1 //===--- PPExpressions.cpp - Preprocessor Expression Evaluation -----------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the Preprocessor::EvaluateDirectiveExpression method,
11 // which parses and evaluates integer constant expressions for #if directives.
13 //===----------------------------------------------------------------------===//
15 // FIXME: implement testing for #assert's.
17 //===----------------------------------------------------------------------===//
19 #include "clang/Lex/Preprocessor.h"
20 #include "clang/Lex/MacroInfo.h"
21 #include "clang/Lex/LiteralSupport.h"
22 #include "clang/Lex/CodeCompletionHandler.h"
23 #include "clang/Basic/TargetInfo.h"
24 #include "clang/Lex/LexDiagnostic.h"
25 #include "llvm/ADT/APSInt.h"
26 #include "llvm/Support/ErrorHandling.h"
27 using namespace clang;
31 /// PPValue - Represents the value of a subexpression of a preprocessor
32 /// conditional and the source range covered by it.
38 // Default ctor - Construct an 'invalid' PPValue.
39 PPValue(unsigned BitWidth) : Val(BitWidth) {}
41 unsigned getBitWidth() const { return Val.getBitWidth(); }
42 bool isUnsigned() const { return Val.isUnsigned(); }
44 const SourceRange &getRange() const { return Range; }
46 void setRange(SourceLocation L) { Range.setBegin(L); Range.setEnd(L); }
47 void setRange(SourceLocation B, SourceLocation E) {
48 Range.setBegin(B); Range.setEnd(E);
50 void setBegin(SourceLocation L) { Range.setBegin(L); }
51 void setEnd(SourceLocation L) { Range.setEnd(L); }
56 static bool EvaluateDirectiveSubExpr(PPValue &LHS, unsigned MinPrec,
57 Token &PeekTok, bool ValueLive,
60 /// DefinedTracker - This struct is used while parsing expressions to keep track
61 /// of whether !defined(X) has been seen.
63 /// With this simple scheme, we handle the basic forms:
64 /// !defined(X) and !defined X
65 /// but we also trivially handle (silly) stuff like:
66 /// !!!defined(X) and +!defined(X) and !+!+!defined(X) and !(defined(X)).
67 struct DefinedTracker {
68 /// Each time a Value is evaluated, it returns information about whether the
69 /// parsed value is of the form defined(X), !defined(X) or is something else.
71 DefinedMacro, // defined(X)
72 NotDefinedMacro, // !defined(X)
73 Unknown // Something else.
75 /// TheMacro - When the state is DefinedMacro or NotDefinedMacro, this
76 /// indicates the macro that was checked.
77 IdentifierInfo *TheMacro;
80 /// EvaluateDefined - Process a 'defined(sym)' expression.
81 static bool EvaluateDefined(PPValue &Result, Token &PeekTok, DefinedTracker &DT,
82 bool ValueLive, Preprocessor &PP) {
84 Result.setBegin(PeekTok.getLocation());
86 // Get the next token, don't expand it.
87 PP.LexUnexpandedNonComment(PeekTok);
89 // Two options, it can either be a pp-identifier or a (.
90 SourceLocation LParenLoc;
91 if (PeekTok.is(tok::l_paren)) {
92 // Found a paren, remember we saw it and skip it.
93 LParenLoc = PeekTok.getLocation();
94 PP.LexUnexpandedNonComment(PeekTok);
97 if (PeekTok.is(tok::code_completion)) {
98 if (PP.getCodeCompletionHandler())
99 PP.getCodeCompletionHandler()->CodeCompleteMacroName(false);
100 PP.setCodeCompletionReached();
101 PP.LexUnexpandedNonComment(PeekTok);
104 // If we don't have a pp-identifier now, this is an error.
105 if ((II = PeekTok.getIdentifierInfo()) == 0) {
106 PP.Diag(PeekTok, diag::err_pp_defined_requires_identifier);
110 // Otherwise, we got an identifier, is it defined to something?
111 Result.Val = II->hasMacroDefinition();
112 Result.Val.setIsUnsigned(false); // Result is signed intmax_t.
114 // If there is a macro, mark it used.
115 if (Result.Val != 0 && ValueLive) {
116 MacroInfo *Macro = PP.getMacroInfo(II);
117 PP.markMacroAsUsed(Macro);
120 // Invoke the 'defined' callback.
121 if (PPCallbacks *Callbacks = PP.getPPCallbacks())
122 Callbacks->Defined(PeekTok);
124 // If we are in parens, ensure we have a trailing ).
125 if (LParenLoc.isValid()) {
126 // Consume identifier.
127 Result.setEnd(PeekTok.getLocation());
128 PP.LexUnexpandedNonComment(PeekTok);
130 if (PeekTok.isNot(tok::r_paren)) {
131 PP.Diag(PeekTok.getLocation(), diag::err_pp_missing_rparen) << "defined";
132 PP.Diag(LParenLoc, diag::note_matching) << "(";
136 Result.setEnd(PeekTok.getLocation());
137 PP.LexNonComment(PeekTok);
139 // Consume identifier.
140 Result.setEnd(PeekTok.getLocation());
141 PP.LexNonComment(PeekTok);
144 // Success, remember that we saw defined(X).
145 DT.State = DefinedTracker::DefinedMacro;
150 /// EvaluateValue - Evaluate the token PeekTok (and any others needed) and
151 /// return the computed value in Result. Return true if there was an error
152 /// parsing. This function also returns information about the form of the
153 /// expression in DT. See above for information on what DT means.
155 /// If ValueLive is false, then this value is being evaluated in a context where
156 /// the result is not used. As such, avoid diagnostics that relate to
158 static bool EvaluateValue(PPValue &Result, Token &PeekTok, DefinedTracker &DT,
159 bool ValueLive, Preprocessor &PP) {
160 DT.State = DefinedTracker::Unknown;
162 if (PeekTok.is(tok::code_completion)) {
163 if (PP.getCodeCompletionHandler())
164 PP.getCodeCompletionHandler()->CodeCompletePreprocessorExpression();
165 PP.setCodeCompletionReached();
166 PP.LexNonComment(PeekTok);
169 // If this token's spelling is a pp-identifier, check to see if it is
170 // 'defined' or if it is a macro. Note that we check here because many
171 // keywords are pp-identifiers, so we can't check the kind.
172 if (IdentifierInfo *II = PeekTok.getIdentifierInfo()) {
173 // Handle "defined X" and "defined(X)".
174 if (II->isStr("defined"))
175 return(EvaluateDefined(Result, PeekTok, DT, ValueLive, PP));
177 // If this identifier isn't 'defined' or one of the special
178 // preprocessor keywords and it wasn't macro expanded, it turns
179 // into a simple 0, unless it is the C++ keyword "true", in which case it
182 II->getTokenID() != tok::kw_true &&
183 II->getTokenID() != tok::kw_false)
184 PP.Diag(PeekTok, diag::warn_pp_undef_identifier) << II;
185 Result.Val = II->getTokenID() == tok::kw_true;
186 Result.Val.setIsUnsigned(false); // "0" is signed intmax_t 0.
187 Result.setRange(PeekTok.getLocation());
188 PP.LexNonComment(PeekTok);
192 switch (PeekTok.getKind()) {
193 default: // Non-value token.
194 PP.Diag(PeekTok, diag::err_pp_expr_bad_token_start_expr);
198 // If there is no expression, report and exit.
199 PP.Diag(PeekTok, diag::err_pp_expected_value_in_expr);
201 case tok::numeric_constant: {
202 SmallString<64> IntegerBuffer;
203 bool NumberInvalid = false;
204 StringRef Spelling = PP.getSpelling(PeekTok, IntegerBuffer,
207 return true; // a diagnostic was already reported
209 NumericLiteralParser Literal(Spelling, PeekTok.getLocation(), PP);
210 if (Literal.hadError)
211 return true; // a diagnostic was already reported.
213 if (Literal.isFloatingLiteral() || Literal.isImaginary) {
214 PP.Diag(PeekTok, diag::err_pp_illegal_floating_literal);
217 assert(Literal.isIntegerLiteral() && "Unknown ppnumber");
219 // Complain about, and drop, any ud-suffix.
220 if (Literal.hasUDSuffix())
221 PP.Diag(PeekTok, diag::err_pp_invalid_udl) << /*integer*/1;
223 // 'long long' is a C99 or C++11 feature.
224 if (!PP.getLangOpts().C99 && Literal.isLongLong) {
225 if (PP.getLangOpts().CPlusPlus)
227 PP.getLangOpts().CPlusPlus0x ?
228 diag::warn_cxx98_compat_longlong : diag::ext_cxx11_longlong);
230 PP.Diag(PeekTok, diag::ext_c99_longlong);
233 // Parse the integer literal into Result.
234 if (Literal.GetIntegerValue(Result.Val)) {
235 // Overflow parsing integer literal.
236 if (ValueLive) PP.Diag(PeekTok, diag::warn_integer_too_large);
237 Result.Val.setIsUnsigned(true);
239 // Set the signedness of the result to match whether there was a U suffix
241 Result.Val.setIsUnsigned(Literal.isUnsigned);
243 // Detect overflow based on whether the value is signed. If signed
244 // and if the value is too large, emit a warning "integer constant is so
245 // large that it is unsigned" e.g. on 12345678901234567890 where intmax_t
247 if (!Literal.isUnsigned && Result.Val.isNegative()) {
248 // Don't warn for a hex literal: 0x8000..0 shouldn't warn.
249 if (ValueLive && Literal.getRadix() != 16)
250 PP.Diag(PeekTok, diag::warn_integer_too_large_for_signed);
251 Result.Val.setIsUnsigned(true);
255 // Consume the token.
256 Result.setRange(PeekTok.getLocation());
257 PP.LexNonComment(PeekTok);
260 case tok::char_constant: // 'x'
261 case tok::wide_char_constant: { // L'x'
262 case tok::utf16_char_constant: // u'x'
263 case tok::utf32_char_constant: // U'x'
264 // Complain about, and drop, any ud-suffix.
265 if (PeekTok.hasUDSuffix())
266 PP.Diag(PeekTok, diag::err_pp_invalid_udl) << /*character*/0;
268 SmallString<32> CharBuffer;
269 bool CharInvalid = false;
270 StringRef ThisTok = PP.getSpelling(PeekTok, CharBuffer, &CharInvalid);
274 CharLiteralParser Literal(ThisTok.begin(), ThisTok.end(),
275 PeekTok.getLocation(), PP, PeekTok.getKind());
276 if (Literal.hadError())
277 return true; // A diagnostic was already emitted.
279 // Character literals are always int or wchar_t, expand to intmax_t.
280 const TargetInfo &TI = PP.getTargetInfo();
282 if (Literal.isMultiChar())
283 NumBits = TI.getIntWidth();
284 else if (Literal.isWide())
285 NumBits = TI.getWCharWidth();
286 else if (Literal.isUTF16())
287 NumBits = TI.getChar16Width();
288 else if (Literal.isUTF32())
289 NumBits = TI.getChar32Width();
291 NumBits = TI.getCharWidth();
294 llvm::APSInt Val(NumBits);
296 Val = Literal.getValue();
297 // Set the signedness. UTF-16 and UTF-32 are always unsigned
298 if (!Literal.isUTF16() && !Literal.isUTF32())
299 Val.setIsUnsigned(!PP.getLangOpts().CharIsSigned);
301 if (Result.Val.getBitWidth() > Val.getBitWidth()) {
302 Result.Val = Val.extend(Result.Val.getBitWidth());
304 assert(Result.Val.getBitWidth() == Val.getBitWidth() &&
305 "intmax_t smaller than char/wchar_t?");
309 // Consume the token.
310 Result.setRange(PeekTok.getLocation());
311 PP.LexNonComment(PeekTok);
315 SourceLocation Start = PeekTok.getLocation();
316 PP.LexNonComment(PeekTok); // Eat the (.
317 // Parse the value and if there are any binary operators involved, parse
319 if (EvaluateValue(Result, PeekTok, DT, ValueLive, PP)) return true;
321 // If this is a silly value like (X), which doesn't need parens, check for
323 if (PeekTok.is(tok::r_paren)) {
324 // Just use DT unmodified as our result.
326 // Otherwise, we have something like (x+y), and we consumed '(x'.
327 if (EvaluateDirectiveSubExpr(Result, 1, PeekTok, ValueLive, PP))
330 if (PeekTok.isNot(tok::r_paren)) {
331 PP.Diag(PeekTok.getLocation(), diag::err_pp_expected_rparen)
332 << Result.getRange();
333 PP.Diag(Start, diag::note_matching) << "(";
336 DT.State = DefinedTracker::Unknown;
338 Result.setRange(Start, PeekTok.getLocation());
339 PP.LexNonComment(PeekTok); // Eat the ).
343 SourceLocation Start = PeekTok.getLocation();
344 // Unary plus doesn't modify the value.
345 PP.LexNonComment(PeekTok);
346 if (EvaluateValue(Result, PeekTok, DT, ValueLive, PP)) return true;
347 Result.setBegin(Start);
351 SourceLocation Loc = PeekTok.getLocation();
352 PP.LexNonComment(PeekTok);
353 if (EvaluateValue(Result, PeekTok, DT, ValueLive, PP)) return true;
354 Result.setBegin(Loc);
356 // C99 6.5.3.3p3: The sign of the result matches the sign of the operand.
357 Result.Val = -Result.Val;
359 // -MININT is the only thing that overflows. Unsigned never overflows.
360 bool Overflow = !Result.isUnsigned() && Result.Val.isMinSignedValue();
362 // If this operator is live and overflowed, report the issue.
363 if (Overflow && ValueLive)
364 PP.Diag(Loc, diag::warn_pp_expr_overflow) << Result.getRange();
366 DT.State = DefinedTracker::Unknown;
371 SourceLocation Start = PeekTok.getLocation();
372 PP.LexNonComment(PeekTok);
373 if (EvaluateValue(Result, PeekTok, DT, ValueLive, PP)) return true;
374 Result.setBegin(Start);
376 // C99 6.5.3.3p4: The sign of the result matches the sign of the operand.
377 Result.Val = ~Result.Val;
378 DT.State = DefinedTracker::Unknown;
383 SourceLocation Start = PeekTok.getLocation();
384 PP.LexNonComment(PeekTok);
385 if (EvaluateValue(Result, PeekTok, DT, ValueLive, PP)) return true;
386 Result.setBegin(Start);
387 Result.Val = !Result.Val;
388 // C99 6.5.3.3p5: The sign of the result is 'int', aka it is signed.
389 Result.Val.setIsUnsigned(false);
391 if (DT.State == DefinedTracker::DefinedMacro)
392 DT.State = DefinedTracker::NotDefinedMacro;
393 else if (DT.State == DefinedTracker::NotDefinedMacro)
394 DT.State = DefinedTracker::DefinedMacro;
398 // FIXME: Handle #assert
404 /// getPrecedence - Return the precedence of the specified binary operator
405 /// token. This returns:
406 /// ~0 - Invalid token.
407 /// 14 -> 3 - various operators.
409 static unsigned getPrecedence(tok::TokenKind Kind) {
414 case tok::star: return 14;
416 case tok::minus: return 13;
418 case tok::greatergreater: return 12;
421 case tok::greaterequal:
422 case tok::greater: return 11;
423 case tok::exclaimequal:
424 case tok::equalequal: return 10;
425 case tok::amp: return 9;
426 case tok::caret: return 8;
427 case tok::pipe: return 7;
428 case tok::ampamp: return 6;
429 case tok::pipepipe: return 5;
430 case tok::question: return 4;
431 case tok::comma: return 3;
432 case tok::colon: return 2;
433 case tok::r_paren: return 0;// Lowest priority, end of expr.
434 case tok::eod: return 0;// Lowest priority, end of directive.
439 /// EvaluateDirectiveSubExpr - Evaluate the subexpression whose first token is
440 /// PeekTok, and whose precedence is PeekPrec. This returns the result in LHS.
442 /// If ValueLive is false, then this value is being evaluated in a context where
443 /// the result is not used. As such, avoid diagnostics that relate to
444 /// evaluation, such as division by zero warnings.
445 static bool EvaluateDirectiveSubExpr(PPValue &LHS, unsigned MinPrec,
446 Token &PeekTok, bool ValueLive,
448 unsigned PeekPrec = getPrecedence(PeekTok.getKind());
449 // If this token isn't valid, report the error.
450 if (PeekPrec == ~0U) {
451 PP.Diag(PeekTok.getLocation(), diag::err_pp_expr_bad_token_binop)
457 // If this token has a lower precedence than we are allowed to parse, return
458 // it so that higher levels of the recursion can parse it.
459 if (PeekPrec < MinPrec)
462 tok::TokenKind Operator = PeekTok.getKind();
464 // If this is a short-circuiting operator, see if the RHS of the operator is
465 // dead. Note that this cannot just clobber ValueLive. Consider
466 // "0 && 1 ? 4 : 1 / 0", which is parsed as "(0 && 1) ? 4 : (1 / 0)". In
467 // this example, the RHS of the && being dead does not make the rest of the
470 if (Operator == tok::ampamp && LHS.Val == 0)
471 RHSIsLive = false; // RHS of "0 && x" is dead.
472 else if (Operator == tok::pipepipe && LHS.Val != 0)
473 RHSIsLive = false; // RHS of "1 || x" is dead.
474 else if (Operator == tok::question && LHS.Val == 0)
475 RHSIsLive = false; // RHS (x) of "0 ? x : y" is dead.
477 RHSIsLive = ValueLive;
479 // Consume the operator, remembering the operator's location for reporting.
480 SourceLocation OpLoc = PeekTok.getLocation();
481 PP.LexNonComment(PeekTok);
483 PPValue RHS(LHS.getBitWidth());
484 // Parse the RHS of the operator.
486 if (EvaluateValue(RHS, PeekTok, DT, RHSIsLive, PP)) return true;
488 // Remember the precedence of this operator and get the precedence of the
489 // operator immediately to the right of the RHS.
490 unsigned ThisPrec = PeekPrec;
491 PeekPrec = getPrecedence(PeekTok.getKind());
493 // If this token isn't valid, report the error.
494 if (PeekPrec == ~0U) {
495 PP.Diag(PeekTok.getLocation(), diag::err_pp_expr_bad_token_binop)
500 // Decide whether to include the next binop in this subexpression. For
501 // example, when parsing x+y*z and looking at '*', we want to recursively
502 // handle y*z as a single subexpression. We do this because the precedence
503 // of * is higher than that of +. The only strange case we have to handle
504 // here is for the ?: operator, where the precedence is actually lower than
505 // the LHS of the '?'. The grammar rule is:
507 // conditional-expression ::=
508 // logical-OR-expression ? expression : conditional-expression
509 // where 'expression' is actually comma-expression.
511 if (Operator == tok::question)
512 // The RHS of "?" should be maximally consumed as an expression.
513 RHSPrec = getPrecedence(tok::comma);
514 else // All others should munch while higher precedence.
515 RHSPrec = ThisPrec+1;
517 if (PeekPrec >= RHSPrec) {
518 if (EvaluateDirectiveSubExpr(RHS, RHSPrec, PeekTok, RHSIsLive, PP))
520 PeekPrec = getPrecedence(PeekTok.getKind());
522 assert(PeekPrec <= ThisPrec && "Recursion didn't work!");
524 // Usual arithmetic conversions (C99 6.3.1.8p1): result is unsigned if
525 // either operand is unsigned.
526 llvm::APSInt Res(LHS.getBitWidth());
528 case tok::question: // No UAC for x and y in "x ? y : z".
529 case tok::lessless: // Shift amount doesn't UAC with shift value.
530 case tok::greatergreater: // Shift amount doesn't UAC with shift value.
531 case tok::comma: // Comma operands are not subject to UACs.
532 case tok::pipepipe: // Logical || does not do UACs.
533 case tok::ampamp: // Logical && does not do UACs.
536 Res.setIsUnsigned(LHS.isUnsigned()|RHS.isUnsigned());
537 // If this just promoted something from signed to unsigned, and if the
538 // value was negative, warn about it.
539 if (ValueLive && Res.isUnsigned()) {
540 if (!LHS.isUnsigned() && LHS.Val.isNegative())
541 PP.Diag(OpLoc, diag::warn_pp_convert_lhs_to_positive)
542 << LHS.Val.toString(10, true) + " to " +
543 LHS.Val.toString(10, false)
544 << LHS.getRange() << RHS.getRange();
545 if (!RHS.isUnsigned() && RHS.Val.isNegative())
546 PP.Diag(OpLoc, diag::warn_pp_convert_rhs_to_positive)
547 << RHS.Val.toString(10, true) + " to " +
548 RHS.Val.toString(10, false)
549 << LHS.getRange() << RHS.getRange();
551 LHS.Val.setIsUnsigned(Res.isUnsigned());
552 RHS.Val.setIsUnsigned(Res.isUnsigned());
555 bool Overflow = false;
557 default: llvm_unreachable("Unknown operator token!");
560 Res = LHS.Val % RHS.Val;
561 else if (ValueLive) {
562 PP.Diag(OpLoc, diag::err_pp_remainder_by_zero)
563 << LHS.getRange() << RHS.getRange();
569 if (LHS.Val.isSigned())
570 Res = llvm::APSInt(LHS.Val.sdiv_ov(RHS.Val, Overflow), false);
572 Res = LHS.Val / RHS.Val;
573 } else if (ValueLive) {
574 PP.Diag(OpLoc, diag::err_pp_division_by_zero)
575 << LHS.getRange() << RHS.getRange();
582 Res = llvm::APSInt(LHS.Val.smul_ov(RHS.Val, Overflow), false);
584 Res = LHS.Val * RHS.Val;
586 case tok::lessless: {
587 // Determine whether overflow is about to happen.
588 unsigned ShAmt = static_cast<unsigned>(RHS.Val.getLimitedValue());
589 if (LHS.isUnsigned()) {
590 Overflow = ShAmt >= LHS.Val.getBitWidth();
592 ShAmt = LHS.Val.getBitWidth()-1;
593 Res = LHS.Val << ShAmt;
595 Res = llvm::APSInt(LHS.Val.sshl_ov(ShAmt, Overflow), false);
599 case tok::greatergreater: {
600 // Determine whether overflow is about to happen.
601 unsigned ShAmt = static_cast<unsigned>(RHS.Val.getLimitedValue());
602 if (ShAmt >= LHS.getBitWidth())
603 Overflow = true, ShAmt = LHS.getBitWidth()-1;
604 Res = LHS.Val >> ShAmt;
608 if (LHS.isUnsigned())
609 Res = LHS.Val + RHS.Val;
611 Res = llvm::APSInt(LHS.Val.sadd_ov(RHS.Val, Overflow), false);
614 if (LHS.isUnsigned())
615 Res = LHS.Val - RHS.Val;
617 Res = llvm::APSInt(LHS.Val.ssub_ov(RHS.Val, Overflow), false);
620 Res = LHS.Val <= RHS.Val;
621 Res.setIsUnsigned(false); // C99 6.5.8p6, result is always int (signed)
624 Res = LHS.Val < RHS.Val;
625 Res.setIsUnsigned(false); // C99 6.5.8p6, result is always int (signed)
627 case tok::greaterequal:
628 Res = LHS.Val >= RHS.Val;
629 Res.setIsUnsigned(false); // C99 6.5.8p6, result is always int (signed)
632 Res = LHS.Val > RHS.Val;
633 Res.setIsUnsigned(false); // C99 6.5.8p6, result is always int (signed)
635 case tok::exclaimequal:
636 Res = LHS.Val != RHS.Val;
637 Res.setIsUnsigned(false); // C99 6.5.9p3, result is always int (signed)
639 case tok::equalequal:
640 Res = LHS.Val == RHS.Val;
641 Res.setIsUnsigned(false); // C99 6.5.9p3, result is always int (signed)
644 Res = LHS.Val & RHS.Val;
647 Res = LHS.Val ^ RHS.Val;
650 Res = LHS.Val | RHS.Val;
653 Res = (LHS.Val != 0 && RHS.Val != 0);
654 Res.setIsUnsigned(false); // C99 6.5.13p3, result is always int (signed)
657 Res = (LHS.Val != 0 || RHS.Val != 0);
658 Res.setIsUnsigned(false); // C99 6.5.14p3, result is always int (signed)
661 // Comma is invalid in pp expressions in c89/c++ mode, but is valid in C99
662 // if not being evaluated.
663 if (!PP.getLangOpts().C99 || ValueLive)
664 PP.Diag(OpLoc, diag::ext_pp_comma_expr)
665 << LHS.getRange() << RHS.getRange();
666 Res = RHS.Val; // LHS = LHS,RHS -> RHS.
668 case tok::question: {
669 // Parse the : part of the expression.
670 if (PeekTok.isNot(tok::colon)) {
671 PP.Diag(PeekTok.getLocation(), diag::err_expected_colon)
672 << LHS.getRange(), RHS.getRange();
673 PP.Diag(OpLoc, diag::note_matching) << "?";
677 PP.LexNonComment(PeekTok);
679 // Evaluate the value after the :.
680 bool AfterColonLive = ValueLive && LHS.Val == 0;
681 PPValue AfterColonVal(LHS.getBitWidth());
683 if (EvaluateValue(AfterColonVal, PeekTok, DT, AfterColonLive, PP))
686 // Parse anything after the : with the same precedence as ?. We allow
687 // things of equal precedence because ?: is right associative.
688 if (EvaluateDirectiveSubExpr(AfterColonVal, ThisPrec,
689 PeekTok, AfterColonLive, PP))
692 // Now that we have the condition, the LHS and the RHS of the :, evaluate.
693 Res = LHS.Val != 0 ? RHS.Val : AfterColonVal.Val;
694 RHS.setEnd(AfterColonVal.getRange().getEnd());
696 // Usual arithmetic conversions (C99 6.3.1.8p1): result is unsigned if
697 // either operand is unsigned.
698 Res.setIsUnsigned(RHS.isUnsigned() | AfterColonVal.isUnsigned());
700 // Figure out the precedence of the token after the : part.
701 PeekPrec = getPrecedence(PeekTok.getKind());
705 // Don't allow :'s to float around without being part of ?: exprs.
706 PP.Diag(OpLoc, diag::err_pp_colon_without_question)
707 << LHS.getRange() << RHS.getRange();
711 // If this operator is live and overflowed, report the issue.
712 if (Overflow && ValueLive)
713 PP.Diag(OpLoc, diag::warn_pp_expr_overflow)
714 << LHS.getRange() << RHS.getRange();
716 // Put the result back into 'LHS' for our next iteration.
718 LHS.setEnd(RHS.getRange().getEnd());
722 /// EvaluateDirectiveExpression - Evaluate an integer constant expression that
723 /// may occur after a #if or #elif directive. If the expression is equivalent
724 /// to "!defined(X)" return X in IfNDefMacro.
726 EvaluateDirectiveExpression(IdentifierInfo *&IfNDefMacro) {
727 // Save the current state of 'DisableMacroExpansion' and reset it to false. If
728 // 'DisableMacroExpansion' is true, then we must be in a macro argument list
729 // in which case a directive is undefined behavior. We want macros to be able
730 // to recursively expand in order to get more gcc-list behavior, so we force
731 // DisableMacroExpansion to false and restore it when we're done parsing the
733 bool DisableMacroExpansionAtStartOfDirective = DisableMacroExpansion;
734 DisableMacroExpansion = false;
736 // Peek ahead one token.
740 // C99 6.10.1p3 - All expressions are evaluated as intmax_t or uintmax_t.
741 unsigned BitWidth = getTargetInfo().getIntMaxTWidth();
743 PPValue ResVal(BitWidth);
745 if (EvaluateValue(ResVal, Tok, DT, true, *this)) {
746 // Parse error, skip the rest of the macro line.
747 if (Tok.isNot(tok::eod))
748 DiscardUntilEndOfDirective();
750 // Restore 'DisableMacroExpansion'.
751 DisableMacroExpansion = DisableMacroExpansionAtStartOfDirective;
755 // If we are at the end of the expression after just parsing a value, there
756 // must be no (unparenthesized) binary operators involved, so we can exit
758 if (Tok.is(tok::eod)) {
759 // If the expression we parsed was of the form !defined(macro), return the
760 // macro in IfNDefMacro.
761 if (DT.State == DefinedTracker::NotDefinedMacro)
762 IfNDefMacro = DT.TheMacro;
764 // Restore 'DisableMacroExpansion'.
765 DisableMacroExpansion = DisableMacroExpansionAtStartOfDirective;
766 return ResVal.Val != 0;
769 // Otherwise, we must have a binary operator (e.g. "#if 1 < 2"), so parse the
770 // operator and the stuff after it.
771 if (EvaluateDirectiveSubExpr(ResVal, getPrecedence(tok::question),
773 // Parse error, skip the rest of the macro line.
774 if (Tok.isNot(tok::eod))
775 DiscardUntilEndOfDirective();
777 // Restore 'DisableMacroExpansion'.
778 DisableMacroExpansion = DisableMacroExpansionAtStartOfDirective;
782 // If we aren't at the tok::eod token, something bad happened, like an extra
784 if (Tok.isNot(tok::eod)) {
785 Diag(Tok, diag::err_pp_expected_eol);
786 DiscardUntilEndOfDirective();
789 // Restore 'DisableMacroExpansion'.
790 DisableMacroExpansion = DisableMacroExpansionAtStartOfDirective;
791 return ResVal.Val != 0;