clang  12.0.0git
InterfaceStubFunctionsConsumer.cpp
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1 //===--- InterfaceStubFunctionsConsumer.cpp -------------------------------===//
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 "clang/AST/Mangle.h"
11 #include "clang/Basic/TargetInfo.h"
15 #include "llvm/BinaryFormat/ELF.h"
16 
17 using namespace clang;
18 
19 namespace {
20 class InterfaceStubFunctionsConsumer : public ASTConsumer {
21  CompilerInstance &Instance;
22  StringRef InFile;
23  StringRef Format;
24  std::set<std::string> ParsedTemplates;
25 
26  enum RootDeclOrigin { TopLevel = 0, FromTU = 1, IsLate = 2 };
27  struct MangledSymbol {
28  std::string ParentName;
29  uint8_t Type;
30  uint8_t Binding;
31  std::vector<std::string> Names;
32  MangledSymbol() = delete;
33 
34  MangledSymbol(const std::string &ParentName, uint8_t Type, uint8_t Binding,
35  std::vector<std::string> Names)
36  : ParentName(ParentName), Type(Type), Binding(Binding), Names(Names) {}
37  };
38  using MangledSymbols = std::map<const NamedDecl *, MangledSymbol>;
39 
40  bool WriteNamedDecl(const NamedDecl *ND, MangledSymbols &Symbols, int RDO) {
41  // Here we filter out anything that's not set to DefaultVisibility.
42  // DefaultVisibility is set on a decl when -fvisibility is not specified on
43  // the command line (or specified as default) and the decl does not have
44  // __attribute__((visibility("hidden"))) set or when the command line
45  // argument is set to hidden but the decl explicitly has
46  // __attribute__((visibility ("default"))) set. We do this so that the user
47  // can have fine grain control of what they want to expose in the stub.
48  auto isVisible = [](const NamedDecl *ND) -> bool {
49  return ND->getVisibility() == DefaultVisibility;
50  };
51 
52  auto ignoreDecl = [this, isVisible](const NamedDecl *ND) -> bool {
53  if (!isVisible(ND))
54  return true;
55 
56  if (const VarDecl *VD = dyn_cast<VarDecl>(ND)) {
57  if (const auto *Parent = VD->getParentFunctionOrMethod())
58  if (isa<BlockDecl>(Parent) || isa<CXXMethodDecl>(Parent))
59  return true;
60 
61  if ((VD->getStorageClass() == StorageClass::SC_Extern) ||
62  (VD->getStorageClass() == StorageClass::SC_Static &&
63  VD->getParentFunctionOrMethod() == nullptr))
64  return true;
65  }
66 
67  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND)) {
68  if (FD->isInlined() && !isa<CXXMethodDecl>(FD) &&
69  !Instance.getLangOpts().GNUInline)
70  return true;
71  if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
72  if (const auto *RC = dyn_cast<CXXRecordDecl>(MD->getParent()))
73  if (isa<ClassTemplateDecl>(RC->getParent()) || !isVisible(RC))
74  return true;
75  if (MD->isDependentContext() || !MD->hasBody())
76  return true;
77  }
78  if (FD->getStorageClass() == StorageClass::SC_Static)
79  return true;
80  }
81  return false;
82  };
83 
84  auto getParentFunctionDecl = [](const NamedDecl *ND) -> const NamedDecl * {
85  if (const VarDecl *VD = dyn_cast<VarDecl>(ND))
86  if (const auto *FD =
87  dyn_cast_or_null<FunctionDecl>(VD->getParentFunctionOrMethod()))
88  return FD;
89  return nullptr;
90  };
91 
92  auto getMangledNames = [](const NamedDecl *ND) -> std::vector<std::string> {
93  if (!ND)
94  return {""};
95  ASTNameGenerator NameGen(ND->getASTContext());
96  std::vector<std::string> MangledNames = NameGen.getAllManglings(ND);
97  if (isa<CXXConstructorDecl>(ND) || isa<CXXDestructorDecl>(ND))
98  return MangledNames;
99 #ifdef EXPENSIVE_CHECKS
100  assert(MangledNames.size() <= 1 && "Expected only one name mangling.");
101 #endif
102  return {NameGen.getName(ND)};
103  };
104 
105  if (!(RDO & FromTU))
106  return true;
107  if (Symbols.find(ND) != Symbols.end())
108  return true;
109  // - Currently have not figured out how to produce the names for FieldDecls.
110  // - Do not want to produce symbols for function paremeters.
111  if (isa<FieldDecl>(ND) || isa<ParmVarDecl>(ND))
112  return true;
113 
114  const NamedDecl *ParentDecl = getParentFunctionDecl(ND);
115  if ((ParentDecl && ignoreDecl(ParentDecl)) || ignoreDecl(ND))
116  return true;
117 
118  if (RDO & IsLate) {
119  Instance.getDiagnostics().Report(diag::err_asm_invalid_type_in_input)
120  << "Generating Interface Stubs is not supported with "
121  "delayed template parsing.";
122  } else {
123  if (const auto *FD = dyn_cast<FunctionDecl>(ND))
124  if (FD->isDependentContext())
125  return true;
126 
127  const bool IsWeak = (ND->hasAttr<WeakAttr>() ||
128  ND->hasAttr<WeakRefAttr>() || ND->isWeakImported());
129 
130  Symbols.insert(std::make_pair(
131  ND,
132  MangledSymbol(getMangledNames(ParentDecl).front(),
133  // Type:
134  isa<VarDecl>(ND) ? llvm::ELF::STT_OBJECT
135  : llvm::ELF::STT_FUNC,
136  // Binding:
137  IsWeak ? llvm::ELF::STB_WEAK : llvm::ELF::STB_GLOBAL,
138  getMangledNames(ND))));
139  }
140  return true;
141  }
142 
143  void
144  HandleDecls(const llvm::iterator_range<DeclContext::decl_iterator> &Decls,
145  MangledSymbols &Symbols, int RDO) {
146  for (const auto *D : Decls)
147  HandleNamedDecl(dyn_cast<NamedDecl>(D), Symbols, RDO);
148  }
149 
150  void HandleTemplateSpecializations(const FunctionTemplateDecl &FTD,
151  MangledSymbols &Symbols, int RDO) {
152  for (const auto *D : FTD.specializations())
153  HandleNamedDecl(dyn_cast<NamedDecl>(D), Symbols, RDO);
154  }
155 
156  void HandleTemplateSpecializations(const ClassTemplateDecl &CTD,
157  MangledSymbols &Symbols, int RDO) {
158  for (const auto *D : CTD.specializations())
159  HandleNamedDecl(dyn_cast<NamedDecl>(D), Symbols, RDO);
160  }
161 
162  bool HandleNamedDecl(const NamedDecl *ND, MangledSymbols &Symbols, int RDO) {
163  if (!ND)
164  return false;
165 
166  switch (ND->getKind()) {
167  default:
168  break;
169  case Decl::Kind::Namespace:
170  HandleDecls(cast<NamespaceDecl>(ND)->decls(), Symbols, RDO);
171  return true;
172  case Decl::Kind::CXXRecord:
173  HandleDecls(cast<CXXRecordDecl>(ND)->decls(), Symbols, RDO);
174  return true;
175  case Decl::Kind::ClassTemplateSpecialization:
176  HandleDecls(cast<ClassTemplateSpecializationDecl>(ND)->decls(), Symbols,
177  RDO);
178  return true;
179  case Decl::Kind::ClassTemplate:
180  HandleTemplateSpecializations(*cast<ClassTemplateDecl>(ND), Symbols, RDO);
181  return true;
182  case Decl::Kind::FunctionTemplate:
183  HandleTemplateSpecializations(*cast<FunctionTemplateDecl>(ND), Symbols,
184  RDO);
185  return true;
186  case Decl::Kind::Record:
187  case Decl::Kind::Typedef:
188  case Decl::Kind::Enum:
189  case Decl::Kind::EnumConstant:
190  case Decl::Kind::TemplateTypeParm:
191  case Decl::Kind::NonTypeTemplateParm:
192  case Decl::Kind::CXXConversion:
193  case Decl::Kind::UnresolvedUsingValue:
194  case Decl::Kind::Using:
195  case Decl::Kind::UsingShadow:
196  case Decl::Kind::TypeAliasTemplate:
197  case Decl::Kind::TypeAlias:
198  case Decl::Kind::VarTemplate:
199  case Decl::Kind::VarTemplateSpecialization:
200  case Decl::Kind::UsingDirective:
201  case Decl::Kind::TemplateTemplateParm:
202  case Decl::Kind::ClassTemplatePartialSpecialization:
203  case Decl::Kind::IndirectField:
204  case Decl::Kind::ConstructorUsingShadow:
205  case Decl::Kind::CXXDeductionGuide:
206  case Decl::Kind::NamespaceAlias:
207  case Decl::Kind::UnresolvedUsingTypename:
208  return true;
209  case Decl::Kind::Var: {
210  // Bail on any VarDecl that either has no named symbol.
211  if (!ND->getIdentifier())
212  return true;
213  const auto *VD = cast<VarDecl>(ND);
214  // Bail on any VarDecl that is a dependent or templated type.
215  if (VD->isTemplated() || VD->getType()->isDependentType())
216  return true;
217  if (WriteNamedDecl(ND, Symbols, RDO))
218  return true;
219  break;
220  }
221  case Decl::Kind::ParmVar:
222  case Decl::Kind::CXXMethod:
223  case Decl::Kind::CXXConstructor:
224  case Decl::Kind::CXXDestructor:
225  case Decl::Kind::Function:
226  case Decl::Kind::Field:
227  if (WriteNamedDecl(ND, Symbols, RDO))
228  return true;
229  }
230 
231  // While interface stubs are in the development stage, it's probably best to
232  // catch anything that's not a VarDecl or Template/FunctionDecl.
233  Instance.getDiagnostics().Report(diag::err_asm_invalid_type_in_input)
234  << "Expected a function or function template decl.";
235  return false;
236  }
237 
238 public:
239  InterfaceStubFunctionsConsumer(CompilerInstance &Instance, StringRef InFile,
240  StringRef Format)
241  : Instance(Instance), InFile(InFile), Format(Format) {}
242 
243  void HandleTranslationUnit(ASTContext &context) override {
244  struct Visitor : public RecursiveASTVisitor<Visitor> {
245  bool VisitNamedDecl(NamedDecl *ND) {
246  if (const auto *FD = dyn_cast<FunctionDecl>(ND))
247  if (FD->isLateTemplateParsed()) {
248  LateParsedDecls.insert(FD);
249  return true;
250  }
251 
252  if (const auto *VD = dyn_cast<ValueDecl>(ND)) {
253  ValueDecls.insert(VD);
254  return true;
255  }
256 
257  NamedDecls.insert(ND);
258  return true;
259  }
260 
261  std::set<const NamedDecl *> LateParsedDecls;
262  std::set<NamedDecl *> NamedDecls;
263  std::set<const ValueDecl *> ValueDecls;
264  } v;
265 
266  v.TraverseDecl(context.getTranslationUnitDecl());
267 
268  MangledSymbols Symbols;
269  auto OS = Instance.createDefaultOutputFile(/*Binary=*/false, InFile, "ifs");
270  if (!OS)
271  return;
272 
273  if (Instance.getLangOpts().DelayedTemplateParsing) {
274  clang::Sema &S = Instance.getSema();
275  for (const auto *FD : v.LateParsedDecls) {
277  *S.LateParsedTemplateMap.find(cast<FunctionDecl>(FD))->second;
279  HandleNamedDecl(FD, Symbols, (FromTU | IsLate));
280  }
281  }
282 
283  for (const NamedDecl *ND : v.ValueDecls)
284  HandleNamedDecl(ND, Symbols, FromTU);
285  for (const NamedDecl *ND : v.NamedDecls)
286  HandleNamedDecl(ND, Symbols, FromTU);
287 
288  auto writeIfsV1 = [this](const llvm::Triple &T,
289  const MangledSymbols &Symbols,
290  const ASTContext &context, StringRef Format,
291  raw_ostream &OS) -> void {
292  OS << "--- !" << Format << "\n";
293  OS << "IfsVersion: 2.0\n";
294  OS << "Triple: " << T.str() << "\n";
295  OS << "ObjectFileFormat: "
296  << "ELF"
297  << "\n"; // TODO: For now, just ELF.
298  OS << "Symbols:\n";
299  for (const auto &E : Symbols) {
300  const MangledSymbol &Symbol = E.second;
301  for (auto Name : Symbol.Names) {
302  OS << " - { Name: \""
303  << (Symbol.ParentName.empty() || Instance.getLangOpts().CPlusPlus
304  ? ""
305  : (Symbol.ParentName + "."))
306  << Name << "\", Type: ";
307  switch (Symbol.Type) {
308  default:
309  llvm_unreachable(
310  "clang -emit-interface-stubs: Unexpected symbol type.");
311  case llvm::ELF::STT_NOTYPE:
312  OS << "NoType";
313  break;
314  case llvm::ELF::STT_OBJECT: {
315  auto VD = cast<ValueDecl>(E.first)->getType();
316  OS << "Object, Size: "
317  << context.getTypeSizeInChars(VD).getQuantity();
318  break;
319  }
320  case llvm::ELF::STT_FUNC:
321  OS << "Func";
322  break;
323  }
324  if (Symbol.Binding == llvm::ELF::STB_WEAK)
325  OS << ", Weak: true";
326  OS << " }\n";
327  }
328  }
329  OS << "...\n";
330  OS.flush();
331  };
332 
333  assert(Format == "experimental-ifs-v2" && "Unexpected IFS Format.");
334  writeIfsV1(Instance.getTarget().getTriple(), Symbols, context, Format, *OS);
335  }
336 };
337 } // namespace
338 
339 std::unique_ptr<ASTConsumer>
341  StringRef InFile) {
342  return std::make_unique<InterfaceStubFunctionsConsumer>(
343  CI, InFile, "experimental-ifs-v2");
344 }
LangOptions & getLangOpts()
Represents a function declaration or definition.
Definition: Decl.h:1783
LateTemplateParserCB * LateTemplateParser
Definition: Sema.h:798
ASTConsumer - This is an abstract interface that should be implemented by clients that read ASTs...
Definition: ASTConsumer.h:33
LateParsedTemplateMapT LateParsedTemplateMap
Definition: Sema.h:793
const llvm::Triple & getTriple() const
Returns the target triple of the primary target.
Definition: TargetInfo.h:1060
spec_range specializations() const
The base class of the type hierarchy.
Definition: Type.h:1472
DiagnosticBuilder Report(SourceLocation Loc, unsigned DiagID)
Issue the message to the client.
Definition: Diagnostic.h:1330
Represents a variable declaration or definition.
Definition: Decl.h:820
IdentifierInfo * getIdentifier() const
Get the identifier that names this declaration, if there is one.
Definition: Decl.h:244
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:174
Objects with "default" visibility are seen by the dynamic linker and act like normal objects...
Definition: Visibility.h:45
spec_range specializations() const
A class that does preorder or postorder depth-first traversal on the entire Clang AST and visits each...
NodeId Parent
Definition: ASTDiff.cpp:192
bool hasAttr() const
Definition: DeclBase.h:547
Sema - This implements semantic analysis and AST building for C.
Definition: Sema.h:340
do v
Definition: arm_acle.h:76
CompilerInstance - Helper class for managing a single instance of the Clang compiler.
std::unique_ptr< ASTConsumer > CreateASTConsumer(CompilerInstance &CI, StringRef InFile) override
Create the AST consumer object for this action, if supported.
ASTContext & getASTContext() const LLVM_READONLY
Definition: DeclBase.cpp:414
Represents a static or instance method of a struct/union/class.
Definition: DeclCXX.h:1960
std::vector< std::string > getAllManglings(const Decl *D)
Definition: Mangle.cpp:537
bool isWeakImported() const
Determine whether this is a weak-imported symbol.
Definition: DeclBase.cpp:718
Dataflow Directional Tag Classes.
Kind getKind() const
Definition: DeclBase.h:433
Indicates that the tracking object is a descendant of a referenced-counted OSObject, used in the Darwin kernel.
TargetInfo & getTarget() const
void * OpaqueParser
Definition: Sema.h:800
std::unique_ptr< raw_pwrite_stream > createDefaultOutputFile(bool Binary=true, StringRef BaseInput="", StringRef Extension="")
Create the default output file (from the invocation&#39;s options) and add it to the list of tracked outp...
TranslationUnitDecl * getTranslationUnitDecl() const
Definition: ASTContext.h:935
Declaration of a class template.
Defines the clang::TargetInfo interface.
DiagnosticsEngine & getDiagnostics() const
Get the current diagnostics engine.
Visibility getVisibility() const
Determines the visibility of this entity.
Definition: Decl.h:373
Contains a late templated function.
Definition: Sema.h:12611
This represents a decl that may have a name.
Definition: Decl.h:223
Declaration of a template function.
Definition: DeclTemplate.h:977