1 //===--- MacroPPCallbacks.cpp ---------------------------------------------===//
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 contains implementation for the macro preprocessors callbacks.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "MacroPPCallbacks.h"
15 #include "CGDebugInfo.h"
16 #include "clang/CodeGen/ModuleBuilder.h"
17 #include "clang/Parse/Parser.h"
18 
19 using namespace clang;
20 
21 void MacroPPCallbacks::writeMacroDefinition(const IdentifierInfo &II,
22                                             const MacroInfo &MI,
23                                             Preprocessor &PP, raw_ostream &Name,
24                                             raw_ostream &Value) {
25   Name << II.getName();
26 
27   if (MI.isFunctionLike()) {
28     Name << '(';
29     if (!MI.arg_empty()) {
30       MacroInfo::arg_iterator AI = MI.arg_begin(), E = MI.arg_end();
31       for (; AI + 1 != E; ++AI) {
32         Name << (*AI)->getName();
33         Name << ',';
34       }
35 
36       // Last argument.
37       if ((*AI)->getName() == "__VA_ARGS__")
38         Name << "...";
39       else
40         Name << (*AI)->getName();
41     }
42 
43     if (MI.isGNUVarargs())
44       // #define foo(x...)
45       Name << "...";
46 
47     Name << ')';
48   }
49 
50   SmallString<128> SpellingBuffer;
51   bool First = true;
52   for (const auto &T : MI.tokens()) {
53     if (!First && T.hasLeadingSpace())
54       Value << ' ';
55 
56     Value << PP.getSpelling(T, SpellingBuffer);
57     First = false;
58   }
59 }
60 
61 MacroPPCallbacks::MacroPPCallbacks(CodeGenerator *Gen, Preprocessor &PP)
62     : Gen(Gen), PP(PP), Status(NoScope) {}
63 
64 /*
65   This is the expected flow of enter/exit compiler and user files:
66   - Main File Enter
67     - <built-in> file enter
68       {Compiler macro definitions} - (Line=0, no scope)
69       - (Optional) <command line> file enter
70       {Command line macro definitions} - (Line=0, no scope)
71       - (Optional) <command line> file exit
72       {Command line file includes} - (Line=0, Main file scope)
73         {macro definitions and file includes} - (Line!=0, Parent scope)
74     - <built-in> file exit
75     {User code macro definitions and file includes} - (Line!=0, Parent scope)
76 */
77 
78 llvm::DIMacroFile *MacroPPCallbacks::getCurrentScope() {
79   if (Status == MainFileScope || Status == CommandLineIncludeScope)
80     return Scopes.back();
81   return nullptr;
82 }
83 
84 SourceLocation MacroPPCallbacks::getCorrectLocation(SourceLocation Loc) {
85   if (Status == MainFileScope || EnteredCommandLineIncludeFiles)
86     return Loc;
87 
88   // While parsing skipped files, location of macros is invalid.
89   // Invalid location represents line zero.
90   return SourceLocation();
91 }
92 
93 static bool isBuiltinFile(SourceManager &SM, SourceLocation Loc) {
94   StringRef Filename(SM.getPresumedLoc(Loc).getFilename());
95   return Filename.equals("<built-in>");
96 }
97 
98 static bool isCommandLineFile(SourceManager &SM, SourceLocation Loc) {
99   StringRef Filename(SM.getPresumedLoc(Loc).getFilename());
100   return Filename.equals("<command line>");
101 }
102 
103 void MacroPPCallbacks::updateStatusToNextScope() {
104   switch (Status) {
105   case NoScope:
106     Status = InitializedScope;
107     break;
108   case InitializedScope:
109     Status = BuiltinScope;
110     break;
111   case BuiltinScope:
112     Status = CommandLineIncludeScope;
113     break;
114   case CommandLineIncludeScope:
115     Status = MainFileScope;
116     break;
117   case MainFileScope:
118     llvm_unreachable("There is no next scope, already in the final scope");
119   }
120 }
121 
122 void MacroPPCallbacks::FileEntered(SourceLocation Loc) {
123   SourceLocation LineLoc = getCorrectLocation(LastHashLoc);
124   switch (Status) {
125   case NoScope:
126     updateStatusToNextScope();
127     break;
128   case InitializedScope:
129     updateStatusToNextScope();
130     return;
131   case BuiltinScope:
132     if (isCommandLineFile(PP.getSourceManager(), Loc))
133       return;
134     updateStatusToNextScope();
135     LLVM_FALLTHROUGH;
136   case CommandLineIncludeScope:
137     EnteredCommandLineIncludeFiles++;
138     break;
139   case MainFileScope:
140     break;
141   }
142 
143   Scopes.push_back(Gen->getCGDebugInfo()->CreateTempMacroFile(getCurrentScope(),
144                                                               LineLoc, Loc));
145 }
146 
147 void MacroPPCallbacks::FileExited(SourceLocation Loc) {
148   switch (Status) {
149   default:
150     llvm_unreachable("Do not expect to exit a file from current scope");
151   case BuiltinScope:
152     if (!isBuiltinFile(PP.getSourceManager(), Loc))
153       // Skip next scope and change status to MainFileScope.
154       Status = MainFileScope;
155     return;
156   case CommandLineIncludeScope:
157     if (!EnteredCommandLineIncludeFiles) {
158       updateStatusToNextScope();
159       return;
160     }
161     EnteredCommandLineIncludeFiles--;
162     break;
163   case MainFileScope:
164     break;
165   }
166 
167   Scopes.pop_back();
168 }
169 
170 void MacroPPCallbacks::FileChanged(SourceLocation Loc, FileChangeReason Reason,
171                                    SrcMgr::CharacteristicKind FileType,
172                                    FileID PrevFID) {
173   // Only care about enter file or exit file changes.
174   if (Reason == EnterFile)
175     FileEntered(Loc);
176   else if (Reason == ExitFile)
177     FileExited(Loc);
178 }
179 
180 void MacroPPCallbacks::InclusionDirective(
181     SourceLocation HashLoc, const Token &IncludeTok, StringRef FileName,
182     bool IsAngled, CharSourceRange FilenameRange, const FileEntry *File,
183     StringRef SearchPath, StringRef RelativePath, const Module *Imported) {
184 
185   // Record the line location of the current included file.
186   LastHashLoc = HashLoc;
187 }
188 
189 void MacroPPCallbacks::MacroDefined(const Token &MacroNameTok,
190                                     const MacroDirective *MD) {
191   IdentifierInfo *Id = MacroNameTok.getIdentifierInfo();
192   SourceLocation location = getCorrectLocation(MacroNameTok.getLocation());
193   std::string NameBuffer, ValueBuffer;
194   llvm::raw_string_ostream Name(NameBuffer);
195   llvm::raw_string_ostream Value(ValueBuffer);
196   writeMacroDefinition(*Id, *MD->getMacroInfo(), PP, Name, Value);
197   Gen->getCGDebugInfo()->CreateMacro(getCurrentScope(),
198                                      llvm::dwarf::DW_MACINFO_define, location,
199                                      Name.str(), Value.str());
200 }
201 
202 void MacroPPCallbacks::MacroUndefined(const Token &MacroNameTok,
203                                       const MacroDefinition &MD) {
204   IdentifierInfo *Id = MacroNameTok.getIdentifierInfo();
205   SourceLocation location = getCorrectLocation(MacroNameTok.getLocation());
206   Gen->getCGDebugInfo()->CreateMacro(getCurrentScope(),
207                                      llvm::dwarf::DW_MACINFO_undef, location,
208                                      Id->getName(), "");
209 }
210