1//===-- SourceBreakpoint.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 "SourceBreakpoint.h"
10#include "BreakpointBase.h"
11#include "DAP.h"
12#include "JSONUtils.h"
13#include "lldb/API/SBBreakpoint.h"
14#include "lldb/API/SBFileSpecList.h"
15#include "lldb/API/SBFrame.h"
16#include "lldb/API/SBInstruction.h"
17#include "lldb/API/SBMutex.h"
18#include "lldb/API/SBSymbol.h"
19#include "lldb/API/SBTarget.h"
20#include "lldb/API/SBThread.h"
21#include "lldb/API/SBValue.h"
22#include "lldb/lldb-enumerations.h"
23#include "llvm/Support/Error.h"
24#include <cassert>
25#include <cctype>
26#include <cstdlib>
27#include <mutex>
28#include <utility>
29
30namespace lldb_dap {
31
32SourceBreakpoint::SourceBreakpoint(DAP &dap,
33 const protocol::SourceBreakpoint &breakpoint)
34 : Breakpoint(dap, breakpoint.condition, breakpoint.hitCondition),
35 m_log_message(breakpoint.logMessage.value_or(u: "")),
36 m_line(breakpoint.line),
37 m_column(breakpoint.column.value_or(LLDB_INVALID_COLUMN_NUMBER)) {}
38
39llvm::Error SourceBreakpoint::SetBreakpoint(const protocol::Source &source) {
40 lldb::SBMutex lock = m_dap.GetAPIMutex();
41 std::lock_guard<lldb::SBMutex> guard(lock);
42
43 if (m_line == 0)
44 return llvm::createStringError(EC: llvm::inconvertibleErrorCode(),
45 S: "Invalid line number.");
46
47 if (source.sourceReference) {
48 // Breakpoint set by assembly source.
49 lldb::SBAddress source_address(*source.sourceReference, m_dap.target);
50 if (!source_address.IsValid())
51 return llvm::createStringError(EC: llvm::inconvertibleErrorCode(),
52 S: "Invalid sourceReference.");
53
54 lldb::SBSymbol symbol = source_address.GetSymbol();
55 if (!symbol.IsValid()) {
56 // FIXME: Support assembly breakpoints without a valid symbol.
57 return llvm::createStringError(EC: llvm::inconvertibleErrorCode(),
58 S: "Breakpoints in assembly without a valid "
59 "symbol are not supported yet.");
60 }
61
62 lldb::SBInstructionList inst_list =
63 m_dap.target.ReadInstructions(base_addr: symbol.GetStartAddress(), count: m_line);
64 if (inst_list.GetSize() < m_line)
65 return llvm::createStringError(EC: llvm::inconvertibleErrorCode(),
66 S: "Invalid instruction list size.");
67
68 lldb::SBAddress address =
69 inst_list.GetInstructionAtIndex(idx: m_line - 1).GetAddress();
70
71 m_bp = m_dap.target.BreakpointCreateBySBAddress(address);
72 } else {
73 // Breakpoint set by a regular source file.
74 const auto source_path = source.path.value_or(u: "");
75 lldb::SBFileSpecList module_list;
76 m_bp = m_dap.target.BreakpointCreateByLocation(file_spec: source_path.c_str(), line: m_line,
77 column: m_column, offset: 0, module_list);
78 }
79
80 if (!m_log_message.empty())
81 SetLogMessage();
82 Breakpoint::SetBreakpoint();
83 return llvm::Error::success();
84}
85
86void SourceBreakpoint::UpdateBreakpoint(const SourceBreakpoint &request_bp) {
87 if (m_log_message != request_bp.m_log_message) {
88 m_log_message = request_bp.m_log_message;
89 SetLogMessage();
90 }
91 BreakpointBase::UpdateBreakpoint(request_bp);
92}
93
94lldb::SBError SourceBreakpoint::AppendLogMessagePart(llvm::StringRef part,
95 bool is_expr) {
96 if (is_expr) {
97 m_log_message_parts.emplace_back(args&: part, args&: is_expr);
98 } else {
99 std::string formatted;
100 lldb::SBError error = FormatLogText(text: part, formatted);
101 if (error.Fail())
102 return error;
103 m_log_message_parts.emplace_back(args&: formatted, args&: is_expr);
104 }
105 return lldb::SBError();
106}
107
108// TODO: consolidate this code with the implementation in
109// FormatEntity::ParseInternal().
110lldb::SBError SourceBreakpoint::FormatLogText(llvm::StringRef text,
111 std::string &formatted) {
112 lldb::SBError error;
113 while (!text.empty()) {
114 size_t backslash_pos = text.find_first_of(C: '\\');
115 if (backslash_pos == std::string::npos) {
116 formatted += text.str();
117 return error;
118 }
119
120 formatted += text.substr(Start: 0, N: backslash_pos).str();
121 // Skip the characters before and including '\'.
122 text = text.drop_front(N: backslash_pos + 1);
123
124 if (text.empty()) {
125 error.SetErrorString(
126 "'\\' character was not followed by another character");
127 return error;
128 }
129
130 const char desens_char = text[0];
131 text = text.drop_front(); // Skip the desensitized char character
132 switch (desens_char) {
133 case 'a':
134 formatted.push_back(c: '\a');
135 break;
136 case 'b':
137 formatted.push_back(c: '\b');
138 break;
139 case 'f':
140 formatted.push_back(c: '\f');
141 break;
142 case 'n':
143 formatted.push_back(c: '\n');
144 break;
145 case 'r':
146 formatted.push_back(c: '\r');
147 break;
148 case 't':
149 formatted.push_back(c: '\t');
150 break;
151 case 'v':
152 formatted.push_back(c: '\v');
153 break;
154 case '\'':
155 formatted.push_back(c: '\'');
156 break;
157 case '\\':
158 formatted.push_back(c: '\\');
159 break;
160 case '0':
161 // 1 to 3 octal chars
162 {
163 if (text.empty()) {
164 error.SetErrorString("missing octal number following '\\0'");
165 return error;
166 }
167
168 // Make a string that can hold onto the initial zero char, up to 3
169 // octal digits, and a terminating NULL.
170 char oct_str[5] = {0, 0, 0, 0, 0};
171
172 size_t i;
173 for (i = 0;
174 i < text.size() && i < 4 && (text[i] >= '0' && text[i] <= '7');
175 ++i) {
176 oct_str[i] = text[i];
177 }
178
179 text = text.drop_front(N: i);
180 unsigned long octal_value = ::strtoul(nptr: oct_str, endptr: nullptr, base: 8);
181 if (octal_value <= UINT8_MAX) {
182 formatted.push_back(c: (char)octal_value);
183 } else {
184 error.SetErrorString("octal number is larger than a single byte");
185 return error;
186 }
187 }
188 break;
189
190 case 'x': {
191 if (text.empty()) {
192 error.SetErrorString("missing hex number following '\\x'");
193 return error;
194 }
195 // hex number in the text
196 if (std::isxdigit(text[0])) {
197 // Make a string that can hold onto two hex chars plus a
198 // NULL terminator
199 char hex_str[3] = {0, 0, 0};
200 hex_str[0] = text[0];
201
202 text = text.drop_front();
203
204 if (!text.empty() && std::isxdigit(text[0])) {
205 hex_str[1] = text[0];
206 text = text.drop_front();
207 }
208
209 unsigned long hex_value = strtoul(nptr: hex_str, endptr: nullptr, base: 16);
210 if (hex_value <= UINT8_MAX) {
211 formatted.push_back(c: (char)hex_value);
212 } else {
213 error.SetErrorString("hex number is larger than a single byte");
214 return error;
215 }
216 } else {
217 formatted.push_back(c: desens_char);
218 }
219 break;
220 }
221
222 default:
223 // Just desensitize any other character by just printing what came
224 // after the '\'
225 formatted.push_back(c: desens_char);
226 break;
227 }
228 }
229 return error;
230}
231
232// logMessage will be divided into array of LogMessagePart as two kinds:
233// 1. raw print text message, and
234// 2. interpolated expression for evaluation which is inside matching curly
235// braces.
236//
237// The function tries to parse logMessage into a list of LogMessageParts
238// for easy later access in BreakpointHitCallback.
239void SourceBreakpoint::SetLogMessage() {
240 m_log_message_parts.clear();
241
242 // Contains unmatched open curly braces indices.
243 std::vector<int> unmatched_curly_braces;
244
245 // Contains all matched curly braces in logMessage.
246 // Loop invariant: matched_curly_braces_ranges are sorted by start index in
247 // ascending order without any overlap between them.
248 std::vector<std::pair<int, int>> matched_curly_braces_ranges;
249
250 lldb::SBError error;
251 // Part1 - parse matched_curly_braces_ranges.
252 // locating all curly braced expression ranges in logMessage.
253 // The algorithm takes care of nested and imbalanced curly braces.
254 for (size_t i = 0; i < m_log_message.size(); ++i) {
255 if (m_log_message[i] == '{') {
256 unmatched_curly_braces.push_back(x: i);
257 } else if (m_log_message[i] == '}') {
258 if (unmatched_curly_braces.empty())
259 // Nothing to match.
260 continue;
261
262 int last_unmatched_index = unmatched_curly_braces.back();
263 unmatched_curly_braces.pop_back();
264
265 // Erase any matched ranges included in the new match.
266 while (!matched_curly_braces_ranges.empty()) {
267 assert(matched_curly_braces_ranges.back().first !=
268 last_unmatched_index &&
269 "How can a curley brace be matched twice?");
270 if (matched_curly_braces_ranges.back().first < last_unmatched_index)
271 break;
272
273 // This is a nested range let's earse it.
274 assert((size_t)matched_curly_braces_ranges.back().second < i);
275 matched_curly_braces_ranges.pop_back();
276 }
277
278 // Assert invariant.
279 assert(matched_curly_braces_ranges.empty() ||
280 matched_curly_braces_ranges.back().first < last_unmatched_index);
281 matched_curly_braces_ranges.emplace_back(args&: last_unmatched_index, args&: i);
282 }
283 }
284
285 // Part2 - parse raw text and expresions parts.
286 // All expression ranges have been parsed in matched_curly_braces_ranges.
287 // The code below uses matched_curly_braces_ranges to divide logMessage
288 // into raw text parts and expression parts.
289 int last_raw_text_start = 0;
290 for (const std::pair<int, int> &curly_braces_range :
291 matched_curly_braces_ranges) {
292 // Raw text before open curly brace.
293 assert(curly_braces_range.first >= last_raw_text_start);
294 size_t raw_text_len = curly_braces_range.first - last_raw_text_start;
295 if (raw_text_len > 0) {
296 error = AppendLogMessagePart(
297 part: llvm::StringRef(m_log_message.c_str() + last_raw_text_start,
298 raw_text_len),
299 /*is_expr=*/false);
300 if (error.Fail()) {
301 NotifyLogMessageError(error: error.GetCString());
302 return;
303 }
304 }
305
306 // Expression between curly braces.
307 assert(curly_braces_range.second > curly_braces_range.first);
308 size_t expr_len = curly_braces_range.second - curly_braces_range.first - 1;
309 error = AppendLogMessagePart(
310 part: llvm::StringRef(m_log_message.c_str() + curly_braces_range.first + 1,
311 expr_len),
312 /*is_expr=*/true);
313 if (error.Fail()) {
314 NotifyLogMessageError(error: error.GetCString());
315 return;
316 }
317
318 last_raw_text_start = curly_braces_range.second + 1;
319 }
320 // Trailing raw text after close curly brace.
321 assert(last_raw_text_start >= 0);
322 if (m_log_message.size() > (size_t)last_raw_text_start) {
323 error = AppendLogMessagePart(
324 part: llvm::StringRef(m_log_message.c_str() + last_raw_text_start,
325 m_log_message.size() - last_raw_text_start),
326 /*is_expr=*/false);
327 if (error.Fail()) {
328 NotifyLogMessageError(error: error.GetCString());
329 return;
330 }
331 }
332
333 m_bp.SetCallback(callback: BreakpointHitCallback, baton: this);
334}
335
336void SourceBreakpoint::NotifyLogMessageError(llvm::StringRef error) {
337 std::string message = "Log message has error: ";
338 message += error;
339 m_dap.SendOutput(o: OutputType::Console, output: message);
340}
341
342/*static*/
343bool SourceBreakpoint::BreakpointHitCallback(
344 void *baton, lldb::SBProcess &process, lldb::SBThread &thread,
345 lldb::SBBreakpointLocation &location) {
346 if (!baton)
347 return true;
348
349 SourceBreakpoint *bp = (SourceBreakpoint *)baton;
350 lldb::SBFrame frame = thread.GetSelectedFrame();
351
352 std::string output;
353 for (const SourceBreakpoint::LogMessagePart &messagePart :
354 bp->m_log_message_parts) {
355 if (messagePart.is_expr) {
356 // Try local frame variables first before fall back to expression
357 // evaluation
358 const std::string &expr_str = messagePart.text;
359 const char *expr = expr_str.c_str();
360 lldb::SBValue value =
361 frame.GetValueForVariablePath(var_expr_cstr: expr, use_dynamic: lldb::eDynamicDontRunTarget);
362 if (value.GetError().Fail())
363 value = frame.EvaluateExpression(expr);
364 output += VariableDescription(
365 value, bp->m_dap.configuration.enableAutoVariableSummaries)
366 .display_value;
367 } else {
368 output += messagePart.text;
369 }
370 }
371 if (!output.empty() && output.back() != '\n')
372 output.push_back(c: '\n'); // Ensure log message has line break.
373 bp->m_dap.SendOutput(o: OutputType::Console, output: output.c_str());
374
375 // Do not stop.
376 return false;
377}
378
379} // namespace lldb_dap
380

source code of lldb/tools/lldb-dap/SourceBreakpoint.cpp