1 //===-- AppleObjCDeclVendor.cpp ---------------------------------*- C++ -*-===//
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 #include "AppleObjCDeclVendor.h"
11 
12 #include "Plugins/ExpressionParser/Clang/ASTDumper.h"
13 #include "lldb/Core/Module.h"
14 #include "lldb/Symbol/ClangExternalASTSourceCommon.h"
15 #include "lldb/Symbol/ClangUtil.h"
16 #include "lldb/Target/ObjCLanguageRuntime.h"
17 #include "lldb/Target/Process.h"
18 #include "lldb/Target/Target.h"
19 #include "lldb/Utility/Log.h"
20 
21 #include "clang/AST/ASTContext.h"
22 #include "clang/AST/DeclObjC.h"
23 
24 using namespace lldb_private;
25 
26 class lldb_private::AppleObjCExternalASTSource
27     : public ClangExternalASTSourceCommon {
28 public:
29   AppleObjCExternalASTSource(AppleObjCDeclVendor &decl_vendor)
30       : m_decl_vendor(decl_vendor) {}
31 
32   bool FindExternalVisibleDeclsByName(const clang::DeclContext *decl_ctx,
33                                       clang::DeclarationName name) override {
34     static unsigned int invocation_id = 0;
35     unsigned int current_id = invocation_id++;
36 
37     Log *log(GetLogIfAllCategoriesSet(
38         LIBLLDB_LOG_EXPRESSIONS)); // FIXME - a more appropriate log channel?
39 
40     if (log) {
41       log->Printf("AppleObjCExternalASTSource::FindExternalVisibleDeclsByName[%"
42                   "u] on (ASTContext*)%p Looking for %s in (%sDecl*)%p",
43                   current_id,
44                   static_cast<void *>(&decl_ctx->getParentASTContext()),
45                   name.getAsString().c_str(), decl_ctx->getDeclKindName(),
46                   static_cast<const void *>(decl_ctx));
47     }
48 
49     do {
50       const clang::ObjCInterfaceDecl *interface_decl =
51           llvm::dyn_cast<clang::ObjCInterfaceDecl>(decl_ctx);
52 
53       if (!interface_decl)
54         break;
55 
56       clang::ObjCInterfaceDecl *non_const_interface_decl =
57           const_cast<clang::ObjCInterfaceDecl *>(interface_decl);
58 
59       if (!m_decl_vendor.FinishDecl(non_const_interface_decl))
60         break;
61 
62       clang::DeclContext::lookup_result result =
63           non_const_interface_decl->lookup(name);
64 
65       return (result.size() != 0);
66     } while (0);
67 
68     SetNoExternalVisibleDeclsForName(decl_ctx, name);
69     return false;
70   }
71 
72   void CompleteType(clang::TagDecl *tag_decl) override {
73     static unsigned int invocation_id = 0;
74     unsigned int current_id = invocation_id++;
75 
76     Log *log(GetLogIfAllCategoriesSet(
77         LIBLLDB_LOG_EXPRESSIONS)); // FIXME - a more appropriate log channel?
78 
79     if (log) {
80       log->Printf("AppleObjCExternalASTSource::CompleteType[%u] on "
81                   "(ASTContext*)%p Completing (TagDecl*)%p named %s",
82                   current_id, static_cast<void *>(&tag_decl->getASTContext()),
83                   static_cast<void *>(tag_decl),
84                   tag_decl->getName().str().c_str());
85 
86       log->Printf("  AOEAS::CT[%u] Before:", current_id);
87       ASTDumper dumper((clang::Decl *)tag_decl);
88       dumper.ToLog(log, "    [CT] ");
89     }
90 
91     if (log) {
92       log->Printf("  AOEAS::CT[%u] After:", current_id);
93       ASTDumper dumper((clang::Decl *)tag_decl);
94       dumper.ToLog(log, "    [CT] ");
95     }
96     return;
97   }
98 
99   void CompleteType(clang::ObjCInterfaceDecl *interface_decl) override {
100     static unsigned int invocation_id = 0;
101     unsigned int current_id = invocation_id++;
102 
103     Log *log(GetLogIfAllCategoriesSet(
104         LIBLLDB_LOG_EXPRESSIONS)); // FIXME - a more appropriate log channel?
105 
106     if (log) {
107       log->Printf("AppleObjCExternalASTSource::CompleteType[%u] on "
108                   "(ASTContext*)%p Completing (ObjCInterfaceDecl*)%p named %s",
109                   current_id,
110                   static_cast<void *>(&interface_decl->getASTContext()),
111                   static_cast<void *>(interface_decl),
112                   interface_decl->getName().str().c_str());
113 
114       log->Printf("  AOEAS::CT[%u] Before:", current_id);
115       ASTDumper dumper((clang::Decl *)interface_decl);
116       dumper.ToLog(log, "    [CT] ");
117     }
118 
119     m_decl_vendor.FinishDecl(interface_decl);
120 
121     if (log) {
122       log->Printf("  [CT] After:");
123       ASTDumper dumper((clang::Decl *)interface_decl);
124       dumper.ToLog(log, "    [CT] ");
125     }
126     return;
127   }
128 
129   bool layoutRecordType(
130       const clang::RecordDecl *Record, uint64_t &Size, uint64_t &Alignment,
131       llvm::DenseMap<const clang::FieldDecl *, uint64_t> &FieldOffsets,
132       llvm::DenseMap<const clang::CXXRecordDecl *, clang::CharUnits>
133           &BaseOffsets,
134       llvm::DenseMap<const clang::CXXRecordDecl *, clang::CharUnits>
135           &VirtualBaseOffsets) override {
136     return false;
137   }
138 
139   void StartTranslationUnit(clang::ASTConsumer *Consumer) override {
140     clang::TranslationUnitDecl *translation_unit_decl =
141         m_decl_vendor.m_ast_ctx.getASTContext()->getTranslationUnitDecl();
142     translation_unit_decl->setHasExternalVisibleStorage();
143     translation_unit_decl->setHasExternalLexicalStorage();
144   }
145 
146 private:
147   AppleObjCDeclVendor &m_decl_vendor;
148 };
149 
150 AppleObjCDeclVendor::AppleObjCDeclVendor(ObjCLanguageRuntime &runtime)
151     : DeclVendor(), m_runtime(runtime), m_ast_ctx(runtime.GetProcess()
152                                                       ->GetTarget()
153                                                       .GetArchitecture()
154                                                       .GetTriple()
155                                                       .getTriple()
156                                                       .c_str()),
157       m_type_realizer_sp(m_runtime.GetEncodingToType()) {
158   m_external_source = new AppleObjCExternalASTSource(*this);
159   llvm::IntrusiveRefCntPtr<clang::ExternalASTSource> external_source_owning_ptr(
160       m_external_source);
161   m_ast_ctx.getASTContext()->setExternalSource(external_source_owning_ptr);
162 }
163 
164 clang::ObjCInterfaceDecl *
165 AppleObjCDeclVendor::GetDeclForISA(ObjCLanguageRuntime::ObjCISA isa) {
166   ISAToInterfaceMap::const_iterator iter = m_isa_to_interface.find(isa);
167 
168   if (iter != m_isa_to_interface.end())
169     return iter->second;
170 
171   clang::ASTContext *ast_ctx = m_ast_ctx.getASTContext();
172 
173   ObjCLanguageRuntime::ClassDescriptorSP descriptor =
174       m_runtime.GetClassDescriptorFromISA(isa);
175 
176   if (!descriptor)
177     return NULL;
178 
179   const ConstString &name(descriptor->GetClassName());
180 
181   clang::IdentifierInfo &identifier_info =
182       ast_ctx->Idents.get(name.GetStringRef());
183 
184   clang::ObjCInterfaceDecl *new_iface_decl = clang::ObjCInterfaceDecl::Create(
185       *ast_ctx, ast_ctx->getTranslationUnitDecl(), clang::SourceLocation(),
186       &identifier_info, nullptr, nullptr);
187 
188   ClangASTMetadata meta_data;
189   meta_data.SetISAPtr(isa);
190   m_external_source->SetMetadata(new_iface_decl, meta_data);
191 
192   new_iface_decl->setHasExternalVisibleStorage();
193   new_iface_decl->setHasExternalLexicalStorage();
194 
195   ast_ctx->getTranslationUnitDecl()->addDecl(new_iface_decl);
196 
197   m_isa_to_interface[isa] = new_iface_decl;
198 
199   return new_iface_decl;
200 }
201 
202 class ObjCRuntimeMethodType {
203 public:
204   ObjCRuntimeMethodType(const char *types) : m_is_valid(false) {
205     const char *cursor = types;
206     enum ParserState { Start = 0, InType, InPos } state = Start;
207     const char *type = NULL;
208     int brace_depth = 0;
209 
210     uint32_t stepsLeft = 256;
211 
212     while (1) {
213       if (--stepsLeft == 0) {
214         m_is_valid = false;
215         return;
216       }
217 
218       switch (state) {
219       case Start: {
220         switch (*cursor) {
221         default:
222           state = InType;
223           type = cursor;
224           break;
225         case '\0':
226           m_is_valid = true;
227           return;
228         case '0':
229         case '1':
230         case '2':
231         case '3':
232         case '4':
233         case '5':
234         case '6':
235         case '7':
236         case '8':
237         case '9':
238           m_is_valid = false;
239           return;
240         }
241       } break;
242       case InType: {
243         switch (*cursor) {
244         default:
245           ++cursor;
246           break;
247         case '0':
248         case '1':
249         case '2':
250         case '3':
251         case '4':
252         case '5':
253         case '6':
254         case '7':
255         case '8':
256         case '9':
257           if (!brace_depth) {
258             state = InPos;
259             if (type) {
260               m_type_vector.push_back(std::string(type, (cursor - type)));
261             } else {
262               m_is_valid = false;
263               return;
264             }
265             type = NULL;
266           } else {
267             ++cursor;
268           }
269           break;
270         case '[':
271         case '{':
272         case '(':
273           ++brace_depth;
274           ++cursor;
275           break;
276         case ']':
277         case '}':
278         case ')':
279           if (!brace_depth) {
280             m_is_valid = false;
281             return;
282           }
283           --brace_depth;
284           ++cursor;
285           break;
286         case '\0':
287           m_is_valid = false;
288           return;
289         }
290       } break;
291       case InPos: {
292         switch (*cursor) {
293         default:
294           state = InType;
295           type = cursor;
296           break;
297         case '0':
298         case '1':
299         case '2':
300         case '3':
301         case '4':
302         case '5':
303         case '6':
304         case '7':
305         case '8':
306         case '9':
307           ++cursor;
308           break;
309         case '\0':
310           m_is_valid = true;
311           return;
312         }
313       } break;
314       }
315     }
316   }
317 
318   clang::ObjCMethodDecl *
319   BuildMethod(clang::ObjCInterfaceDecl *interface_decl, const char *name,
320               bool instance,
321               ObjCLanguageRuntime::EncodingToTypeSP type_realizer_sp) {
322     if (!m_is_valid || m_type_vector.size() < 3)
323       return NULL;
324 
325     clang::ASTContext &ast_ctx(interface_decl->getASTContext());
326 
327     clang::QualType return_qual_type;
328 
329     const bool isInstance = instance;
330     const bool isVariadic = false;
331     const bool isSynthesized = false;
332     const bool isImplicitlyDeclared = true;
333     const bool isDefined = false;
334     const clang::ObjCMethodDecl::ImplementationControl impControl =
335         clang::ObjCMethodDecl::None;
336     const bool HasRelatedResultType = false;
337     const bool for_expression = true;
338 
339     std::vector<clang::IdentifierInfo *> selector_components;
340 
341     const char *name_cursor = name;
342     bool is_zero_argument = true;
343 
344     while (*name_cursor != '\0') {
345       const char *colon_loc = strchr(name_cursor, ':');
346       if (!colon_loc) {
347         selector_components.push_back(
348             &ast_ctx.Idents.get(llvm::StringRef(name_cursor)));
349         break;
350       } else {
351         is_zero_argument = false;
352         selector_components.push_back(&ast_ctx.Idents.get(
353             llvm::StringRef(name_cursor, colon_loc - name_cursor)));
354         name_cursor = colon_loc + 1;
355       }
356     }
357 
358     clang::IdentifierInfo **identifier_infos = selector_components.data();
359     if (!identifier_infos) {
360       return NULL;
361     }
362 
363     clang::Selector sel = ast_ctx.Selectors.getSelector(
364         is_zero_argument ? 0 : selector_components.size(),
365         identifier_infos);
366 
367     clang::QualType ret_type =
368         ClangUtil::GetQualType(type_realizer_sp->RealizeType(
369             interface_decl->getASTContext(), m_type_vector[0].c_str(),
370             for_expression));
371 
372     if (ret_type.isNull())
373       return NULL;
374 
375     clang::ObjCMethodDecl *ret = clang::ObjCMethodDecl::Create(
376         ast_ctx, clang::SourceLocation(), clang::SourceLocation(), sel,
377         ret_type, NULL, interface_decl, isInstance, isVariadic, isSynthesized,
378         isImplicitlyDeclared, isDefined, impControl, HasRelatedResultType);
379 
380     std::vector<clang::ParmVarDecl *> parm_vars;
381 
382     for (size_t ai = 3, ae = m_type_vector.size(); ai != ae; ++ai) {
383       const bool for_expression = true;
384       clang::QualType arg_type =
385           ClangUtil::GetQualType(type_realizer_sp->RealizeType(
386               ast_ctx, m_type_vector[ai].c_str(), for_expression));
387 
388       if (arg_type.isNull())
389         return NULL; // well, we just wasted a bunch of time.  Wish we could
390                      // delete the stuff we'd just made!
391 
392       parm_vars.push_back(clang::ParmVarDecl::Create(
393           ast_ctx, ret, clang::SourceLocation(), clang::SourceLocation(), NULL,
394           arg_type, NULL, clang::SC_None, NULL));
395     }
396 
397     ret->setMethodParams(ast_ctx,
398                          llvm::ArrayRef<clang::ParmVarDecl *>(parm_vars),
399                          llvm::ArrayRef<clang::SourceLocation>());
400 
401     return ret;
402   }
403 
404   explicit operator bool() { return m_is_valid; }
405 
406   size_t GetNumTypes() { return m_type_vector.size(); }
407 
408   const char *GetTypeAtIndex(size_t idx) { return m_type_vector[idx].c_str(); }
409 
410 private:
411   typedef std::vector<std::string> TypeVector;
412 
413   TypeVector m_type_vector;
414   bool m_is_valid;
415 };
416 
417 bool AppleObjCDeclVendor::FinishDecl(clang::ObjCInterfaceDecl *interface_decl) {
418   Log *log(GetLogIfAllCategoriesSet(
419       LIBLLDB_LOG_EXPRESSIONS)); // FIXME - a more appropriate log channel?
420 
421   ClangASTMetadata *metadata = m_external_source->GetMetadata(interface_decl);
422   ObjCLanguageRuntime::ObjCISA objc_isa = 0;
423   if (metadata)
424     objc_isa = metadata->GetISAPtr();
425 
426   if (!objc_isa)
427     return false;
428 
429   if (!interface_decl->hasExternalVisibleStorage())
430     return true;
431 
432   interface_decl->startDefinition();
433 
434   interface_decl->setHasExternalVisibleStorage(false);
435   interface_decl->setHasExternalLexicalStorage(false);
436 
437   ObjCLanguageRuntime::ClassDescriptorSP descriptor =
438       m_runtime.GetClassDescriptorFromISA(objc_isa);
439 
440   if (!descriptor)
441     return false;
442 
443   auto superclass_func = [interface_decl,
444                           this](ObjCLanguageRuntime::ObjCISA isa) {
445     clang::ObjCInterfaceDecl *superclass_decl = GetDeclForISA(isa);
446 
447     if (!superclass_decl)
448       return;
449 
450     FinishDecl(superclass_decl);
451     clang::ASTContext *context = m_ast_ctx.getASTContext();
452     interface_decl->setSuperClass(context->getTrivialTypeSourceInfo(
453         context->getObjCInterfaceType(superclass_decl)));
454   };
455 
456   auto instance_method_func =
457       [log, interface_decl, this](const char *name, const char *types) -> bool {
458     if (!name || !types)
459       return false; // skip this one
460 
461     ObjCRuntimeMethodType method_type(types);
462 
463     clang::ObjCMethodDecl *method_decl =
464         method_type.BuildMethod(interface_decl, name, true, m_type_realizer_sp);
465 
466     if (log)
467       log->Printf("[  AOTV::FD] Instance method [%s] [%s]", name, types);
468 
469     if (method_decl)
470       interface_decl->addDecl(method_decl);
471 
472     return false;
473   };
474 
475   auto class_method_func = [log, interface_decl,
476                             this](const char *name, const char *types) -> bool {
477     if (!name || !types)
478       return false; // skip this one
479 
480     ObjCRuntimeMethodType method_type(types);
481 
482     clang::ObjCMethodDecl *method_decl = method_type.BuildMethod(
483         interface_decl, name, false, m_type_realizer_sp);
484 
485     if (log)
486       log->Printf("[  AOTV::FD] Class method [%s] [%s]", name, types);
487 
488     if (method_decl)
489       interface_decl->addDecl(method_decl);
490 
491     return false;
492   };
493 
494   auto ivar_func = [log, interface_decl,
495                     this](const char *name, const char *type,
496                           lldb::addr_t offset_ptr, uint64_t size) -> bool {
497     if (!name || !type)
498       return false;
499 
500     const bool for_expression = false;
501 
502     if (log)
503       log->Printf(
504           "[  AOTV::FD] Instance variable [%s] [%s], offset at %" PRIx64, name,
505           type, offset_ptr);
506 
507     CompilerType ivar_type = m_runtime.GetEncodingToType()->RealizeType(
508         m_ast_ctx, type, for_expression);
509 
510     if (ivar_type.IsValid()) {
511       clang::TypeSourceInfo *const type_source_info = nullptr;
512       const bool is_synthesized = false;
513       clang::ObjCIvarDecl *ivar_decl = clang::ObjCIvarDecl::Create(
514           *m_ast_ctx.getASTContext(), interface_decl, clang::SourceLocation(),
515           clang::SourceLocation(), &m_ast_ctx.getASTContext()->Idents.get(name),
516           ClangUtil::GetQualType(ivar_type),
517           type_source_info, // TypeSourceInfo *
518           clang::ObjCIvarDecl::Public, 0, is_synthesized);
519 
520       if (ivar_decl) {
521         interface_decl->addDecl(ivar_decl);
522       }
523     }
524 
525     return false;
526   };
527 
528   if (log) {
529     ASTDumper method_dumper((clang::Decl *)interface_decl);
530 
531     log->Printf("[AppleObjCDeclVendor::FinishDecl] Finishing Objective-C "
532                 "interface for %s",
533                 descriptor->GetClassName().AsCString());
534   }
535 
536   if (!descriptor->Describe(superclass_func, instance_method_func,
537                             class_method_func, ivar_func))
538     return false;
539 
540   if (log) {
541     ASTDumper method_dumper((clang::Decl *)interface_decl);
542 
543     log->Printf(
544         "[AppleObjCDeclVendor::FinishDecl] Finished Objective-C interface");
545 
546     method_dumper.ToLog(log, "  [AOTV::FD] ");
547   }
548 
549   return true;
550 }
551 
552 uint32_t
553 AppleObjCDeclVendor::FindDecls(const ConstString &name, bool append,
554                                uint32_t max_matches,
555                                std::vector<clang::NamedDecl *> &decls) {
556   static unsigned int invocation_id = 0;
557   unsigned int current_id = invocation_id++;
558 
559   Log *log(GetLogIfAllCategoriesSet(
560       LIBLLDB_LOG_EXPRESSIONS)); // FIXME - a more appropriate log channel?
561 
562   if (log)
563     log->Printf("AppleObjCDeclVendor::FindTypes [%u] ('%s', %s, %u, )",
564                 current_id, (const char *)name.AsCString(),
565                 append ? "true" : "false", max_matches);
566 
567   if (!append)
568     decls.clear();
569 
570   uint32_t ret = 0;
571 
572   do {
573     // See if the type is already in our ASTContext.
574 
575     clang::ASTContext *ast_ctx = m_ast_ctx.getASTContext();
576 
577     clang::IdentifierInfo &identifier_info =
578         ast_ctx->Idents.get(name.GetStringRef());
579     clang::DeclarationName decl_name =
580         ast_ctx->DeclarationNames.getIdentifier(&identifier_info);
581 
582     clang::DeclContext::lookup_result lookup_result =
583         ast_ctx->getTranslationUnitDecl()->lookup(decl_name);
584 
585     if (!lookup_result.empty()) {
586       if (clang::ObjCInterfaceDecl *result_iface_decl =
587               llvm::dyn_cast<clang::ObjCInterfaceDecl>(lookup_result[0])) {
588         if (log) {
589           clang::QualType result_iface_type =
590               ast_ctx->getObjCInterfaceType(result_iface_decl);
591           ASTDumper dumper(result_iface_type);
592 
593           uint64_t isa_value = LLDB_INVALID_ADDRESS;
594           ClangASTMetadata *metadata =
595               m_external_source->GetMetadata(result_iface_decl);
596           if (metadata)
597             isa_value = metadata->GetISAPtr();
598 
599           log->Printf("AOCTV::FT [%u] Found %s (isa 0x%" PRIx64
600                       ") in the ASTContext",
601                       current_id, dumper.GetCString(), isa_value);
602         }
603 
604         decls.push_back(result_iface_decl);
605         ret++;
606         break;
607       } else {
608         if (log)
609           log->Printf("AOCTV::FT [%u] There's something in the ASTContext, but "
610                       "it's not something we know about",
611                       current_id);
612         break;
613       }
614     } else if (log) {
615       log->Printf("AOCTV::FT [%u] Couldn't find %s in the ASTContext",
616                   current_id, name.AsCString());
617     }
618 
619     // It's not.  If it exists, we have to put it into our ASTContext.
620 
621     ObjCLanguageRuntime::ObjCISA isa = m_runtime.GetISA(name);
622 
623     if (!isa) {
624       if (log)
625         log->Printf("AOCTV::FT [%u] Couldn't find the isa", current_id);
626 
627       break;
628     }
629 
630     clang::ObjCInterfaceDecl *iface_decl = GetDeclForISA(isa);
631 
632     if (!iface_decl) {
633       if (log)
634         log->Printf("AOCTV::FT [%u] Couldn't get the Objective-C interface for "
635                     "isa 0x%" PRIx64,
636                     current_id, (uint64_t)isa);
637 
638       break;
639     }
640 
641     if (log) {
642       clang::QualType new_iface_type =
643           ast_ctx->getObjCInterfaceType(iface_decl);
644       ASTDumper dumper(new_iface_type);
645       log->Printf("AOCTV::FT [%u] Created %s (isa 0x%" PRIx64 ")", current_id,
646                   dumper.GetCString(), (uint64_t)isa);
647     }
648 
649     decls.push_back(iface_decl);
650     ret++;
651     break;
652   } while (0);
653 
654   return ret;
655 }
656