1//===- MacroInfo.cpp - Information about #defined identifiers -------------===//
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// This file implements the MacroInfo interface.
10//
11//===----------------------------------------------------------------------===//
12
13#include "clang/Lex/MacroInfo.h"
14#include "clang/Basic/IdentifierTable.h"
15#include "clang/Basic/LLVM.h"
16#include "clang/Basic/SourceLocation.h"
17#include "clang/Basic/SourceManager.h"
18#include "clang/Basic/TokenKinds.h"
19#include "clang/Lex/Preprocessor.h"
20#include "clang/Lex/Token.h"
21#include "llvm/ADT/Optional.h"
22#include "llvm/ADT/StringRef.h"
23#include "llvm/Support/Casting.h"
24#include "llvm/Support/Compiler.h"
25#include "llvm/Support/raw_ostream.h"
26#include <cassert>
27#include <utility>
28
29using namespace clang;
30
31MacroInfo::MacroInfo(SourceLocation DefLoc)
32    : Location(DefLoc), IsDefinitionLengthCached(false), IsFunctionLike(false),
33      IsC99Varargs(false), IsGNUVarargs(false), IsBuiltinMacro(false),
34      HasCommaPasting(false), IsDisabled(false), IsUsed(false),
35      IsAllowRedefinitionsWithoutWarning(false), IsWarnIfUnused(false),
36      UsedForHeaderGuard(false) {}
37
38unsigned MacroInfo::getDefinitionLengthSlow(const SourceManager &SM) const {
39  assert(!IsDefinitionLengthCached);
40  IsDefinitionLengthCached = true;
41
42  if (ReplacementTokens.empty())
43    return (DefinitionLength = 0);
44
45  const Token &firstToken = ReplacementTokens.front();
46  const Token &lastToken = ReplacementTokens.back();
47  SourceLocation macroStart = firstToken.getLocation();
48  SourceLocation macroEnd = lastToken.getLocation();
49  assert(macroStart.isValid() && macroEnd.isValid());
50  assert((macroStart.isFileID() || firstToken.is(tok::comment)) &&
51         "Macro defined in macro?");
52  assert((macroEnd.isFileID() || lastToken.is(tok::comment)) &&
53         "Macro defined in macro?");
54  std::pair<FileID, unsigned>
55      startInfo = SM.getDecomposedExpansionLoc(macroStart);
56  std::pair<FileID, unsigned>
57      endInfo = SM.getDecomposedExpansionLoc(macroEnd);
58  assert(startInfo.first == endInfo.first &&
59         "Macro definition spanning multiple FileIDs ?");
60  assert(startInfo.second <= endInfo.second);
61  DefinitionLength = endInfo.second - startInfo.second;
62  DefinitionLength += lastToken.getLength();
63
64  return DefinitionLength;
65}
66
67/// Return true if the specified macro definition is equal to
68/// this macro in spelling, arguments, and whitespace.
69///
70/// \param Syntactically if true, the macro definitions can be identical even
71/// if they use different identifiers for the function macro parameters.
72/// Otherwise the comparison is lexical and this implements the rules in
73/// C99 6.10.3.
74bool MacroInfo::isIdenticalTo(const MacroInfo &Other, Preprocessor &PP,
75                              bool Syntactically) const {
76  bool Lexically = !Syntactically;
77
78  // Check # tokens in replacement, number of args, and various flags all match.
79  if (ReplacementTokens.size() != Other.ReplacementTokens.size() ||
80      getNumParams() != Other.getNumParams() ||
81      isFunctionLike() != Other.isFunctionLike() ||
82      isC99Varargs() != Other.isC99Varargs() ||
83      isGNUVarargs() != Other.isGNUVarargs())
84    return false;
85
86  if (Lexically) {
87    // Check arguments.
88    for (param_iterator I = param_begin(), OI = Other.param_begin(),
89                        E = param_end();
90         I != E; ++I, ++OI)
91      if (*I != *OI) return false;
92  }
93
94  // Check all the tokens.
95  for (unsigned i = 0, e = ReplacementTokens.size(); i != e; ++i) {
96    const Token &A = ReplacementTokens[i];
97    const Token &B = Other.ReplacementTokens[i];
98    if (A.getKind() != B.getKind())
99      return false;
100
101    // If this isn't the first first token, check that the whitespace and
102    // start-of-line characteristics match.
103    if (i != 0 &&
104        (A.isAtStartOfLine() != B.isAtStartOfLine() ||
105         A.hasLeadingSpace() != B.hasLeadingSpace()))
106      return false;
107
108    // If this is an identifier, it is easy.
109    if (A.getIdentifierInfo() || B.getIdentifierInfo()) {
110      if (A.getIdentifierInfo() == B.getIdentifierInfo())
111        continue;
112      if (Lexically)
113        return false;
114      // With syntactic equivalence the parameter names can be different as long
115      // as they are used in the same place.
116      int AArgNum = getParameterNum(A.getIdentifierInfo());
117      if (AArgNum == -1)
118        return false;
119      if (AArgNum != Other.getParameterNum(B.getIdentifierInfo()))
120        return false;
121      continue;
122    }
123
124    // Otherwise, check the spelling.
125    if (PP.getSpelling(A) != PP.getSpelling(B))
126      return false;
127  }
128
129  return true;
130}
131
132LLVM_DUMP_METHOD void MacroInfo::dump() const {
133  llvm::raw_ostream &Out = llvm::errs();
134
135  // FIXME: Dump locations.
136  Out << "MacroInfo " << this;
137  if (IsBuiltinMacro) Out << " builtin";
138  if (IsDisabled) Out << " disabled";
139  if (IsUsed) Out << " used";
140  if (IsAllowRedefinitionsWithoutWarning)
141    Out << " allow_redefinitions_without_warning";
142  if (IsWarnIfUnused) Out << " warn_if_unused";
143  if (UsedForHeaderGuard) Out << " header_guard";
144
145  Out << "\n    #define <macro>";
146  if (IsFunctionLike) {
147    Out << "(";
148    for (unsigned I = 0; I != NumParameters; ++I) {
149      if (I) Out << ", ";
150      Out << ParameterList[I]->getName();
151    }
152    if (IsC99Varargs || IsGNUVarargs) {
153      if (NumParameters && IsC99Varargs) Out << ", ";
154      Out << "...";
155    }
156    Out << ")";
157  }
158
159  bool First = true;
160  for (const Token &Tok : ReplacementTokens) {
161    // Leading space is semantically meaningful in a macro definition,
162    // so preserve it in the dump output.
163    if (First || Tok.hasLeadingSpace())
164      Out << " ";
165    First = false;
166
167    if (const char *Punc = tok::getPunctuatorSpelling(Tok.getKind()))
168      Out << Punc;
169    else if (Tok.isLiteral() && Tok.getLiteralData())
170      Out << StringRef(Tok.getLiteralData(), Tok.getLength());
171    else if (auto *II = Tok.getIdentifierInfo())
172      Out << II->getName();
173    else
174      Out << Tok.getName();
175  }
176}
177
178MacroDirective::DefInfo MacroDirective::getDefinition() {
179  MacroDirective *MD = this;
180  SourceLocation UndefLoc;
181  Optional<bool> isPublic;
182  for (; MD; MD = MD->getPrevious()) {
183    if (DefMacroDirective *DefMD = dyn_cast<DefMacroDirective>(MD))
184      return DefInfo(DefMD, UndefLoc,
185                     !isPublic.hasValue() || isPublic.getValue());
186
187    if (UndefMacroDirective *UndefMD = dyn_cast<UndefMacroDirective>(MD)) {
188      UndefLoc = UndefMD->getLocation();
189      continue;
190    }
191
192    VisibilityMacroDirective *VisMD = cast<VisibilityMacroDirective>(MD);
193    if (!isPublic.hasValue())
194      isPublic = VisMD->isPublic();
195  }
196
197  return DefInfo(nullptr, UndefLoc,
198                 !isPublic.hasValue() || isPublic.getValue());
199}
200
201const MacroDirective::DefInfo
202MacroDirective::findDirectiveAtLoc(SourceLocation L,
203                                   const SourceManager &SM) const {
204  assert(L.isValid() && "SourceLocation is invalid.");
205  for (DefInfo Def = getDefinition(); Def; Def = Def.getPreviousDefinition()) {
206    if (Def.getLocation().isInvalid() ||  // For macros defined on the command line.
207        SM.isBeforeInTranslationUnit(Def.getLocation(), L))
208      return (!Def.isUndefined() ||
209              SM.isBeforeInTranslationUnit(L, Def.getUndefLocation()))
210                  ? Def : DefInfo();
211  }
212  return DefInfo();
213}
214
215LLVM_DUMP_METHOD void MacroDirective::dump() const {
216  llvm::raw_ostream &Out = llvm::errs();
217
218  switch (getKind()) {
219  case MD_Define: Out << "DefMacroDirective"; break;
220  case MD_Undefine: Out << "UndefMacroDirective"; break;
221  case MD_Visibility: Out << "VisibilityMacroDirective"; break;
222  }
223  Out << " " << this;
224  // FIXME: Dump SourceLocation.
225  if (auto *Prev = getPrevious())
226    Out << " prev " << Prev;
227  if (IsFromPCH) Out << " from_pch";
228
229  if (isa<VisibilityMacroDirective>(this))
230    Out << (IsPublic ? " public" : " private");
231
232  if (auto *DMD = dyn_cast<DefMacroDirective>(this)) {
233    if (auto *Info = DMD->getInfo()) {
234      Out << "\n  ";
235      Info->dump();
236    }
237  }
238  Out << "\n";
239}
240
241ModuleMacro *ModuleMacro::create(Preprocessor &PP, Module *OwningModule,
242                                 IdentifierInfo *II, MacroInfo *Macro,
243                                 ArrayRef<ModuleMacro *> Overrides) {
244  void *Mem = PP.getPreprocessorAllocator().Allocate(
245      sizeof(ModuleMacro) + sizeof(ModuleMacro *) * Overrides.size(),
246      alignof(ModuleMacro));
247  return new (Mem) ModuleMacro(OwningModule, II, Macro, Overrides);
248}
249