1 //===--------------- Implementation of PublicAPICommand ----------*-C++ -*-===//
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 #include "PublicAPICommand.h"
10 
11 #include "llvm/ADT/StringExtras.h"
12 #include "llvm/ADT/StringRef.h"
13 #include "llvm/Support/SourceMgr.h"
14 #include "llvm/TableGen/Error.h"
15 #include "llvm/TableGen/Record.h"
16 
17 static const char NamedTypeClassName[] = "NamedType";
18 static const char PtrTypeClassName[] = "PtrType";
19 static const char RestrictedPtrTypeClassName[] = "RestrictedPtrType";
20 static const char ConstTypeClassName[] = "ConstType";
21 static const char StructTypeClassName[] = "Struct";
22 
23 static const char StandardSpecClassName[] = "StandardSpec";
24 static const char PublicAPIClassName[] = "PublicAPI";
25 
26 static bool isa(llvm::Record *Def, llvm::Record *TypeClass) {
27   llvm::RecordRecTy *RecordType = Def->getType();
28   llvm::ArrayRef<llvm::Record *> Classes = RecordType->getClasses();
29   // We want exact types. That is, we don't want the classes listed in
30   // spec.td to be subclassed. Hence, we do not want the record |Def|
31   // to be of more than one class type..
32   if (Classes.size() != 1)
33     return false;
34   return Classes[0] == TypeClass;
35 }
36 
37 // Text blocks for macro definitions and type decls can be indented to
38 // suit the surrounding tablegen listing. We need to dedent such blocks
39 // before writing them out.
40 static void dedentAndWrite(llvm::StringRef Text, llvm::raw_ostream &OS) {
41   llvm::SmallVector<llvm::StringRef, 10> Lines;
42   llvm::SplitString(Text, Lines, "\n");
43   size_t shortest_indent = 1024;
44   for (llvm::StringRef L : Lines) {
45     llvm::StringRef Indent = L.take_while([](char c) { return c == ' '; });
46     size_t IndentSize = Indent.size();
47     if (Indent.size() == L.size()) {
48       // Line is all spaces so no point noting the indent.
49       continue;
50     }
51     if (IndentSize < shortest_indent)
52       shortest_indent = IndentSize;
53   }
54   for (llvm::StringRef L : Lines) {
55     if (L.size() >= shortest_indent)
56       OS << L.drop_front(shortest_indent) << '\n';
57   }
58 }
59 
60 class APIGenerator {
61   llvm::StringRef StdHeader;
62 
63   // TableGen classes in spec.td.
64   llvm::Record *NamedTypeClass;
65   llvm::Record *PtrTypeClass;
66   llvm::Record *RestrictedPtrTypeClass;
67   llvm::Record *ConstTypeClass;
68   llvm::Record *StructClass;
69   llvm::Record *StandardSpecClass;
70   llvm::Record *PublicAPIClass;
71 
72   using NameToRecordMapping = std::unordered_map<std::string, llvm::Record *>;
73   using NameSet = std::unordered_set<std::string>;
74 
75   // Mapping from names to records defining them.
76   NameToRecordMapping MacroSpecMap;
77   NameToRecordMapping TypeSpecMap;
78   NameToRecordMapping FunctionSpecMap;
79   NameToRecordMapping MacroDefsMap;
80   NameToRecordMapping TypeDeclsMap;
81 
82   NameSet Structs;
83   NameSet Functions;
84 
85   bool isaNamedType(llvm::Record *Def) { return isa(Def, NamedTypeClass); }
86 
87   bool isaStructType(llvm::Record *Def) { return isa(Def, StructClass); }
88 
89   bool isaPtrType(llvm::Record *Def) { return isa(Def, PtrTypeClass); }
90 
91   bool isaConstType(llvm::Record *Def) { return isa(Def, ConstTypeClass); }
92 
93   bool isaRestrictedPtrType(llvm::Record *Def) {
94     return isa(Def, RestrictedPtrTypeClass);
95   }
96 
97   bool isaStandardSpec(llvm::Record *Def) {
98     return isa(Def, StandardSpecClass);
99   }
100 
101   bool isaPublicAPI(llvm::Record *Def) { return isa(Def, PublicAPIClass); }
102 
103   std::string getTypeAsString(llvm::Record *TypeRecord) {
104     if (isaNamedType(TypeRecord) || isaStructType(TypeRecord)) {
105       return std::string(TypeRecord->getValueAsString("Name"));
106     } else if (isaPtrType(TypeRecord)) {
107       return getTypeAsString(TypeRecord->getValueAsDef("PointeeType")) + " *";
108     } else if (isaConstType(TypeRecord)) {
109       return std::string("const ") +
110              getTypeAsString(TypeRecord->getValueAsDef("UnqualifiedType"));
111     } else if (isaRestrictedPtrType(TypeRecord)) {
112       return getTypeAsString(TypeRecord->getValueAsDef("PointeeType")) +
113              " *__restrict";
114     } else {
115       llvm::PrintFatalError(TypeRecord->getLoc(), "Invalid type.\n");
116     }
117   }
118 
119   void indexStandardSpecDef(llvm::Record *StandardSpec) {
120     auto HeaderSpecList = StandardSpec->getValueAsListOfDefs("Headers");
121     for (llvm::Record *HeaderSpec : HeaderSpecList) {
122       if (HeaderSpec->getValueAsString("Name") == StdHeader) {
123         auto MacroSpecList = HeaderSpec->getValueAsListOfDefs("Macros");
124         // TODO: Trigger a fatal error on duplicate specs.
125         for (llvm::Record *MacroSpec : MacroSpecList)
126           MacroSpecMap[std::string(MacroSpec->getValueAsString("Name"))] =
127               MacroSpec;
128 
129         auto TypeSpecList = HeaderSpec->getValueAsListOfDefs("Types");
130         for (llvm::Record *TypeSpec : TypeSpecList)
131           TypeSpecMap[std::string(TypeSpec->getValueAsString("Name"))] =
132               TypeSpec;
133 
134         auto FunctionSpecList = HeaderSpec->getValueAsListOfDefs("Functions");
135         for (llvm::Record *FunctionSpec : FunctionSpecList) {
136           FunctionSpecMap[std::string(FunctionSpec->getValueAsString("Name"))] =
137               FunctionSpec;
138         }
139       }
140     }
141   }
142 
143   void indexPublicAPIDef(llvm::Record *PublicAPI) {
144     // While indexing the public API, we do not check if any of the entities
145     // requested is from an included standard. Such a check is done while
146     // generating the API.
147     auto MacroDefList = PublicAPI->getValueAsListOfDefs("Macros");
148     for (llvm::Record *MacroDef : MacroDefList)
149       MacroDefsMap[std::string(MacroDef->getValueAsString("Name"))] = MacroDef;
150 
151     auto TypeDeclList = PublicAPI->getValueAsListOfDefs("TypeDeclarations");
152     for (llvm::Record *TypeDecl : TypeDeclList)
153       TypeDeclsMap[std::string(TypeDecl->getValueAsString("Name"))] = TypeDecl;
154 
155     auto StructList = PublicAPI->getValueAsListOfStrings("Structs");
156     for (llvm::StringRef StructName : StructList)
157       Structs.insert(std::string(StructName));
158 
159     auto FunctionList = PublicAPI->getValueAsListOfStrings("Functions");
160     for (llvm::StringRef FunctionName : FunctionList)
161       Functions.insert(std::string(FunctionName));
162   }
163 
164   void index(llvm::RecordKeeper &Records) {
165     NamedTypeClass = Records.getClass(NamedTypeClassName);
166     PtrTypeClass = Records.getClass(PtrTypeClassName);
167     RestrictedPtrTypeClass = Records.getClass(RestrictedPtrTypeClassName);
168     StructClass = Records.getClass(StructTypeClassName);
169     ConstTypeClass = Records.getClass(ConstTypeClassName);
170     StandardSpecClass = Records.getClass(StandardSpecClassName);
171     PublicAPIClass = Records.getClass(PublicAPIClassName);
172 
173     const auto &DefsMap = Records.getDefs();
174     for (auto &Pair : DefsMap) {
175       llvm::Record *Def = Pair.second.get();
176       if (isaStandardSpec(Def))
177         indexStandardSpecDef(Def);
178       if (isaPublicAPI(Def)) {
179         if (Def->getValueAsString("HeaderName") == StdHeader)
180           indexPublicAPIDef(Def);
181       }
182     }
183   }
184 
185 public:
186   APIGenerator(llvm::StringRef Header, llvm::RecordKeeper &Records)
187       : StdHeader(Header) {
188     index(Records);
189   }
190 
191   void write(llvm::raw_ostream &OS) {
192     for (auto &Pair : MacroDefsMap) {
193       const std::string &Name = Pair.first;
194       if (MacroSpecMap.find(Name) == MacroSpecMap.end())
195         llvm::PrintFatalError(Name + " not found in any standard spec.\n");
196 
197       llvm::Record *MacroDef = Pair.second;
198       dedentAndWrite(MacroDef->getValueAsString("Defn"), OS);
199 
200       OS << '\n';
201     }
202 
203     for (auto &Pair : TypeDeclsMap) {
204       const std::string &Name = Pair.first;
205       if (TypeSpecMap.find(Name) == TypeSpecMap.end())
206         llvm::PrintFatalError(Name + " not found in any standard spec.\n");
207 
208       llvm::Record *TypeDecl = Pair.second;
209       dedentAndWrite(TypeDecl->getValueAsString("Decl"), OS);
210 
211       OS << '\n';
212     }
213 
214     OS << "__BEGIN_C_DECLS\n\n";
215     for (auto &Name : Functions) {
216       if (FunctionSpecMap.find(Name) == FunctionSpecMap.end())
217         llvm::PrintFatalError(Name + " not found in any standard spec.\n");
218 
219       llvm::Record *FunctionSpec = FunctionSpecMap[Name];
220       llvm::Record *RetValSpec = FunctionSpec->getValueAsDef("Return");
221       llvm::Record *ReturnType = RetValSpec->getValueAsDef("ReturnType");
222 
223       OS << getTypeAsString(ReturnType) << " " << Name << "(";
224 
225       auto ArgsList = FunctionSpec->getValueAsListOfDefs("Args");
226       for (size_t i = 0; i < ArgsList.size(); ++i) {
227         llvm::Record *ArgType = ArgsList[i]->getValueAsDef("ArgType");
228         OS << getTypeAsString(ArgType);
229         if (i < ArgsList.size() - 1)
230           OS << ", ";
231       }
232 
233       OS << ");\n\n";
234     }
235     OS << "__END_C_DECLS\n";
236   }
237 };
238 
239 namespace llvm_libc {
240 
241 void writePublicAPI(llvm::raw_ostream &OS, llvm::RecordKeeper &Records) {}
242 
243 const char PublicAPICommand::Name[] = "public_api";
244 
245 void PublicAPICommand::run(llvm::raw_ostream &OS, const ArgVector &Args,
246                            llvm::StringRef StdHeader,
247                            llvm::RecordKeeper &Records,
248                            const Command::ErrorReporter &Reporter) const {
249   if (Args.size() != 0) {
250     Reporter.printFatalError("public_api command does not take any arguments.");
251   }
252 
253   APIGenerator G(StdHeader, Records);
254   G.write(OS);
255 }
256 
257 } // namespace llvm_libc
258