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   return base.GetLoadAddress(&target) + return_pc;
184 }
185 
186 //----------------------------------------------------------------------
187 //
188 //----------------------------------------------------------------------
189 Function::Function(CompileUnit *comp_unit, lldb::user_id_t func_uid,
190                    lldb::user_id_t type_uid, const Mangled &mangled, Type *type,
191                    const AddressRange &range)
192     : UserID(func_uid), m_comp_unit(comp_unit), m_type_uid(type_uid),
193       m_type(type), m_mangled(mangled), m_block(func_uid), m_range(range),
194       m_frame_base(nullptr), m_flags(), m_prologue_byte_size(0) {
195   m_block.SetParentScope(this);
196   assert(comp_unit != nullptr);
197 }
198 
199 Function::~Function() {}
200 
201 void Function::GetStartLineSourceInfo(FileSpec &source_file,
202                                       uint32_t &line_no) {
203   line_no = 0;
204   source_file.Clear();
205 
206   if (m_comp_unit == nullptr)
207     return;
208 
209   // Initialize m_type if it hasn't been initialized already
210   GetType();
211 
212   if (m_type != nullptr && m_type->GetDeclaration().GetLine() != 0) {
213     source_file = m_type->GetDeclaration().GetFile();
214     line_no = m_type->GetDeclaration().GetLine();
215   } else {
216     LineTable *line_table = m_comp_unit->GetLineTable();
217     if (line_table == nullptr)
218       return;
219 
220     LineEntry line_entry;
221     if (line_table->FindLineEntryByAddress(GetAddressRange().GetBaseAddress(),
222                                            line_entry, nullptr)) {
223       line_no = line_entry.line;
224       source_file = line_entry.file;
225     }
226   }
227 }
228 
229 void Function::GetEndLineSourceInfo(FileSpec &source_file, uint32_t &line_no) {
230   line_no = 0;
231   source_file.Clear();
232 
233   // The -1 is kind of cheesy, but I want to get the last line entry for the
234   // given function, not the first entry of the next.
235   Address scratch_addr(GetAddressRange().GetBaseAddress());
236   scratch_addr.SetOffset(scratch_addr.GetOffset() +
237                          GetAddressRange().GetByteSize() - 1);
238 
239   LineTable *line_table = m_comp_unit->GetLineTable();
240   if (line_table == nullptr)
241     return;
242 
243   LineEntry line_entry;
244   if (line_table->FindLineEntryByAddress(scratch_addr, line_entry, nullptr)) {
245     line_no = line_entry.line;
246     source_file = line_entry.file;
247   }
248 }
249 
250 llvm::MutableArrayRef<CallEdge> Function::GetCallEdges() {
251   if (m_call_edges_resolved)
252     return m_call_edges;
253 
254   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
255   LLDB_LOG(log, "GetCallEdges: Attempting to parse call site info for {0}",
256            GetDisplayName());
257 
258   m_call_edges_resolved = true;
259 
260   // Find the SymbolFile which provided this function's definition.
261   Block &block = GetBlock(/*can_create*/true);
262   SymbolFile *sym_file = block.GetSymbolFile();
263   if (!sym_file)
264     return llvm::None;
265 
266   // Lazily read call site information from the SymbolFile.
267   m_call_edges = sym_file->ParseCallEdgesInFunction(GetID());
268 
269   // Sort the call edges to speed up return_pc lookups.
270   std::sort(m_call_edges.begin(), m_call_edges.end(),
271             [](const CallEdge &LHS, const CallEdge &RHS) {
272               return LHS.GetUnresolvedReturnPCAddress() <
273                      RHS.GetUnresolvedReturnPCAddress();
274             });
275 
276   return m_call_edges;
277 }
278 
279 llvm::MutableArrayRef<CallEdge> Function::GetTailCallingEdges() {
280   // Call edges are sorted by return PC, and tail calling edges have invalid
281   // return PCs. Find them at the end of the list.
282   return GetCallEdges().drop_until([](const CallEdge &edge) {
283     return edge.GetUnresolvedReturnPCAddress() == LLDB_INVALID_ADDRESS;
284   });
285 }
286 
287 Block &Function::GetBlock(bool can_create) {
288   if (!m_block.BlockInfoHasBeenParsed() && can_create) {
289     SymbolContext sc;
290     CalculateSymbolContext(&sc);
291     if (sc.module_sp) {
292       sc.module_sp->GetSymbolVendor()->ParseFunctionBlocks(sc);
293     } else {
294       Host::SystemLog(Host::eSystemLogError, "error: unable to find module "
295                                              "shared pointer for function '%s' "
296                                              "in %s\n",
297                       GetName().GetCString(), m_comp_unit->GetPath().c_str());
298     }
299     m_block.SetBlockInfoHasBeenParsed(true, true);
300   }
301   return m_block;
302 }
303 
304 CompileUnit *Function::GetCompileUnit() { return m_comp_unit; }
305 
306 const CompileUnit *Function::GetCompileUnit() const { return m_comp_unit; }
307 
308 void Function::GetDescription(Stream *s, lldb::DescriptionLevel level,
309                               Target *target) {
310   ConstString name = GetName();
311   ConstString mangled = m_mangled.GetMangledName();
312 
313   *s << "id = " << (const UserID &)*this;
314   if (name)
315     *s << ", name = \"" << name.GetCString() << '"';
316   if (mangled)
317     *s << ", mangled = \"" << mangled.GetCString() << '"';
318   *s << ", range = ";
319   Address::DumpStyle fallback_style;
320   if (level == eDescriptionLevelVerbose)
321     fallback_style = Address::DumpStyleModuleWithFileAddress;
322   else
323     fallback_style = Address::DumpStyleFileAddress;
324   GetAddressRange().Dump(s, target, Address::DumpStyleLoadAddress,
325                          fallback_style);
326 }
327 
328 void Function::Dump(Stream *s, bool show_context) const {
329   s->Printf("%p: ", static_cast<const void *>(this));
330   s->Indent();
331   *s << "Function" << static_cast<const UserID &>(*this);
332 
333   m_mangled.Dump(s);
334 
335   if (m_type)
336     s->Printf(", type = %p", static_cast<void *>(m_type));
337   else if (m_type_uid != LLDB_INVALID_UID)
338     s->Printf(", type_uid = 0x%8.8" PRIx64, m_type_uid);
339 
340   s->EOL();
341   // Dump the root object
342   if (m_block.BlockInfoHasBeenParsed())
343     m_block.Dump(s, m_range.GetBaseAddress().GetFileAddress(), INT_MAX,
344                  show_context);
345 }
346 
347 void Function::CalculateSymbolContext(SymbolContext *sc) {
348   sc->function = this;
349   m_comp_unit->CalculateSymbolContext(sc);
350 }
351 
352 ModuleSP Function::CalculateSymbolContextModule() {
353   SectionSP section_sp(m_range.GetBaseAddress().GetSection());
354   if (section_sp)
355     return section_sp->GetModule();
356 
357   return this->GetCompileUnit()->GetModule();
358 }
359 
360 CompileUnit *Function::CalculateSymbolContextCompileUnit() {
361   return this->GetCompileUnit();
362 }
363 
364 Function *Function::CalculateSymbolContextFunction() { return this; }
365 
366 lldb::DisassemblerSP Function::GetInstructions(const ExecutionContext &exe_ctx,
367                                                const char *flavor,
368                                                bool prefer_file_cache) {
369   ModuleSP module_sp(GetAddressRange().GetBaseAddress().GetModule());
370   if (module_sp) {
371     const bool prefer_file_cache = false;
372     return Disassembler::DisassembleRange(module_sp->GetArchitecture(), nullptr,
373                                           flavor, exe_ctx, GetAddressRange(),
374                                           prefer_file_cache);
375   }
376   return lldb::DisassemblerSP();
377 }
378 
379 bool Function::GetDisassembly(const ExecutionContext &exe_ctx,
380                               const char *flavor, bool prefer_file_cache,
381                               Stream &strm) {
382   lldb::DisassemblerSP disassembler_sp =
383       GetInstructions(exe_ctx, flavor, prefer_file_cache);
384   if (disassembler_sp) {
385     const bool show_address = true;
386     const bool show_bytes = false;
387     disassembler_sp->GetInstructionList().Dump(&strm, show_address, show_bytes,
388                                                &exe_ctx);
389     return true;
390   }
391   return false;
392 }
393 
394 // Symbol *
395 // Function::CalculateSymbolContextSymbol ()
396 //{
397 //    return // TODO: find the symbol for the function???
398 //}
399 
400 void Function::DumpSymbolContext(Stream *s) {
401   m_comp_unit->DumpSymbolContext(s);
402   s->Printf(", Function{0x%8.8" PRIx64 "}", GetID());
403 }
404 
405 size_t Function::MemorySize() const {
406   size_t mem_size = sizeof(Function) + m_block.MemorySize();
407   return mem_size;
408 }
409 
410 bool Function::GetIsOptimized() {
411   bool result = false;
412 
413   // Currently optimization is only indicted by the vendor extension
414   // DW_AT_APPLE_optimized which is set on a compile unit level.
415   if (m_comp_unit) {
416     result = m_comp_unit->GetIsOptimized();
417   }
418   return result;
419 }
420 
421 bool Function::IsTopLevelFunction() {
422   bool result = false;
423 
424   if (Language *language = Language::FindPlugin(GetLanguage()))
425     result = language->IsTopLevelFunction(*this);
426 
427   return result;
428 }
429 
430 ConstString Function::GetDisplayName() const {
431   return m_mangled.GetDisplayDemangledName(GetLanguage());
432 }
433 
434 CompilerDeclContext Function::GetDeclContext() {
435   ModuleSP module_sp = CalculateSymbolContextModule();
436 
437   if (module_sp) {
438     SymbolVendor *sym_vendor = module_sp->GetSymbolVendor();
439 
440     if (sym_vendor) {
441       SymbolFile *sym_file = sym_vendor->GetSymbolFile();
442 
443       if (sym_file)
444         return sym_file->GetDeclContextForUID(GetID());
445     }
446   }
447   return CompilerDeclContext();
448 }
449 
450 Type *Function::GetType() {
451   if (m_type == nullptr) {
452     SymbolContext sc;
453 
454     CalculateSymbolContext(&sc);
455 
456     if (!sc.module_sp)
457       return nullptr;
458 
459     SymbolVendor *sym_vendor = sc.module_sp->GetSymbolVendor();
460 
461     if (sym_vendor == nullptr)
462       return nullptr;
463 
464     SymbolFile *sym_file = sym_vendor->GetSymbolFile();
465 
466     if (sym_file == nullptr)
467       return nullptr;
468 
469     m_type = sym_file->ResolveTypeUID(m_type_uid);
470   }
471   return m_type;
472 }
473 
474 const Type *Function::GetType() const { return m_type; }
475 
476 CompilerType Function::GetCompilerType() {
477   Type *function_type = GetType();
478   if (function_type)
479     return function_type->GetFullCompilerType();
480   return CompilerType();
481 }
482 
483 uint32_t Function::GetPrologueByteSize() {
484   if (m_prologue_byte_size == 0 &&
485       m_flags.IsClear(flagsCalculatedPrologueSize)) {
486     m_flags.Set(flagsCalculatedPrologueSize);
487     LineTable *line_table = m_comp_unit->GetLineTable();
488     uint32_t prologue_end_line_idx = 0;
489 
490     if (line_table) {
491       LineEntry first_line_entry;
492       uint32_t first_line_entry_idx = UINT32_MAX;
493       if (line_table->FindLineEntryByAddress(GetAddressRange().GetBaseAddress(),
494                                              first_line_entry,
495                                              &first_line_entry_idx)) {
496         // Make sure the first line entry isn't already the end of the prologue
497         addr_t prologue_end_file_addr = LLDB_INVALID_ADDRESS;
498         addr_t line_zero_end_file_addr = LLDB_INVALID_ADDRESS;
499 
500         if (first_line_entry.is_prologue_end) {
501           prologue_end_file_addr =
502               first_line_entry.range.GetBaseAddress().GetFileAddress();
503           prologue_end_line_idx = first_line_entry_idx;
504         } else {
505           // Check the first few instructions and look for one that has
506           // is_prologue_end set to true.
507           const uint32_t last_line_entry_idx = first_line_entry_idx + 6;
508           for (uint32_t idx = first_line_entry_idx + 1;
509                idx < last_line_entry_idx; ++idx) {
510             LineEntry line_entry;
511             if (line_table->GetLineEntryAtIndex(idx, line_entry)) {
512               if (line_entry.is_prologue_end) {
513                 prologue_end_file_addr =
514                     line_entry.range.GetBaseAddress().GetFileAddress();
515                 prologue_end_line_idx = idx;
516                 break;
517               }
518             }
519           }
520         }
521 
522         // If we didn't find the end of the prologue in the line tables, then
523         // just use the end address of the first line table entry
524         if (prologue_end_file_addr == LLDB_INVALID_ADDRESS) {
525           // Check the first few instructions and look for one that has a line
526           // number that's different than the first entry.
527           uint32_t last_line_entry_idx = first_line_entry_idx + 6;
528           for (uint32_t idx = first_line_entry_idx + 1;
529                idx < last_line_entry_idx; ++idx) {
530             LineEntry line_entry;
531             if (line_table->GetLineEntryAtIndex(idx, line_entry)) {
532               if (line_entry.line != first_line_entry.line) {
533                 prologue_end_file_addr =
534                     line_entry.range.GetBaseAddress().GetFileAddress();
535                 prologue_end_line_idx = idx;
536                 break;
537               }
538             }
539           }
540 
541           if (prologue_end_file_addr == LLDB_INVALID_ADDRESS) {
542             prologue_end_file_addr =
543                 first_line_entry.range.GetBaseAddress().GetFileAddress() +
544                 first_line_entry.range.GetByteSize();
545             prologue_end_line_idx = first_line_entry_idx;
546           }
547         }
548 
549         const addr_t func_start_file_addr =
550             m_range.GetBaseAddress().GetFileAddress();
551         const addr_t func_end_file_addr =
552             func_start_file_addr + m_range.GetByteSize();
553 
554         // Now calculate the offset to pass the subsequent line 0 entries.
555         uint32_t first_non_zero_line = prologue_end_line_idx;
556         while (1) {
557           LineEntry line_entry;
558           if (line_table->GetLineEntryAtIndex(first_non_zero_line,
559                                               line_entry)) {
560             if (line_entry.line != 0)
561               break;
562           }
563           if (line_entry.range.GetBaseAddress().GetFileAddress() >=
564               func_end_file_addr)
565             break;
566 
567           first_non_zero_line++;
568         }
569 
570         if (first_non_zero_line > prologue_end_line_idx) {
571           LineEntry first_non_zero_entry;
572           if (line_table->GetLineEntryAtIndex(first_non_zero_line,
573                                               first_non_zero_entry)) {
574             line_zero_end_file_addr =
575                 first_non_zero_entry.range.GetBaseAddress().GetFileAddress();
576           }
577         }
578 
579         // Verify that this prologue end file address in the function's address
580         // range just to be sure
581         if (func_start_file_addr < prologue_end_file_addr &&
582             prologue_end_file_addr < func_end_file_addr) {
583           m_prologue_byte_size = prologue_end_file_addr - func_start_file_addr;
584         }
585 
586         if (prologue_end_file_addr < line_zero_end_file_addr &&
587             line_zero_end_file_addr < func_end_file_addr) {
588           m_prologue_byte_size +=
589               line_zero_end_file_addr - prologue_end_file_addr;
590         }
591       }
592     }
593   }
594 
595   return m_prologue_byte_size;
596 }
597 
598 lldb::LanguageType Function::GetLanguage() const {
599   if (m_comp_unit)
600     return m_comp_unit->GetLanguage();
601   else
602     return lldb::eLanguageTypeUnknown;
603 }
604 
605 ConstString Function::GetName() const {
606   LanguageType language = lldb::eLanguageTypeUnknown;
607   if (m_comp_unit)
608     language = m_comp_unit->GetLanguage();
609   return m_mangled.GetName(language);
610 }
611 
612 ConstString Function::GetNameNoArguments() const {
613   LanguageType language = lldb::eLanguageTypeUnknown;
614   if (m_comp_unit)
615     language = m_comp_unit->GetLanguage();
616   return m_mangled.GetName(language, Mangled::ePreferDemangledWithoutArguments);
617 }
618