1 //===--- MacroInfo.cpp - Information about #defined identifiers -----------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements the MacroInfo interface.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/Lex/MacroInfo.h"
15 #include "clang/Lex/Preprocessor.h"
16 using namespace clang;
17 
18 MacroInfo::MacroInfo(SourceLocation DefLoc)
19   : Location(DefLoc),
20     ParameterList(nullptr),
21     NumParameters(0),
22     IsDefinitionLengthCached(false),
23     IsFunctionLike(false),
24     IsC99Varargs(false),
25     IsGNUVarargs(false),
26     IsBuiltinMacro(false),
27     HasCommaPasting(false),
28     IsDisabled(false),
29     IsUsed(false),
30     IsAllowRedefinitionsWithoutWarning(false),
31     IsWarnIfUnused(false),
32     UsedForHeaderGuard(false) {
33 }
34 
35 unsigned MacroInfo::getDefinitionLengthSlow(const SourceManager &SM) const {
36   assert(!IsDefinitionLengthCached);
37   IsDefinitionLengthCached = true;
38 
39   if (ReplacementTokens.empty())
40     return (DefinitionLength = 0);
41 
42   const Token &firstToken = ReplacementTokens.front();
43   const Token &lastToken = ReplacementTokens.back();
44   SourceLocation macroStart = firstToken.getLocation();
45   SourceLocation macroEnd = lastToken.getLocation();
46   assert(macroStart.isValid() && macroEnd.isValid());
47   assert((macroStart.isFileID() || firstToken.is(tok::comment)) &&
48          "Macro defined in macro?");
49   assert((macroEnd.isFileID() || lastToken.is(tok::comment)) &&
50          "Macro defined in macro?");
51   std::pair<FileID, unsigned>
52       startInfo = SM.getDecomposedExpansionLoc(macroStart);
53   std::pair<FileID, unsigned>
54       endInfo = SM.getDecomposedExpansionLoc(macroEnd);
55   assert(startInfo.first == endInfo.first &&
56          "Macro definition spanning multiple FileIDs ?");
57   assert(startInfo.second <= endInfo.second);
58   DefinitionLength = endInfo.second - startInfo.second;
59   DefinitionLength += lastToken.getLength();
60 
61   return DefinitionLength;
62 }
63 
64 /// \brief Return true if the specified macro definition is equal to
65 /// this macro in spelling, arguments, and whitespace.
66 ///
67 /// \param Syntactically if true, the macro definitions can be identical even
68 /// if they use different identifiers for the function macro parameters.
69 /// Otherwise the comparison is lexical and this implements the rules in
70 /// C99 6.10.3.
71 bool MacroInfo::isIdenticalTo(const MacroInfo &Other, Preprocessor &PP,
72                               bool Syntactically) const {
73   bool Lexically = !Syntactically;
74 
75   // Check # tokens in replacement, number of args, and various flags all match.
76   if (ReplacementTokens.size() != Other.ReplacementTokens.size() ||
77       getNumParams() != Other.getNumParams() ||
78       isFunctionLike() != Other.isFunctionLike() ||
79       isC99Varargs() != Other.isC99Varargs() ||
80       isGNUVarargs() != Other.isGNUVarargs())
81     return false;
82 
83   if (Lexically) {
84     // Check arguments.
85     for (param_iterator I = param_begin(), OI = Other.param_begin(),
86                         E = param_end();
87          I != E; ++I, ++OI)
88       if (*I != *OI) return false;
89   }
90 
91   // Check all the tokens.
92   for (unsigned i = 0, e = ReplacementTokens.size(); i != e; ++i) {
93     const Token &A = ReplacementTokens[i];
94     const Token &B = Other.ReplacementTokens[i];
95     if (A.getKind() != B.getKind())
96       return false;
97 
98     // If this isn't the first first token, check that the whitespace and
99     // start-of-line characteristics match.
100     if (i != 0 &&
101         (A.isAtStartOfLine() != B.isAtStartOfLine() ||
102          A.hasLeadingSpace() != B.hasLeadingSpace()))
103       return false;
104 
105     // If this is an identifier, it is easy.
106     if (A.getIdentifierInfo() || B.getIdentifierInfo()) {
107       if (A.getIdentifierInfo() == B.getIdentifierInfo())
108         continue;
109       if (Lexically)
110         return false;
111       // With syntactic equivalence the parameter names can be different as long
112       // as they are used in the same place.
113       int AArgNum = getParameterNum(A.getIdentifierInfo());
114       if (AArgNum == -1)
115         return false;
116       if (AArgNum != Other.getParameterNum(B.getIdentifierInfo()))
117         return false;
118       continue;
119     }
120 
121     // Otherwise, check the spelling.
122     if (PP.getSpelling(A) != PP.getSpelling(B))
123       return false;
124   }
125 
126   return true;
127 }
128 
129 LLVM_DUMP_METHOD void MacroInfo::dump() const {
130   llvm::raw_ostream &Out = llvm::errs();
131 
132   // FIXME: Dump locations.
133   Out << "MacroInfo " << this;
134   if (IsBuiltinMacro) Out << " builtin";
135   if (IsDisabled) Out << " disabled";
136   if (IsUsed) Out << " used";
137   if (IsAllowRedefinitionsWithoutWarning)
138     Out << " allow_redefinitions_without_warning";
139   if (IsWarnIfUnused) Out << " warn_if_unused";
140   if (UsedForHeaderGuard) Out << " header_guard";
141 
142   Out << "\n    #define <macro>";
143   if (IsFunctionLike) {
144     Out << "(";
145     for (unsigned I = 0; I != NumParameters; ++I) {
146       if (I) Out << ", ";
147       Out << ParameterList[I]->getName();
148     }
149     if (IsC99Varargs || IsGNUVarargs) {
150       if (NumParameters && IsC99Varargs) Out << ", ";
151       Out << "...";
152     }
153     Out << ")";
154   }
155 
156   bool First = true;
157   for (const Token &Tok : ReplacementTokens) {
158     // Leading space is semantically meaningful in a macro definition,
159     // so preserve it in the dump output.
160     if (First || Tok.hasLeadingSpace())
161       Out << " ";
162     First = false;
163 
164     if (const char *Punc = tok::getPunctuatorSpelling(Tok.getKind()))
165       Out << Punc;
166     else if (Tok.isLiteral() && Tok.getLiteralData())
167       Out << StringRef(Tok.getLiteralData(), Tok.getLength());
168     else if (auto *II = Tok.getIdentifierInfo())
169       Out << II->getName();
170     else
171       Out << Tok.getName();
172   }
173 }
174 
175 MacroDirective::DefInfo MacroDirective::getDefinition() {
176   MacroDirective *MD = this;
177   SourceLocation UndefLoc;
178   Optional<bool> isPublic;
179   for (; MD; MD = MD->getPrevious()) {
180     if (DefMacroDirective *DefMD = dyn_cast<DefMacroDirective>(MD))
181       return DefInfo(DefMD, UndefLoc,
182                      !isPublic.hasValue() || isPublic.getValue());
183 
184     if (UndefMacroDirective *UndefMD = dyn_cast<UndefMacroDirective>(MD)) {
185       UndefLoc = UndefMD->getLocation();
186       continue;
187     }
188 
189     VisibilityMacroDirective *VisMD = cast<VisibilityMacroDirective>(MD);
190     if (!isPublic.hasValue())
191       isPublic = VisMD->isPublic();
192   }
193 
194   return DefInfo(nullptr, UndefLoc,
195                  !isPublic.hasValue() || isPublic.getValue());
196 }
197 
198 const MacroDirective::DefInfo
199 MacroDirective::findDirectiveAtLoc(SourceLocation L, SourceManager &SM) const {
200   assert(L.isValid() && "SourceLocation is invalid.");
201   for (DefInfo Def = getDefinition(); Def; Def = Def.getPreviousDefinition()) {
202     if (Def.getLocation().isInvalid() ||  // For macros defined on the command line.
203         SM.isBeforeInTranslationUnit(Def.getLocation(), L))
204       return (!Def.isUndefined() ||
205               SM.isBeforeInTranslationUnit(L, Def.getUndefLocation()))
206                   ? Def : DefInfo();
207   }
208   return DefInfo();
209 }
210 
211 LLVM_DUMP_METHOD void MacroDirective::dump() const {
212   llvm::raw_ostream &Out = llvm::errs();
213 
214   switch (getKind()) {
215   case MD_Define: Out << "DefMacroDirective"; break;
216   case MD_Undefine: Out << "UndefMacroDirective"; break;
217   case MD_Visibility: Out << "VisibilityMacroDirective"; break;
218   }
219   Out << " " << this;
220   // FIXME: Dump SourceLocation.
221   if (auto *Prev = getPrevious())
222     Out << " prev " << Prev;
223   if (IsFromPCH) Out << " from_pch";
224 
225   if (isa<VisibilityMacroDirective>(this))
226     Out << (IsPublic ? " public" : " private");
227 
228   if (auto *DMD = dyn_cast<DefMacroDirective>(this)) {
229     if (auto *Info = DMD->getInfo()) {
230       Out << "\n  ";
231       Info->dump();
232     }
233   }
234   Out << "\n";
235 }
236 
237 ModuleMacro *ModuleMacro::create(Preprocessor &PP, Module *OwningModule,
238                                  IdentifierInfo *II, MacroInfo *Macro,
239                                  ArrayRef<ModuleMacro *> Overrides) {
240   void *Mem = PP.getPreprocessorAllocator().Allocate(
241       sizeof(ModuleMacro) + sizeof(ModuleMacro *) * Overrides.size(),
242       alignof(ModuleMacro));
243   return new (Mem) ModuleMacro(OwningModule, II, Macro, Overrides);
244 }
245