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/Language.h"
27#include "lldb/Target/Target.h"
28#include "lldb/Utility/LLDBLog.h"
29#include "lldb/Utility/Log.h"
30#include "lldb/Utility/Stream.h"
31#include "lldb/Utility/StreamString.h"
32#include <optional>
33
34using namespace lldb_private;
35using namespace lldb;
36
37// BreakpointResolver:
38const char *BreakpointResolver::g_ty_to_name[] = {"FileAndLine", "Address",
39 "SymbolName", "SourceRegex",
40 "Python", "Exception",
41 "Unknown"};
42
43const char *BreakpointResolver::g_option_names[static_cast<uint32_t>(
44 BreakpointResolver::OptionNames::LastOptionName)] = {
45 "AddressOffset", "Exact", "FileName", "Inlines", "Language",
46 "LineNumber", "Column", "ModuleName", "NameMask", "Offset",
47 "PythonClass", "Regex", "ScriptArgs", "SectionName", "SearchDepth",
48 "SkipPrologue", "SymbolNames"};
49
50const char *BreakpointResolver::ResolverTyToName(enum ResolverTy type) {
51 if (type > LastKnownResolverType)
52 return g_ty_to_name[UnknownResolver];
53
54 return g_ty_to_name[type];
55}
56
57BreakpointResolver::ResolverTy
58BreakpointResolver::NameToResolverTy(llvm::StringRef name) {
59 for (size_t i = 0; i < LastKnownResolverType; i++) {
60 if (name == g_ty_to_name[i])
61 return (ResolverTy)i;
62 }
63 return UnknownResolver;
64}
65
66BreakpointResolver::BreakpointResolver(const BreakpointSP &bkpt,
67 const unsigned char resolverTy,
68 lldb::addr_t offset)
69 : m_breakpoint(bkpt), m_offset(offset), SubclassID(resolverTy) {}
70
71BreakpointResolver::~BreakpointResolver() = default;
72
73BreakpointResolverSP BreakpointResolver::CreateFromStructuredData(
74 const StructuredData::Dictionary &resolver_dict, Status &error) {
75 BreakpointResolverSP result_sp;
76 if (!resolver_dict.IsValid()) {
77 error = Status::FromErrorString(
78 str: "Can't deserialize from an invalid data object.");
79 return result_sp;
80 }
81
82 llvm::StringRef subclass_name;
83
84 bool success = resolver_dict.GetValueForKeyAsString(
85 key: GetSerializationSubclassKey(), result&: subclass_name);
86
87 if (!success) {
88 error =
89 Status::FromErrorString(str: "Resolver data missing subclass resolver key");
90 return result_sp;
91 }
92
93 ResolverTy resolver_type = NameToResolverTy(name: subclass_name);
94 if (resolver_type == UnknownResolver) {
95 error = Status::FromErrorStringWithFormatv(format: "Unknown resolver type: {0}.",
96 args&: subclass_name);
97 return result_sp;
98 }
99
100 StructuredData::Dictionary *subclass_options = nullptr;
101 success = resolver_dict.GetValueForKeyAsDictionary(
102 key: GetSerializationSubclassOptionsKey(), result&: subclass_options);
103 if (!success || !subclass_options || !subclass_options->IsValid()) {
104 error =
105 Status::FromErrorString(str: "Resolver data missing subclass options key.");
106 return result_sp;
107 }
108
109 lldb::offset_t offset;
110 success = subclass_options->GetValueForKeyAsInteger(
111 key: GetKey(enum_value: OptionNames::Offset), result&: offset);
112 if (!success) {
113 error =
114 Status::FromErrorString(str: "Resolver data missing offset options key.");
115 return result_sp;
116 }
117
118 switch (resolver_type) {
119 case FileLineResolver:
120 result_sp = BreakpointResolverFileLine::CreateFromStructuredData(
121 data_dict: *subclass_options, error);
122 break;
123 case AddressResolver:
124 result_sp = BreakpointResolverAddress::CreateFromStructuredData(
125 options_dict: *subclass_options, error);
126 break;
127 case NameResolver:
128 result_sp = BreakpointResolverName::CreateFromStructuredData(
129 data_dict: *subclass_options, error);
130 break;
131 case FileRegexResolver:
132 result_sp = BreakpointResolverFileRegex::CreateFromStructuredData(
133 options_dict: *subclass_options, error);
134 break;
135 case PythonResolver:
136 result_sp = BreakpointResolverScripted::CreateFromStructuredData(
137 options_dict: *subclass_options, error);
138 break;
139 case ExceptionResolver:
140 error = Status::FromErrorString(str: "Exception resolvers are hard.");
141 break;
142 default:
143 llvm_unreachable("Should never get an unresolvable resolver type.");
144 }
145
146 if (error.Fail() || !result_sp)
147 return {};
148
149 // Add on the global offset option:
150 result_sp->SetOffset(offset);
151 return result_sp;
152}
153
154StructuredData::DictionarySP BreakpointResolver::WrapOptionsDict(
155 StructuredData::DictionarySP options_dict_sp) {
156 if (!options_dict_sp || !options_dict_sp->IsValid())
157 return StructuredData::DictionarySP();
158
159 StructuredData::DictionarySP type_dict_sp(new StructuredData::Dictionary());
160 type_dict_sp->AddStringItem(key: GetSerializationSubclassKey(), value: GetResolverName());
161 type_dict_sp->AddItem(key: GetSerializationSubclassOptionsKey(), value_sp: options_dict_sp);
162
163 // Add the m_offset to the dictionary:
164 options_dict_sp->AddIntegerItem(key: GetKey(enum_value: OptionNames::Offset), value: m_offset);
165
166 return type_dict_sp;
167}
168
169void BreakpointResolver::SetBreakpoint(const BreakpointSP &bkpt) {
170 assert(bkpt);
171 m_breakpoint = bkpt;
172 NotifyBreakpointSet();
173}
174
175void BreakpointResolver::ResolveBreakpointInModules(SearchFilter &filter,
176 ModuleList &modules) {
177 filter.SearchInModuleList(searcher&: *this, modules);
178}
179
180void BreakpointResolver::ResolveBreakpoint(SearchFilter &filter) {
181 filter.Search(searcher&: *this);
182}
183
184namespace {
185struct SourceLoc {
186 uint32_t line = UINT32_MAX;
187 uint16_t column;
188 SourceLoc(uint32_t l, std::optional<uint16_t> c)
189 : line(l), column(c ? *c : LLDB_INVALID_COLUMN_NUMBER) {}
190 SourceLoc(const SymbolContext &sc)
191 : line(sc.line_entry.line),
192 column(sc.line_entry.column ? sc.line_entry.column
193 : LLDB_INVALID_COLUMN_NUMBER) {}
194};
195
196bool operator<(const SourceLoc lhs, const SourceLoc rhs) {
197 if (lhs.line < rhs.line)
198 return true;
199 if (lhs.line > rhs.line)
200 return false;
201 // uint32_t a_col = lhs.column ? lhs.column : LLDB_INVALID_COLUMN_NUMBER;
202 // uint32_t b_col = rhs.column ? rhs.column : LLDB_INVALID_COLUMN_NUMBER;
203 return lhs.column < rhs.column;
204}
205} // namespace
206
207void BreakpointResolver::SetSCMatchesByLine(
208 SearchFilter &filter, SymbolContextList &sc_list, bool skip_prologue,
209 llvm::StringRef log_ident, uint32_t line, std::optional<uint16_t> column) {
210 llvm::SmallVector<SymbolContext, 16> all_scs(sc_list.begin(), sc_list.end());
211
212 // Let the language plugin filter `sc_list`. Because all symbol contexts in
213 // sc_list are assumed to belong to the same File, Line and CU, the code below
214 // assumes they have the same language.
215 if (!sc_list.IsEmpty() && Language::GetGlobalLanguageProperties()
216 .GetEnableFilterForLineBreakpoints())
217 if (Language *lang = Language::FindPlugin(language: sc_list[0].GetLanguage()))
218 lang->FilterForLineBreakpoints(all_scs);
219
220 while (all_scs.size()) {
221 uint32_t closest_line = UINT32_MAX;
222
223 // Move all the elements with a matching file spec to the end.
224 auto &match = all_scs[0];
225 auto worklist_begin = std::partition(
226 first: all_scs.begin(), last: all_scs.end(), pred: [&](const SymbolContext &sc) {
227 if (sc.line_entry.GetFile() == match.line_entry.GetFile() ||
228 sc.line_entry.original_file_sp->Equal(
229 other: *match.line_entry.original_file_sp,
230 equality: SupportFile::eEqualFileSpecAndChecksumIfSet)) {
231 // When a match is found, keep track of the smallest line number.
232 closest_line = std::min(a: closest_line, b: sc.line_entry.line);
233 return false;
234 }
235 return true;
236 });
237
238 // (worklist_begin, worklist_end) now contains all entries for one filespec.
239 auto worklist_end = all_scs.end();
240
241 if (column) {
242 // If a column was requested, do a more precise match and only
243 // return the first location that comes before or at the
244 // requested location.
245 SourceLoc requested(line, *column);
246 // First, filter out all entries left of the requested column.
247 worklist_end = std::remove_if(
248 first: worklist_begin, last: worklist_end,
249 pred: [&](const SymbolContext &sc) { return requested < SourceLoc(sc); });
250 // Sort the remaining entries by (line, column).
251 llvm::sort(Start: worklist_begin, End: worklist_end,
252 Comp: [](const SymbolContext &a, const SymbolContext &b) {
253 return SourceLoc(a) < SourceLoc(b);
254 });
255
256 // Filter out all locations with a source location after the closest match.
257 if (worklist_begin != worklist_end)
258 worklist_end = std::remove_if(
259 first: worklist_begin, last: worklist_end, pred: [&](const SymbolContext &sc) {
260 return SourceLoc(*worklist_begin) < SourceLoc(sc);
261 });
262 } else {
263 // Remove all entries with a larger line number.
264 // ResolveSymbolContext will always return a number that is >=
265 // the line number you pass in. So the smaller line number is
266 // always better.
267 worklist_end = std::remove_if(first: worklist_begin, last: worklist_end,
268 pred: [&](const SymbolContext &sc) {
269 return closest_line != sc.line_entry.line;
270 });
271 }
272
273 // Sort by file address.
274 llvm::sort(Start: worklist_begin, End: worklist_end,
275 Comp: [](const SymbolContext &a, const SymbolContext &b) {
276 return a.line_entry.range.GetBaseAddress().GetFileAddress() <
277 b.line_entry.range.GetBaseAddress().GetFileAddress();
278 });
279
280 // Go through and see if there are line table entries that are
281 // contiguous, and if so keep only the first of the contiguous range.
282 // We do this by picking the first location in each lexical block.
283 llvm::SmallDenseSet<Block *, 8> blocks_with_breakpoints;
284 for (auto first = worklist_begin; first != worklist_end; ++first) {
285 assert(!blocks_with_breakpoints.count(first->block));
286 blocks_with_breakpoints.insert(V: first->block);
287 worklist_end =
288 std::remove_if(first: std::next(x: first), last: worklist_end,
289 pred: [&](const SymbolContext &sc) {
290 return blocks_with_breakpoints.count(V: sc.block);
291 });
292 }
293
294 // Make breakpoints out of the closest line number match.
295 for (auto &sc : llvm::make_range(x: worklist_begin, y: worklist_end))
296 AddLocation(filter, sc, skip_prologue, log_ident);
297
298 // Remove all contexts processed by this iteration.
299 all_scs.erase(CS: worklist_begin, CE: all_scs.end());
300 }
301}
302
303void BreakpointResolver::AddLocation(SearchFilter &filter,
304 const SymbolContext &sc,
305 bool skip_prologue,
306 llvm::StringRef log_ident) {
307 Log *log = GetLog(mask: LLDBLog::Breakpoints);
308 Address line_start = sc.line_entry.range.GetBaseAddress();
309 if (!line_start.IsValid()) {
310 LLDB_LOGF(log,
311 "error: Unable to set breakpoint %s at file address "
312 "0x%" PRIx64 "\n",
313 log_ident.str().c_str(), line_start.GetFileAddress());
314 return;
315 }
316
317 if (!filter.AddressPasses(addr&: line_start)) {
318 LLDB_LOGF(log,
319 "Breakpoint %s at file address 0x%" PRIx64
320 " didn't pass the filter.\n",
321 log_ident.str().c_str(), line_start.GetFileAddress());
322 }
323
324 // If the line number is before the prologue end, move it there...
325 bool skipped_prologue = false;
326 if (skip_prologue && sc.function) {
327 Address prologue_addr = sc.function->GetAddress();
328 if (prologue_addr.IsValid() && (line_start == prologue_addr)) {
329 const uint32_t prologue_byte_size = sc.function->GetPrologueByteSize();
330 if (prologue_byte_size) {
331 prologue_addr.Slide(offset: prologue_byte_size);
332
333 if (filter.AddressPasses(addr&: prologue_addr)) {
334 skipped_prologue = true;
335 line_start = prologue_addr;
336 }
337 }
338 }
339 }
340
341 BreakpointLocationSP bp_loc_sp(AddLocation(loc_addr: line_start));
342 // If the address that we resolved the location to returns a different
343 // LineEntry from the one in the incoming SC, we're probably dealing with an
344 // inlined call site, so set that as the preferred LineEntry:
345 LineEntry resolved_entry;
346 if (!skipped_prologue && bp_loc_sp &&
347 line_start.CalculateSymbolContextLineEntry(line_entry&: resolved_entry) &&
348 LineEntry::Compare(lhs: resolved_entry, rhs: sc.line_entry)) {
349 // FIXME: The function name will also be wrong here. Do we need to record
350 // that as well, or can we figure that out again when we report this
351 // breakpoint location.
352 if (!bp_loc_sp->SetPreferredLineEntry(sc.line_entry)) {
353 LLDB_LOG(log, "Tried to add a preferred line entry that didn't have the "
354 "same address as this location's address.");
355 }
356 }
357 if (log && bp_loc_sp && !GetBreakpoint()->IsInternal()) {
358 StreamString s;
359 bp_loc_sp->GetDescription(s: &s, level: lldb::eDescriptionLevelVerbose);
360 LLDB_LOGF(log, "Added location (skipped prologue: %s): %s \n",
361 skipped_prologue ? "yes" : "no", s.GetData());
362 }
363}
364
365BreakpointLocationSP BreakpointResolver::AddLocation(Address loc_addr,
366 bool *new_location) {
367 loc_addr.Slide(offset: m_offset);
368 return GetBreakpoint()->AddLocation(addr: loc_addr, new_location);
369}
370
371void BreakpointResolver::SetOffset(lldb::addr_t offset) {
372 // There may already be an offset, so we are actually adjusting location
373 // addresses by the difference.
374 // lldb::addr_t slide = offset - m_offset;
375 // FIXME: We should go fix up all the already set locations for the new
376 // slide.
377
378 m_offset = offset;
379}
380

source code of lldb/source/Breakpoint/BreakpointResolver.cpp