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 path) const {
169   if (m_pairs.empty() || path.empty())
170     return {};
171   LazyBool path_is_relative = eLazyBoolCalculate;
172   for (const auto &it : m_pairs) {
173     auto prefix = it.first.GetStringRef();
174     if (!path.consume_front(prefix)) {
175       // Relative paths won't have a leading "./" in them unless "." is the
176       // only thing in the relative path so we need to work around "."
177       // carefully.
178       if (prefix != ".")
179         continue;
180       // We need to figure out if the "path" argument is relative. If it is,
181       // then we should remap, else skip this entry.
182       if (path_is_relative == eLazyBoolCalculate) {
183         path_is_relative =
184             FileSpec(path).IsRelative() ? eLazyBoolYes : eLazyBoolNo;
185       }
186       if (!path_is_relative)
187         continue;
188     }
189     FileSpec remapped(it.second.GetStringRef());
190     auto orig_style = FileSpec::GuessPathStyle(prefix).getValueOr(
191         llvm::sys::path::Style::native);
192     AppendPathComponents(remapped, path, orig_style);
193     return remapped;
194   }
195   return {};
196 }
197 
198 bool PathMappingList::ReverseRemapPath(const FileSpec &file, FileSpec &fixed) const {
199   std::string path = file.GetPath();
200   llvm::StringRef path_ref(path);
201   for (const auto &it : m_pairs) {
202     if (!path_ref.consume_front(it.second.GetStringRef()))
203       continue;
204     auto orig_file = it.first.GetStringRef();
205     auto orig_style = FileSpec::GuessPathStyle(orig_file).getValueOr(
206         llvm::sys::path::Style::native);
207     fixed.SetFile(orig_file, orig_style);
208     AppendPathComponents(fixed, path_ref, orig_style);
209     return true;
210   }
211   return false;
212 }
213 
214 
215 llvm::Optional<FileSpec> PathMappingList::FindFile(const FileSpec &orig_spec) const {
216   if (auto remapped = RemapPath(orig_spec.GetPath()))
217     if (FileSystem::Instance().Exists(*remapped))
218       return remapped;
219 
220   return {};
221 }
222 
223 bool PathMappingList::Replace(ConstString path,
224                               ConstString new_path, bool notify) {
225   uint32_t idx = FindIndexForPath(path);
226   if (idx < m_pairs.size()) {
227     ++m_mod_id;
228     m_pairs[idx].second = new_path;
229     if (notify && m_callback)
230       m_callback(*this, m_callback_baton);
231     return true;
232   }
233   return false;
234 }
235 
236 bool PathMappingList::Remove(ConstString path, bool notify) {
237   iterator pos = FindIteratorForPath(path);
238   if (pos != m_pairs.end()) {
239     ++m_mod_id;
240     m_pairs.erase(pos);
241     if (notify && m_callback)
242       m_callback(*this, m_callback_baton);
243     return true;
244   }
245   return false;
246 }
247 
248 PathMappingList::const_iterator
249 PathMappingList::FindIteratorForPath(ConstString path) const {
250   const_iterator pos;
251   const_iterator begin = m_pairs.begin();
252   const_iterator end = m_pairs.end();
253 
254   for (pos = begin; pos != end; ++pos) {
255     if (pos->first == path)
256       break;
257   }
258   return pos;
259 }
260 
261 PathMappingList::iterator
262 PathMappingList::FindIteratorForPath(ConstString path) {
263   iterator pos;
264   iterator begin = m_pairs.begin();
265   iterator end = m_pairs.end();
266 
267   for (pos = begin; pos != end; ++pos) {
268     if (pos->first == path)
269       break;
270   }
271   return pos;
272 }
273 
274 bool PathMappingList::GetPathsAtIndex(uint32_t idx, ConstString &path,
275                                       ConstString &new_path) const {
276   if (idx < m_pairs.size()) {
277     path = m_pairs[idx].first;
278     new_path = m_pairs[idx].second;
279     return true;
280   }
281   return false;
282 }
283 
284 uint32_t PathMappingList::FindIndexForPath(ConstString orig_path) const {
285   const ConstString path = NormalizePath(orig_path);
286   const_iterator pos;
287   const_iterator begin = m_pairs.begin();
288   const_iterator end = m_pairs.end();
289 
290   for (pos = begin; pos != end; ++pos) {
291     if (pos->first == path)
292       return std::distance(begin, pos);
293   }
294   return UINT32_MAX;
295 }
296