1//===-- BreakpointResolver.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/BreakpointResolver.h"
10
11#include "lldb/Breakpoint/Breakpoint.h"
12#include "lldb/Breakpoint/BreakpointLocation.h"
13// Have to include the other breakpoint resolver types here so the static
14// create from StructuredData can call them.
15#include "lldb/Breakpoint/BreakpointResolverAddress.h"
16#include "lldb/Breakpoint/BreakpointResolverFileLine.h"
17#include "lldb/Breakpoint/BreakpointResolverFileRegex.h"
18#include "lldb/Breakpoint/BreakpointResolverName.h"
19#include "lldb/Breakpoint/BreakpointResolverScripted.h"
20#include "lldb/Core/Address.h"
21#include "lldb/Core/ModuleList.h"
22#include "lldb/Core/SearchFilter.h"
23#include "lldb/Symbol/CompileUnit.h"
24#include "lldb/Symbol/Function.h"
25#include "lldb/Symbol/SymbolContext.h"
26#include "lldb/Target/Target.h"
27#include "lldb/Utility/LLDBLog.h"
28#include "lldb/Utility/Log.h"
29#include "lldb/Utility/Stream.h"
30#include "lldb/Utility/StreamString.h"
31#include <optional>
32
33using namespace lldb_private;
34using namespace lldb;
35
36// BreakpointResolver:
37const char *BreakpointResolver::g_ty_to_name[] = {"FileAndLine", "Address",
38                                                  "SymbolName",  "SourceRegex",
39                                                  "Python",   "Exception",
40                                                  "Unknown"};
41
42const char *BreakpointResolver::g_option_names[static_cast<uint32_t>(
43    BreakpointResolver::OptionNames::LastOptionName)] = {
44    "AddressOffset", "Exact",     "FileName",     "Inlines",     "Language",
45    "LineNumber",    "Column",    "ModuleName",   "NameMask",    "Offset",
46    "PythonClass",   "Regex",     "ScriptArgs",   "SectionName", "SearchDepth",
47    "SkipPrologue",  "SymbolNames"};
48
49const char *BreakpointResolver::ResolverTyToName(enum ResolverTy type) {
50  if (type > LastKnownResolverType)
51    return g_ty_to_name[UnknownResolver];
52
53  return g_ty_to_name[type];
54}
55
56BreakpointResolver::ResolverTy
57BreakpointResolver::NameToResolverTy(llvm::StringRef name) {
58  for (size_t i = 0; i < LastKnownResolverType; i++) {
59    if (name == g_ty_to_name[i])
60      return (ResolverTy)i;
61  }
62  return UnknownResolver;
63}
64
65BreakpointResolver::BreakpointResolver(const BreakpointSP &bkpt,
66                                       const unsigned char resolverTy,
67                                       lldb::addr_t offset)
68    : m_breakpoint(bkpt), m_offset(offset), SubclassID(resolverTy) {}
69
70BreakpointResolver::~BreakpointResolver() = default;
71
72BreakpointResolverSP BreakpointResolver::CreateFromStructuredData(
73    const StructuredData::Dictionary &resolver_dict, Status &error) {
74  BreakpointResolverSP result_sp;
75  if (!resolver_dict.IsValid()) {
76    error.SetErrorString("Can't deserialize from an invalid data object.");
77    return result_sp;
78  }
79
80  llvm::StringRef subclass_name;
81
82  bool success = resolver_dict.GetValueForKeyAsString(
83      GetSerializationSubclassKey(), subclass_name);
84
85  if (!success) {
86    error.SetErrorString("Resolver data missing subclass resolver key");
87    return result_sp;
88  }
89
90  ResolverTy resolver_type = NameToResolverTy(subclass_name);
91  if (resolver_type == UnknownResolver) {
92    error.SetErrorStringWithFormatv("Unknown resolver type: {0}.",
93                                    subclass_name);
94    return result_sp;
95  }
96
97  StructuredData::Dictionary *subclass_options = nullptr;
98  success = resolver_dict.GetValueForKeyAsDictionary(
99      GetSerializationSubclassOptionsKey(), subclass_options);
100  if (!success || !subclass_options || !subclass_options->IsValid()) {
101    error.SetErrorString("Resolver data missing subclass options key.");
102    return result_sp;
103  }
104
105  lldb::offset_t offset;
106  success = subclass_options->GetValueForKeyAsInteger(
107      GetKey(OptionNames::Offset), offset);
108  if (!success) {
109    error.SetErrorString("Resolver data missing offset options key.");
110    return result_sp;
111  }
112
113  switch (resolver_type) {
114  case FileLineResolver:
115    result_sp = BreakpointResolverFileLine::CreateFromStructuredData(
116        *subclass_options, error);
117    break;
118  case AddressResolver:
119    result_sp = BreakpointResolverAddress::CreateFromStructuredData(
120        *subclass_options, error);
121    break;
122  case NameResolver:
123    result_sp = BreakpointResolverName::CreateFromStructuredData(
124        *subclass_options, error);
125    break;
126  case FileRegexResolver:
127    result_sp = BreakpointResolverFileRegex::CreateFromStructuredData(
128        *subclass_options, error);
129    break;
130  case PythonResolver:
131    result_sp = BreakpointResolverScripted::CreateFromStructuredData(
132        *subclass_options, error);
133    break;
134  case ExceptionResolver:
135    error.SetErrorString("Exception resolvers are hard.");
136    break;
137  default:
138    llvm_unreachable("Should never get an unresolvable resolver type.");
139  }
140
141  if (error.Fail() || !result_sp)
142    return {};
143
144  // Add on the global offset option:
145  result_sp->SetOffset(offset);
146  return result_sp;
147}
148
149StructuredData::DictionarySP BreakpointResolver::WrapOptionsDict(
150    StructuredData::DictionarySP options_dict_sp) {
151  if (!options_dict_sp || !options_dict_sp->IsValid())
152    return StructuredData::DictionarySP();
153
154  StructuredData::DictionarySP type_dict_sp(new StructuredData::Dictionary());
155  type_dict_sp->AddStringItem(GetSerializationSubclassKey(), GetResolverName());
156  type_dict_sp->AddItem(GetSerializationSubclassOptionsKey(), options_dict_sp);
157
158  // Add the m_offset to the dictionary:
159  options_dict_sp->AddIntegerItem(GetKey(OptionNames::Offset), m_offset);
160
161  return type_dict_sp;
162}
163
164void BreakpointResolver::SetBreakpoint(const BreakpointSP &bkpt) {
165  assert(bkpt);
166  m_breakpoint = bkpt;
167  NotifyBreakpointSet();
168}
169
170void BreakpointResolver::ResolveBreakpointInModules(SearchFilter &filter,
171                                                    ModuleList &modules) {
172  filter.SearchInModuleList(*this, modules);
173}
174
175void BreakpointResolver::ResolveBreakpoint(SearchFilter &filter) {
176  filter.Search(*this);
177}
178
179namespace {
180struct SourceLoc {
181  uint32_t line = UINT32_MAX;
182  uint16_t column;
183  SourceLoc(uint32_t l, std::optional<uint16_t> c)
184      : line(l), column(c ? *c : LLDB_INVALID_COLUMN_NUMBER) {}
185  SourceLoc(const SymbolContext &sc)
186      : line(sc.line_entry.line),
187        column(sc.line_entry.column ? sc.line_entry.column
188                                    : LLDB_INVALID_COLUMN_NUMBER) {}
189};
190
191bool operator<(const SourceLoc lhs, const SourceLoc rhs) {
192  if (lhs.line < rhs.line)
193    return true;
194  if (lhs.line > rhs.line)
195    return false;
196  //  uint32_t a_col = lhs.column ? lhs.column : LLDB_INVALID_COLUMN_NUMBER;
197  //  uint32_t b_col = rhs.column ? rhs.column : LLDB_INVALID_COLUMN_NUMBER;
198  return lhs.column < rhs.column;
199}
200} // namespace
201
202void BreakpointResolver::SetSCMatchesByLine(
203    SearchFilter &filter, SymbolContextList &sc_list, bool skip_prologue,
204    llvm::StringRef log_ident, uint32_t line, std::optional<uint16_t> column) {
205  llvm::SmallVector<SymbolContext, 16> all_scs;
206  for (uint32_t i = 0; i < sc_list.GetSize(); ++i)
207    all_scs.push_back(sc_list[i]);
208
209  while (all_scs.size()) {
210    uint32_t closest_line = UINT32_MAX;
211
212    // Move all the elements with a matching file spec to the end.
213    auto &match = all_scs[0];
214    auto worklist_begin = std::partition(
215        all_scs.begin(), all_scs.end(), [&](const SymbolContext &sc) {
216          if (sc.line_entry.file == match.line_entry.file ||
217              *sc.line_entry.original_file_sp ==
218                  *match.line_entry.original_file_sp) {
219            // When a match is found, keep track of the smallest line number.
220            closest_line = std::min(closest_line, sc.line_entry.line);
221            return false;
222          }
223          return true;
224        });
225
226    // (worklist_begin, worklist_end) now contains all entries for one filespec.
227    auto worklist_end = all_scs.end();
228
229    if (column) {
230      // If a column was requested, do a more precise match and only
231      // return the first location that comes before or at the
232      // requested location.
233      SourceLoc requested(line, *column);
234      // First, filter out all entries left of the requested column.
235      worklist_end = std::remove_if(
236          worklist_begin, worklist_end,
237          [&](const SymbolContext &sc) { return requested < SourceLoc(sc); });
238      // Sort the remaining entries by (line, column).
239      llvm::sort(worklist_begin, worklist_end,
240                 [](const SymbolContext &a, const SymbolContext &b) {
241                   return SourceLoc(a) < SourceLoc(b);
242                 });
243
244      // Filter out all locations with a source location after the closest match.
245      if (worklist_begin != worklist_end)
246        worklist_end = std::remove_if(
247            worklist_begin, worklist_end, [&](const SymbolContext &sc) {
248              return SourceLoc(*worklist_begin) < SourceLoc(sc);
249            });
250    } else {
251      // Remove all entries with a larger line number.
252      // ResolveSymbolContext will always return a number that is >=
253      // the line number you pass in. So the smaller line number is
254      // always better.
255      worklist_end = std::remove_if(worklist_begin, worklist_end,
256                                    [&](const SymbolContext &sc) {
257                                      return closest_line != sc.line_entry.line;
258                                    });
259    }
260
261    // Sort by file address.
262    llvm::sort(worklist_begin, worklist_end,
263               [](const SymbolContext &a, const SymbolContext &b) {
264                 return a.line_entry.range.GetBaseAddress().GetFileAddress() <
265                        b.line_entry.range.GetBaseAddress().GetFileAddress();
266               });
267
268    // Go through and see if there are line table entries that are
269    // contiguous, and if so keep only the first of the contiguous range.
270    // We do this by picking the first location in each lexical block.
271    llvm::SmallDenseSet<Block *, 8> blocks_with_breakpoints;
272    for (auto first = worklist_begin; first != worklist_end; ++first) {
273      assert(!blocks_with_breakpoints.count(first->block));
274      blocks_with_breakpoints.insert(first->block);
275      worklist_end =
276          std::remove_if(std::next(first), worklist_end,
277                         [&](const SymbolContext &sc) {
278                           return blocks_with_breakpoints.count(sc.block);
279                         });
280    }
281
282    // Make breakpoints out of the closest line number match.
283    for (auto &sc : llvm::make_range(worklist_begin, worklist_end))
284      AddLocation(filter, sc, skip_prologue, log_ident);
285
286    // Remove all contexts processed by this iteration.
287    all_scs.erase(worklist_begin, all_scs.end());
288  }
289}
290
291void BreakpointResolver::AddLocation(SearchFilter &filter,
292                                     const SymbolContext &sc,
293                                     bool skip_prologue,
294                                     llvm::StringRef log_ident) {
295  Log *log = GetLog(LLDBLog::Breakpoints);
296  Address line_start = sc.line_entry.range.GetBaseAddress();
297  if (!line_start.IsValid()) {
298    LLDB_LOGF(log,
299              "error: Unable to set breakpoint %s at file address "
300              "0x%" PRIx64 "\n",
301              log_ident.str().c_str(), line_start.GetFileAddress());
302    return;
303  }
304
305  if (!filter.AddressPasses(line_start)) {
306    LLDB_LOGF(log,
307              "Breakpoint %s at file address 0x%" PRIx64
308              " didn't pass the filter.\n",
309              log_ident.str().c_str(), line_start.GetFileAddress());
310  }
311
312  // If the line number is before the prologue end, move it there...
313  bool skipped_prologue = false;
314  if (skip_prologue && sc.function) {
315    Address prologue_addr(sc.function->GetAddressRange().GetBaseAddress());
316    if (prologue_addr.IsValid() && (line_start == prologue_addr)) {
317      const uint32_t prologue_byte_size = sc.function->GetPrologueByteSize();
318      if (prologue_byte_size) {
319        prologue_addr.Slide(prologue_byte_size);
320
321        if (filter.AddressPasses(prologue_addr)) {
322          skipped_prologue = true;
323          line_start = prologue_addr;
324        }
325      }
326    }
327  }
328
329  BreakpointLocationSP bp_loc_sp(AddLocation(line_start));
330  if (log && bp_loc_sp && !GetBreakpoint()->IsInternal()) {
331    StreamString s;
332    bp_loc_sp->GetDescription(&s, lldb::eDescriptionLevelVerbose);
333    LLDB_LOGF(log, "Added location (skipped prologue: %s): %s \n",
334              skipped_prologue ? "yes" : "no", s.GetData());
335  }
336}
337
338BreakpointLocationSP BreakpointResolver::AddLocation(Address loc_addr,
339                                                     bool *new_location) {
340  loc_addr.Slide(m_offset);
341  return GetBreakpoint()->AddLocation(loc_addr, new_location);
342}
343
344void BreakpointResolver::SetOffset(lldb::addr_t offset) {
345  // There may already be an offset, so we are actually adjusting location
346  // addresses by the difference.
347  // lldb::addr_t slide = offset - m_offset;
348  // FIXME: We should go fix up all the already set locations for the new
349  // slide.
350
351  m_offset = offset;
352}
353