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/Support/Compiler.h"
22#include "llvm/Support/raw_ostream.h"
23#include <cassert>
24#include <optional>
25
26using namespace clang;
27
28namespace {
29
30// MacroInfo is expected to take 40 bytes on platforms with an 8 byte pointer
31// and 4 byte SourceLocation.
32template <int> class MacroInfoSizeChecker {
33public:
34 [[maybe_unused]] constexpr static bool AsExpected = true;
35};
36template <> class MacroInfoSizeChecker<8> {
37public:
38 [[maybe_unused]] constexpr static bool AsExpected =
39 sizeof(MacroInfo) == (32 + sizeof(SourceLocation) * 2);
40};
41
42static_assert(MacroInfoSizeChecker<sizeof(void *)>::AsExpected,
43 "Unexpected size of MacroInfo");
44
45} // end namespace
46
47MacroInfo::MacroInfo(SourceLocation DefLoc)
48 : Location(DefLoc), IsDefinitionLengthCached(false), IsFunctionLike(false),
49 IsC99Varargs(false), IsGNUVarargs(false), IsBuiltinMacro(false),
50 HasCommaPasting(false), IsDisabled(false), IsUsed(false),
51 IsAllowRedefinitionsWithoutWarning(false), IsWarnIfUnused(false),
52 UsedForHeaderGuard(false) {}
53
54unsigned MacroInfo::getDefinitionLengthSlow(const SourceManager &SM) const {
55 assert(!IsDefinitionLengthCached);
56 IsDefinitionLengthCached = true;
57
58 ArrayRef<Token> ReplacementTokens = tokens();
59 if (ReplacementTokens.empty())
60 return (DefinitionLength = 0);
61
62 const Token &firstToken = ReplacementTokens.front();
63 const Token &lastToken = ReplacementTokens.back();
64 SourceLocation macroStart = firstToken.getLocation();
65 SourceLocation macroEnd = lastToken.getLocation();
66 assert(macroStart.isValid() && macroEnd.isValid());
67 assert((macroStart.isFileID() || firstToken.is(tok::comment)) &&
68 "Macro defined in macro?");
69 assert((macroEnd.isFileID() || lastToken.is(tok::comment)) &&
70 "Macro defined in macro?");
71 FileIDAndOffset startInfo = SM.getDecomposedExpansionLoc(Loc: macroStart);
72 FileIDAndOffset endInfo = SM.getDecomposedExpansionLoc(Loc: macroEnd);
73 assert(startInfo.first == endInfo.first &&
74 "Macro definition spanning multiple FileIDs ?");
75 assert(startInfo.second <= endInfo.second);
76 DefinitionLength = endInfo.second - startInfo.second;
77 DefinitionLength += lastToken.getLength();
78
79 return DefinitionLength;
80}
81
82/// Return true if the specified macro definition is equal to
83/// this macro in spelling, arguments, and whitespace.
84///
85/// \param Syntactically if true, the macro definitions can be identical even
86/// if they use different identifiers for the function macro parameters.
87/// Otherwise the comparison is lexical and this implements the rules in
88/// C99 6.10.3.
89bool MacroInfo::isIdenticalTo(const MacroInfo &Other, Preprocessor &PP,
90 bool Syntactically) const {
91 bool Lexically = !Syntactically;
92
93 // Check # tokens in replacement, number of args, and various flags all match.
94 if (getNumTokens() != Other.getNumTokens() ||
95 getNumParams() != Other.getNumParams() ||
96 isFunctionLike() != Other.isFunctionLike() ||
97 isC99Varargs() != Other.isC99Varargs() ||
98 isGNUVarargs() != Other.isGNUVarargs())
99 return false;
100
101 if (Lexically) {
102 // Check arguments.
103 for (param_iterator I = param_begin(), OI = Other.param_begin(),
104 E = param_end();
105 I != E; ++I, ++OI)
106 if (*I != *OI) return false;
107 }
108
109 // Check all the tokens.
110 for (unsigned i = 0; i != NumReplacementTokens; ++i) {
111 const Token &A = ReplacementTokens[i];
112 const Token &B = Other.ReplacementTokens[i];
113 if (A.getKind() != B.getKind())
114 return false;
115
116 // If this isn't the first token, check that the whitespace and
117 // start-of-line characteristics match.
118 if (i != 0 &&
119 (A.isAtStartOfLine() != B.isAtStartOfLine() ||
120 A.hasLeadingSpace() != B.hasLeadingSpace()))
121 return false;
122
123 // If this is an identifier, it is easy.
124 if (A.getIdentifierInfo() || B.getIdentifierInfo()) {
125 if (A.getIdentifierInfo() == B.getIdentifierInfo())
126 continue;
127 if (Lexically)
128 return false;
129 // With syntactic equivalence the parameter names can be different as long
130 // as they are used in the same place.
131 int AArgNum = getParameterNum(Arg: A.getIdentifierInfo());
132 if (AArgNum == -1)
133 return false;
134 if (AArgNum != Other.getParameterNum(Arg: B.getIdentifierInfo()))
135 return false;
136 continue;
137 }
138
139 // Otherwise, check the spelling.
140 if (PP.getSpelling(Tok: A) != PP.getSpelling(Tok: B))
141 return false;
142 }
143
144 return true;
145}
146
147LLVM_DUMP_METHOD void MacroInfo::dump() const {
148 llvm::raw_ostream &Out = llvm::errs();
149
150 // FIXME: Dump locations.
151 Out << "MacroInfo " << this;
152 if (IsBuiltinMacro) Out << " builtin";
153 if (IsDisabled) Out << " disabled";
154 if (IsUsed) Out << " used";
155 if (IsAllowRedefinitionsWithoutWarning)
156 Out << " allow_redefinitions_without_warning";
157 if (IsWarnIfUnused) Out << " warn_if_unused";
158 if (UsedForHeaderGuard) Out << " header_guard";
159
160 Out << "\n #define <macro>";
161 if (IsFunctionLike) {
162 Out << "(";
163 for (unsigned I = 0; I != NumParameters; ++I) {
164 if (I) Out << ", ";
165 Out << ParameterList[I]->getName();
166 }
167 if (IsC99Varargs || IsGNUVarargs) {
168 if (NumParameters && IsC99Varargs) Out << ", ";
169 Out << "...";
170 }
171 Out << ")";
172 }
173
174 bool First = true;
175 for (const Token &Tok : tokens()) {
176 // Leading space is semantically meaningful in a macro definition,
177 // so preserve it in the dump output.
178 if (First || Tok.hasLeadingSpace())
179 Out << " ";
180 First = false;
181
182 if (const char *Punc = tok::getPunctuatorSpelling(Kind: Tok.getKind()))
183 Out << Punc;
184 else if (Tok.isLiteral() && Tok.getLiteralData())
185 Out << StringRef(Tok.getLiteralData(), Tok.getLength());
186 else if (auto *II = Tok.getIdentifierInfo())
187 Out << II->getName();
188 else
189 Out << Tok.getName();
190 }
191}
192
193MacroDirective::DefInfo MacroDirective::getDefinition() {
194 MacroDirective *MD = this;
195 SourceLocation UndefLoc;
196 std::optional<bool> isPublic;
197 for (; MD; MD = MD->getPrevious()) {
198 if (DefMacroDirective *DefMD = dyn_cast<DefMacroDirective>(Val: MD))
199 return DefInfo(DefMD, UndefLoc, !isPublic || *isPublic);
200
201 if (UndefMacroDirective *UndefMD = dyn_cast<UndefMacroDirective>(Val: MD)) {
202 UndefLoc = UndefMD->getLocation();
203 continue;
204 }
205
206 VisibilityMacroDirective *VisMD = cast<VisibilityMacroDirective>(Val: MD);
207 if (!isPublic)
208 isPublic = VisMD->isPublic();
209 }
210
211 return DefInfo(nullptr, UndefLoc, !isPublic || *isPublic);
212}
213
214const MacroDirective::DefInfo
215MacroDirective::findDirectiveAtLoc(SourceLocation L,
216 const SourceManager &SM) const {
217 assert(L.isValid() && "SourceLocation is invalid.");
218 for (DefInfo Def = getDefinition(); Def; Def = Def.getPreviousDefinition()) {
219 if (Def.getLocation().isInvalid() || // For macros defined on the command line.
220 SM.isBeforeInTranslationUnit(LHS: Def.getLocation(), RHS: L))
221 return (!Def.isUndefined() ||
222 SM.isBeforeInTranslationUnit(LHS: L, RHS: Def.getUndefLocation()))
223 ? Def : DefInfo();
224 }
225 return DefInfo();
226}
227
228LLVM_DUMP_METHOD void MacroDirective::dump() const {
229 llvm::raw_ostream &Out = llvm::errs();
230
231 switch (getKind()) {
232 case MD_Define: Out << "DefMacroDirective"; break;
233 case MD_Undefine: Out << "UndefMacroDirective"; break;
234 case MD_Visibility: Out << "VisibilityMacroDirective"; break;
235 }
236 Out << " " << this;
237 // FIXME: Dump SourceLocation.
238 if (auto *Prev = getPrevious())
239 Out << " prev " << Prev;
240 if (IsFromPCH) Out << " from_pch";
241
242 if (isa<VisibilityMacroDirective>(Val: this))
243 Out << (IsPublic ? " public" : " private");
244
245 if (auto *DMD = dyn_cast<DefMacroDirective>(Val: this)) {
246 if (auto *Info = DMD->getInfo()) {
247 Out << "\n ";
248 Info->dump();
249 }
250 }
251 Out << "\n";
252}
253
254ModuleMacro *ModuleMacro::create(Preprocessor &PP, Module *OwningModule,
255 const IdentifierInfo *II, MacroInfo *Macro,
256 ArrayRef<ModuleMacro *> Overrides) {
257 void *Mem = PP.getPreprocessorAllocator().Allocate(
258 Size: sizeof(ModuleMacro) + sizeof(ModuleMacro *) * Overrides.size(),
259 Alignment: alignof(ModuleMacro));
260 return new (Mem) ModuleMacro(OwningModule, II, Macro, Overrides);
261}
262