Function.cpp revision 360784 
1//===-- Function.cpp --------------------------------------------*- C++ -*-===//
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 "lldb/Symbol/Function.h"
10#include "lldb/Core/Disassembler.h"
11#include "lldb/Core/Module.h"
12#include "lldb/Core/ModuleList.h"
13#include "lldb/Core/Section.h"
14#include "lldb/Host/Host.h"
15#include "lldb/Symbol/CompileUnit.h"
16#include "lldb/Symbol/CompilerType.h"
17#include "lldb/Symbol/LineTable.h"
18#include "lldb/Symbol/SymbolFile.h"
19#include "lldb/Target/Language.h"
20#include "lldb/Target/Target.h"
21#include "lldb/Utility/Log.h"
22#include "llvm/Support/Casting.h"
23
24using namespace lldb;
25using namespace lldb_private;
26
27// Basic function information is contained in the FunctionInfo class. It is
28// designed to contain the name, linkage name, and declaration location.
29FunctionInfo::FunctionInfo(const char *name, const Declaration *decl_ptr)
30    : m_name(name), m_declaration(decl_ptr) {}
31
32FunctionInfo::FunctionInfo(ConstString name, const Declaration *decl_ptr)
33    : m_name(name), m_declaration(decl_ptr) {}
34
35FunctionInfo::~FunctionInfo() {}
36
37void FunctionInfo::Dump(Stream *s, bool show_fullpaths) const {
38  if (m_name)
39    *s << ", name = \"" << m_name << "\"";
40  m_declaration.Dump(s, show_fullpaths);
41}
42
43int FunctionInfo::Compare(const FunctionInfo &a, const FunctionInfo &b) {
44  int result = ConstString::Compare(a.GetName(), b.GetName());
45  if (result)
46    return result;
47
48  return Declaration::Compare(a.m_declaration, b.m_declaration);
49}
50
51Declaration &FunctionInfo::GetDeclaration() { return m_declaration; }
52
53const Declaration &FunctionInfo::GetDeclaration() const {
54  return m_declaration;
55}
56
57ConstString FunctionInfo::GetName() const { return m_name; }
58
59size_t FunctionInfo::MemorySize() const {
60  return m_name.MemorySize() + m_declaration.MemorySize();
61}
62
63InlineFunctionInfo::InlineFunctionInfo(const char *name,
64                                       llvm::StringRef mangled,
65                                       const Declaration *decl_ptr,
66                                       const Declaration *call_decl_ptr)
67    : FunctionInfo(name, decl_ptr), m_mangled(mangled),
68      m_call_decl(call_decl_ptr) {}
69
70InlineFunctionInfo::InlineFunctionInfo(ConstString name,
71                                       const Mangled &mangled,
72                                       const Declaration *decl_ptr,
73                                       const Declaration *call_decl_ptr)
74    : FunctionInfo(name, decl_ptr), m_mangled(mangled),
75      m_call_decl(call_decl_ptr) {}
76
77InlineFunctionInfo::~InlineFunctionInfo() {}
78
79void InlineFunctionInfo::Dump(Stream *s, bool show_fullpaths) const {
80  FunctionInfo::Dump(s, show_fullpaths);
81  if (m_mangled)
82    m_mangled.Dump(s);
83}
84
85void InlineFunctionInfo::DumpStopContext(Stream *s,
86                                         LanguageType language) const {
87  //    s->Indent("[inlined] ");
88  s->Indent();
89  if (m_mangled)
90    s->PutCString(m_mangled.GetName(language).AsCString());
91  else
92    s->PutCString(m_name.AsCString());
93}
94
95ConstString InlineFunctionInfo::GetName(LanguageType language) const {
96  if (m_mangled)
97    return m_mangled.GetName(language);
98  return m_name;
99}
100
101ConstString InlineFunctionInfo::GetDisplayName(LanguageType language) const {
102  if (m_mangled)
103    return m_mangled.GetDisplayDemangledName(language);
104  return m_name;
105}
106
107Declaration &InlineFunctionInfo::GetCallSite() { return m_call_decl; }
108
109const Declaration &InlineFunctionInfo::GetCallSite() const {
110  return m_call_decl;
111}
112
113Mangled &InlineFunctionInfo::GetMangled() { return m_mangled; }
114
115const Mangled &InlineFunctionInfo::GetMangled() const { return m_mangled; }
116
117size_t InlineFunctionInfo::MemorySize() const {
118  return FunctionInfo::MemorySize() + m_mangled.MemorySize();
119}
120
121/// @name Call site related structures
122/// @{
123
124lldb::addr_t CallEdge::GetReturnPCAddress(Function &caller,
125                                          Target &target) const {
126  const Address &base = caller.GetAddressRange().GetBaseAddress();
127  return base.GetLoadAddress(&target) + return_pc;
128}
129
130void DirectCallEdge::ParseSymbolFileAndResolve(ModuleList &images) {
131  if (resolved)
132    return;
133
134  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
135  LLDB_LOG(log, "DirectCallEdge: Lazily parsing the call graph for {0}",
136           lazy_callee.symbol_name);
137
138  auto resolve_lazy_callee = [&]() -> Function * {
139    ConstString callee_name{lazy_callee.symbol_name};
140    SymbolContextList sc_list;
141    images.FindFunctionSymbols(callee_name, eFunctionNameTypeAuto, sc_list);
142    size_t num_matches = sc_list.GetSize();
143    if (num_matches == 0 || !sc_list[0].symbol) {
144      LLDB_LOG(log,
145               "DirectCallEdge: Found no symbols for {0}, cannot resolve it",
146               callee_name);
147      return nullptr;
148    }
149    Address callee_addr = sc_list[0].symbol->GetAddress();
150    if (!callee_addr.IsValid()) {
151      LLDB_LOG(log, "DirectCallEdge: Invalid symbol address");
152      return nullptr;
153    }
154    Function *f = callee_addr.CalculateSymbolContextFunction();
155    if (!f) {
156      LLDB_LOG(log, "DirectCallEdge: Could not find complete function");
157      return nullptr;
158    }
159    return f;
160  };
161  lazy_callee.def = resolve_lazy_callee();
162  resolved = true;
163}
164
165Function *DirectCallEdge::GetCallee(ModuleList &images, ExecutionContext &) {
166  ParseSymbolFileAndResolve(images);
167  assert(resolved && "Did not resolve lazy callee");
168  return lazy_callee.def;
169}
170
171Function *IndirectCallEdge::GetCallee(ModuleList &images,
172                                      ExecutionContext &exe_ctx) {
173  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
174  Status error;
175  Value callee_addr_val;
176  if (!call_target.Evaluate(&exe_ctx, exe_ctx.GetRegisterContext(),
177                            /*loclist_base_addr=*/LLDB_INVALID_ADDRESS,
178                            /*initial_value_ptr=*/nullptr,
179                            /*object_address_ptr=*/nullptr, callee_addr_val,
180                            &error)) {
181    LLDB_LOGF(log, "IndirectCallEdge: Could not evaluate expression: %s",
182              error.AsCString());
183    return nullptr;
184  }
185
186  addr_t raw_addr = callee_addr_val.GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
187  if (raw_addr == LLDB_INVALID_ADDRESS) {
188    LLDB_LOG(log, "IndirectCallEdge: Could not extract address from scalar");
189    return nullptr;
190  }
191
192  Address callee_addr;
193  if (!exe_ctx.GetTargetPtr()->ResolveLoadAddress(raw_addr, callee_addr)) {
194    LLDB_LOG(log, "IndirectCallEdge: Could not resolve callee's load address");
195    return nullptr;
196  }
197
198  Function *f = callee_addr.CalculateSymbolContextFunction();
199  if (!f) {
200    LLDB_LOG(log, "IndirectCallEdge: Could not find complete function");
201    return nullptr;
202  }
203
204  return f;
205}
206
207/// @}
208
209//
210Function::Function(CompileUnit *comp_unit, lldb::user_id_t func_uid,
211                   lldb::user_id_t type_uid, const Mangled &mangled, Type *type,
212                   const AddressRange &range)
213    : UserID(func_uid), m_comp_unit(comp_unit), m_type_uid(type_uid),
214      m_type(type), m_mangled(mangled), m_block(func_uid), m_range(range),
215      m_frame_base(), m_flags(), m_prologue_byte_size(0) {
216  m_block.SetParentScope(this);
217  assert(comp_unit != nullptr);
218}
219
220Function::~Function() {}
221
222void Function::GetStartLineSourceInfo(FileSpec &source_file,
223                                      uint32_t &line_no) {
224  line_no = 0;
225  source_file.Clear();
226
227  if (m_comp_unit == nullptr)
228    return;
229
230  // Initialize m_type if it hasn't been initialized already
231  GetType();
232
233  if (m_type != nullptr && m_type->GetDeclaration().GetLine() != 0) {
234    source_file = m_type->GetDeclaration().GetFile();
235    line_no = m_type->GetDeclaration().GetLine();
236  } else {
237    LineTable *line_table = m_comp_unit->GetLineTable();
238    if (line_table == nullptr)
239      return;
240
241    LineEntry line_entry;
242    if (line_table->FindLineEntryByAddress(GetAddressRange().GetBaseAddress(),
243                                           line_entry, nullptr)) {
244      line_no = line_entry.line;
245      source_file = line_entry.file;
246    }
247  }
248}
249
250void Function::GetEndLineSourceInfo(FileSpec &source_file, uint32_t &line_no) {
251  line_no = 0;
252  source_file.Clear();
253
254  // The -1 is kind of cheesy, but I want to get the last line entry for the
255  // given function, not the first entry of the next.
256  Address scratch_addr(GetAddressRange().GetBaseAddress());
257  scratch_addr.SetOffset(scratch_addr.GetOffset() +
258                         GetAddressRange().GetByteSize() - 1);
259
260  LineTable *line_table = m_comp_unit->GetLineTable();
261  if (line_table == nullptr)
262    return;
263
264  LineEntry line_entry;
265  if (line_table->FindLineEntryByAddress(scratch_addr, line_entry, nullptr)) {
266    line_no = line_entry.line;
267    source_file = line_entry.file;
268  }
269}
270
271llvm::ArrayRef<std::unique_ptr<CallEdge>> Function::GetCallEdges() {
272  if (m_call_edges_resolved)
273    return m_call_edges;
274
275  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
276  LLDB_LOG(log, "GetCallEdges: Attempting to parse call site info for {0}",
277           GetDisplayName());
278
279  m_call_edges_resolved = true;
280
281  // Find the SymbolFile which provided this function's definition.
282  Block &block = GetBlock(/*can_create*/true);
283  SymbolFile *sym_file = block.GetSymbolFile();
284  if (!sym_file)
285    return llvm::None;
286
287  // Lazily read call site information from the SymbolFile.
288  m_call_edges = sym_file->ParseCallEdgesInFunction(GetID());
289
290  // Sort the call edges to speed up return_pc lookups.
291  llvm::sort(m_call_edges.begin(), m_call_edges.end(),
292             [](const std::unique_ptr<CallEdge> &LHS,
293                const std::unique_ptr<CallEdge> &RHS) {
294               return LHS->GetUnresolvedReturnPCAddress() <
295                      RHS->GetUnresolvedReturnPCAddress();
296             });
297
298  return m_call_edges;
299}
300
301llvm::ArrayRef<std::unique_ptr<CallEdge>> Function::GetTailCallingEdges() {
302  // Call edges are sorted by return PC, and tail calling edges have invalid
303  // return PCs. Find them at the end of the list.
304  return GetCallEdges().drop_until([](const std::unique_ptr<CallEdge> &edge) {
305    return edge->GetUnresolvedReturnPCAddress() == LLDB_INVALID_ADDRESS;
306  });
307}
308
309CallEdge *Function::GetCallEdgeForReturnAddress(addr_t return_pc,
310                                                Target &target) {
311  auto edges = GetCallEdges();
312  auto edge_it =
313      std::lower_bound(edges.begin(), edges.end(), return_pc,
314                       [&](const std::unique_ptr<CallEdge> &edge, addr_t pc) {
315                         return edge->GetReturnPCAddress(*this, target) < pc;
316                       });
317  if (edge_it == edges.end() ||
318      edge_it->get()->GetReturnPCAddress(*this, target) != return_pc)
319    return nullptr;
320  return &const_cast<CallEdge &>(*edge_it->get());
321}
322
323Block &Function::GetBlock(bool can_create) {
324  if (!m_block.BlockInfoHasBeenParsed() && can_create) {
325    ModuleSP module_sp = CalculateSymbolContextModule();
326    if (module_sp) {
327      module_sp->GetSymbolFile()->ParseBlocksRecursive(*this);
328    } else {
329      Host::SystemLog(Host::eSystemLogError,
330                      "error: unable to find module "
331                      "shared pointer for function '%s' "
332                      "in %s\n",
333                      GetName().GetCString(),
334                      m_comp_unit->GetPrimaryFile().GetPath().c_str());
335    }
336    m_block.SetBlockInfoHasBeenParsed(true, true);
337  }
338  return m_block;
339}
340
341CompileUnit *Function::GetCompileUnit() { return m_comp_unit; }
342
343const CompileUnit *Function::GetCompileUnit() const { return m_comp_unit; }
344
345void Function::GetDescription(Stream *s, lldb::DescriptionLevel level,
346                              Target *target) {
347  ConstString name = GetName();
348  ConstString mangled = m_mangled.GetMangledName();
349
350  *s << "id = " << (const UserID &)*this;
351  if (name)
352    *s << ", name = \"" << name.GetCString() << '"';
353  if (mangled)
354    *s << ", mangled = \"" << mangled.GetCString() << '"';
355  *s << ", range = ";
356  Address::DumpStyle fallback_style;
357  if (level == eDescriptionLevelVerbose)
358    fallback_style = Address::DumpStyleModuleWithFileAddress;
359  else
360    fallback_style = Address::DumpStyleFileAddress;
361  GetAddressRange().Dump(s, target, Address::DumpStyleLoadAddress,
362                         fallback_style);
363}
364
365void Function::Dump(Stream *s, bool show_context) const {
366  s->Printf("%p: ", static_cast<const void *>(this));
367  s->Indent();
368  *s << "Function" << static_cast<const UserID &>(*this);
369
370  m_mangled.Dump(s);
371
372  if (m_type)
373    s->Printf(", type = %p", static_cast<void *>(m_type));
374  else if (m_type_uid != LLDB_INVALID_UID)
375    s->Printf(", type_uid = 0x%8.8" PRIx64, m_type_uid);
376
377  s->EOL();
378  // Dump the root object
379  if (m_block.BlockInfoHasBeenParsed())
380    m_block.Dump(s, m_range.GetBaseAddress().GetFileAddress(), INT_MAX,
381                 show_context);
382}
383
384void Function::CalculateSymbolContext(SymbolContext *sc) {
385  sc->function = this;
386  m_comp_unit->CalculateSymbolContext(sc);
387}
388
389ModuleSP Function::CalculateSymbolContextModule() {
390  SectionSP section_sp(m_range.GetBaseAddress().GetSection());
391  if (section_sp)
392    return section_sp->GetModule();
393
394  return this->GetCompileUnit()->GetModule();
395}
396
397CompileUnit *Function::CalculateSymbolContextCompileUnit() {
398  return this->GetCompileUnit();
399}
400
401Function *Function::CalculateSymbolContextFunction() { return this; }
402
403lldb::DisassemblerSP Function::GetInstructions(const ExecutionContext &exe_ctx,
404                                               const char *flavor,
405                                               bool prefer_file_cache) {
406  ModuleSP module_sp(GetAddressRange().GetBaseAddress().GetModule());
407  if (module_sp) {
408    const bool prefer_file_cache = false;
409    return Disassembler::DisassembleRange(module_sp->GetArchitecture(), nullptr,
410                                          flavor, exe_ctx, GetAddressRange(),
411                                          prefer_file_cache);
412  }
413  return lldb::DisassemblerSP();
414}
415
416bool Function::GetDisassembly(const ExecutionContext &exe_ctx,
417                              const char *flavor, bool prefer_file_cache,
418                              Stream &strm) {
419  lldb::DisassemblerSP disassembler_sp =
420      GetInstructions(exe_ctx, flavor, prefer_file_cache);
421  if (disassembler_sp) {
422    const bool show_address = true;
423    const bool show_bytes = false;
424    disassembler_sp->GetInstructionList().Dump(&strm, show_address, show_bytes,
425                                               &exe_ctx);
426    return true;
427  }
428  return false;
429}
430
431// Symbol *
432// Function::CalculateSymbolContextSymbol ()
433//{
434//    return // TODO: find the symbol for the function???
435//}
436
437void Function::DumpSymbolContext(Stream *s) {
438  m_comp_unit->DumpSymbolContext(s);
439  s->Printf(", Function{0x%8.8" PRIx64 "}", GetID());
440}
441
442size_t Function::MemorySize() const {
443  size_t mem_size = sizeof(Function) + m_block.MemorySize();
444  return mem_size;
445}
446
447bool Function::GetIsOptimized() {
448  bool result = false;
449
450  // Currently optimization is only indicted by the vendor extension
451  // DW_AT_APPLE_optimized which is set on a compile unit level.
452  if (m_comp_unit) {
453    result = m_comp_unit->GetIsOptimized();
454  }
455  return result;
456}
457
458bool Function::IsTopLevelFunction() {
459  bool result = false;
460
461  if (Language *language = Language::FindPlugin(GetLanguage()))
462    result = language->IsTopLevelFunction(*this);
463
464  return result;
465}
466
467ConstString Function::GetDisplayName() const {
468  return m_mangled.GetDisplayDemangledName(GetLanguage());
469}
470
471CompilerDeclContext Function::GetDeclContext() {
472  ModuleSP module_sp = CalculateSymbolContextModule();
473
474  if (module_sp) {
475    if (SymbolFile *sym_file = module_sp->GetSymbolFile())
476      return sym_file->GetDeclContextForUID(GetID());
477  }
478  return CompilerDeclContext();
479}
480
481Type *Function::GetType() {
482  if (m_type == nullptr) {
483    SymbolContext sc;
484
485    CalculateSymbolContext(&sc);
486
487    if (!sc.module_sp)
488      return nullptr;
489
490    SymbolFile *sym_file = sc.module_sp->GetSymbolFile();
491
492    if (sym_file == nullptr)
493      return nullptr;
494
495    m_type = sym_file->ResolveTypeUID(m_type_uid);
496  }
497  return m_type;
498}
499
500const Type *Function::GetType() const { return m_type; }
501
502CompilerType Function::GetCompilerType() {
503  Type *function_type = GetType();
504  if (function_type)
505    return function_type->GetFullCompilerType();
506  return CompilerType();
507}
508
509uint32_t Function::GetPrologueByteSize() {
510  if (m_prologue_byte_size == 0 &&
511      m_flags.IsClear(flagsCalculatedPrologueSize)) {
512    m_flags.Set(flagsCalculatedPrologueSize);
513    LineTable *line_table = m_comp_unit->GetLineTable();
514    uint32_t prologue_end_line_idx = 0;
515
516    if (line_table) {
517      LineEntry first_line_entry;
518      uint32_t first_line_entry_idx = UINT32_MAX;
519      if (line_table->FindLineEntryByAddress(GetAddressRange().GetBaseAddress(),
520                                             first_line_entry,
521                                             &first_line_entry_idx)) {
522        // Make sure the first line entry isn't already the end of the prologue
523        addr_t prologue_end_file_addr = LLDB_INVALID_ADDRESS;
524        addr_t line_zero_end_file_addr = LLDB_INVALID_ADDRESS;
525
526        if (first_line_entry.is_prologue_end) {
527          prologue_end_file_addr =
528              first_line_entry.range.GetBaseAddress().GetFileAddress();
529          prologue_end_line_idx = first_line_entry_idx;
530        } else {
531          // Check the first few instructions and look for one that has
532          // is_prologue_end set to true.
533          const uint32_t last_line_entry_idx = first_line_entry_idx + 6;
534          for (uint32_t idx = first_line_entry_idx + 1;
535               idx < last_line_entry_idx; ++idx) {
536            LineEntry line_entry;
537            if (line_table->GetLineEntryAtIndex(idx, line_entry)) {
538              if (line_entry.is_prologue_end) {
539                prologue_end_file_addr =
540                    line_entry.range.GetBaseAddress().GetFileAddress();
541                prologue_end_line_idx = idx;
542                break;
543              }
544            }
545          }
546        }
547
548        // If we didn't find the end of the prologue in the line tables, then
549        // just use the end address of the first line table entry
550        if (prologue_end_file_addr == LLDB_INVALID_ADDRESS) {
551          // Check the first few instructions and look for one that has a line
552          // number that's different than the first entry.
553          uint32_t last_line_entry_idx = first_line_entry_idx + 6;
554          for (uint32_t idx = first_line_entry_idx + 1;
555               idx < last_line_entry_idx; ++idx) {
556            LineEntry line_entry;
557            if (line_table->GetLineEntryAtIndex(idx, line_entry)) {
558              if (line_entry.line != first_line_entry.line) {
559                prologue_end_file_addr =
560                    line_entry.range.GetBaseAddress().GetFileAddress();
561                prologue_end_line_idx = idx;
562                break;
563              }
564            }
565          }
566
567          if (prologue_end_file_addr == LLDB_INVALID_ADDRESS) {
568            prologue_end_file_addr =
569                first_line_entry.range.GetBaseAddress().GetFileAddress() +
570                first_line_entry.range.GetByteSize();
571            prologue_end_line_idx = first_line_entry_idx;
572          }
573        }
574
575        const addr_t func_start_file_addr =
576            m_range.GetBaseAddress().GetFileAddress();
577        const addr_t func_end_file_addr =
578            func_start_file_addr + m_range.GetByteSize();
579
580        // Now calculate the offset to pass the subsequent line 0 entries.
581        uint32_t first_non_zero_line = prologue_end_line_idx;
582        while (true) {
583          LineEntry line_entry;
584          if (line_table->GetLineEntryAtIndex(first_non_zero_line,
585                                              line_entry)) {
586            if (line_entry.line != 0)
587              break;
588          }
589          if (line_entry.range.GetBaseAddress().GetFileAddress() >=
590              func_end_file_addr)
591            break;
592
593          first_non_zero_line++;
594        }
595
596        if (first_non_zero_line > prologue_end_line_idx) {
597          LineEntry first_non_zero_entry;
598          if (line_table->GetLineEntryAtIndex(first_non_zero_line,
599                                              first_non_zero_entry)) {
600            line_zero_end_file_addr =
601                first_non_zero_entry.range.GetBaseAddress().GetFileAddress();
602          }
603        }
604
605        // Verify that this prologue end file address in the function's address
606        // range just to be sure
607        if (func_start_file_addr < prologue_end_file_addr &&
608            prologue_end_file_addr < func_end_file_addr) {
609          m_prologue_byte_size = prologue_end_file_addr - func_start_file_addr;
610        }
611
612        if (prologue_end_file_addr < line_zero_end_file_addr &&
613            line_zero_end_file_addr < func_end_file_addr) {
614          m_prologue_byte_size +=
615              line_zero_end_file_addr - prologue_end_file_addr;
616        }
617      }
618    }
619  }
620
621  return m_prologue_byte_size;
622}
623
624lldb::LanguageType Function::GetLanguage() const {
625  lldb::LanguageType lang = m_mangled.GuessLanguage();
626  if (lang != lldb::eLanguageTypeUnknown)
627    return lang;
628
629  if (m_comp_unit)
630    return m_comp_unit->GetLanguage();
631
632  return lldb::eLanguageTypeUnknown;
633}
634
635ConstString Function::GetName() const {
636  LanguageType language = lldb::eLanguageTypeUnknown;
637  if (m_comp_unit)
638    language = m_comp_unit->GetLanguage();
639  return m_mangled.GetName(language);
640}
641
642ConstString Function::GetNameNoArguments() const {
643  LanguageType language = lldb::eLanguageTypeUnknown;
644  if (m_comp_unit)
645    language = m_comp_unit->GetLanguage();
646  return m_mangled.GetName(language, Mangled::ePreferDemangledWithoutArguments);
647}
648