |
| // Parse the RHS of the operator. |
| DefinedTracker DT; |
| if (EvaluateValue(RHS, PeekTok, DT, RHSIsLive, PP)) return true; |
| |
| // Remember the precedence of this operator and get the precedence of the |
| // operator immediately to the right of the RHS. |
| unsigned ThisPrec = PeekPrec; |
| PeekPrec = getPrecedence(PeekTok.getKind()); |
| |
| // If this token isn't valid, report the error. |
| if (PeekPrec == ~0U) { |
| PP.Diag(PeekTok, diag::err_pp_expr_bad_token); |
| return true; |
| } |
| |
| bool isRightAssoc = Operator == tok::question; |
| |
| // Get the precedence of the operator to the right of the RHS. If it binds |
| // more tightly with RHS than we do, evaluate it completely first. |
| if (ThisPrec < PeekPrec || |
| (ThisPrec == PeekPrec && isRightAssoc)) { |
| if (EvaluateDirectiveSubExpr(RHS, ThisPrec+1, PeekTok, RHSIsLive, PP)) |
| return true; |
| PeekPrec = getPrecedence(PeekTok.getKind()); |
| } |
| assert(PeekPrec <= ThisPrec && "Recursion didn't work!"); |
| |
| // Usual arithmetic conversions (C99 6.3.1.8p1): result is unsigned if |
| // either operand is unsigned. Don't do this for x and y in "x ? y : z". |
| llvm::APSInt Res(LHS.getBitWidth()); |
| if (Operator != tok::question) { |
| Res.setIsUnsigned(LHS.isUnsigned()|RHS.isUnsigned()); |
| // If this just promoted something from signed to unsigned, and if the |
| // value was negative, warn about it. |
| if (ValueLive && Res.isUnsigned()) { |
| if (!LHS.isUnsigned() && LHS.isNegative()) |
| PP.Diag(OpToken, diag::warn_pp_convert_lhs_to_positive, |
| LHS.toStringSigned() + " to " + LHS.toStringUnsigned()); |
| if (!RHS.isUnsigned() && RHS.isNegative()) |
| PP.Diag(OpToken, diag::warn_pp_convert_rhs_to_positive, |
| RHS.toStringSigned() + " to " + RHS.toStringUnsigned()); |
| } |
| LHS.setIsUnsigned(Res.isUnsigned()); |
| RHS.setIsUnsigned(Res.isUnsigned()); |
| } |
| |
| // FIXME: All of these should detect and report overflow?? |
| bool Overflow = false; |
| switch (Operator) { |
| default: assert(0 && "Unknown operator token!"); |
| case tok::percent: |
| if (RHS == 0) { |
| if (ValueLive) PP.Diag(OpToken, diag::err_pp_remainder_by_zero); |
| return true; |
| } |
| Res = LHS % RHS; |
| break; |
| case tok::slash: |
| if (RHS == 0) { |
| if (ValueLive) PP.Diag(OpToken, diag::err_pp_division_by_zero); |
| return true; |
| } |
| Res = LHS / RHS; |
| if (LHS.isSigned()) |
| Overflow = LHS.isMinSignedValue() && RHS.isAllOnesValue(); // MININT/-1 |
| break; |
| case tok::star: |
| Res = LHS * RHS; |
| if (LHS != 0 && RHS != 0) |
| Overflow = Res/RHS != LHS || Res/LHS != RHS; |
| break; |
| case tok::lessless: { |
| // Determine whether overflow is about to happen. |
| unsigned ShAmt = static_cast<unsigned>(RHS.getLimitedValue()); |
| if (ShAmt >= LHS.getBitWidth()) |
| Overflow = true, ShAmt = LHS.getBitWidth()-1; |
| else if (LHS.isUnsigned()) |
| Overflow = ShAmt > LHS.countLeadingZeros(); |
| else if (LHS.isPositive()) |
| Overflow = ShAmt >= LHS.countLeadingZeros(); // Don't allow sign change. |
| else |
| Overflow = ShAmt >= LHS.countLeadingOnes(); |
| |
| Res = LHS << ShAmt; |
| break; |
| } |
| case tok::greatergreater: { |
| // Determine whether overflow is about to happen. |
| unsigned ShAmt = static_cast<unsigned>(RHS.getLimitedValue()); |
| if (ShAmt >= LHS.getBitWidth()) |
| Overflow = true, ShAmt = LHS.getBitWidth()-1; |
| Res = LHS >> ShAmt; |
| break; |
| } |
| case tok::plus: |
| Res = LHS + RHS; |
| if (LHS.isUnsigned()) |
| Overflow = Res.ult(LHS); |
| else if (LHS.isPositive() == RHS.isPositive() && |
| Res.isPositive() != LHS.isPositive()) |
| Overflow = true; // Overflow for signed addition. |
| break; |
| case tok::minus: |
| Res = LHS - RHS; |
| if (LHS.isUnsigned()) |
| Overflow = Res.ugt(LHS); |
| else if (LHS.isPositive() != RHS.isPositive() && |
| Res.isPositive() != LHS.isPositive()) |
| Overflow = true; // Overflow for signed subtraction. |
| break; |
| case tok::lessequal: |
| Res = LHS <= RHS; |
| Res.setIsUnsigned(false); // C99 6.5.8p6, result is always int (signed) |
| break; |
| case tok::less: |
| Res = LHS < RHS; |
| Res.setIsUnsigned(false); // C99 6.5.8p6, result is always int (signed) |
| break; |
| case tok::greaterequal: |
| Res = LHS >= RHS; |
| Res.setIsUnsigned(false); // C99 6.5.8p6, result is always int (signed) |
| break; |
| case tok::greater: |
| Res = LHS > RHS; |
| Res.setIsUnsigned(false); // C99 6.5.8p6, result is always int (signed) |
| break; |
| case tok::exclaimequal: |
| Res = LHS != RHS; |
| Res.setIsUnsigned(false); // C99 6.5.9p3, result is always int (signed) |
| break; |
| case tok::equalequal: |
| Res = LHS == RHS; |
| Res.setIsUnsigned(false); // C99 6.5.9p3, result is always int (signed) |
| break; |
| case tok::amp: |
| Res = LHS & RHS; |
| break; |
| case tok::caret: |
| Res = LHS ^ RHS; |
| break; |
| case tok::pipe: |
| Res = LHS | RHS; |
| break; |
| case tok::ampamp: |
| Res = (LHS != 0 && RHS != 0); |
| Res.setIsUnsigned(false); // C99 6.5.13p3, result is always int (signed) |
| break; |
| case tok::pipepipe: |
| Res = (LHS != 0 || RHS != 0); |
| Res.setIsUnsigned(false); // C99 6.5.14p3, result is always int (signed) |
| break; |
| case tok::comma: |
| PP.Diag(OpToken, diag::ext_pp_comma_expr); |
| Res = RHS; // LHS = LHS,RHS -> RHS. |
| break; |
| case tok::question: { |
| // Parse the : part of the expression. |
| if (PeekTok.isNot(tok::colon)) { |
| PP.Diag(OpToken, diag::err_pp_question_without_colon); |
| return true; |
| } |
| // Consume the :. |
| PP.LexNonComment(PeekTok); |
| |
| // Evaluate the value after the :. |
| bool AfterColonLive = ValueLive && LHS == 0; |
| llvm::APSInt AfterColonVal(LHS.getBitWidth()); |
| DefinedTracker DT; |
| if (EvaluateValue(AfterColonVal, PeekTok, DT, AfterColonLive, PP)) |
| return true; |
| |
| // Parse anything after the : RHS that has a higher precedence than ?. |
| if (EvaluateDirectiveSubExpr(AfterColonVal, ThisPrec+1, |
| PeekTok, AfterColonLive, PP)) |
| return true; |
| |
| // Now that we have the condition, the LHS and the RHS of the :, evaluate. |
| Res = LHS != 0 ? RHS : AfterColonVal; |
| |
| // Usual arithmetic conversions (C99 6.3.1.8p1): result is unsigned if |
| // either operand is unsigned. |
| Res.setIsUnsigned(RHS.isUnsigned() | AfterColonVal.isUnsigned()); |
| |
| // Figure out the precedence of the token after the : part. |
| PeekPrec = getPrecedence(PeekTok.getKind()); |
| break; |
| } |
| case tok::colon: |
| // Don't allow :'s to float around without being part of ?: exprs. |
| PP.Diag(OpToken, diag::err_pp_colon_without_question); |
| return true; |
| } |
| |
| // If this operator is live and overflowed, report the issue. |
| if (Overflow && ValueLive) |
| PP.Diag(OpToken, diag::warn_pp_expr_overflow); |
| |
| // Put the result back into 'LHS' for our next iteration. |
| LHS = Res; |
| } |
| |
| return false; |
| } |
| |
| /// EvaluateDirectiveExpression - Evaluate an integer constant expression that |
| /// may occur after a #if or #elif directive. If the expression is equivalent |
| /// to "!defined(X)" return X in IfNDefMacro. |
| bool Preprocessor:: |
| EvaluateDirectiveExpression(IdentifierInfo *&IfNDefMacro) { |
| // Peek ahead one token. |
| Token Tok; |
| Lex(Tok); |
| |
| // C99 6.10.1p3 - All expressions are evaluated as intmax_t or uintmax_t. |
| unsigned BitWidth = getTargetInfo().getIntMaxTWidth(Tok.getLocation()); |
| llvm::APSInt ResVal(BitWidth); |
| DefinedTracker DT; |
| if (EvaluateValue(ResVal, Tok, DT, true, *this)) { |
| // Parse error, skip the rest of the macro line. |
| if (Tok.isNot(tok::eom)) |
| DiscardUntilEndOfDirective(); |
| return false; |
| } |
| |
| // If we are at the end of the expression after just parsing a value, there |
| // must be no (unparenthesized) binary operators involved, so we can exit |
| // directly. |
| if (Tok.is(tok::eom)) { |
| // If the expression we parsed was of the form !defined(macro), return the |
| // macro in IfNDefMacro. |
| if (DT.State == DefinedTracker::NotDefinedMacro) |
| IfNDefMacro = DT.TheMacro; |
| |
| return ResVal != 0; |
| } |
| |
| // Otherwise, we must have a binary operator (e.g. "#if 1 < 2"), so parse the |
| // operator and the stuff after it. |
| if (EvaluateDirectiveSubExpr(ResVal, 1, Tok, true, *this)) { |
| // Parse error, skip the rest of the macro line. |
| if (Tok.isNot(tok::eom)) |
| DiscardUntilEndOfDirective(); |
| return false; |
| } |
| |
| // If we aren't at the tok::eom token, something bad happened, like an extra |
| // ')' token. |
| if (Tok.isNot(tok::eom)) { |
| Diag(Tok, diag::err_pp_expected_eol); |
| DiscardUntilEndOfDirective(); |
| } |
| |
| return ResVal != 0; |
| } |
| |