1 //===-- Function.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 "lldb/Symbol/Function.h"
11 #include "lldb/Core/Disassembler.h"
12 #include "lldb/Core/Module.h"
13 #include "lldb/Core/ModuleList.h"
14 #include "lldb/Core/Section.h"
15 #include "lldb/Host/Host.h"
16 #include "lldb/Symbol/CompileUnit.h"
17 #include "lldb/Symbol/CompilerType.h"
18 #include "lldb/Symbol/LineTable.h"
19 #include "lldb/Symbol/SymbolFile.h"
20 #include "lldb/Symbol/SymbolVendor.h"
21 #include "lldb/Target/Language.h"
22 #include "lldb/Utility/Log.h"
23 #include "llvm/Support/Casting.h"
24 
25 using namespace lldb;
26 using namespace lldb_private;
27 
28 //----------------------------------------------------------------------
29 // Basic function information is contained in the FunctionInfo class. It is
30 // designed to contain the name, linkage name, and declaration location.
31 //----------------------------------------------------------------------
32 FunctionInfo::FunctionInfo(const char *name, const Declaration *decl_ptr)
33     : m_name(name), m_declaration(decl_ptr) {}
34 
35 FunctionInfo::FunctionInfo(const ConstString &name, const Declaration *decl_ptr)
36     : m_name(name), m_declaration(decl_ptr) {}
37 
38 FunctionInfo::~FunctionInfo() {}
39 
40 void FunctionInfo::Dump(Stream *s, bool show_fullpaths) const {
41   if (m_name)
42     *s << ", name = \"" << m_name << "\"";
43   m_declaration.Dump(s, show_fullpaths);
44 }
45 
46 int FunctionInfo::Compare(const FunctionInfo &a, const FunctionInfo &b) {
47   int result = ConstString::Compare(a.GetName(), b.GetName());
48   if (result)
49     return result;
50 
51   return Declaration::Compare(a.m_declaration, b.m_declaration);
52 }
53 
54 Declaration &FunctionInfo::GetDeclaration() { return m_declaration; }
55 
56 const Declaration &FunctionInfo::GetDeclaration() const {
57   return m_declaration;
58 }
59 
60 ConstString FunctionInfo::GetName() const { return m_name; }
61 
62 size_t FunctionInfo::MemorySize() const {
63   return m_name.MemorySize() + m_declaration.MemorySize();
64 }
65 
66 InlineFunctionInfo::InlineFunctionInfo(const char *name, const char *mangled,
67                                        const Declaration *decl_ptr,
68                                        const Declaration *call_decl_ptr)
69     : FunctionInfo(name, decl_ptr), m_mangled(ConstString(mangled), true),
70       m_call_decl(call_decl_ptr) {}
71 
72 InlineFunctionInfo::InlineFunctionInfo(const ConstString &name,
73                                        const Mangled &mangled,
74                                        const Declaration *decl_ptr,
75                                        const Declaration *call_decl_ptr)
76     : FunctionInfo(name, decl_ptr), m_mangled(mangled),
77       m_call_decl(call_decl_ptr) {}
78 
79 InlineFunctionInfo::~InlineFunctionInfo() {}
80 
81 int InlineFunctionInfo::Compare(const InlineFunctionInfo &a,
82                                 const InlineFunctionInfo &b) {
83 
84   int result = FunctionInfo::Compare(a, b);
85   if (result)
86     return result;
87   // only compare the mangled names if both have them
88   return Mangled::Compare(a.m_mangled, a.m_mangled);
89 }
90 
91 void InlineFunctionInfo::Dump(Stream *s, bool show_fullpaths) const {
92   FunctionInfo::Dump(s, show_fullpaths);
93   if (m_mangled)
94     m_mangled.Dump(s);
95 }
96 
97 void InlineFunctionInfo::DumpStopContext(Stream *s,
98                                          LanguageType language) const {
99   //    s->Indent("[inlined] ");
100   s->Indent();
101   if (m_mangled)
102     s->PutCString(m_mangled.GetName(language).AsCString());
103   else
104     s->PutCString(m_name.AsCString());
105 }
106 
107 ConstString InlineFunctionInfo::GetName(LanguageType language) const {
108   if (m_mangled)
109     return m_mangled.GetName(language);
110   return m_name;
111 }
112 
113 ConstString InlineFunctionInfo::GetDisplayName(LanguageType language) const {
114   if (m_mangled)
115     return m_mangled.GetDisplayDemangledName(language);
116   return m_name;
117 }
118 
119 Declaration &InlineFunctionInfo::GetCallSite() { return m_call_decl; }
120 
121 const Declaration &InlineFunctionInfo::GetCallSite() const {
122   return m_call_decl;
123 }
124 
125 Mangled &InlineFunctionInfo::GetMangled() { return m_mangled; }
126 
127 const Mangled &InlineFunctionInfo::GetMangled() const { return m_mangled; }
128 
129 size_t InlineFunctionInfo::MemorySize() const {
130   return FunctionInfo::MemorySize() + m_mangled.MemorySize();
131 }
132 
133 //----------------------------------------------------------------------
134 //
135 //----------------------------------------------------------------------
136 CallEdge::CallEdge(const char *symbol_name, lldb::addr_t return_pc)
137     : return_pc(return_pc), resolved(false) {
138   lazy_callee.symbol_name = symbol_name;
139 }
140 
141 void CallEdge::ParseSymbolFileAndResolve(ModuleList &images) {
142   if (resolved)
143     return;
144 
145   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
146   LLDB_LOG(log, "CallEdge: Lazily parsing the call graph for {0}",
147            lazy_callee.symbol_name);
148 
149   auto resolve_lazy_callee = [&]() -> Function * {
150     ConstString callee_name{lazy_callee.symbol_name};
151     SymbolContextList sc_list;
152     size_t num_matches =
153         images.FindFunctionSymbols(callee_name, eFunctionNameTypeAuto, sc_list);
154     if (num_matches == 0 || !sc_list[0].symbol) {
155       LLDB_LOG(log, "CallEdge: Found no symbols for {0}, cannot resolve it",
156                callee_name);
157       return nullptr;
158     }
159     Address callee_addr = sc_list[0].symbol->GetAddress();
160     if (!callee_addr.IsValid()) {
161       LLDB_LOG(log, "CallEdge: Invalid symbol address");
162       return nullptr;
163     }
164     Function *f = callee_addr.CalculateSymbolContextFunction();
165     if (!f) {
166       LLDB_LOG(log, "CallEdge: Could not find complete function");
167       return nullptr;
168     }
169     return f;
170   };
171   lazy_callee.def = resolve_lazy_callee();
172   resolved = true;
173 }
174 
175 Function *CallEdge::GetCallee(ModuleList &images) {
176   ParseSymbolFileAndResolve(images);
177   return lazy_callee.def;
178 }
179 
180 lldb::addr_t CallEdge::GetReturnPCAddress(Function &caller,
181                                           Target &target) const {
182   const Address &base = caller.GetAddressRange().GetBaseAddress();
183   Address return_pc_addr{base.GetSection(), return_pc};
184   return return_pc_addr.GetLoadAddress(&target);
185 }
186 
187 //----------------------------------------------------------------------
188 //
189 //----------------------------------------------------------------------
190 Function::Function(CompileUnit *comp_unit, lldb::user_id_t func_uid,
191                    lldb::user_id_t type_uid, const Mangled &mangled, Type *type,
192                    const AddressRange &range)
193     : UserID(func_uid), m_comp_unit(comp_unit), m_type_uid(type_uid),
194       m_type(type), m_mangled(mangled), m_block(func_uid), m_range(range),
195       m_frame_base(nullptr), m_flags(), m_prologue_byte_size(0) {
196   m_block.SetParentScope(this);
197   assert(comp_unit != nullptr);
198 }
199 
200 Function::~Function() {}
201 
202 void Function::GetStartLineSourceInfo(FileSpec &source_file,
203                                       uint32_t &line_no) {
204   line_no = 0;
205   source_file.Clear();
206 
207   if (m_comp_unit == nullptr)
208     return;
209 
210   // Initialize m_type if it hasn't been initialized already
211   GetType();
212 
213   if (m_type != nullptr && m_type->GetDeclaration().GetLine() != 0) {
214     source_file = m_type->GetDeclaration().GetFile();
215     line_no = m_type->GetDeclaration().GetLine();
216   } else {
217     LineTable *line_table = m_comp_unit->GetLineTable();
218     if (line_table == nullptr)
219       return;
220 
221     LineEntry line_entry;
222     if (line_table->FindLineEntryByAddress(GetAddressRange().GetBaseAddress(),
223                                            line_entry, nullptr)) {
224       line_no = line_entry.line;
225       source_file = line_entry.file;
226     }
227   }
228 }
229 
230 void Function::GetEndLineSourceInfo(FileSpec &source_file, uint32_t &line_no) {
231   line_no = 0;
232   source_file.Clear();
233 
234   // The -1 is kind of cheesy, but I want to get the last line entry for the
235   // given function, not the first entry of the next.
236   Address scratch_addr(GetAddressRange().GetBaseAddress());
237   scratch_addr.SetOffset(scratch_addr.GetOffset() +
238                          GetAddressRange().GetByteSize() - 1);
239 
240   LineTable *line_table = m_comp_unit->GetLineTable();
241   if (line_table == nullptr)
242     return;
243 
244   LineEntry line_entry;
245   if (line_table->FindLineEntryByAddress(scratch_addr, line_entry, nullptr)) {
246     line_no = line_entry.line;
247     source_file = line_entry.file;
248   }
249 }
250 
251 llvm::MutableArrayRef<CallEdge> Function::GetCallEdges() {
252   if (m_call_edges_resolved)
253     return m_call_edges;
254 
255   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
256   LLDB_LOG(log, "GetCallEdges: Attempting to parse call site info for {0}",
257            GetDisplayName());
258 
259   m_call_edges_resolved = true;
260 
261   // Find the SymbolFile which provided this function's definition.
262   Block &block = GetBlock(/*can_create*/true);
263   SymbolFile *sym_file = block.GetSymbolFile();
264   if (!sym_file)
265     return llvm::None;
266 
267   // Lazily read call site information from the SymbolFile.
268   m_call_edges = sym_file->ParseCallEdgesInFunction(GetID());
269 
270   // Sort the call edges to speed up return_pc lookups.
271   std::sort(m_call_edges.begin(), m_call_edges.end(),
272             [](const CallEdge &LHS, const CallEdge &RHS) {
273               return LHS.GetUnresolvedReturnPCAddress() <
274                      RHS.GetUnresolvedReturnPCAddress();
275             });
276 
277   return m_call_edges;
278 }
279 
280 llvm::MutableArrayRef<CallEdge> Function::GetTailCallingEdges() {
281   // Call edges are sorted by return PC, and tail calling edges have invalid
282   // return PCs. Find them at the end of the list.
283   return GetCallEdges().drop_until([](const CallEdge &edge) {
284     return edge.GetUnresolvedReturnPCAddress() == LLDB_INVALID_ADDRESS;
285   });
286 }
287 
288 Block &Function::GetBlock(bool can_create) {
289   if (!m_block.BlockInfoHasBeenParsed() && can_create) {
290     SymbolContext sc;
291     CalculateSymbolContext(&sc);
292     if (sc.module_sp) {
293       sc.module_sp->GetSymbolVendor()->ParseFunctionBlocks(sc);
294     } else {
295       Host::SystemLog(Host::eSystemLogError, "error: unable to find module "
296                                              "shared pointer for function '%s' "
297                                              "in %s\n",
298                       GetName().GetCString(), m_comp_unit->GetPath().c_str());
299     }
300     m_block.SetBlockInfoHasBeenParsed(true, true);
301   }
302   return m_block;
303 }
304 
305 CompileUnit *Function::GetCompileUnit() { return m_comp_unit; }
306 
307 const CompileUnit *Function::GetCompileUnit() const { return m_comp_unit; }
308 
309 void Function::GetDescription(Stream *s, lldb::DescriptionLevel level,
310                               Target *target) {
311   ConstString name = GetName();
312   ConstString mangled = m_mangled.GetMangledName();
313 
314   *s << "id = " << (const UserID &)*this;
315   if (name)
316     *s << ", name = \"" << name.GetCString() << '"';
317   if (mangled)
318     *s << ", mangled = \"" << mangled.GetCString() << '"';
319   *s << ", range = ";
320   Address::DumpStyle fallback_style;
321   if (level == eDescriptionLevelVerbose)
322     fallback_style = Address::DumpStyleModuleWithFileAddress;
323   else
324     fallback_style = Address::DumpStyleFileAddress;
325   GetAddressRange().Dump(s, target, Address::DumpStyleLoadAddress,
326                          fallback_style);
327 }
328 
329 void Function::Dump(Stream *s, bool show_context) const {
330   s->Printf("%p: ", static_cast<const void *>(this));
331   s->Indent();
332   *s << "Function" << static_cast<const UserID &>(*this);
333 
334   m_mangled.Dump(s);
335 
336   if (m_type)
337     s->Printf(", type = %p", static_cast<void *>(m_type));
338   else if (m_type_uid != LLDB_INVALID_UID)
339     s->Printf(", type_uid = 0x%8.8" PRIx64, m_type_uid);
340 
341   s->EOL();
342   // Dump the root object
343   if (m_block.BlockInfoHasBeenParsed())
344     m_block.Dump(s, m_range.GetBaseAddress().GetFileAddress(), INT_MAX,
345                  show_context);
346 }
347 
348 void Function::CalculateSymbolContext(SymbolContext *sc) {
349   sc->function = this;
350   m_comp_unit->CalculateSymbolContext(sc);
351 }
352 
353 ModuleSP Function::CalculateSymbolContextModule() {
354   SectionSP section_sp(m_range.GetBaseAddress().GetSection());
355   if (section_sp)
356     return section_sp->GetModule();
357 
358   return this->GetCompileUnit()->GetModule();
359 }
360 
361 CompileUnit *Function::CalculateSymbolContextCompileUnit() {
362   return this->GetCompileUnit();
363 }
364 
365 Function *Function::CalculateSymbolContextFunction() { return this; }
366 
367 lldb::DisassemblerSP Function::GetInstructions(const ExecutionContext &exe_ctx,
368                                                const char *flavor,
369                                                bool prefer_file_cache) {
370   ModuleSP module_sp(GetAddressRange().GetBaseAddress().GetModule());
371   if (module_sp) {
372     const bool prefer_file_cache = false;
373     return Disassembler::DisassembleRange(module_sp->GetArchitecture(), nullptr,
374                                           flavor, exe_ctx, GetAddressRange(),
375                                           prefer_file_cache);
376   }
377   return lldb::DisassemblerSP();
378 }
379 
380 bool Function::GetDisassembly(const ExecutionContext &exe_ctx,
381                               const char *flavor, bool prefer_file_cache,
382                               Stream &strm) {
383   lldb::DisassemblerSP disassembler_sp =
384       GetInstructions(exe_ctx, flavor, prefer_file_cache);
385   if (disassembler_sp) {
386     const bool show_address = true;
387     const bool show_bytes = false;
388     disassembler_sp->GetInstructionList().Dump(&strm, show_address, show_bytes,
389                                                &exe_ctx);
390     return true;
391   }
392   return false;
393 }
394 
395 // Symbol *
396 // Function::CalculateSymbolContextSymbol ()
397 //{
398 //    return // TODO: find the symbol for the function???
399 //}
400 
401 void Function::DumpSymbolContext(Stream *s) {
402   m_comp_unit->DumpSymbolContext(s);
403   s->Printf(", Function{0x%8.8" PRIx64 "}", GetID());
404 }
405 
406 size_t Function::MemorySize() const {
407   size_t mem_size = sizeof(Function) + m_block.MemorySize();
408   return mem_size;
409 }
410 
411 bool Function::GetIsOptimized() {
412   bool result = false;
413 
414   // Currently optimization is only indicted by the vendor extension
415   // DW_AT_APPLE_optimized which is set on a compile unit level.
416   if (m_comp_unit) {
417     result = m_comp_unit->GetIsOptimized();
418   }
419   return result;
420 }
421 
422 bool Function::IsTopLevelFunction() {
423   bool result = false;
424 
425   if (Language *language = Language::FindPlugin(GetLanguage()))
426     result = language->IsTopLevelFunction(*this);
427 
428   return result;
429 }
430 
431 ConstString Function::GetDisplayName() const {
432   return m_mangled.GetDisplayDemangledName(GetLanguage());
433 }
434 
435 CompilerDeclContext Function::GetDeclContext() {
436   ModuleSP module_sp = CalculateSymbolContextModule();
437 
438   if (module_sp) {
439     SymbolVendor *sym_vendor = module_sp->GetSymbolVendor();
440 
441     if (sym_vendor) {
442       SymbolFile *sym_file = sym_vendor->GetSymbolFile();
443 
444       if (sym_file)
445         return sym_file->GetDeclContextForUID(GetID());
446     }
447   }
448   return CompilerDeclContext();
449 }
450 
451 Type *Function::GetType() {
452   if (m_type == nullptr) {
453     SymbolContext sc;
454 
455     CalculateSymbolContext(&sc);
456 
457     if (!sc.module_sp)
458       return nullptr;
459 
460     SymbolVendor *sym_vendor = sc.module_sp->GetSymbolVendor();
461 
462     if (sym_vendor == nullptr)
463       return nullptr;
464 
465     SymbolFile *sym_file = sym_vendor->GetSymbolFile();
466 
467     if (sym_file == nullptr)
468       return nullptr;
469 
470     m_type = sym_file->ResolveTypeUID(m_type_uid);
471   }
472   return m_type;
473 }
474 
475 const Type *Function::GetType() const { return m_type; }
476 
477 CompilerType Function::GetCompilerType() {
478   Type *function_type = GetType();
479   if (function_type)
480     return function_type->GetFullCompilerType();
481   return CompilerType();
482 }
483 
484 uint32_t Function::GetPrologueByteSize() {
485   if (m_prologue_byte_size == 0 &&
486       m_flags.IsClear(flagsCalculatedPrologueSize)) {
487     m_flags.Set(flagsCalculatedPrologueSize);
488     LineTable *line_table = m_comp_unit->GetLineTable();
489     uint32_t prologue_end_line_idx = 0;
490 
491     if (line_table) {
492       LineEntry first_line_entry;
493       uint32_t first_line_entry_idx = UINT32_MAX;
494       if (line_table->FindLineEntryByAddress(GetAddressRange().GetBaseAddress(),
495                                              first_line_entry,
496                                              &first_line_entry_idx)) {
497         // Make sure the first line entry isn't already the end of the prologue
498         addr_t prologue_end_file_addr = LLDB_INVALID_ADDRESS;
499         addr_t line_zero_end_file_addr = LLDB_INVALID_ADDRESS;
500 
501         if (first_line_entry.is_prologue_end) {
502           prologue_end_file_addr =
503               first_line_entry.range.GetBaseAddress().GetFileAddress();
504           prologue_end_line_idx = first_line_entry_idx;
505         } else {
506           // Check the first few instructions and look for one that has
507           // is_prologue_end set to true.
508           const uint32_t last_line_entry_idx = first_line_entry_idx + 6;
509           for (uint32_t idx = first_line_entry_idx + 1;
510                idx < last_line_entry_idx; ++idx) {
511             LineEntry line_entry;
512             if (line_table->GetLineEntryAtIndex(idx, line_entry)) {
513               if (line_entry.is_prologue_end) {
514                 prologue_end_file_addr =
515                     line_entry.range.GetBaseAddress().GetFileAddress();
516                 prologue_end_line_idx = idx;
517                 break;
518               }
519             }
520           }
521         }
522 
523         // If we didn't find the end of the prologue in the line tables, then
524         // just use the end address of the first line table entry
525         if (prologue_end_file_addr == LLDB_INVALID_ADDRESS) {
526           // Check the first few instructions and look for one that has a line
527           // number that's different than the first entry.
528           uint32_t last_line_entry_idx = first_line_entry_idx + 6;
529           for (uint32_t idx = first_line_entry_idx + 1;
530                idx < last_line_entry_idx; ++idx) {
531             LineEntry line_entry;
532             if (line_table->GetLineEntryAtIndex(idx, line_entry)) {
533               if (line_entry.line != first_line_entry.line) {
534                 prologue_end_file_addr =
535                     line_entry.range.GetBaseAddress().GetFileAddress();
536                 prologue_end_line_idx = idx;
537                 break;
538               }
539             }
540           }
541 
542           if (prologue_end_file_addr == LLDB_INVALID_ADDRESS) {
543             prologue_end_file_addr =
544                 first_line_entry.range.GetBaseAddress().GetFileAddress() +
545                 first_line_entry.range.GetByteSize();
546             prologue_end_line_idx = first_line_entry_idx;
547           }
548         }
549 
550         const addr_t func_start_file_addr =
551             m_range.GetBaseAddress().GetFileAddress();
552         const addr_t func_end_file_addr =
553             func_start_file_addr + m_range.GetByteSize();
554 
555         // Now calculate the offset to pass the subsequent line 0 entries.
556         uint32_t first_non_zero_line = prologue_end_line_idx;
557         while (1) {
558           LineEntry line_entry;
559           if (line_table->GetLineEntryAtIndex(first_non_zero_line,
560                                               line_entry)) {
561             if (line_entry.line != 0)
562               break;
563           }
564           if (line_entry.range.GetBaseAddress().GetFileAddress() >=
565               func_end_file_addr)
566             break;
567 
568           first_non_zero_line++;
569         }
570 
571         if (first_non_zero_line > prologue_end_line_idx) {
572           LineEntry first_non_zero_entry;
573           if (line_table->GetLineEntryAtIndex(first_non_zero_line,
574                                               first_non_zero_entry)) {
575             line_zero_end_file_addr =
576                 first_non_zero_entry.range.GetBaseAddress().GetFileAddress();
577           }
578         }
579 
580         // Verify that this prologue end file address in the function's address
581         // range just to be sure
582         if (func_start_file_addr < prologue_end_file_addr &&
583             prologue_end_file_addr < func_end_file_addr) {
584           m_prologue_byte_size = prologue_end_file_addr - func_start_file_addr;
585         }
586 
587         if (prologue_end_file_addr < line_zero_end_file_addr &&
588             line_zero_end_file_addr < func_end_file_addr) {
589           m_prologue_byte_size +=
590               line_zero_end_file_addr - prologue_end_file_addr;
591         }
592       }
593     }
594   }
595 
596   return m_prologue_byte_size;
597 }
598 
599 lldb::LanguageType Function::GetLanguage() const {
600   if (m_comp_unit)
601     return m_comp_unit->GetLanguage();
602   else
603     return lldb::eLanguageTypeUnknown;
604 }
605 
606 ConstString Function::GetName() const {
607   LanguageType language = lldb::eLanguageTypeUnknown;
608   if (m_comp_unit)
609     language = m_comp_unit->GetLanguage();
610   return m_mangled.GetName(language);
611 }
612 
613 ConstString Function::GetNameNoArguments() const {
614   LanguageType language = lldb::eLanguageTypeUnknown;
615   if (m_comp_unit)
616     language = m_comp_unit->GetLanguage();
617   return m_mangled.GetName(language, Mangled::ePreferDemangledWithoutArguments);
618 }
619