lldb/source/Breakpoint/BreakpointResolverFileLine.cpp

   1 //===-- BreakpointResolverFileLine.cpp ------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "lldb/Breakpoint/BreakpointResolverFileLine.h"
  10
  11 #include "lldb/Breakpoint/BreakpointLocation.h"
  12 #include "lldb/Core/Module.h"
  13 #include "lldb/Symbol/CompileUnit.h"
  14 #include "lldb/Symbol/Function.h"
  15 #include "lldb/Target/Target.h"
  16 #include "lldb/Utility/LLDBLog.h"
  17 #include "lldb/Utility/Log.h"
  18 #include "lldb/Utility/StreamString.h"
  19 #include <optional>
  20
  21 using namespace lldb;
  22 using namespace lldb_private;
  23
  24 // BreakpointResolverFileLine:
  25 BreakpointResolverFileLine::BreakpointResolverFileLine(
  26     const BreakpointSP &bkpt, lldb::addr_t offset, bool skip_prologue,
  27     const SourceLocationSpec &location_spec,
  28     std::optional<llvm::StringRef> removed_prefix_opt)
  29     : BreakpointResolver(bkpt, BreakpointResolver::FileLineResolver, offset),
  30       m_location_spec(location_spec), m_skip_prologue(skip_prologue),
  31       m_removed_prefix_opt(removed_prefix_opt) {}
  32
  33 BreakpointResolver *BreakpointResolverFileLine::CreateFromStructuredData(
  34     const BreakpointSP &bkpt, const StructuredData::Dictionary &options_dict,
  35     Status &error) {
  36   llvm::StringRef filename;
  37   uint32_t line;
  38   uint16_t column;
  39   bool check_inlines;
  40   bool skip_prologue;
  41   bool exact_match;
  42   bool success;
  43
  44   lldb::addr_t offset = 0;
  45
  46   success = options_dict.GetValueForKeyAsString(GetKey(OptionNames::FileName),
  47                                                 filename);
  48   if (!success) {
  49     error.SetErrorString("BRFL::CFSD: Couldn't find filename entry.");
  50     return nullptr;
  51   }
  52
  53   success = options_dict.GetValueForKeyAsInteger(
  54       GetKey(OptionNames::LineNumber), line);
  55   if (!success) {
  56     error.SetErrorString("BRFL::CFSD: Couldn't find line number entry.");
  57     return nullptr;
  58   }
  59
  60   success =
  61       options_dict.GetValueForKeyAsInteger(GetKey(OptionNames::Column), column);
  62   if (!success) {
  63     // Backwards compatibility.
  64     column = 0;
  65   }
  66
  67   success = options_dict.GetValueForKeyAsBoolean(GetKey(OptionNames::Inlines),
  68                                                  check_inlines);
  69   if (!success) {
  70     error.SetErrorString("BRFL::CFSD: Couldn't find check inlines entry.");
  71     return nullptr;
  72   }
  73
  74   success = options_dict.GetValueForKeyAsBoolean(
  75       GetKey(OptionNames::SkipPrologue), skip_prologue);
  76   if (!success) {
  77     error.SetErrorString("BRFL::CFSD: Couldn't find skip prologue entry.");
  78     return nullptr;
  79   }
  80
  81   success = options_dict.GetValueForKeyAsBoolean(
  82       GetKey(OptionNames::ExactMatch), exact_match);
  83   if (!success) {
  84     error.SetErrorString("BRFL::CFSD: Couldn't find exact match entry.");
  85     return nullptr;
  86   }
  87
  88   SourceLocationSpec location_spec(FileSpec(filename), line, column,
  89                                    check_inlines, exact_match);
  90   if (!location_spec)
  91     return nullptr;
  92
  93   return new BreakpointResolverFileLine(bkpt, offset, skip_prologue,
  94                                         location_spec);
  95 }
  96
  97 StructuredData::ObjectSP
  98 BreakpointResolverFileLine::SerializeToStructuredData() {
  99   StructuredData::DictionarySP options_dict_sp(
 100       new StructuredData::Dictionary());
 101
 102   options_dict_sp->AddBooleanItem(GetKey(OptionNames::SkipPrologue),
 103                                   m_skip_prologue);
 104   options_dict_sp->AddStringItem(GetKey(OptionNames::FileName),
 105                                  m_location_spec.GetFileSpec().GetPath());
 106   options_dict_sp->AddIntegerItem(GetKey(OptionNames::LineNumber),
 107                                   m_location_spec.GetLine().value_or(0));
 108   options_dict_sp->AddIntegerItem(
 109       GetKey(OptionNames::Column),
 110       m_location_spec.GetColumn().value_or(LLDB_INVALID_COLUMN_NUMBER));
 111   options_dict_sp->AddBooleanItem(GetKey(OptionNames::Inlines),
 112                                   m_location_spec.GetCheckInlines());
 113   options_dict_sp->AddBooleanItem(GetKey(OptionNames::ExactMatch),
 114                                   m_location_spec.GetExactMatch());
 115
 116   return WrapOptionsDict(options_dict_sp);
 117 }
 118
 119 // Filter the symbol context list to remove contexts where the line number was
 120 // moved into a new function. We do this conservatively, so if e.g. we cannot
 121 // resolve the function in the context (which can happen in case of line-table-
 122 // only debug info), we leave the context as is. The trickiest part here is
 123 // handling inlined functions -- in this case we need to make sure we look at
 124 // the declaration line of the inlined function, NOT the function it was
 125 // inlined into.
 126 void BreakpointResolverFileLine::FilterContexts(SymbolContextList &sc_list) {
 127   if (m_location_spec.GetExactMatch())
 128     return; // Nothing to do. Contexts are precise.
 129
 130   Log *log = GetLog(LLDBLog::Breakpoints);
 131   for(uint32_t i = 0; i < sc_list.GetSize(); ++i) {
 132     SymbolContext sc;
 133     sc_list.GetContextAtIndex(i, sc);
 134     if (!sc.block)
 135       continue;
 136
 137     FileSpec file;
 138     uint32_t line;
 139     const Block *inline_block = sc.block->GetContainingInlinedBlock();
 140     if (inline_block) {
 141       const Declaration &inline_declaration = inline_block->GetInlinedFunctionInfo()->GetDeclaration();
 142       if (!inline_declaration.IsValid())
 143         continue;
 144       file = inline_declaration.GetFile();
 145       line = inline_declaration.GetLine();
 146     } else if (sc.function)
 147       sc.function->GetStartLineSourceInfo(file, line);
 148     else
 149       continue;
 150
 151     if (file != sc.line_entry.file) {
 152       LLDB_LOG(log, "unexpected symbol context file {0}", sc.line_entry.file);
 153       continue;
 154     }
 155
 156     // Compare the requested line number with the line of the function
 157     // declaration. In case of a function declared as:
 158     //
 159     // int
 160     // foo()
 161     // {
 162     //   ...
 163     //
 164     // the compiler will set the declaration line to the "foo" line, which is
 165     // the reason why we have -1 here. This can fail in case of two inline
 166     // functions defined back-to-back:
 167     //
 168     // inline int foo1() { ... }
 169     // inline int foo2() { ... }
 170     //
 171     // but that's the best we can do for now.
 172     // One complication, if the line number returned from GetStartLineSourceInfo
 173     // is 0, then we can't do this calculation.  That can happen if
 174     // GetStartLineSourceInfo gets an error, or if the first line number in
 175     // the function really is 0 - which happens for some languages.
 176
 177     // But only do this calculation if the line number we found in the SC
 178     // was different from the one requested in the source file.  If we actually
 179     // found an exact match it must be valid.
 180
 181     if (m_location_spec.GetLine() == sc.line_entry.line)
 182       continue;
 183
 184     const int decl_line_is_too_late_fudge = 1;
 185     if (line &&
 186         m_location_spec.GetLine() < line - decl_line_is_too_late_fudge) {
 187       LLDB_LOG(log, "removing symbol context at {0}:{1}", file, line);
 188       sc_list.RemoveContextAtIndex(i);
 189       --i;
 190     }
 191   }
 192 }
 193
 194 void BreakpointResolverFileLine::DeduceSourceMapping(
 195     const SymbolContextList &sc_list) {
 196   Target &target = GetBreakpoint()->GetTarget();
 197   if (!target.GetAutoSourceMapRelative())
 198     return;
 199
 200   Log *log = GetLog(LLDBLog::Breakpoints);
 201   const llvm::StringRef path_separator = llvm::sys::path::get_separator(
 202       m_location_spec.GetFileSpec().GetPathStyle());
 203   // Check if "b" is a suffix of "a".
 204   // And return std::nullopt if not or the new path
 205   // of "a" after consuming "b" from the back.
 206   auto check_suffix =
 207       [path_separator](llvm::StringRef a, llvm::StringRef b,
 208                        bool case_sensitive) -> std::optional<llvm::StringRef> {
 209     if (case_sensitive ? a.consume_back(b) : a.consume_back_insensitive(b)) {
 210       if (a.empty() || a.endswith(path_separator)) {
 211         return a;
 212       }
 213     }
 214     return std::nullopt;
 215   };
 216
 217   FileSpec request_file = m_location_spec.GetFileSpec();
 218
 219   // Only auto deduce source map if breakpoint is full path.
 220   // Note: an existing source map reverse mapping (m_removed_prefix_opt has
 221   // value) may make request_file relative.
 222   if (!m_removed_prefix_opt.has_value() && request_file.IsRelative())
 223     return;
 224
 225   const bool case_sensitive = request_file.IsCaseSensitive();
 226   for (const SymbolContext &sc : sc_list) {
 227     FileSpec sc_file = sc.line_entry.file;
 228
 229     if (FileSpec::Equal(sc_file, request_file, /*full*/ true))
 230       continue;
 231
 232     llvm::StringRef sc_file_dir = sc_file.GetDirectory().GetStringRef();
 233     llvm::StringRef request_file_dir =
 234         request_file.GetDirectory().GetStringRef();
 235
 236     llvm::StringRef new_mapping_from;
 237     llvm::SmallString<256> new_mapping_to;
 238
 239     // Adding back any potentially reverse mapping stripped prefix.
 240     // for new_mapping_to.
 241     if (m_removed_prefix_opt.has_value())
 242       llvm::sys::path::append(new_mapping_to, *m_removed_prefix_opt);
 243
 244     std::optional<llvm::StringRef> new_mapping_from_opt =
 245         check_suffix(sc_file_dir, request_file_dir, case_sensitive);
 246     if (new_mapping_from_opt) {
 247       new_mapping_from = *new_mapping_from_opt;
 248       if (new_mapping_to.empty())
 249         new_mapping_to = ".";
 250     } else {
 251       std::optional<llvm::StringRef> new_mapping_to_opt =
 252           check_suffix(request_file_dir, sc_file_dir, case_sensitive);
 253       if (new_mapping_to_opt) {
 254         new_mapping_from = ".";
 255         llvm::sys::path::append(new_mapping_to, *new_mapping_to_opt);
 256       }
 257     }
 258
 259     if (!new_mapping_from.empty() && !new_mapping_to.empty()) {
 260       LLDB_LOG(log, "generating auto source map from {0} to {1}",
 261                new_mapping_from, new_mapping_to);
 262       if (target.GetSourcePathMap().AppendUnique(new_mapping_from,
 263                                                  new_mapping_to,
 264                                                  /*notify*/ true))
 265         target.GetStatistics().IncreaseSourceMapDeduceCount();
 266     }
 267   }
 268 }
 269
 270 Searcher::CallbackReturn BreakpointResolverFileLine::SearchCallback(
 271     SearchFilter &filter, SymbolContext &context, Address *addr) {
 272   SymbolContextList sc_list;
 273
 274   // There is a tricky bit here.  You can have two compilation units that
 275   // #include the same file, and in one of them the function at m_line_number
 276   // is used (and so code and a line entry for it is generated) but in the
 277   // other it isn't.  If we considered the CU's independently, then in the
 278   // second inclusion, we'd move the breakpoint to the next function that
 279   // actually generated code in the header file.  That would end up being
 280   // confusing.  So instead, we do the CU iterations by hand here, then scan
 281   // through the complete list of matches, and figure out the closest line
 282   // number match, and only set breakpoints on that match.
 283
 284   // Note also that if file_spec only had a file name and not a directory,
 285   // there may be many different file spec's in the resultant list.  The
 286   // closest line match for one will not be right for some totally different
 287   // file.  So we go through the match list and pull out the sets that have the
 288   // same file spec in their line_entry and treat each set separately.
 289
 290   const uint32_t line = m_location_spec.GetLine().value_or(0);
 291   const std::optional<uint16_t> column = m_location_spec.GetColumn();
 292
 293   const size_t num_comp_units = context.module_sp->GetNumCompileUnits();
 294   for (size_t i = 0; i < num_comp_units; i++) {
 295     CompUnitSP cu_sp(context.module_sp->GetCompileUnitAtIndex(i));
 296     if (cu_sp) {
 297       if (filter.CompUnitPasses(*cu_sp))
 298         cu_sp->ResolveSymbolContext(m_location_spec, eSymbolContextEverything,
 299                                     sc_list);
 300     }
 301   }
 302
 303   FilterContexts(sc_list);
 304
 305   DeduceSourceMapping(sc_list);
 306
 307   StreamString s;
 308   s.Printf("for %s:%d ",
 309            m_location_spec.GetFileSpec().GetFilename().AsCString("<Unknown>"),
 310            line);
 311
 312   SetSCMatchesByLine(filter, sc_list, m_skip_prologue, s.GetString(), line,
 313                      column);
 314
 315   return Searcher::eCallbackReturnContinue;
 316 }
 317
 318 lldb::SearchDepth BreakpointResolverFileLine::GetDepth() {
 319   return lldb::eSearchDepthModule;
 320 }
 321
 322 void BreakpointResolverFileLine::GetDescription(Stream *s) {
 323   s->Printf("file = '%s', line = %u, ",
 324             m_location_spec.GetFileSpec().GetPath().c_str(),
 325             m_location_spec.GetLine().value_or(0));
 326   auto column = m_location_spec.GetColumn();
 327   if (column)
 328     s->Printf("column = %u, ", *column);
 329   s->Printf("exact_match = %d", m_location_spec.GetExactMatch());
 330 }
 331
 332 void BreakpointResolverFileLine::Dump(Stream *s) const {}
 333
 334 lldb::BreakpointResolverSP
 335 BreakpointResolverFileLine::CopyForBreakpoint(BreakpointSP &breakpoint) {
 336   lldb::BreakpointResolverSP ret_sp(new BreakpointResolverFileLine(
 337       breakpoint, GetOffset(), m_skip_prologue, m_location_spec));
 338
 339   return ret_sp;
 340 }