768 lines
28 KiB
C++
768 lines
28 KiB
C++
//===--- PPExpressions.cpp - Preprocessor Expression Evaluation -----------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements the Preprocessor::EvaluateDirectiveExpression method,
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// which parses and evaluates integer constant expressions for #if directives.
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//
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//===----------------------------------------------------------------------===//
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//
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// FIXME: implement testing for #assert's.
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//
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//===----------------------------------------------------------------------===//
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#include "clang/Lex/Preprocessor.h"
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#include "clang/Lex/MacroInfo.h"
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#include "clang/Lex/LiteralSupport.h"
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#include "clang/Lex/CodeCompletionHandler.h"
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#include "clang/Basic/TargetInfo.h"
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#include "clang/Lex/LexDiagnostic.h"
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#include "llvm/ADT/APSInt.h"
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using namespace clang;
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namespace {
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/// PPValue - Represents the value of a subexpression of a preprocessor
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/// conditional and the source range covered by it.
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class PPValue {
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SourceRange Range;
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public:
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llvm::APSInt Val;
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// Default ctor - Construct an 'invalid' PPValue.
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PPValue(unsigned BitWidth) : Val(BitWidth) {}
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unsigned getBitWidth() const { return Val.getBitWidth(); }
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bool isUnsigned() const { return Val.isUnsigned(); }
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const SourceRange &getRange() const { return Range; }
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void setRange(SourceLocation L) { Range.setBegin(L); Range.setEnd(L); }
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void setRange(SourceLocation B, SourceLocation E) {
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Range.setBegin(B); Range.setEnd(E);
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}
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void setBegin(SourceLocation L) { Range.setBegin(L); }
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void setEnd(SourceLocation L) { Range.setEnd(L); }
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};
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}
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static bool EvaluateDirectiveSubExpr(PPValue &LHS, unsigned MinPrec,
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Token &PeekTok, bool ValueLive,
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Preprocessor &PP);
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/// DefinedTracker - This struct is used while parsing expressions to keep track
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/// of whether !defined(X) has been seen.
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///
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/// With this simple scheme, we handle the basic forms:
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/// !defined(X) and !defined X
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/// but we also trivially handle (silly) stuff like:
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/// !!!defined(X) and +!defined(X) and !+!+!defined(X) and !(defined(X)).
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struct DefinedTracker {
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/// Each time a Value is evaluated, it returns information about whether the
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/// parsed value is of the form defined(X), !defined(X) or is something else.
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enum TrackerState {
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DefinedMacro, // defined(X)
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NotDefinedMacro, // !defined(X)
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Unknown // Something else.
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} State;
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/// TheMacro - When the state is DefinedMacro or NotDefinedMacro, this
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/// indicates the macro that was checked.
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IdentifierInfo *TheMacro;
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};
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/// EvaluateDefined - Process a 'defined(sym)' expression.
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static bool EvaluateDefined(PPValue &Result, Token &PeekTok, DefinedTracker &DT,
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bool ValueLive, Preprocessor &PP) {
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IdentifierInfo *II;
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Result.setBegin(PeekTok.getLocation());
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// Get the next token, don't expand it.
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PP.LexUnexpandedToken(PeekTok);
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// Two options, it can either be a pp-identifier or a (.
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SourceLocation LParenLoc;
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if (PeekTok.is(tok::l_paren)) {
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// Found a paren, remember we saw it and skip it.
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LParenLoc = PeekTok.getLocation();
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PP.LexUnexpandedToken(PeekTok);
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}
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if (PeekTok.is(tok::code_completion)) {
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if (PP.getCodeCompletionHandler())
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PP.getCodeCompletionHandler()->CodeCompleteMacroName(false);
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PP.LexUnexpandedToken(PeekTok);
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}
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// If we don't have a pp-identifier now, this is an error.
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if ((II = PeekTok.getIdentifierInfo()) == 0) {
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PP.Diag(PeekTok, diag::err_pp_defined_requires_identifier);
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return true;
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}
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// Otherwise, we got an identifier, is it defined to something?
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Result.Val = II->hasMacroDefinition();
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Result.Val.setIsUnsigned(false); // Result is signed intmax_t.
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// If there is a macro, mark it used.
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if (Result.Val != 0 && ValueLive) {
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MacroInfo *Macro = PP.getMacroInfo(II);
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Macro->setIsUsed(true);
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}
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// Consume identifier.
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Result.setEnd(PeekTok.getLocation());
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PP.LexUnexpandedToken(PeekTok);
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// If we are in parens, ensure we have a trailing ).
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if (LParenLoc.isValid()) {
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if (PeekTok.isNot(tok::r_paren)) {
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PP.Diag(PeekTok.getLocation(), diag::err_pp_missing_rparen) << "defined";
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PP.Diag(LParenLoc, diag::note_matching) << "(";
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return true;
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}
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// Consume the ).
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Result.setEnd(PeekTok.getLocation());
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PP.LexNonComment(PeekTok);
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}
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// Success, remember that we saw defined(X).
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DT.State = DefinedTracker::DefinedMacro;
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DT.TheMacro = II;
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return false;
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}
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/// EvaluateValue - Evaluate the token PeekTok (and any others needed) and
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/// return the computed value in Result. Return true if there was an error
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/// parsing. This function also returns information about the form of the
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/// expression in DT. See above for information on what DT means.
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///
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/// If ValueLive is false, then this value is being evaluated in a context where
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/// the result is not used. As such, avoid diagnostics that relate to
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/// evaluation.
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static bool EvaluateValue(PPValue &Result, Token &PeekTok, DefinedTracker &DT,
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bool ValueLive, Preprocessor &PP) {
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DT.State = DefinedTracker::Unknown;
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if (PeekTok.is(tok::code_completion)) {
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if (PP.getCodeCompletionHandler())
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PP.getCodeCompletionHandler()->CodeCompletePreprocessorExpression();
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PP.LexUnexpandedToken(PeekTok);
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}
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// If this token's spelling is a pp-identifier, check to see if it is
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// 'defined' or if it is a macro. Note that we check here because many
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// keywords are pp-identifiers, so we can't check the kind.
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if (IdentifierInfo *II = PeekTok.getIdentifierInfo()) {
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// Handle "defined X" and "defined(X)".
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if (II->isStr("defined"))
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return(EvaluateDefined(Result, PeekTok, DT, ValueLive, PP));
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// If this identifier isn't 'defined' or one of the special
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// preprocessor keywords and it wasn't macro expanded, it turns
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// into a simple 0, unless it is the C++ keyword "true", in which case it
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// turns into "1".
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if (ValueLive)
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PP.Diag(PeekTok, diag::warn_pp_undef_identifier) << II;
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Result.Val = II->getTokenID() == tok::kw_true;
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Result.Val.setIsUnsigned(false); // "0" is signed intmax_t 0.
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Result.setRange(PeekTok.getLocation());
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PP.LexNonComment(PeekTok);
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return false;
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}
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switch (PeekTok.getKind()) {
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default: // Non-value token.
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PP.Diag(PeekTok, diag::err_pp_expr_bad_token_start_expr);
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return true;
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case tok::eom:
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case tok::r_paren:
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// If there is no expression, report and exit.
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PP.Diag(PeekTok, diag::err_pp_expected_value_in_expr);
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return true;
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case tok::numeric_constant: {
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llvm::SmallString<64> IntegerBuffer;
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bool NumberInvalid = false;
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llvm::StringRef Spelling = PP.getSpelling(PeekTok, IntegerBuffer,
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&NumberInvalid);
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if (NumberInvalid)
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return true; // a diagnostic was already reported
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NumericLiteralParser Literal(Spelling.begin(), Spelling.end(),
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PeekTok.getLocation(), PP);
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if (Literal.hadError)
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return true; // a diagnostic was already reported.
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if (Literal.isFloatingLiteral() || Literal.isImaginary) {
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PP.Diag(PeekTok, diag::err_pp_illegal_floating_literal);
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return true;
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}
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assert(Literal.isIntegerLiteral() && "Unknown ppnumber");
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// long long is a C99 feature.
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if (!PP.getLangOptions().C99 && !PP.getLangOptions().CPlusPlus0x
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&& Literal.isLongLong)
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PP.Diag(PeekTok, diag::ext_longlong);
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// Parse the integer literal into Result.
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if (Literal.GetIntegerValue(Result.Val)) {
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// Overflow parsing integer literal.
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if (ValueLive) PP.Diag(PeekTok, diag::warn_integer_too_large);
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Result.Val.setIsUnsigned(true);
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} else {
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// Set the signedness of the result to match whether there was a U suffix
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// or not.
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Result.Val.setIsUnsigned(Literal.isUnsigned);
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// Detect overflow based on whether the value is signed. If signed
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// and if the value is too large, emit a warning "integer constant is so
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// large that it is unsigned" e.g. on 12345678901234567890 where intmax_t
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// is 64-bits.
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if (!Literal.isUnsigned && Result.Val.isNegative()) {
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// Don't warn for a hex literal: 0x8000..0 shouldn't warn.
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if (ValueLive && Literal.getRadix() != 16)
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PP.Diag(PeekTok, diag::warn_integer_too_large_for_signed);
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Result.Val.setIsUnsigned(true);
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}
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}
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// Consume the token.
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Result.setRange(PeekTok.getLocation());
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PP.LexNonComment(PeekTok);
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return false;
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}
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case tok::char_constant: { // 'x'
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llvm::SmallString<32> CharBuffer;
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bool CharInvalid = false;
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llvm::StringRef ThisTok = PP.getSpelling(PeekTok, CharBuffer, &CharInvalid);
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if (CharInvalid)
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return true;
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CharLiteralParser Literal(ThisTok.begin(), ThisTok.end(),
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PeekTok.getLocation(), PP);
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if (Literal.hadError())
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return true; // A diagnostic was already emitted.
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// Character literals are always int or wchar_t, expand to intmax_t.
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const TargetInfo &TI = PP.getTargetInfo();
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unsigned NumBits;
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if (Literal.isMultiChar())
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NumBits = TI.getIntWidth();
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else if (Literal.isWide())
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NumBits = TI.getWCharWidth();
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else
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NumBits = TI.getCharWidth();
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// Set the width.
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llvm::APSInt Val(NumBits);
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// Set the value.
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Val = Literal.getValue();
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// Set the signedness.
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Val.setIsUnsigned(!PP.getLangOptions().CharIsSigned);
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if (Result.Val.getBitWidth() > Val.getBitWidth()) {
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Result.Val = Val.extend(Result.Val.getBitWidth());
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} else {
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assert(Result.Val.getBitWidth() == Val.getBitWidth() &&
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"intmax_t smaller than char/wchar_t?");
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Result.Val = Val;
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}
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// Consume the token.
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Result.setRange(PeekTok.getLocation());
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PP.LexNonComment(PeekTok);
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return false;
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}
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case tok::l_paren: {
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SourceLocation Start = PeekTok.getLocation();
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PP.LexNonComment(PeekTok); // Eat the (.
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// Parse the value and if there are any binary operators involved, parse
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// them.
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if (EvaluateValue(Result, PeekTok, DT, ValueLive, PP)) return true;
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// If this is a silly value like (X), which doesn't need parens, check for
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// !(defined X).
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if (PeekTok.is(tok::r_paren)) {
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// Just use DT unmodified as our result.
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} else {
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// Otherwise, we have something like (x+y), and we consumed '(x'.
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if (EvaluateDirectiveSubExpr(Result, 1, PeekTok, ValueLive, PP))
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return true;
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if (PeekTok.isNot(tok::r_paren)) {
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PP.Diag(PeekTok.getLocation(), diag::err_pp_expected_rparen)
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<< Result.getRange();
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PP.Diag(Start, diag::note_matching) << "(";
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return true;
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}
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DT.State = DefinedTracker::Unknown;
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}
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Result.setRange(Start, PeekTok.getLocation());
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PP.LexNonComment(PeekTok); // Eat the ).
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return false;
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}
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case tok::plus: {
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SourceLocation Start = PeekTok.getLocation();
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// Unary plus doesn't modify the value.
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PP.LexNonComment(PeekTok);
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if (EvaluateValue(Result, PeekTok, DT, ValueLive, PP)) return true;
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Result.setBegin(Start);
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return false;
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}
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case tok::minus: {
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SourceLocation Loc = PeekTok.getLocation();
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PP.LexNonComment(PeekTok);
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if (EvaluateValue(Result, PeekTok, DT, ValueLive, PP)) return true;
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Result.setBegin(Loc);
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// C99 6.5.3.3p3: The sign of the result matches the sign of the operand.
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Result.Val = -Result.Val;
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// -MININT is the only thing that overflows. Unsigned never overflows.
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bool Overflow = !Result.isUnsigned() && Result.Val.isMinSignedValue();
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// If this operator is live and overflowed, report the issue.
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if (Overflow && ValueLive)
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PP.Diag(Loc, diag::warn_pp_expr_overflow) << Result.getRange();
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DT.State = DefinedTracker::Unknown;
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return false;
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}
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case tok::tilde: {
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SourceLocation Start = PeekTok.getLocation();
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PP.LexNonComment(PeekTok);
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if (EvaluateValue(Result, PeekTok, DT, ValueLive, PP)) return true;
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Result.setBegin(Start);
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// C99 6.5.3.3p4: The sign of the result matches the sign of the operand.
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Result.Val = ~Result.Val;
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DT.State = DefinedTracker::Unknown;
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return false;
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}
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case tok::exclaim: {
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SourceLocation Start = PeekTok.getLocation();
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PP.LexNonComment(PeekTok);
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if (EvaluateValue(Result, PeekTok, DT, ValueLive, PP)) return true;
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Result.setBegin(Start);
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Result.Val = !Result.Val;
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// C99 6.5.3.3p5: The sign of the result is 'int', aka it is signed.
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Result.Val.setIsUnsigned(false);
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if (DT.State == DefinedTracker::DefinedMacro)
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DT.State = DefinedTracker::NotDefinedMacro;
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else if (DT.State == DefinedTracker::NotDefinedMacro)
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DT.State = DefinedTracker::DefinedMacro;
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return false;
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}
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// FIXME: Handle #assert
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}
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}
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/// getPrecedence - Return the precedence of the specified binary operator
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/// token. This returns:
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/// ~0 - Invalid token.
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/// 14 -> 3 - various operators.
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/// 0 - 'eom' or ')'
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static unsigned getPrecedence(tok::TokenKind Kind) {
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switch (Kind) {
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default: return ~0U;
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case tok::percent:
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case tok::slash:
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case tok::star: return 14;
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case tok::plus:
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case tok::minus: return 13;
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case tok::lessless:
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case tok::greatergreater: return 12;
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case tok::lessequal:
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case tok::less:
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case tok::greaterequal:
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case tok::greater: return 11;
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case tok::exclaimequal:
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case tok::equalequal: return 10;
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case tok::amp: return 9;
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case tok::caret: return 8;
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case tok::pipe: return 7;
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case tok::ampamp: return 6;
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case tok::pipepipe: return 5;
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case tok::question: return 4;
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case tok::comma: return 3;
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case tok::colon: return 2;
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case tok::r_paren: return 0; // Lowest priority, end of expr.
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case tok::eom: return 0; // Lowest priority, end of macro.
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}
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}
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/// EvaluateDirectiveSubExpr - Evaluate the subexpression whose first token is
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/// PeekTok, and whose precedence is PeekPrec. This returns the result in LHS.
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///
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/// If ValueLive is false, then this value is being evaluated in a context where
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/// the result is not used. As such, avoid diagnostics that relate to
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/// evaluation, such as division by zero warnings.
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static bool EvaluateDirectiveSubExpr(PPValue &LHS, unsigned MinPrec,
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Token &PeekTok, bool ValueLive,
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Preprocessor &PP) {
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unsigned PeekPrec = getPrecedence(PeekTok.getKind());
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// If this token isn't valid, report the error.
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if (PeekPrec == ~0U) {
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PP.Diag(PeekTok.getLocation(), diag::err_pp_expr_bad_token_binop)
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<< LHS.getRange();
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return true;
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}
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while (1) {
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// If this token has a lower precedence than we are allowed to parse, return
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// it so that higher levels of the recursion can parse it.
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if (PeekPrec < MinPrec)
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return false;
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tok::TokenKind Operator = PeekTok.getKind();
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// If this is a short-circuiting operator, see if the RHS of the operator is
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// dead. Note that this cannot just clobber ValueLive. Consider
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// "0 && 1 ? 4 : 1 / 0", which is parsed as "(0 && 1) ? 4 : (1 / 0)". In
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// this example, the RHS of the && being dead does not make the rest of the
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// expr dead.
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bool RHSIsLive;
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if (Operator == tok::ampamp && LHS.Val == 0)
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RHSIsLive = false; // RHS of "0 && x" is dead.
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else if (Operator == tok::pipepipe && LHS.Val != 0)
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RHSIsLive = false; // RHS of "1 || x" is dead.
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else if (Operator == tok::question && LHS.Val == 0)
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RHSIsLive = false; // RHS (x) of "0 ? x : y" is dead.
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else
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RHSIsLive = ValueLive;
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// Consume the operator, remembering the operator's location for reporting.
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SourceLocation OpLoc = PeekTok.getLocation();
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PP.LexNonComment(PeekTok);
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PPValue RHS(LHS.getBitWidth());
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// Parse the RHS of the operator.
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DefinedTracker DT;
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if (EvaluateValue(RHS, PeekTok, DT, RHSIsLive, PP)) return true;
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// Remember the precedence of this operator and get the precedence of the
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// operator immediately to the right of the RHS.
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unsigned ThisPrec = PeekPrec;
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PeekPrec = getPrecedence(PeekTok.getKind());
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// If this token isn't valid, report the error.
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if (PeekPrec == ~0U) {
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PP.Diag(PeekTok.getLocation(), diag::err_pp_expr_bad_token_binop)
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<< RHS.getRange();
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return true;
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}
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// Decide whether to include the next binop in this subexpression. For
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// example, when parsing x+y*z and looking at '*', we want to recursively
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// handle y*z as a single subexpression. We do this because the precedence
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// of * is higher than that of +. The only strange case we have to handle
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// here is for the ?: operator, where the precedence is actually lower than
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// the LHS of the '?'. The grammar rule is:
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//
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// conditional-expression ::=
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// logical-OR-expression ? expression : conditional-expression
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// where 'expression' is actually comma-expression.
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|
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, 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_lhs_to_positive)
|
|
<< 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_rhs_to_positive)
|
|
<< 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());
|
|
}
|
|
|
|
// 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.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) {
|
|
Res = LHS.Val / RHS.Val;
|
|
if (LHS.Val.isSigned()) // MININT/-1 --> overflow.
|
|
Overflow = LHS.Val.isMinSignedValue() && RHS.Val.isAllOnesValue();
|
|
} else if (ValueLive) {
|
|
PP.Diag(OpLoc, diag::err_pp_division_by_zero)
|
|
<< LHS.getRange() << RHS.getRange();
|
|
return true;
|
|
}
|
|
break;
|
|
|
|
case tok::star:
|
|
Res = LHS.Val * RHS.Val;
|
|
if (Res.isSigned() && LHS.Val != 0 && RHS.Val != 0)
|
|
Overflow = Res/RHS.Val != LHS.Val || Res/LHS.Val != RHS.Val;
|
|
break;
|
|
case tok::lessless: {
|
|
// Determine whether overflow is about to happen.
|
|
unsigned ShAmt = static_cast<unsigned>(RHS.Val.getLimitedValue());
|
|
if (ShAmt >= LHS.Val.getBitWidth())
|
|
Overflow = true, ShAmt = LHS.Val.getBitWidth()-1;
|
|
else if (LHS.isUnsigned())
|
|
Overflow = false;
|
|
else if (LHS.Val.isNonNegative()) // Don't allow sign change.
|
|
Overflow = ShAmt >= LHS.Val.countLeadingZeros();
|
|
else
|
|
Overflow = ShAmt >= LHS.Val.countLeadingOnes();
|
|
|
|
Res = LHS.Val << ShAmt;
|
|
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:
|
|
Res = LHS.Val + RHS.Val;
|
|
if (LHS.isUnsigned())
|
|
Overflow = false;
|
|
else if (LHS.Val.isNonNegative() == RHS.Val.isNonNegative() &&
|
|
Res.isNonNegative() != LHS.Val.isNonNegative())
|
|
Overflow = true; // Overflow for signed addition.
|
|
break;
|
|
case tok::minus:
|
|
Res = LHS.Val - RHS.Val;
|
|
if (LHS.isUnsigned())
|
|
Overflow = false;
|
|
else if (LHS.Val.isNonNegative() != RHS.Val.isNonNegative() &&
|
|
Res.isNonNegative() != LHS.Val.isNonNegative())
|
|
Overflow = true; // Overflow for signed subtraction.
|
|
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.getLangOptions().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_colon)
|
|
<< LHS.getRange(), RHS.getRange();
|
|
PP.Diag(OpLoc, diag::note_matching) << "?";
|
|
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, 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());
|
|
}
|
|
|
|
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) {
|
|
// 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;
|
|
Lex(Tok);
|
|
|
|
// C99 6.10.1p3 - All expressions are evaluated as intmax_t or uintmax_t.
|
|
unsigned BitWidth = getTargetInfo().getIntMaxTWidth();
|
|
|
|
PPValue 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();
|
|
|
|
// Restore 'DisableMacroExpansion'.
|
|
DisableMacroExpansion = DisableMacroExpansionAtStartOfDirective;
|
|
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;
|
|
|
|
// Restore 'DisableMacroExpansion'.
|
|
DisableMacroExpansion = DisableMacroExpansionAtStartOfDirective;
|
|
return ResVal.Val != 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, getPrecedence(tok::question),
|
|
Tok, true, *this)) {
|
|
// Parse error, skip the rest of the macro line.
|
|
if (Tok.isNot(tok::eom))
|
|
DiscardUntilEndOfDirective();
|
|
|
|
// Restore 'DisableMacroExpansion'.
|
|
DisableMacroExpansion = DisableMacroExpansionAtStartOfDirective;
|
|
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();
|
|
}
|
|
|
|
// Restore 'DisableMacroExpansion'.
|
|
DisableMacroExpansion = DisableMacroExpansionAtStartOfDirective;
|
|
return ResVal.Val != 0;
|
|
}
|
|
|