| //===--- PPExpressions.cpp - Preprocessor Expression Evaluation -----------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // 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/Basic/IdentifierTable.h" |
| #include "clang/Basic/SourceLocation.h" |
| #include "clang/Basic/SourceManager.h" |
| #include "clang/Basic/TargetInfo.h" |
| #include "clang/Basic/TokenKinds.h" |
| #include "clang/Lex/CodeCompletionHandler.h" |
| #include "clang/Lex/LexDiagnostic.h" |
| #include "clang/Lex/LiteralSupport.h" |
| #include "clang/Lex/MacroInfo.h" |
| #include "clang/Lex/PPCallbacks.h" |
| #include "clang/Lex/Preprocessor.h" |
| #include "clang/Lex/Token.h" |
| #include "llvm/ADT/APSInt.h" |
| #include "llvm/ADT/STLExtras.h" |
| #include "llvm/ADT/SmallString.h" |
| #include "llvm/ADT/StringExtras.h" |
| #include "llvm/ADT/StringRef.h" |
| #include "llvm/Support/ErrorHandling.h" |
| #include "llvm/Support/SaveAndRestore.h" |
| #include <cassert> |
| |
| using namespace clang; |
| |
| namespace { |
| |
| /// PPValue - Represents the value of a subexpression of a preprocessor |
| /// conditional and the source range covered by it. |
| class PPValue { |
| SourceRange Range; |
| IdentifierInfo *II; |
| |
| public: |
| llvm::APSInt Val; |
| |
| // Default ctor - Construct an 'invalid' PPValue. |
| PPValue(unsigned BitWidth) : Val(BitWidth) {} |
| |
| // If this value was produced by directly evaluating an identifier, produce |
| // that identifier. |
| IdentifierInfo *getIdentifier() const { return II; } |
| void setIdentifier(IdentifierInfo *II) { this->II = II; } |
| |
| unsigned getBitWidth() const { return Val.getBitWidth(); } |
| bool isUnsigned() const { return Val.isUnsigned(); } |
| |
| SourceRange getRange() const { return Range; } |
| |
| void setRange(SourceLocation L) { Range.setBegin(L); Range.setEnd(L); } |
| void setRange(SourceLocation B, SourceLocation E) { |
| Range.setBegin(B); Range.setEnd(E); |
| } |
| void setBegin(SourceLocation L) { Range.setBegin(L); } |
| void setEnd(SourceLocation L) { Range.setEnd(L); } |
| }; |
| |
| } // end anonymous namespace |
| |
| static bool EvaluateDirectiveSubExpr(PPValue &LHS, unsigned MinPrec, |
| Token &PeekTok, bool ValueLive, |
| bool &IncludedUndefinedIds, |
| 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; |
| bool IncludedUndefinedIds = false; |
| }; |
| |
| /// EvaluateDefined - Process a 'defined(sym)' expression. |
| static bool EvaluateDefined(PPValue &Result, Token &PeekTok, DefinedTracker &DT, |
| bool ValueLive, Preprocessor &PP) { |
| SourceLocation beginLoc(PeekTok.getLocation()); |
| Result.setBegin(beginLoc); |
| |
| // Get the next token, don't expand it. |
| PP.LexUnexpandedNonComment(PeekTok); |
| |
| // Two options, it can either be a pp-identifier or a (. |
| SourceLocation LParenLoc; |
| if (PeekTok.is(tok::l_paren)) { |
| // Found a paren, remember we saw it and skip it. |
| LParenLoc = PeekTok.getLocation(); |
| PP.LexUnexpandedNonComment(PeekTok); |
| } |
| |
| if (PeekTok.is(tok::code_completion)) { |
| if (PP.getCodeCompletionHandler()) |
| PP.getCodeCompletionHandler()->CodeCompleteMacroName(false); |
| PP.setCodeCompletionReached(); |
| PP.LexUnexpandedNonComment(PeekTok); |
| } |
| |
| // If we don't have a pp-identifier now, this is an error. |
| if (PP.CheckMacroName(PeekTok, MU_Other)) |
| return true; |
| |
| // Otherwise, we got an identifier, is it defined to something? |
| IdentifierInfo *II = PeekTok.getIdentifierInfo(); |
| MacroDefinition Macro = PP.getMacroDefinition(II); |
| Result.Val = !!Macro; |
| Result.Val.setIsUnsigned(false); // Result is signed intmax_t. |
| DT.IncludedUndefinedIds = !Macro; |
| |
| // If there is a macro, mark it used. |
| if (Result.Val != 0 && ValueLive) |
| PP.markMacroAsUsed(Macro.getMacroInfo()); |
| |
| // Save macro token for callback. |
| Token macroToken(PeekTok); |
| |
| // If we are in parens, ensure we have a trailing ). |
| if (LParenLoc.isValid()) { |
| // Consume identifier. |
| Result.setEnd(PeekTok.getLocation()); |
| PP.LexUnexpandedNonComment(PeekTok); |
| |
| if (PeekTok.isNot(tok::r_paren)) { |
| PP.Diag(PeekTok.getLocation(), diag::err_pp_expected_after) |
| << "'defined'" << tok::r_paren; |
| PP.Diag(LParenLoc, diag::note_matching) << tok::l_paren; |
| return true; |
| } |
| // Consume the ). |
| PP.LexNonComment(PeekTok); |
| Result.setEnd(PeekTok.getLocation()); |
| } else { |
| // Consume identifier. |
| Result.setEnd(PeekTok.getLocation()); |
| PP.LexNonComment(PeekTok); |
| } |
| |
| // [cpp.cond]p4: |
| // Prior to evaluation, macro invocations in the list of preprocessing |
| // tokens that will become the controlling constant expression are replaced |
| // (except for those macro names modified by the 'defined' unary operator), |
| // just as in normal text. If the token 'defined' is generated as a result |
| // of this replacement process or use of the 'defined' unary operator does |
| // not match one of the two specified forms prior to macro replacement, the |
| // behavior is undefined. |
| // This isn't an idle threat, consider this program: |
| // #define FOO |
| // #define BAR defined(FOO) |
| // #if BAR |
| // ... |
| // #else |
| // ... |
| // #endif |
| // clang and gcc will pick the #if branch while Visual Studio will take the |
| // #else branch. Emit a warning about this undefined behavior. |
| if (beginLoc.isMacroID()) { |
| bool IsFunctionTypeMacro = |
| PP.getSourceManager() |
| .getSLocEntry(PP.getSourceManager().getFileID(beginLoc)) |
| .getExpansion() |
| .isFunctionMacroExpansion(); |
| // For object-type macros, it's easy to replace |
| // #define FOO defined(BAR) |
| // with |
| // #if defined(BAR) |
| // #define FOO 1 |
| // #else |
| // #define FOO 0 |
| // #endif |
| // and doing so makes sense since compilers handle this differently in |
| // practice (see example further up). But for function-type macros, |
| // there is no good way to write |
| // # define FOO(x) (defined(M_ ## x) && M_ ## x) |
| // in a different way, and compilers seem to agree on how to behave here. |
| // So warn by default on object-type macros, but only warn in -pedantic |
| // mode on function-type macros. |
| if (IsFunctionTypeMacro) |
| PP.Diag(beginLoc, diag::warn_defined_in_function_type_macro); |
| else |
| PP.Diag(beginLoc, diag::warn_defined_in_object_type_macro); |
| } |
| |
| // Invoke the 'defined' callback. |
| if (PPCallbacks *Callbacks = PP.getPPCallbacks()) { |
| Callbacks->Defined(macroToken, Macro, |
| SourceRange(beginLoc, PeekTok.getLocation())); |
| } |
| |
| // Success, remember that we saw defined(X). |
| DT.State = DefinedTracker::DefinedMacro; |
| DT.TheMacro = II; |
| return false; |
| } |
| |
| /// 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(PPValue &Result, Token &PeekTok, DefinedTracker &DT, |
| bool ValueLive, Preprocessor &PP) { |
| DT.State = DefinedTracker::Unknown; |
| |
| Result.setIdentifier(nullptr); |
| |
| if (PeekTok.is(tok::code_completion)) { |
| if (PP.getCodeCompletionHandler()) |
| PP.getCodeCompletionHandler()->CodeCompletePreprocessorExpression(); |
| PP.setCodeCompletionReached(); |
| PP.LexNonComment(PeekTok); |
| } |
| |
| switch (PeekTok.getKind()) { |
| default: |
| // 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()) { |
| // Handle "defined X" and "defined(X)". |
| if (II->isStr("defined")) |
| return EvaluateDefined(Result, PeekTok, DT, ValueLive, PP); |
| |
| if (!II->isCPlusPlusOperatorKeyword()) { |
| // If this identifier isn't 'defined' or one of the special |
| // preprocessor keywords and it wasn't macro expanded, it turns |
| // into a simple 0 |
| if (ValueLive) { |
| PP.Diag(PeekTok, diag::warn_pp_undef_identifier) << II; |
| |
| const DiagnosticsEngine &DiagEngine = PP.getDiagnostics(); |
| // If 'Wundef' is enabled, do not emit 'undef-prefix' diagnostics. |
| if (DiagEngine.isIgnored(diag::warn_pp_undef_identifier, |
| PeekTok.getLocation())) { |
| const std::vector<std::string> UndefPrefixes = |
| DiagEngine.getDiagnosticOptions().UndefPrefixes; |
| const StringRef IdentifierName = II->getName(); |
| if (llvm::any_of(UndefPrefixes, |
| [&IdentifierName](const std::string &Prefix) { |
| return IdentifierName.startswith(Prefix); |
| })) |
| PP.Diag(PeekTok, diag::warn_pp_undef_prefix) |
| << AddFlagValue{llvm::join(UndefPrefixes, ",")} << II; |
| } |
| } |
| Result.Val = 0; |
| Result.Val.setIsUnsigned(false); // "0" is signed intmax_t 0. |
| Result.setIdentifier(II); |
| Result.setRange(PeekTok.getLocation()); |
| DT.IncludedUndefinedIds = true; |
| PP.LexNonComment(PeekTok); |
| return false; |
| } |
| } |
| PP.Diag(PeekTok, diag::err_pp_expr_bad_token_start_expr); |
| return true; |
| case tok::eod: |
| 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: { |
| SmallString<64> IntegerBuffer; |
| bool NumberInvalid = false; |
| StringRef Spelling = PP.getSpelling(PeekTok, IntegerBuffer, |
| &NumberInvalid); |
| if (NumberInvalid) |
| return true; // a diagnostic was already reported |
| |
| NumericLiteralParser Literal(Spelling, PeekTok.getLocation(), |
| PP.getSourceManager(), PP.getLangOpts(), |
| PP.getTargetInfo(), PP.getDiagnostics()); |
| 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"); |
| |
| // Complain about, and drop, any ud-suffix. |
| if (Literal.hasUDSuffix()) |
| PP.Diag(PeekTok, diag::err_pp_invalid_udl) << /*integer*/1; |
| |
| // 'long long' is a C99 or C++11 feature. |
| if (!PP.getLangOpts().C99 && Literal.isLongLong) { |
| if (PP.getLangOpts().CPlusPlus) |
| PP.Diag(PeekTok, |
| PP.getLangOpts().CPlusPlus11 ? |
| diag::warn_cxx98_compat_longlong : diag::ext_cxx11_longlong); |
| else |
| PP.Diag(PeekTok, diag::ext_c99_longlong); |
| } |
| |
| // 'z/uz' literals are a C++2b feature. |
| if (Literal.isSizeT) |
| PP.Diag(PeekTok, PP.getLangOpts().CPlusPlus |
| ? PP.getLangOpts().CPlusPlus2b |
| ? diag::warn_cxx20_compat_size_t_suffix |
| : diag::ext_cxx2b_size_t_suffix |
| : diag::err_cxx2b_size_t_suffix); |
| |
| // Parse the integer literal into Result. |
| if (Literal.GetIntegerValue(Result.Val)) { |
| // Overflow parsing integer literal. |
| if (ValueLive) |
| PP.Diag(PeekTok, diag::err_integer_literal_too_large) |
| << /* Unsigned */ 1; |
| Result.Val.setIsUnsigned(true); |
| } else { |
| // Set the signedness of the result to match whether there was a U suffix |
| // or not. |
| Result.Val.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.Val.isNegative()) { |
| // Octal, hexadecimal, and binary literals are implicitly unsigned if |
| // the value does not fit into a signed integer type. |
| if (ValueLive && Literal.getRadix() == 10) |
| PP.Diag(PeekTok, diag::ext_integer_literal_too_large_for_signed); |
| Result.Val.setIsUnsigned(true); |
| } |
| } |
| |
| // Consume the token. |
| Result.setRange(PeekTok.getLocation()); |
| PP.LexNonComment(PeekTok); |
| return false; |
| } |
| case tok::char_constant: // 'x' |
| case tok::wide_char_constant: // L'x' |
| case tok::utf8_char_constant: // u8'x' |
| case tok::utf16_char_constant: // u'x' |
| case tok::utf32_char_constant: { // U'x' |
| // Complain about, and drop, any ud-suffix. |
| if (PeekTok.hasUDSuffix()) |
| PP.Diag(PeekTok, diag::err_pp_invalid_udl) << /*character*/0; |
| |
| SmallString<32> CharBuffer; |
| bool CharInvalid = false; |
| StringRef ThisTok = PP.getSpelling(PeekTok, CharBuffer, &CharInvalid); |
| if (CharInvalid) |
| return true; |
| |
| CharLiteralParser Literal(ThisTok.begin(), ThisTok.end(), |
| PeekTok.getLocation(), PP, PeekTok.getKind()); |
| if (Literal.hadError()) |
| return true; // A diagnostic was already emitted. |
| |
| // Character literals are always int or wchar_t, expand to intmax_t. |
| const TargetInfo &TI = PP.getTargetInfo(); |
| unsigned NumBits; |
| if (Literal.isMultiChar()) |
| NumBits = TI.getIntWidth(); |
| else if (Literal.isWide()) |
| NumBits = TI.getWCharWidth(); |
| else if (Literal.isUTF16()) |
| NumBits = TI.getChar16Width(); |
| else if (Literal.isUTF32()) |
| NumBits = TI.getChar32Width(); |
| else // char or char8_t |
| NumBits = TI.getCharWidth(); |
| |
| // Set the width. |
| llvm::APSInt Val(NumBits); |
| // Set the value. |
| Val = Literal.getValue(); |
| // Set the signedness. UTF-16 and UTF-32 are always unsigned |
| if (Literal.isWide()) |
| Val.setIsUnsigned(!TargetInfo::isTypeSigned(TI.getWCharType())); |
| else if (!Literal.isUTF16() && !Literal.isUTF32()) |
| Val.setIsUnsigned(!PP.getLangOpts().CharIsSigned); |
| |
| if (Result.Val.getBitWidth() > Val.getBitWidth()) { |
| Result.Val = Val.extend(Result.Val.getBitWidth()); |
| } else { |
| assert(Result.Val.getBitWidth() == Val.getBitWidth() && |
| "intmax_t smaller than char/wchar_t?"); |
| Result.Val = Val; |
| } |
| |
| // Consume the token. |
| Result.setRange(PeekTok.getLocation()); |
| PP.LexNonComment(PeekTok); |
| return false; |
| } |
| case tok::l_paren: { |
| SourceLocation Start = PeekTok.getLocation(); |
| 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 { |
| // Otherwise, we have something like (x+y), and we consumed '(x'. |
| if (EvaluateDirectiveSubExpr(Result, 1, PeekTok, ValueLive, |
| DT.IncludedUndefinedIds, PP)) |
| return true; |
| |
| if (PeekTok.isNot(tok::r_paren)) { |
| PP.Diag(PeekTok.getLocation(), diag::err_pp_expected_rparen) |
| << Result.getRange(); |
| PP.Diag(Start, diag::note_matching) << tok::l_paren; |
| return true; |
| } |
| DT.State = DefinedTracker::Unknown; |
| } |
| Result.setRange(Start, PeekTok.getLocation()); |
| Result.setIdentifier(nullptr); |
| PP.LexNonComment(PeekTok); // Eat the ). |
| return false; |
| } |
| case tok::plus: { |
| SourceLocation Start = PeekTok.getLocation(); |
| // Unary plus doesn't modify the value. |
| PP.LexNonComment(PeekTok); |
| if (EvaluateValue(Result, PeekTok, DT, ValueLive, PP)) return true; |
| Result.setBegin(Start); |
| Result.setIdentifier(nullptr); |
| return false; |
| } |
| case tok::minus: { |
| SourceLocation Loc = PeekTok.getLocation(); |
| PP.LexNonComment(PeekTok); |
| if (EvaluateValue(Result, PeekTok, DT, ValueLive, PP)) return true; |
| Result.setBegin(Loc); |
| Result.setIdentifier(nullptr); |
| |
| // C99 6.5.3.3p3: The sign of the result matches the sign of the operand. |
| Result.Val = -Result.Val; |
| |
| // -MININT is the only thing that overflows. Unsigned never overflows. |
| bool Overflow = !Result.isUnsigned() && Result.Val.isMinSignedValue(); |
| |
| // If this operator is live and overflowed, report the issue. |
| if (Overflow && ValueLive) |
| PP.Diag(Loc, diag::warn_pp_expr_overflow) << Result.getRange(); |
| |
| DT.State = DefinedTracker::Unknown; |
| return false; |
| } |
| |
| case tok::tilde: { |
| SourceLocation Start = PeekTok.getLocation(); |
| PP.LexNonComment(PeekTok); |
| if (EvaluateValue(Result, PeekTok, DT, ValueLive, PP)) return true; |
| Result.setBegin(Start); |
| Result.setIdentifier(nullptr); |
| |
| // C99 6.5.3.3p4: The sign of the result matches the sign of the operand. |
| Result.Val = ~Result.Val; |
| DT.State = DefinedTracker::Unknown; |
| return false; |
| } |
| |
| case tok::exclaim: { |
| SourceLocation Start = PeekTok.getLocation(); |
| PP.LexNonComment(PeekTok); |
| if (EvaluateValue(Result, PeekTok, DT, ValueLive, PP)) return true; |
| Result.setBegin(Start); |
| Result.Val = !Result.Val; |
| // C99 6.5.3.3p5: The sign of the result is 'int', aka it is signed. |
| Result.Val.setIsUnsigned(false); |
| Result.setIdentifier(nullptr); |
| |
| if (DT.State == DefinedTracker::DefinedMacro) |
| DT.State = DefinedTracker::NotDefinedMacro; |
| else if (DT.State == DefinedTracker::NotDefinedMacro) |
| DT.State = DefinedTracker::DefinedMacro; |
| return false; |
| } |
| case tok::kw_true: |
| case tok::kw_false: |
| Result.Val = PeekTok.getKind() == tok::kw_true; |
| Result.Val.setIsUnsigned(false); // "0" is signed intmax_t 0. |
| Result.setIdentifier(PeekTok.getIdentifierInfo()); |
| Result.setRange(PeekTok.getLocation()); |
| PP.LexNonComment(PeekTok); |
| return false; |
| |
| // FIXME: Handle #assert |
| } |
| } |
| |
| /// getPrecedence - Return the precedence of the specified binary operator |
| /// token. This returns: |
| /// ~0 - Invalid token. |
| /// 14 -> 3 - various operators. |
| /// 0 - 'eod' or ')' |
| 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::comma: return 3; |
| case tok::colon: return 2; |
| case tok::r_paren: return 0;// Lowest priority, end of expr. |
| case tok::eod: return 0;// Lowest priority, end of directive. |
| } |
| } |
| |
| static void diagnoseUnexpectedOperator(Preprocessor &PP, PPValue &LHS, |
| Token &Tok) { |
| if (Tok.is(tok::l_paren) && LHS.getIdentifier()) |
| PP.Diag(LHS.getRange().getBegin(), diag::err_pp_expr_bad_token_lparen) |
| << LHS.getIdentifier(); |
| else |
| PP.Diag(Tok.getLocation(), diag::err_pp_expr_bad_token_binop) |
| << LHS.getRange(); |
| } |
| |
| /// EvaluateDirectiveSubExpr - Evaluate the subexpression whose first token is |
| /// PeekTok, and whose precedence is PeekPrec. This returns the result in LHS. |
| /// |
| /// 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, such as division by zero warnings. |
| static bool EvaluateDirectiveSubExpr(PPValue &LHS, unsigned MinPrec, |
| Token &PeekTok, bool ValueLive, |
| bool &IncludedUndefinedIds, |
| Preprocessor &PP) { |
| unsigned PeekPrec = getPrecedence(PeekTok.getKind()); |
| // If this token isn't valid, report the error. |
| if (PeekPrec == ~0U) { |
| diagnoseUnexpectedOperator(PP, LHS, PeekTok); |
| return true; |
| } |
| |
| while (true) { |
| // 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.Val == 0) |
| RHSIsLive = false; // RHS of "0 && x" is dead. |
| else if (Operator == tok::pipepipe && LHS.Val != 0) |
| RHSIsLive = false; // RHS of "1 || x" is dead. |
| else if (Operator == tok::question && LHS.Val == 0) |
| RHSIsLive = false; // RHS (x) of "0 ? x : y" is dead. |
| else |
| RHSIsLive = ValueLive; |
| |
| // Consume the operator, remembering the operator's location for reporting. |
| SourceLocation OpLoc = PeekTok.getLocation(); |
| PP.LexNonComment(PeekTok); |
| |
| PPValue RHS(LHS.getBitWidth()); |
| // Parse the RHS of the operator. |
| DefinedTracker DT; |
| if (EvaluateValue(RHS, PeekTok, DT, RHSIsLive, PP)) return true; |
| IncludedUndefinedIds = DT.IncludedUndefinedIds; |
| |
| // 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) { |
| diagnoseUnexpectedOperator(PP, RHS, PeekTok); |
| return true; |
| } |
| |
| // Decide whether to include the next binop in this subexpression. For |
| // example, when parsing x+y*z and looking at '*', we want to recursively |
| // handle y*z as a single subexpression. We do this because the precedence |
| // of * is higher than that of +. The only strange case we have to handle |
| // here is for the ?: operator, where the precedence is actually lower than |
| // the LHS of the '?'. The grammar rule is: |
| // |
| // conditional-expression ::= |
| // logical-OR-expression ? expression : conditional-expression |
| // where 'expression' is actually comma-expression. |
| unsigned RHSPrec; |
| if (Operator == tok::question) |
| // The RHS of "?" should be maximally consumed as an expression. |
| RHSPrec = getPrecedence(tok::comma); |
| else // All others should munch while higher precedence. |
| RHSPrec = ThisPrec+1; |
| |
| if (PeekPrec >= RHSPrec) { |
| if (EvaluateDirectiveSubExpr(RHS, RHSPrec, PeekTok, RHSIsLive, |
| IncludedUndefinedIds, 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. |
| llvm::APSInt Res(LHS.getBitWidth()); |
| switch (Operator) { |
| case tok::question: // No UAC for x and y in "x ? y : z". |
| case tok::lessless: // Shift amount doesn't UAC with shift value. |
| case tok::greatergreater: // Shift amount doesn't UAC with shift value. |
| case tok::comma: // Comma operands are not subject to UACs. |
| case tok::pipepipe: // Logical || does not do UACs. |
| case tok::ampamp: // Logical && does not do UACs. |
| break; // No UAC |
| default: |
| 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.Val.isNegative()) |
| PP.Diag(OpLoc, diag::warn_pp_convert_to_positive) << 0 |
| << LHS.Val.toString(10, true) + " to " + |
| LHS.Val.toString(10, false) |
| << LHS.getRange() << RHS.getRange(); |
| if (!RHS.isUnsigned() && RHS.Val.isNegative()) |
| PP.Diag(OpLoc, diag::warn_pp_convert_to_positive) << 1 |
| << RHS.Val.toString(10, true) + " to " + |
| RHS.Val.toString(10, false) |
| << LHS.getRange() << RHS.getRange(); |
| } |
| LHS.Val.setIsUnsigned(Res.isUnsigned()); |
| RHS.Val.setIsUnsigned(Res.isUnsigned()); |
| } |
| |
| bool Overflow = false; |
| switch (Operator) { |
| default: llvm_unreachable("Unknown operator token!"); |
| case tok::percent: |
| if (RHS.Val != 0) |
| Res = LHS.Val % RHS.Val; |
| else if (ValueLive) { |
| PP.Diag(OpLoc, diag::err_pp_remainder_by_zero) |
| << LHS.getRange() << RHS.getRange(); |
| return true; |
| } |
| break; |
| case tok::slash: |
| if (RHS.Val != 0) { |
| if (LHS.Val.isSigned()) |
| Res = llvm::APSInt(LHS.Val.sdiv_ov(RHS.Val, Overflow), false); |
| else |
| Res = LHS.Val / RHS.Val; |
| } else if (ValueLive) { |
| PP.Diag(OpLoc, diag::err_pp_division_by_zero) |
| << LHS.getRange() << RHS.getRange(); |
| return true; |
| } |
| break; |
| |
| case tok::star: |
| if (Res.isSigned()) |
| Res = llvm::APSInt(LHS.Val.smul_ov(RHS.Val, Overflow), false); |
| else |
| Res = LHS.Val * RHS.Val; |
| break; |
| case tok::lessless: { |
| // Determine whether overflow is about to happen. |
| if (LHS.isUnsigned()) |
| Res = LHS.Val.ushl_ov(RHS.Val, Overflow); |
| else |
| Res = llvm::APSInt(LHS.Val.sshl_ov(RHS.Val, Overflow), false); |
| break; |
| } |
| case tok::greatergreater: { |
| // Determine whether overflow is about to happen. |
| unsigned ShAmt = static_cast<unsigned>(RHS.Val.getLimitedValue()); |
| if (ShAmt >= LHS.getBitWidth()) { |
| Overflow = true; |
| ShAmt = LHS.getBitWidth()-1; |
| } |
| Res = LHS.Val >> ShAmt; |
| break; |
| } |
| case tok::plus: |
| if (LHS.isUnsigned()) |
| Res = LHS.Val + RHS.Val; |
| else |
| Res = llvm::APSInt(LHS.Val.sadd_ov(RHS.Val, Overflow), false); |
| break; |
| case tok::minus: |
| if (LHS.isUnsigned()) |
| Res = LHS.Val - RHS.Val; |
| else |
| Res = llvm::APSInt(LHS.Val.ssub_ov(RHS.Val, Overflow), false); |
| break; |
| case tok::lessequal: |
| Res = LHS.Val <= RHS.Val; |
| Res.setIsUnsigned(false); // C99 6.5.8p6, result is always int (signed) |
| break; |
| case tok::less: |
| Res = LHS.Val < RHS.Val; |
| Res.setIsUnsigned(false); // C99 6.5.8p6, result is always int (signed) |
| break; |
| case tok::greaterequal: |
| Res = LHS.Val >= RHS.Val; |
| Res.setIsUnsigned(false); // C99 6.5.8p6, result is always int (signed) |
| break; |
| case tok::greater: |
| Res = LHS.Val > RHS.Val; |
| Res.setIsUnsigned(false); // C99 6.5.8p6, result is always int (signed) |
| break; |
| case tok::exclaimequal: |
| Res = LHS.Val != RHS.Val; |
| Res.setIsUnsigned(false); // C99 6.5.9p3, result is always int (signed) |
| break; |
| case tok::equalequal: |
| Res = LHS.Val == RHS.Val; |
| Res.setIsUnsigned(false); // C99 6.5.9p3, result is always int (signed) |
| break; |
| case tok::amp: |
| Res = LHS.Val & RHS.Val; |
| break; |
| case tok::caret: |
| Res = LHS.Val ^ RHS.Val; |
| break; |
| case tok::pipe: |
| Res = LHS.Val | RHS.Val; |
| break; |
| case tok::ampamp: |
| Res = (LHS.Val != 0 && RHS.Val != 0); |
| Res.setIsUnsigned(false); // C99 6.5.13p3, result is always int (signed) |
| break; |
| case tok::pipepipe: |
| Res = (LHS.Val != 0 || RHS.Val != 0); |
| Res.setIsUnsigned(false); // C99 6.5.14p3, result is always int (signed) |
| break; |
| case tok::comma: |
| // Comma is invalid in pp expressions in c89/c++ mode, but is valid in C99 |
| // if not being evaluated. |
| if (!PP.getLangOpts().C99 || ValueLive) |
| PP.Diag(OpLoc, diag::ext_pp_comma_expr) |
| << LHS.getRange() << RHS.getRange(); |
| Res = RHS.Val; // LHS = LHS,RHS -> RHS. |
| break; |
| case tok::question: { |
| // Parse the : part of the expression. |
| if (PeekTok.isNot(tok::colon)) { |
| PP.Diag(PeekTok.getLocation(), diag::err_expected) |
| << tok::colon << LHS.getRange() << RHS.getRange(); |
| PP.Diag(OpLoc, diag::note_matching) << tok::question; |
| return true; |
| } |
| // Consume the :. |
| PP.LexNonComment(PeekTok); |
| |
| // Evaluate the value after the :. |
| bool AfterColonLive = ValueLive && LHS.Val == 0; |
| PPValue AfterColonVal(LHS.getBitWidth()); |
| DefinedTracker DT; |
| if (EvaluateValue(AfterColonVal, PeekTok, DT, AfterColonLive, PP)) |
| return true; |
| |
| // Parse anything after the : with the same precedence as ?. We allow |
| // things of equal precedence because ?: is right associative. |
| if (EvaluateDirectiveSubExpr(AfterColonVal, ThisPrec, |
| PeekTok, AfterColonLive, |
| IncludedUndefinedIds, PP)) |
| return true; |
| |
| // Now that we have the condition, the LHS and the RHS of the :, evaluate. |
| Res = LHS.Val != 0 ? RHS.Val : AfterColonVal.Val; |
| RHS.setEnd(AfterColonVal.getRange().getEnd()); |
| |
| // 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(OpLoc, diag::err_pp_colon_without_question) |
| << LHS.getRange() << RHS.getRange(); |
| return true; |
| } |
| |
| // If this operator is live and overflowed, report the issue. |
| if (Overflow && ValueLive) |
| PP.Diag(OpLoc, diag::warn_pp_expr_overflow) |
| << LHS.getRange() << RHS.getRange(); |
| |
| // Put the result back into 'LHS' for our next iteration. |
| LHS.Val = Res; |
| LHS.setEnd(RHS.getRange().getEnd()); |
| RHS.setIdentifier(nullptr); |
| } |
| } |
| |
| /// 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. |
| Preprocessor::DirectiveEvalResult |
| Preprocessor::EvaluateDirectiveExpression(IdentifierInfo *&IfNDefMacro) { |
| SaveAndRestore<bool> PPDir(ParsingIfOrElifDirective, true); |
| // Save the current state of 'DisableMacroExpansion' and reset it to false. If |
| // 'DisableMacroExpansion' is true, then we must be in a macro argument list |
| // in which case a directive is undefined behavior. We want macros to be able |
| // to recursively expand in order to get more gcc-list behavior, so we force |
| // DisableMacroExpansion to false and restore it when we're done parsing the |
| // expression. |
| bool DisableMacroExpansionAtStartOfDirective = DisableMacroExpansion; |
| DisableMacroExpansion = false; |
| |
| // Peek ahead one token. |
| Token Tok; |
| LexNonComment(Tok); |
| |
| // C99 6.10.1p3 - All expressions are evaluated as intmax_t or uintmax_t. |
| unsigned BitWidth = getTargetInfo().getIntMaxTWidth(); |
| |
| PPValue ResVal(BitWidth); |
| DefinedTracker DT; |
| SourceLocation ExprStartLoc = SourceMgr.getExpansionLoc(Tok.getLocation()); |
| if (EvaluateValue(ResVal, Tok, DT, true, *this)) { |
| // Parse error, skip the rest of the macro line. |
| SourceRange ConditionRange = ExprStartLoc; |
| if (Tok.isNot(tok::eod)) |
| ConditionRange = DiscardUntilEndOfDirective(); |
| |
| // Restore 'DisableMacroExpansion'. |
| DisableMacroExpansion = DisableMacroExpansionAtStartOfDirective; |
| |
| // We cannot trust the source range from the value because there was a |
| // parse error. Track the range manually -- the end of the directive is the |
| // end of the condition range. |
| return {false, |
| DT.IncludedUndefinedIds, |
| {ExprStartLoc, ConditionRange.getEnd()}}; |
| } |
| |
| // 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::eod)) { |
| // If the expression we parsed was of the form !defined(macro), return the |
| // macro in IfNDefMacro. |
| if (DT.State == DefinedTracker::NotDefinedMacro) |
| IfNDefMacro = DT.TheMacro; |
| |
| // Restore 'DisableMacroExpansion'. |
| DisableMacroExpansion = DisableMacroExpansionAtStartOfDirective; |
| return {ResVal.Val != 0, DT.IncludedUndefinedIds, ResVal.getRange()}; |
| } |
| |
| // Otherwise, we must have a binary operator (e.g. "#if 1 < 2"), so parse the |
| // operator and the stuff after it. |
| if (EvaluateDirectiveSubExpr(ResVal, getPrecedence(tok::question), |
| Tok, true, DT.IncludedUndefinedIds, *this)) { |
| // Parse error, skip the rest of the macro line. |
| if (Tok.isNot(tok::eod)) |
| DiscardUntilEndOfDirective(); |
| |
| // Restore 'DisableMacroExpansion'. |
| DisableMacroExpansion = DisableMacroExpansionAtStartOfDirective; |
| return {false, DT.IncludedUndefinedIds, ResVal.getRange()}; |
| } |
| |
| // If we aren't at the tok::eod token, something bad happened, like an extra |
| // ')' token. |
| if (Tok.isNot(tok::eod)) { |
| Diag(Tok, diag::err_pp_expected_eol); |
| DiscardUntilEndOfDirective(); |
| } |
| |
| // Restore 'DisableMacroExpansion'. |
| DisableMacroExpansion = DisableMacroExpansionAtStartOfDirective; |
| return {ResVal.Val != 0, DT.IncludedUndefinedIds, ResVal.getRange()}; |
| } |
