clang  10.0.0git
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"
14 #include "llvm/BinaryFormat/ELF.h"
15 
16 using namespace clang;
17 
18 namespace {
19 class InterfaceStubFunctionsConsumer : public ASTConsumer {
20  CompilerInstance &Instance;
21  StringRef InFile;
22  StringRef Format;
23  std::set<std::string> ParsedTemplates;
24 
25  enum RootDeclOrigin { TopLevel = 0, FromTU = 1, IsLate = 2 };
26  struct MangledSymbol {
27  std::string ParentName;
28  uint8_t Type;
29  uint8_t Binding;
30  std::vector<std::string> Names;
31  MangledSymbol() = delete;
32 
33  MangledSymbol(const std::string &ParentName, uint8_t Type, uint8_t Binding,
34  std::vector<std::string> Names)
35  : ParentName(ParentName), Type(Type), Binding(Binding), Names(Names) {}
36  };
37  using MangledSymbols = std::map<const NamedDecl *, MangledSymbol>;
38 
39  bool WriteNamedDecl(const NamedDecl *ND, MangledSymbols &Symbols, int RDO) {
40  // Here we filter out anything that's not set to DefaultVisibility.
41  // DefaultVisibility is set on a decl when -fvisibility is not specified on
42  // the command line (or specified as default) and the decl does not have
43  // __attribute__((visibility("hidden"))) set or when the command line
44  // argument is set to hidden but the decl explicitly has
45  // __attribute__((visibility ("default"))) set. We do this so that the user
46  // can have fine grain control of what they want to expose in the stub.
47  auto isVisible = [](const NamedDecl *ND) -> bool {
48  return ND->getVisibility() == DefaultVisibility;
49  };
50 
51  auto ignoreDecl = [this, isVisible](const NamedDecl *ND) -> bool {
52  if (!isVisible(ND))
53  return true;
54 
55  if (const VarDecl *VD = dyn_cast<VarDecl>(ND)) {
56  if (const auto *Parent = VD->getParentFunctionOrMethod())
57  if (isa<BlockDecl>(Parent) || isa<CXXMethodDecl>(Parent))
58  return true;
59 
60  if ((VD->getStorageClass() == StorageClass::SC_Extern) ||
61  (VD->getStorageClass() == StorageClass::SC_Static &&
62  VD->getParentFunctionOrMethod() == nullptr))
63  return true;
64  }
65 
66  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND)) {
67  if (FD->isInlined() && !isa<CXXMethodDecl>(FD) &&
68  !Instance.getLangOpts().GNUInline)
69  return true;
70  if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
71  if (const auto *RC = dyn_cast<CXXRecordDecl>(MD->getParent()))
72  if (isa<ClassTemplateDecl>(RC->getParent()) || !isVisible(RC))
73  return true;
74  if (MD->isDependentContext() || !MD->hasBody())
75  return true;
76  }
77  if (FD->getStorageClass() == StorageClass::SC_Static)
78  return true;
79  }
80  return false;
81  };
82 
83  auto getParentFunctionDecl = [](const NamedDecl *ND) -> const NamedDecl * {
84  if (const VarDecl *VD = dyn_cast<VarDecl>(ND))
85  if (const auto *FD =
86  dyn_cast_or_null<FunctionDecl>(VD->getParentFunctionOrMethod()))
87  return FD;
88  return nullptr;
89  };
90 
91  auto getMangledNames = [](const NamedDecl *ND) -> std::vector<std::string> {
92  if (!ND)
93  return {""};
94  ASTNameGenerator NameGen(ND->getASTContext());
95  std::vector<std::string> MangledNames = NameGen.getAllManglings(ND);
96  if (isa<CXXConstructorDecl>(ND) || isa<CXXDestructorDecl>(ND))
97  return MangledNames;
98 #ifdef EXPENSIVE_CHECKS
99  assert(MangledNames.size() <= 1 && "Expected only one name mangling.");
100 #endif
101  return {NameGen.getName(ND)};
102  };
103 
104  if (!(RDO & FromTU))
105  return true;
106  if (Symbols.find(ND) != Symbols.end())
107  return true;
108  // - Currently have not figured out how to produce the names for FieldDecls.
109  // - Do not want to produce symbols for function paremeters.
110  if (isa<FieldDecl>(ND) || isa<ParmVarDecl>(ND))
111  return true;
112 
113  const NamedDecl *ParentDecl = getParentFunctionDecl(ND);
114  if ((ParentDecl && ignoreDecl(ParentDecl)) || ignoreDecl(ND))
115  return true;
116 
117  if (RDO & IsLate) {
118  Instance.getDiagnostics().Report(diag::err_asm_invalid_type_in_input)
119  << "Generating Interface Stubs is not supported with "
120  "delayed template parsing.";
121  } else {
122  if (const auto *FD = dyn_cast<FunctionDecl>(ND))
123  if (FD->isDependentContext())
124  return true;
125 
126  const bool IsWeak = (ND->hasAttr<WeakAttr>() ||
127  ND->hasAttr<WeakRefAttr>() || ND->isWeakImported());
128 
129  Symbols.insert(std::make_pair(
130  ND,
131  MangledSymbol(getMangledNames(ParentDecl).front(),
132  // Type:
133  isa<VarDecl>(ND) ? llvm::ELF::STT_OBJECT
134  : llvm::ELF::STT_FUNC,
135  // Binding:
136  IsWeak ? llvm::ELF::STB_WEAK : llvm::ELF::STB_GLOBAL,
137  getMangledNames(ND))));
138  }
139  return true;
140  }
141 
142  void
143  HandleDecls(const llvm::iterator_range<DeclContext::decl_iterator> &Decls,
144  MangledSymbols &Symbols, int RDO) {
145  for (const auto *D : Decls)
146  HandleNamedDecl(dyn_cast<NamedDecl>(D), Symbols, RDO);
147  }
148 
149  void HandleTemplateSpecializations(const FunctionTemplateDecl &FTD,
150  MangledSymbols &Symbols, int RDO) {
151  for (const auto *D : FTD.specializations())
152  HandleNamedDecl(dyn_cast<NamedDecl>(D), Symbols, RDO);
153  }
154 
155  void HandleTemplateSpecializations(const ClassTemplateDecl &CTD,
156  MangledSymbols &Symbols, int RDO) {
157  for (const auto *D : CTD.specializations())
158  HandleNamedDecl(dyn_cast<NamedDecl>(D), Symbols, RDO);
159  }
160 
161  bool HandleNamedDecl(const NamedDecl *ND, MangledSymbols &Symbols, int RDO) {
162  if (!ND)
163  return false;
164 
165  switch (ND->getKind()) {
166  default:
167  break;
168  case Decl::Kind::Namespace:
169  HandleDecls(cast<NamespaceDecl>(ND)->decls(), Symbols, RDO);
170  return true;
171  case Decl::Kind::CXXRecord:
172  HandleDecls(cast<CXXRecordDecl>(ND)->decls(), Symbols, RDO);
173  return true;
174  case Decl::Kind::ClassTemplateSpecialization:
175  HandleDecls(cast<ClassTemplateSpecializationDecl>(ND)->decls(), Symbols,
176  RDO);
177  return true;
178  case Decl::Kind::ClassTemplate:
179  HandleTemplateSpecializations(*cast<ClassTemplateDecl>(ND), Symbols, RDO);
180  return true;
181  case Decl::Kind::FunctionTemplate:
182  HandleTemplateSpecializations(*cast<FunctionTemplateDecl>(ND), Symbols,
183  RDO);
184  return true;
185  case Decl::Kind::Record:
186  case Decl::Kind::Typedef:
187  case Decl::Kind::Enum:
188  case Decl::Kind::EnumConstant:
189  case Decl::Kind::TemplateTypeParm:
190  case Decl::Kind::NonTypeTemplateParm:
191  case Decl::Kind::CXXConversion:
192  case Decl::Kind::UnresolvedUsingValue:
193  case Decl::Kind::Using:
194  case Decl::Kind::UsingShadow:
195  case Decl::Kind::TypeAliasTemplate:
196  case Decl::Kind::TypeAlias:
197  case Decl::Kind::VarTemplate:
198  case Decl::Kind::VarTemplateSpecialization:
199  case Decl::Kind::UsingDirective:
200  case Decl::Kind::TemplateTemplateParm:
201  case Decl::Kind::ClassTemplatePartialSpecialization:
202  case Decl::Kind::IndirectField:
203  case Decl::Kind::ConstructorUsingShadow:
204  case Decl::Kind::CXXDeductionGuide:
205  case Decl::Kind::NamespaceAlias:
206  case Decl::Kind::UnresolvedUsingTypename:
207  return true;
208  case Decl::Kind::Var: {
209  // Bail on any VarDecl that either has no named symbol.
210  if (!ND->getIdentifier())
211  return true;
212  const auto *VD = cast<VarDecl>(ND);
213  // Bail on any VarDecl that is a dependent or templated type.
214  if (VD->isTemplated() || VD->getType()->isDependentType())
215  return true;
216  if (WriteNamedDecl(ND, Symbols, RDO))
217  return true;
218  break;
219  }
220  case Decl::Kind::ParmVar:
221  case Decl::Kind::CXXMethod:
222  case Decl::Kind::CXXConstructor:
223  case Decl::Kind::CXXDestructor:
225  case Decl::Kind::Field:
226  if (WriteNamedDecl(ND, Symbols, RDO))
227  return true;
228  }
229 
230  // While interface stubs are in the development stage, it's probably best to
231  // catch anything that's not a VarDecl or Template/FunctionDecl.
232  Instance.getDiagnostics().Report(diag::err_asm_invalid_type_in_input)
233  << "Expected a function or function template decl.";
234  return false;
235  }
236 
237 public:
238  InterfaceStubFunctionsConsumer(CompilerInstance &Instance, StringRef InFile,
239  StringRef Format)
240  : Instance(Instance), InFile(InFile), Format(Format) {}
241 
242  void HandleTranslationUnit(ASTContext &context) override {
243  struct Visitor : public RecursiveASTVisitor<Visitor> {
244  bool VisitNamedDecl(NamedDecl *ND) {
245  if (const auto *FD = dyn_cast<FunctionDecl>(ND))
246  if (FD->isLateTemplateParsed()) {
247  LateParsedDecls.insert(FD);
248  return true;
249  }
250 
251  if (const auto *VD = dyn_cast<ValueDecl>(ND)) {
252  ValueDecls.insert(VD);
253  return true;
254  }
255 
256  NamedDecls.insert(ND);
257  return true;
258  }
259 
260  std::set<const NamedDecl *> LateParsedDecls;
261  std::set<NamedDecl *> NamedDecls;
262  std::set<const ValueDecl *> ValueDecls;
263  } v;
264 
265  v.TraverseDecl(context.getTranslationUnitDecl());
266 
267  MangledSymbols Symbols;
268  auto OS = Instance.createDefaultOutputFile(/*Binary=*/false, InFile, "ifs");
269  if (!OS)
270  return;
271 
272  if (Instance.getLangOpts().DelayedTemplateParsing) {
273  clang::Sema &S = Instance.getSema();
274  for (const auto *FD : v.LateParsedDecls) {
276  *S.LateParsedTemplateMap.find(cast<FunctionDecl>(FD))->second;
278  HandleNamedDecl(FD, Symbols, (FromTU | IsLate));
279  }
280  }
281 
282  for (const NamedDecl *ND : v.ValueDecls)
283  HandleNamedDecl(ND, Symbols, FromTU);
284  for (const NamedDecl *ND : v.NamedDecls)
285  HandleNamedDecl(ND, Symbols, FromTU);
286 
287  auto writeIfsV1 = [this](const llvm::Triple &T,
288  const MangledSymbols &Symbols,
289  const ASTContext &context, StringRef Format,
290  raw_ostream &OS) -> void {
291  OS << "--- !" << Format << "\n";
292  OS << "IfsVersion: 1.0\n";
293  OS << "Triple: " << T.str() << "\n";
294  OS << "ObjectFileFormat: "
295  << "ELF"
296  << "\n"; // TODO: For now, just ELF.
297  OS << "Symbols:\n";
298  for (const auto &E : Symbols) {
299  const MangledSymbol &Symbol = E.second;
300  for (auto Name : Symbol.Names) {
301  OS << " \""
302  << (Symbol.ParentName.empty() || Instance.getLangOpts().CPlusPlus
303  ? ""
304  : (Symbol.ParentName + "."))
305  << Name << "\" : { Type: ";
306  switch (Symbol.Type) {
307  default:
308  llvm_unreachable(
309  "clang -emit-interface-stubs: Unexpected symbol type.");
310  case llvm::ELF::STT_NOTYPE:
311  OS << "NoType";
312  break;
313  case llvm::ELF::STT_OBJECT: {
314  auto VD = cast<ValueDecl>(E.first)->getType();
315  OS << "Object, Size: "
316  << context.getTypeSizeInChars(VD).getQuantity();
317  break;
318  }
319  case llvm::ELF::STT_FUNC:
320  OS << "Func";
321  break;
322  }
323  if (Symbol.Binding == llvm::ELF::STB_WEAK)
324  OS << ", Weak: true";
325  OS << " }\n";
326  }
327  }
328  OS << "...\n";
329  OS.flush();
330  };
331 
332  assert(Format == "experimental-ifs-v1" && "Unexpected IFS Format.");
333  writeIfsV1(Instance.getTarget().getTriple(), Symbols, context, Format, *OS);
334  }
335 };
336 } // namespace
337 
338 std::unique_ptr<ASTConsumer>
340  StringRef InFile) {
341  return std::make_unique<InterfaceStubFunctionsConsumer>(
342  CI, InFile, "experimental-ifs-v1");
343 }
LangOptions & getLangOpts()
Represents a function declaration or definition.
Definition: Decl.h:1783
LateTemplateParserCB * LateTemplateParser
Definition: Sema.h:722
ASTConsumer - This is an abstract interface that should be implemented by clients that read ASTs...
Definition: ASTConsumer.h:33
LateParsedTemplateMapT LateParsedTemplateMap
Definition: Sema.h:717
const llvm::Triple & getTriple() const
Returns the target triple of the primary target.
Definition: TargetInfo.h:994
spec_range specializations() const
The base class of the type hierarchy.
Definition: Type.h:1450
DiagnosticBuilder Report(SourceLocation Loc, unsigned DiagID)
Issue the message to the client.
Definition: Diagnostic.h:1300
constexpr XRayInstrMask Function
Definition: XRayInstr.h:38
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:168
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:191
bool hasAttr() const
Definition: DeclBase.h:542
Sema - This implements semantic analysis and AST building for C.
Definition: Sema.h:336
do v
Definition: arm_acle.h:64
CompilerInstance - Helper class for managing a single instance of the Clang compiler.
ASTContext & getASTContext() const LLVM_READONLY
Definition: DeclBase.cpp:377
Represents a static or instance method of a struct/union/class.
Definition: DeclCXX.h:1931
std::vector< std::string > getAllManglings(const Decl *D)
Definition: Mangle.cpp:489
bool isWeakImported() const
Determine whether this is a weak-imported symbol.
Definition: DeclBase.cpp:670
std::unique_ptr< ASTConsumer > CreateASTConsumer(CompilerInstance &CI, StringRef InFile) override
Create the AST consumer object for this action, if supported.
Dataflow Directional Tag Classes.
Kind getKind() const
Definition: DeclBase.h:432
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:724
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:1009
Declaration of a class template.
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:12083
This represents a decl that may have a name.
Definition: Decl.h:223
Declaration of a template function.
Definition: DeclTemplate.h:977