1 //===-- PathMappingList.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 <climits>
10 #include <cstring>
11 
12 #include "lldb/Host/FileSystem.h"
13 #include "lldb/Host/PosixApi.h"
14 #include "lldb/Target/PathMappingList.h"
15 #include "lldb/Utility/FileSpec.h"
16 #include "lldb/Utility/Status.h"
17 #include "lldb/Utility/Stream.h"
18 #include "lldb/lldb-private-enumerations.h"
19 
20 using namespace lldb;
21 using namespace lldb_private;
22 
23 namespace {
24   // We must normalize our path pairs that we store because if we don't then
25   // things won't always work. We found a case where if we did:
26   // (lldb) settings set target.source-map . /tmp
27   // We would store a path pairs of "." and "/tmp" as raw strings. If the debug
28   // info contains "./foo/bar.c", the path will get normalized to "foo/bar.c".
29   // When PathMappingList::RemapPath() is called, it expects the path to start
30   // with the raw path pair, which doesn't work anymore because the paths have
31   // been normalized when the debug info was loaded. So we need to store
32   // nomalized path pairs to ensure things match up.
33   ConstString NormalizePath(ConstString path) {
34     // If we use "path" to construct a FileSpec, it will normalize the path for
35     // us. We then grab the string and turn it back into a ConstString.
36     return ConstString(FileSpec(path.GetStringRef()).GetPath());
37   }
38 }
39 // PathMappingList constructor
40 PathMappingList::PathMappingList() : m_pairs() {}
41 
42 PathMappingList::PathMappingList(ChangedCallback callback, void *callback_baton)
43     : m_pairs(), m_callback(callback), m_callback_baton(callback_baton),
44       m_mod_id(0) {}
45 
46 PathMappingList::PathMappingList(const PathMappingList &rhs)
47     : m_pairs(rhs.m_pairs), m_callback(nullptr), m_callback_baton(nullptr),
48       m_mod_id(0) {}
49 
50 const PathMappingList &PathMappingList::operator=(const PathMappingList &rhs) {
51   if (this != &rhs) {
52     m_pairs = rhs.m_pairs;
53     m_callback = nullptr;
54     m_callback_baton = nullptr;
55     m_mod_id = rhs.m_mod_id;
56   }
57   return *this;
58 }
59 
60 PathMappingList::~PathMappingList() = default;
61 
62 void PathMappingList::Append(ConstString path,
63                              ConstString replacement, bool notify) {
64   ++m_mod_id;
65   m_pairs.emplace_back(pair(NormalizePath(path), NormalizePath(replacement)));
66   if (notify && m_callback)
67     m_callback(*this, m_callback_baton);
68 }
69 
70 void PathMappingList::Append(const PathMappingList &rhs, bool notify) {
71   ++m_mod_id;
72   if (!rhs.m_pairs.empty()) {
73     const_iterator pos, end = rhs.m_pairs.end();
74     for (pos = rhs.m_pairs.begin(); pos != end; ++pos)
75       m_pairs.push_back(*pos);
76     if (notify && m_callback)
77       m_callback(*this, m_callback_baton);
78   }
79 }
80 
81 void PathMappingList::Insert(ConstString path,
82                              ConstString replacement, uint32_t index,
83                              bool notify) {
84   ++m_mod_id;
85   iterator insert_iter;
86   if (index >= m_pairs.size())
87     insert_iter = m_pairs.end();
88   else
89     insert_iter = m_pairs.begin() + index;
90   m_pairs.emplace(insert_iter, pair(NormalizePath(path),
91                                     NormalizePath(replacement)));
92   if (notify && m_callback)
93     m_callback(*this, m_callback_baton);
94 }
95 
96 bool PathMappingList::Replace(ConstString path,
97                               ConstString replacement, uint32_t index,
98                               bool notify) {
99   if (index >= m_pairs.size())
100     return false;
101   ++m_mod_id;
102   m_pairs[index] = pair(NormalizePath(path), NormalizePath(replacement));
103   if (notify && m_callback)
104     m_callback(*this, m_callback_baton);
105   return true;
106 }
107 
108 bool PathMappingList::Remove(size_t index, bool notify) {
109   if (index >= m_pairs.size())
110     return false;
111 
112   ++m_mod_id;
113   iterator iter = m_pairs.begin() + index;
114   m_pairs.erase(iter);
115   if (notify && m_callback)
116     m_callback(*this, m_callback_baton);
117   return true;
118 }
119 
120 // For clients which do not need the pair index dumped, pass a pair_index >= 0
121 // to only dump the indicated pair.
122 void PathMappingList::Dump(Stream *s, int pair_index) {
123   unsigned int numPairs = m_pairs.size();
124 
125   if (pair_index < 0) {
126     unsigned int index;
127     for (index = 0; index < numPairs; ++index)
128       s->Printf("[%d] \"%s\" -> \"%s\"\n", index,
129                 m_pairs[index].first.GetCString(),
130                 m_pairs[index].second.GetCString());
131   } else {
132     if (static_cast<unsigned int>(pair_index) < numPairs)
133       s->Printf("%s -> %s", m_pairs[pair_index].first.GetCString(),
134                 m_pairs[pair_index].second.GetCString());
135   }
136 }
137 
138 void PathMappingList::Clear(bool notify) {
139   if (!m_pairs.empty())
140     ++m_mod_id;
141   m_pairs.clear();
142   if (notify && m_callback)
143     m_callback(*this, m_callback_baton);
144 }
145 
146 bool PathMappingList::RemapPath(ConstString path,
147                                 ConstString &new_path) const {
148   if (llvm::Optional<FileSpec> remapped = RemapPath(path.GetStringRef())) {
149     new_path.SetString(remapped->GetPath());
150     return true;
151   }
152   return false;
153 }
154 
155 /// Append components to path, applying style.
156 static void AppendPathComponents(FileSpec &path, llvm::StringRef components,
157                                  llvm::sys::path::Style style) {
158     auto component = llvm::sys::path::begin(components, style);
159     auto e = llvm::sys::path::end(components);
160     while (component != e &&
161         llvm::sys::path::is_separator(*component->data(), style))
162       ++component;
163     for (; component != e; ++component)
164       path.AppendPathComponent(*component);
165 }
166 
167 llvm::Optional<FileSpec>
168 PathMappingList::RemapPath(llvm::StringRef mapping_path,
169                            bool only_if_exists) const {
170   if (m_pairs.empty() || mapping_path.empty())
171     return {};
172   LazyBool path_is_relative = eLazyBoolCalculate;
173 
174   for (const auto &it : m_pairs) {
175     llvm::StringRef prefix = it.first.GetStringRef();
176     // We create a copy of mapping_path because StringRef::consume_from
177     // effectively modifies the instance itself.
178     llvm::StringRef path = mapping_path;
179     if (!path.consume_front(prefix)) {
180       // Relative paths won't have a leading "./" in them unless "." is the
181       // only thing in the relative path so we need to work around "."
182       // carefully.
183       if (prefix != ".")
184         continue;
185       // We need to figure out if the "path" argument is relative. If it is,
186       // then we should remap, else skip this entry.
187       if (path_is_relative == eLazyBoolCalculate) {
188         path_is_relative =
189             FileSpec(path).IsRelative() ? eLazyBoolYes : eLazyBoolNo;
190       }
191       if (!path_is_relative)
192         continue;
193     }
194     FileSpec remapped(it.second.GetStringRef());
195     auto orig_style = FileSpec::GuessPathStyle(prefix).getValueOr(
196         llvm::sys::path::Style::native);
197     AppendPathComponents(remapped, path, orig_style);
198     if (!only_if_exists || FileSystem::Instance().Exists(remapped))
199       return remapped;
200   }
201   return {};
202 }
203 
204 bool PathMappingList::ReverseRemapPath(const FileSpec &file, FileSpec &fixed) const {
205   std::string path = file.GetPath();
206   llvm::StringRef path_ref(path);
207   for (const auto &it : m_pairs) {
208     if (!path_ref.consume_front(it.second.GetStringRef()))
209       continue;
210     auto orig_file = it.first.GetStringRef();
211     auto orig_style = FileSpec::GuessPathStyle(orig_file).getValueOr(
212         llvm::sys::path::Style::native);
213     fixed.SetFile(orig_file, orig_style);
214     AppendPathComponents(fixed, path_ref, orig_style);
215     return true;
216   }
217   return false;
218 }
219 
220 llvm::Optional<FileSpec> PathMappingList::FindFile(const FileSpec &orig_spec) const {
221   // We must normalize the orig_spec again using the host's path style,
222   // otherwise there will be mismatch between the host and remote platform
223   // if they use different path styles.
224   if (auto remapped = RemapPath(
225           NormalizePath(ConstString(orig_spec.GetCString())).GetStringRef(),
226           /*only_if_exists=*/true))
227     return remapped;
228 
229   return {};
230 }
231 
232 bool PathMappingList::Replace(ConstString path,
233                               ConstString new_path, bool notify) {
234   uint32_t idx = FindIndexForPath(path);
235   if (idx < m_pairs.size()) {
236     ++m_mod_id;
237     m_pairs[idx].second = new_path;
238     if (notify && m_callback)
239       m_callback(*this, m_callback_baton);
240     return true;
241   }
242   return false;
243 }
244 
245 bool PathMappingList::Remove(ConstString path, bool notify) {
246   iterator pos = FindIteratorForPath(path);
247   if (pos != m_pairs.end()) {
248     ++m_mod_id;
249     m_pairs.erase(pos);
250     if (notify && m_callback)
251       m_callback(*this, m_callback_baton);
252     return true;
253   }
254   return false;
255 }
256 
257 PathMappingList::const_iterator
258 PathMappingList::FindIteratorForPath(ConstString path) const {
259   const_iterator pos;
260   const_iterator begin = m_pairs.begin();
261   const_iterator end = m_pairs.end();
262 
263   for (pos = begin; pos != end; ++pos) {
264     if (pos->first == path)
265       break;
266   }
267   return pos;
268 }
269 
270 PathMappingList::iterator
271 PathMappingList::FindIteratorForPath(ConstString path) {
272   iterator pos;
273   iterator begin = m_pairs.begin();
274   iterator end = m_pairs.end();
275 
276   for (pos = begin; pos != end; ++pos) {
277     if (pos->first == path)
278       break;
279   }
280   return pos;
281 }
282 
283 bool PathMappingList::GetPathsAtIndex(uint32_t idx, ConstString &path,
284                                       ConstString &new_path) const {
285   if (idx < m_pairs.size()) {
286     path = m_pairs[idx].first;
287     new_path = m_pairs[idx].second;
288     return true;
289   }
290   return false;
291 }
292 
293 uint32_t PathMappingList::FindIndexForPath(ConstString orig_path) const {
294   const ConstString path = NormalizePath(orig_path);
295   const_iterator pos;
296   const_iterator begin = m_pairs.begin();
297   const_iterator end = m_pairs.end();
298 
299   for (pos = begin; pos != end; ++pos) {
300     if (pos->first == path)
301       return std::distance(begin, pos);
302   }
303   return UINT32_MAX;
304 }
305