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 #include <utility> 26 27 using namespace clang; 28 29 namespace { 30 31 // MacroInfo is expected to take 40 bytes on platforms with an 8 byte pointer 32 // and 4 byte SourceLocation. 33 template <int> class MacroInfoSizeChecker { 34 public: 35 [[maybe_unused]] constexpr static bool AsExpected = true; 36 }; 37 template <> class MacroInfoSizeChecker<8> { 38 public: 39 [[maybe_unused]] constexpr static bool AsExpected = 40 sizeof(MacroInfo) == (32 + sizeof(SourceLocation) * 2); 41 }; 42 43 static_assert(MacroInfoSizeChecker<sizeof(void *)>::AsExpected, 44 "Unexpected size of MacroInfo"); 45 46 } // end namespace 47 48 MacroInfo::MacroInfo(SourceLocation DefLoc) 49 : Location(DefLoc), IsDefinitionLengthCached(false), IsFunctionLike(false), 50 IsC99Varargs(false), IsGNUVarargs(false), IsBuiltinMacro(false), 51 HasCommaPasting(false), IsDisabled(false), IsUsed(false), 52 IsAllowRedefinitionsWithoutWarning(false), IsWarnIfUnused(false), 53 UsedForHeaderGuard(false) {} 54 55 unsigned MacroInfo::getDefinitionLengthSlow(const SourceManager &SM) const { 56 assert(!IsDefinitionLengthCached); 57 IsDefinitionLengthCached = true; 58 59 ArrayRef<Token> ReplacementTokens = tokens(); 60 if (ReplacementTokens.empty()) 61 return (DefinitionLength = 0); 62 63 const Token &firstToken = ReplacementTokens.front(); 64 const Token &lastToken = ReplacementTokens.back(); 65 SourceLocation macroStart = firstToken.getLocation(); 66 SourceLocation macroEnd = lastToken.getLocation(); 67 assert(macroStart.isValid() && macroEnd.isValid()); 68 assert((macroStart.isFileID() || firstToken.is(tok::comment)) && 69 "Macro defined in macro?"); 70 assert((macroEnd.isFileID() || lastToken.is(tok::comment)) && 71 "Macro defined in macro?"); 72 std::pair<FileID, unsigned> 73 startInfo = SM.getDecomposedExpansionLoc(macroStart); 74 std::pair<FileID, unsigned> 75 endInfo = SM.getDecomposedExpansionLoc(macroEnd); 76 assert(startInfo.first == endInfo.first && 77 "Macro definition spanning multiple FileIDs ?"); 78 assert(startInfo.second <= endInfo.second); 79 DefinitionLength = endInfo.second - startInfo.second; 80 DefinitionLength += lastToken.getLength(); 81 82 return DefinitionLength; 83 } 84 85 /// Return true if the specified macro definition is equal to 86 /// this macro in spelling, arguments, and whitespace. 87 /// 88 /// \param Syntactically if true, the macro definitions can be identical even 89 /// if they use different identifiers for the function macro parameters. 90 /// Otherwise the comparison is lexical and this implements the rules in 91 /// C99 6.10.3. 92 bool MacroInfo::isIdenticalTo(const MacroInfo &Other, Preprocessor &PP, 93 bool Syntactically) const { 94 bool Lexically = !Syntactically; 95 96 // Check # tokens in replacement, number of args, and various flags all match. 97 if (getNumTokens() != Other.getNumTokens() || 98 getNumParams() != Other.getNumParams() || 99 isFunctionLike() != Other.isFunctionLike() || 100 isC99Varargs() != Other.isC99Varargs() || 101 isGNUVarargs() != Other.isGNUVarargs()) 102 return false; 103 104 if (Lexically) { 105 // Check arguments. 106 for (param_iterator I = param_begin(), OI = Other.param_begin(), 107 E = param_end(); 108 I != E; ++I, ++OI) 109 if (*I != *OI) return false; 110 } 111 112 // Check all the tokens. 113 for (unsigned i = 0; i != NumReplacementTokens; ++i) { 114 const Token &A = ReplacementTokens[i]; 115 const Token &B = Other.ReplacementTokens[i]; 116 if (A.getKind() != B.getKind()) 117 return false; 118 119 // If this isn't the first token, check that the whitespace and 120 // start-of-line characteristics match. 121 if (i != 0 && 122 (A.isAtStartOfLine() != B.isAtStartOfLine() || 123 A.hasLeadingSpace() != B.hasLeadingSpace())) 124 return false; 125 126 // If this is an identifier, it is easy. 127 if (A.getIdentifierInfo() || B.getIdentifierInfo()) { 128 if (A.getIdentifierInfo() == B.getIdentifierInfo()) 129 continue; 130 if (Lexically) 131 return false; 132 // With syntactic equivalence the parameter names can be different as long 133 // as they are used in the same place. 134 int AArgNum = getParameterNum(A.getIdentifierInfo()); 135 if (AArgNum == -1) 136 return false; 137 if (AArgNum != Other.getParameterNum(B.getIdentifierInfo())) 138 return false; 139 continue; 140 } 141 142 // Otherwise, check the spelling. 143 if (PP.getSpelling(A) != PP.getSpelling(B)) 144 return false; 145 } 146 147 return true; 148 } 149 150 LLVM_DUMP_METHOD void MacroInfo::dump() const { 151 llvm::raw_ostream &Out = llvm::errs(); 152 153 // FIXME: Dump locations. 154 Out << "MacroInfo " << this; 155 if (IsBuiltinMacro) Out << " builtin"; 156 if (IsDisabled) Out << " disabled"; 157 if (IsUsed) Out << " used"; 158 if (IsAllowRedefinitionsWithoutWarning) 159 Out << " allow_redefinitions_without_warning"; 160 if (IsWarnIfUnused) Out << " warn_if_unused"; 161 if (UsedForHeaderGuard) Out << " header_guard"; 162 163 Out << "\n #define <macro>"; 164 if (IsFunctionLike) { 165 Out << "("; 166 for (unsigned I = 0; I != NumParameters; ++I) { 167 if (I) Out << ", "; 168 Out << ParameterList[I]->getName(); 169 } 170 if (IsC99Varargs || IsGNUVarargs) { 171 if (NumParameters && IsC99Varargs) Out << ", "; 172 Out << "..."; 173 } 174 Out << ")"; 175 } 176 177 bool First = true; 178 for (const Token &Tok : tokens()) { 179 // Leading space is semantically meaningful in a macro definition, 180 // so preserve it in the dump output. 181 if (First || Tok.hasLeadingSpace()) 182 Out << " "; 183 First = false; 184 185 if (const char *Punc = tok::getPunctuatorSpelling(Tok.getKind())) 186 Out << Punc; 187 else if (Tok.isLiteral() && Tok.getLiteralData()) 188 Out << StringRef(Tok.getLiteralData(), Tok.getLength()); 189 else if (auto *II = Tok.getIdentifierInfo()) 190 Out << II->getName(); 191 else 192 Out << Tok.getName(); 193 } 194 } 195 196 MacroDirective::DefInfo MacroDirective::getDefinition() { 197 MacroDirective *MD = this; 198 SourceLocation UndefLoc; 199 std::optional<bool> isPublic; 200 for (; MD; MD = MD->getPrevious()) { 201 if (DefMacroDirective *DefMD = dyn_cast<DefMacroDirective>(MD)) 202 return DefInfo(DefMD, UndefLoc, !isPublic || *isPublic); 203 204 if (UndefMacroDirective *UndefMD = dyn_cast<UndefMacroDirective>(MD)) { 205 UndefLoc = UndefMD->getLocation(); 206 continue; 207 } 208 209 VisibilityMacroDirective *VisMD = cast<VisibilityMacroDirective>(MD); 210 if (!isPublic) 211 isPublic = VisMD->isPublic(); 212 } 213 214 return DefInfo(nullptr, UndefLoc, !isPublic || *isPublic); 215 } 216 217 const MacroDirective::DefInfo 218 MacroDirective::findDirectiveAtLoc(SourceLocation L, 219 const SourceManager &SM) const { 220 assert(L.isValid() && "SourceLocation is invalid."); 221 for (DefInfo Def = getDefinition(); Def; Def = Def.getPreviousDefinition()) { 222 if (Def.getLocation().isInvalid() || // For macros defined on the command line. 223 SM.isBeforeInTranslationUnit(Def.getLocation(), L)) 224 return (!Def.isUndefined() || 225 SM.isBeforeInTranslationUnit(L, Def.getUndefLocation())) 226 ? Def : DefInfo(); 227 } 228 return DefInfo(); 229 } 230 231 LLVM_DUMP_METHOD void MacroDirective::dump() const { 232 llvm::raw_ostream &Out = llvm::errs(); 233 234 switch (getKind()) { 235 case MD_Define: Out << "DefMacroDirective"; break; 236 case MD_Undefine: Out << "UndefMacroDirective"; break; 237 case MD_Visibility: Out << "VisibilityMacroDirective"; break; 238 } 239 Out << " " << this; 240 // FIXME: Dump SourceLocation. 241 if (auto *Prev = getPrevious()) 242 Out << " prev " << Prev; 243 if (IsFromPCH) Out << " from_pch"; 244 245 if (isa<VisibilityMacroDirective>(this)) 246 Out << (IsPublic ? " public" : " private"); 247 248 if (auto *DMD = dyn_cast<DefMacroDirective>(this)) { 249 if (auto *Info = DMD->getInfo()) { 250 Out << "\n "; 251 Info->dump(); 252 } 253 } 254 Out << "\n"; 255 } 256 257 ModuleMacro *ModuleMacro::create(Preprocessor &PP, Module *OwningModule, 258 const IdentifierInfo *II, MacroInfo *Macro, 259 ArrayRef<ModuleMacro *> Overrides) { 260 void *Mem = PP.getPreprocessorAllocator().Allocate( 261 sizeof(ModuleMacro) + sizeof(ModuleMacro *) * Overrides.size(), 262 alignof(ModuleMacro)); 263 return new (Mem) ModuleMacro(OwningModule, II, Macro, Overrides); 264 } 265