1//===- MacroInfo.h - Information about #defined identifiers -----*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9/// \file
10/// Defines the clang::MacroInfo and clang::MacroDirective classes.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_CLANG_LEX_MACROINFO_H
15#define LLVM_CLANG_LEX_MACROINFO_H
16
17#include "clang/Lex/Token.h"
18#include "clang/Basic/LLVM.h"
19#include "clang/Basic/SourceLocation.h"
20#include "llvm/ADT/ArrayRef.h"
21#include "llvm/ADT/FoldingSet.h"
22#include "llvm/ADT/PointerIntPair.h"
23#include "llvm/ADT/SmallVector.h"
24#include "llvm/Support/Allocator.h"
25#include <algorithm>
26#include <cassert>
27
28namespace clang {
29
30class DefMacroDirective;
31class IdentifierInfo;
32class Module;
33class Preprocessor;
34class SourceManager;
35
36/// Encapsulates the data about a macro definition (e.g. its tokens).
37///
38/// There's an instance of this class for every #define.
39class MacroInfo {
40 //===--------------------------------------------------------------------===//
41 // State set when the macro is defined.
42
43 /// The location the macro is defined.
44 SourceLocation Location;
45
46 /// The location of the last token in the macro.
47 SourceLocation EndLocation;
48
49 /// The list of arguments for a function-like macro.
50 ///
51 /// ParameterList points to the first of NumParameters pointers.
52 ///
53 /// This can be empty, for, e.g. "#define X()". In a C99-style variadic
54 /// macro, this includes the \c __VA_ARGS__ identifier on the list.
55 IdentifierInfo **ParameterList = nullptr;
56
57 /// \see ParameterList
58 unsigned NumParameters = 0;
59
60 /// This is the list of tokens that the macro is defined to.
61 SmallVector<Token, 8> ReplacementTokens;
62
63 /// Length in characters of the macro definition.
64 mutable unsigned DefinitionLength;
65 mutable bool IsDefinitionLengthCached : 1;
66
67 /// True if this macro is function-like, false if it is object-like.
68 bool IsFunctionLike : 1;
69
70 /// True if this macro is of the form "#define X(...)" or
71 /// "#define X(Y,Z,...)".
72 ///
73 /// The __VA_ARGS__ token should be replaced with the contents of "..." in an
74 /// invocation.
75 bool IsC99Varargs : 1;
76
77 /// True if this macro is of the form "#define X(a...)".
78 ///
79 /// The "a" identifier in the replacement list will be replaced with all
80 /// arguments of the macro starting with the specified one.
81 bool IsGNUVarargs : 1;
82
83 /// True if this macro requires processing before expansion.
84 ///
85 /// This is the case for builtin macros such as __LINE__, so long as they have
86 /// not been redefined, but not for regular predefined macros from the
87 /// "<built-in>" memory buffer (see Preprocessing::getPredefinesFileID).
88 bool IsBuiltinMacro : 1;
89
90 /// Whether this macro contains the sequence ", ## __VA_ARGS__"
91 bool HasCommaPasting : 1;
92
93 //===--------------------------------------------------------------------===//
94 // State that changes as the macro is used.
95
96 /// True if we have started an expansion of this macro already.
97 ///
98 /// This disables recursive expansion, which would be quite bad for things
99 /// like \#define A A.
100 bool IsDisabled : 1;
101
102 /// True if this macro is either defined in the main file and has
103 /// been used, or if it is not defined in the main file.
104 ///
105 /// This is used to emit -Wunused-macros diagnostics.
106 bool IsUsed : 1;
107
108 /// True if this macro can be redefined without emitting a warning.
109 bool IsAllowRedefinitionsWithoutWarning : 1;
110
111 /// Must warn if the macro is unused at the end of translation unit.
112 bool IsWarnIfUnused : 1;
113
114 /// Whether this macro was used as header guard.
115 bool UsedForHeaderGuard : 1;
116
117 // Only the Preprocessor gets to create and destroy these.
118 MacroInfo(SourceLocation DefLoc);
119 ~MacroInfo() = default;
120
121public:
122 /// Return the location that the macro was defined at.
123 SourceLocation getDefinitionLoc() const { return Location; }
124
125 /// Set the location of the last token in the macro.
126 void setDefinitionEndLoc(SourceLocation EndLoc) { EndLocation = EndLoc; }
127
128 /// Return the location of the last token in the macro.
129 SourceLocation getDefinitionEndLoc() const { return EndLocation; }
130
131 /// Get length in characters of the macro definition.
132 unsigned getDefinitionLength(const SourceManager &SM) const {
133 if (IsDefinitionLengthCached)
134 return DefinitionLength;
135 return getDefinitionLengthSlow(SM);
136 }
137
138 /// Return true if the specified macro definition is equal to
139 /// this macro in spelling, arguments, and whitespace.
140 ///
141 /// \param Syntactically if true, the macro definitions can be identical even
142 /// if they use different identifiers for the function macro parameters.
143 /// Otherwise the comparison is lexical and this implements the rules in
144 /// C99 6.10.3.
145 bool isIdenticalTo(const MacroInfo &Other, Preprocessor &PP,
146 bool Syntactically) const;
147
148 /// Set or clear the isBuiltinMacro flag.
149 void setIsBuiltinMacro(bool Val = true) { IsBuiltinMacro = Val; }
150
151 /// Set the value of the IsUsed flag.
152 void setIsUsed(bool Val) { IsUsed = Val; }
153
154 /// Set the value of the IsAllowRedefinitionsWithoutWarning flag.
155 void setIsAllowRedefinitionsWithoutWarning(bool Val) {
156 IsAllowRedefinitionsWithoutWarning = Val;
157 }
158
159 /// Set the value of the IsWarnIfUnused flag.
160 void setIsWarnIfUnused(bool val) { IsWarnIfUnused = val; }
161
162 /// Set the specified list of identifiers as the parameter list for
163 /// this macro.
164 void setParameterList(ArrayRef<IdentifierInfo *> List,
165 llvm::BumpPtrAllocator &PPAllocator) {
166 assert(ParameterList == nullptr && NumParameters == 0 &&
167 "Parameter list already set!");
168 if (List.empty())
169 return;
170
171 NumParameters = List.size();
172 ParameterList = PPAllocator.Allocate<IdentifierInfo *>(List.size());
173 std::copy(List.begin(), List.end(), ParameterList);
174 }
175
176 /// Parameters - The list of parameters for a function-like macro. This can
177 /// be empty, for, e.g. "#define X()".
178 using param_iterator = IdentifierInfo *const *;
179 bool param_empty() const { return NumParameters == 0; }
180 param_iterator param_begin() const { return ParameterList; }
181 param_iterator param_end() const { return ParameterList + NumParameters; }
182 unsigned getNumParams() const { return NumParameters; }
183 ArrayRef<const IdentifierInfo *> params() const {
184 return ArrayRef<const IdentifierInfo *>(ParameterList, NumParameters);
185 }
186
187 /// Return the parameter number of the specified identifier,
188 /// or -1 if the identifier is not a formal parameter identifier.
189 int getParameterNum(const IdentifierInfo *Arg) const {
190 for (param_iterator I = param_begin(), E = param_end(); I != E; ++I)
191 if (*I == Arg)
192 return I - param_begin();
193 return -1;
194 }
195
196 /// Function/Object-likeness. Keep track of whether this macro has formal
197 /// parameters.
198 void setIsFunctionLike() { IsFunctionLike = true; }
199 bool isFunctionLike() const { return IsFunctionLike; }
200 bool isObjectLike() const { return !IsFunctionLike; }
201
202 /// Varargs querying methods. This can only be set for function-like macros.
203 void setIsC99Varargs() { IsC99Varargs = true; }
204 void setIsGNUVarargs() { IsGNUVarargs = true; }
205 bool isC99Varargs() const { return IsC99Varargs; }
206 bool isGNUVarargs() const { return IsGNUVarargs; }
207 bool isVariadic() const { return IsC99Varargs | IsGNUVarargs; }
208
209 /// Return true if this macro requires processing before expansion.
210 ///
211 /// This is true only for builtin macro, such as \__LINE__, whose values
212 /// are not given by fixed textual expansions. Regular predefined macros
213 /// from the "<built-in>" buffer are not reported as builtins by this
214 /// function.
215 bool isBuiltinMacro() const { return IsBuiltinMacro; }
216
217 bool hasCommaPasting() const { return HasCommaPasting; }
218 void setHasCommaPasting() { HasCommaPasting = true; }
219
220 /// Return false if this macro is defined in the main file and has
221 /// not yet been used.
222 bool isUsed() const { return IsUsed; }
223
224 /// Return true if this macro can be redefined without warning.
225 bool isAllowRedefinitionsWithoutWarning() const {
226 return IsAllowRedefinitionsWithoutWarning;
227 }
228
229 /// Return true if we should emit a warning if the macro is unused.
230 bool isWarnIfUnused() const { return IsWarnIfUnused; }
231
232 /// Return the number of tokens that this macro expands to.
233 unsigned getNumTokens() const { return ReplacementTokens.size(); }
234
235 const Token &getReplacementToken(unsigned Tok) const {
236 assert(Tok < ReplacementTokens.size() && "Invalid token #");
237 return ReplacementTokens[Tok];
238 }
239
240 using tokens_iterator = SmallVectorImpl<Token>::const_iterator;
241
242 tokens_iterator tokens_begin() const { return ReplacementTokens.begin(); }
243 tokens_iterator tokens_end() const { return ReplacementTokens.end(); }
244 bool tokens_empty() const { return ReplacementTokens.empty(); }
245 ArrayRef<Token> tokens() const { return ReplacementTokens; }
246
247 /// Add the specified token to the replacement text for the macro.
248 void AddTokenToBody(const Token &Tok) {
249 assert(
250 !IsDefinitionLengthCached &&
251 "Changing replacement tokens after definition length got calculated");
252 ReplacementTokens.push_back(Tok);
253 }
254
255 /// Return true if this macro is enabled.
256 ///
257 /// In other words, that we are not currently in an expansion of this macro.
258 bool isEnabled() const { return !IsDisabled; }
259
260 void EnableMacro() {
261 assert(IsDisabled && "Cannot enable an already-enabled macro!");
262 IsDisabled = false;
263 }
264
265 void DisableMacro() {
266 assert(!IsDisabled && "Cannot disable an already-disabled macro!");
267 IsDisabled = true;
268 }
269
270 /// Determine whether this macro was used for a header guard.
271 bool isUsedForHeaderGuard() const { return UsedForHeaderGuard; }
272
273 void setUsedForHeaderGuard(bool Val) { UsedForHeaderGuard = Val; }
274
275 void dump() const;
276
277private:
278 friend class Preprocessor;
279
280 unsigned getDefinitionLengthSlow(const SourceManager &SM) const;
281};
282
283/// Encapsulates changes to the "macros namespace" (the location where
284/// the macro name became active, the location where it was undefined, etc.).
285///
286/// MacroDirectives, associated with an identifier, are used to model the macro
287/// history. Usually a macro definition (MacroInfo) is where a macro name
288/// becomes active (MacroDirective) but #pragma push_macro / pop_macro can
289/// create additional DefMacroDirectives for the same MacroInfo.
290class MacroDirective {
291public:
292 enum Kind {
293 MD_Define,
294 MD_Undefine,
295 MD_Visibility
296 };
297
298protected:
299 /// Previous macro directive for the same identifier, or nullptr.
300 MacroDirective *Previous = nullptr;
301
302 SourceLocation Loc;
303
304 /// MacroDirective kind.
305 unsigned MDKind : 2;
306
307 /// True if the macro directive was loaded from a PCH file.
308 unsigned IsFromPCH : 1;
309
310 // Used by VisibilityMacroDirective ----------------------------------------//
311
312 /// Whether the macro has public visibility (when described in a
313 /// module).
314 unsigned IsPublic : 1;
315
316 MacroDirective(Kind K, SourceLocation Loc)
317 : Loc(Loc), MDKind(K), IsFromPCH(false), IsPublic(true) {}
318
319public:
320 Kind getKind() const { return Kind(MDKind); }
321
322 SourceLocation getLocation() const { return Loc; }
323
324 /// Set previous definition of the macro with the same name.
325 void setPrevious(MacroDirective *Prev) { Previous = Prev; }
326
327 /// Get previous definition of the macro with the same name.
328 const MacroDirective *getPrevious() const { return Previous; }
329
330 /// Get previous definition of the macro with the same name.
331 MacroDirective *getPrevious() { return Previous; }
332
333 /// Return true if the macro directive was loaded from a PCH file.
334 bool isFromPCH() const { return IsFromPCH; }
335
336 void setIsFromPCH() { IsFromPCH = true; }
337
338 class DefInfo {
339 DefMacroDirective *DefDirective = nullptr;
340 SourceLocation UndefLoc;
341 bool IsPublic = true;
342
343 public:
344 DefInfo() = default;
345 DefInfo(DefMacroDirective *DefDirective, SourceLocation UndefLoc,
346 bool isPublic)
347 : DefDirective(DefDirective), UndefLoc(UndefLoc), IsPublic(isPublic) {}
348
349 const DefMacroDirective *getDirective() const { return DefDirective; }
350 DefMacroDirective *getDirective() { return DefDirective; }
351
352 inline SourceLocation getLocation() const;
353 inline MacroInfo *getMacroInfo();
354
355 const MacroInfo *getMacroInfo() const {
356 return const_cast<DefInfo *>(this)->getMacroInfo();
357 }
358
359 SourceLocation getUndefLocation() const { return UndefLoc; }
360 bool isUndefined() const { return UndefLoc.isValid(); }
361
362 bool isPublic() const { return IsPublic; }
363
364 bool isValid() const { return DefDirective != nullptr; }
365 bool isInvalid() const { return !isValid(); }
366
367 explicit operator bool() const { return isValid(); }
368
369 inline DefInfo getPreviousDefinition();
370
371 const DefInfo getPreviousDefinition() const {
372 return const_cast<DefInfo *>(this)->getPreviousDefinition();
373 }
374 };
375
376 /// Traverses the macro directives history and returns the next
377 /// macro definition directive along with info about its undefined location
378 /// (if there is one) and if it is public or private.
379 DefInfo getDefinition();
380 const DefInfo getDefinition() const {
381 return const_cast<MacroDirective *>(this)->getDefinition();
382 }
383
384 bool isDefined() const {
385 if (const DefInfo Def = getDefinition())
386 return !Def.isUndefined();
387 return false;
388 }
389
390 const MacroInfo *getMacroInfo() const {
391 return getDefinition().getMacroInfo();
392 }
393 MacroInfo *getMacroInfo() { return getDefinition().getMacroInfo(); }
394
395 /// Find macro definition active in the specified source location. If
396 /// this macro was not defined there, return NULL.
397 const DefInfo findDirectiveAtLoc(SourceLocation L,
398 const SourceManager &SM) const;
399
400 void dump() const;
401
402 static bool classof(const MacroDirective *) { return true; }
403};
404
405/// A directive for a defined macro or a macro imported from a module.
406class DefMacroDirective : public MacroDirective {
407 MacroInfo *Info;
408
409public:
410 DefMacroDirective(MacroInfo *MI, SourceLocation Loc)
411 : MacroDirective(MD_Define, Loc), Info(MI) {
412 assert(MI && "MacroInfo is null");
413 }
414 explicit DefMacroDirective(MacroInfo *MI)
415 : DefMacroDirective(MI, MI->getDefinitionLoc()) {}
416
417 /// The data for the macro definition.
418 const MacroInfo *getInfo() const { return Info; }
419 MacroInfo *getInfo() { return Info; }
420
421 static bool classof(const MacroDirective *MD) {
422 return MD->getKind() == MD_Define;
423 }
424
425 static bool classof(const DefMacroDirective *) { return true; }
426};
427
428/// A directive for an undefined macro.
429class UndefMacroDirective : public MacroDirective {
430public:
431 explicit UndefMacroDirective(SourceLocation UndefLoc)
432 : MacroDirective(MD_Undefine, UndefLoc) {
433 assert(UndefLoc.isValid() && "Invalid UndefLoc!");
434 }
435
436 static bool classof(const MacroDirective *MD) {
437 return MD->getKind() == MD_Undefine;
438 }
439
440 static bool classof(const UndefMacroDirective *) { return true; }
441};
442
443/// A directive for setting the module visibility of a macro.
444class VisibilityMacroDirective : public MacroDirective {
445public:
446 explicit VisibilityMacroDirective(SourceLocation Loc, bool Public)
447 : MacroDirective(MD_Visibility, Loc) {
448 IsPublic = Public;
449 }
450
451 /// Determine whether this macro is part of the public API of its
452 /// module.
453 bool isPublic() const { return IsPublic; }
454
455 static bool classof(const MacroDirective *MD) {
456 return MD->getKind() == MD_Visibility;
457 }
458
459 static bool classof(const VisibilityMacroDirective *) { return true; }
460};
461
462inline SourceLocation MacroDirective::DefInfo::getLocation() const {
463 if (isInvalid())
464 return {};
465 return DefDirective->getLocation();
466}
467
468inline MacroInfo *MacroDirective::DefInfo::getMacroInfo() {
469 if (isInvalid())
470 return nullptr;
471 return DefDirective->getInfo();
472}
473
474inline MacroDirective::DefInfo
475MacroDirective::DefInfo::getPreviousDefinition() {
476 if (isInvalid() || DefDirective->getPrevious() == nullptr)
477 return {};
478 return DefDirective->getPrevious()->getDefinition();
479}
480
481/// Represents a macro directive exported by a module.
482///
483/// There's an instance of this class for every macro #define or #undef that is
484/// the final directive for a macro name within a module. These entities also
485/// represent the macro override graph.
486///
487/// These are stored in a FoldingSet in the preprocessor.
488class ModuleMacro : public llvm::FoldingSetNode {
489 friend class Preprocessor;
490
491 /// The name defined by the macro.
492 IdentifierInfo *II;
493
494 /// The body of the #define, or nullptr if this is a #undef.
495 MacroInfo *Macro;
496
497 /// The module that exports this macro.
498 Module *OwningModule;
499
500 /// The number of module macros that override this one.
501 unsigned NumOverriddenBy = 0;
502
503 /// The number of modules whose macros are directly overridden by this one.
504 unsigned NumOverrides;
505
506 ModuleMacro(Module *OwningModule, IdentifierInfo *II, MacroInfo *Macro,
507 ArrayRef<ModuleMacro *> Overrides)
508 : II(II), Macro(Macro), OwningModule(OwningModule),
509 NumOverrides(Overrides.size()) {
510 std::copy(Overrides.begin(), Overrides.end(),
511 reinterpret_cast<ModuleMacro **>(this + 1));
512 }
513
514public:
515 static ModuleMacro *create(Preprocessor &PP, Module *OwningModule,
516 IdentifierInfo *II, MacroInfo *Macro,
517 ArrayRef<ModuleMacro *> Overrides);
518
519 void Profile(llvm::FoldingSetNodeID &ID) const {
520 return Profile(ID, OwningModule, II);
521 }
522
523 static void Profile(llvm::FoldingSetNodeID &ID, Module *OwningModule,
524 const IdentifierInfo *II) {
525 ID.AddPointer(OwningModule);
526 ID.AddPointer(II);
527 }
528
529 /// Get the name of the macro.
530 IdentifierInfo *getName() const { return II; }
531
532 /// Get the ID of the module that exports this macro.
533 Module *getOwningModule() const { return OwningModule; }
534
535 /// Get definition for this exported #define, or nullptr if this
536 /// represents a #undef.
537 MacroInfo *getMacroInfo() const { return Macro; }
538
539 /// Iterators over the overridden module IDs.
540 /// \{
541 using overrides_iterator = ModuleMacro *const *;
542
543 overrides_iterator overrides_begin() const {
544 return reinterpret_cast<overrides_iterator>(this + 1);
545 }
546
547 overrides_iterator overrides_end() const {
548 return overrides_begin() + NumOverrides;
549 }
550
551 ArrayRef<ModuleMacro *> overrides() const {
552 return llvm::makeArrayRef(overrides_begin(), overrides_end());
553 }
554 /// \}
555
556 /// Get the number of macros that override this one.
557 unsigned getNumOverridingMacros() const { return NumOverriddenBy; }
558};
559
560/// A description of the current definition of a macro.
561///
562/// The definition of a macro comprises a set of (at least one) defining
563/// entities, which are either local MacroDirectives or imported ModuleMacros.
564class MacroDefinition {
565 llvm::PointerIntPair<DefMacroDirective *, 1, bool> LatestLocalAndAmbiguous;
566 ArrayRef<ModuleMacro *> ModuleMacros;
567
568public:
569 MacroDefinition() = default;
570 MacroDefinition(DefMacroDirective *MD, ArrayRef<ModuleMacro *> MMs,
571 bool IsAmbiguous)
572 : LatestLocalAndAmbiguous(MD, IsAmbiguous), ModuleMacros(MMs) {}
573
574 /// Determine whether there is a definition of this macro.
575 explicit operator bool() const {
576 return getLocalDirective() || !ModuleMacros.empty();
577 }
578
579 /// Get the MacroInfo that should be used for this definition.
580 MacroInfo *getMacroInfo() const {
581 if (!ModuleMacros.empty())
582 return ModuleMacros.back()->getMacroInfo();
583 if (auto *MD = getLocalDirective())
584 return MD->getMacroInfo();
585 return nullptr;
586 }
587
588 /// \c true if the definition is ambiguous, \c false otherwise.
589 bool isAmbiguous() const { return LatestLocalAndAmbiguous.getInt(); }
590
591 /// Get the latest non-imported, non-\#undef'd macro definition
592 /// for this macro.
593 DefMacroDirective *getLocalDirective() const {
594 return LatestLocalAndAmbiguous.getPointer();
595 }
596
597 /// Get the active module macros for this macro.
598 ArrayRef<ModuleMacro *> getModuleMacros() const { return ModuleMacros; }
599
600 template <typename Fn> void forAllDefinitions(Fn F) const {
601 if (auto *MD = getLocalDirective())
602 F(MD->getMacroInfo());
603 for (auto *MM : getModuleMacros())
604 F(MM->getMacroInfo());
605 }
606};
607
608} // namespace clang
609
610#endif // LLVM_CLANG_LEX_MACROINFO_H
611