Support workspaces as symlinks and symlinks within a workspace

Fix #639

Author: MaskRay

src/clang_tu.cc

@@ -17,15 +17,21 @@
 #include <llvm/Support/Path.h>
 
 using namespace clang;
+using namespace llvm;
 
 namespace ccls {
 std::string pathFromFileEntry(const FileEntry &file) {
-  StringRef name = file.tryGetRealPathName();
-  if (name.empty())
-    name = file.getName();
-  std::string ret = normalizePath(name);
-  // Resolve symlinks outside of workspace folders, e.g. /usr/include/c++/7.3.0
-  return normalizeFolder(ret) ? ret : realPath(ret);
+  // If getName() refers to a file within a workspace folder, we prefer it
+  // (which may be a symlink).
+  std::string ret = normalizePath(file.getName());
+  if (normalizeFolder(ret))
+    return ret;
+  // Resolve symlinks outside of working folders. This handles leading path
+  // components, e.g. (/lib -> /usr/lib) in
+  // /../lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/utility
+  ret = realPath(ret);
+  normalizeFolder(ret);
+  return ret;
 }
 
 bool isInsideMainFile(const SourceManager &sm, SourceLocation sl) {

src/messages/initialize.cc

@@ -348,17 +348,16 @@ void do_initialize(MessageHandler *m, InitializeParam &param,
     std::string path = wf.uri.getPath();
     ensureEndsInSlash(path);
     std::string real = realPath(path) + '/';
-    workspaceFolders.emplace_back(path, path == real ? "" : real);
+    workspaceFolders.emplace_back(path, real);
   }
   if (workspaceFolders.empty()) {
     std::string real = realPath(project_path) + '/';
-    workspaceFolders.emplace_back(project_path,
-                                  project_path == real ? "" : real);
+    workspaceFolders.emplace_back(project_path, real);
   }
   std::sort(workspaceFolders.begin(), workspaceFolders.end(),
             [](auto &l, auto &r) { return l.first.size() > r.first.size(); });
   for (auto &[folder, real] : workspaceFolders)
-    if (real.empty())
+    if (real == folder)
       LOG_S(INFO) << "workspace folder: " << folder;
     else
       LOG_S(INFO) << "workspace folder: " << folder << " -> " << real;

src/project.cc

@@ -433,7 +433,9 @@ void Project::loadDirectory(const std::string &root, Project::Folder &folder) {
       // If workspace folder is real/ but entries use symlink/, convert to
       // real/.
       entry.directory = realPath(cmd.Directory);
+      entry.directory.push_back('/');
       normalizeFolder(entry.directory);
+      entry.directory.pop_back();
       doPathMapping(entry.directory);
       entry.filename =
           realPath(resolveIfRelative(entry.directory, cmd.Filename));

src/utils.cc

@@ -138,11 +138,15 @@ std::string realPath(const std::string &path) {
 }
 
 bool normalizeFolder(std::string &path) {
-  for (auto &[root, real] : g_config->workspaceFolders)
-    if (real.size() && llvm::StringRef(path).startswith(real)) {
+  for (auto &[root, real] : g_config->workspaceFolders) {
+    StringRef p(path);
+    if (p.startswith(root))
+      return true;
+    if (p.startswith(real)) {
       path = root + path.substr(real.size());
       return true;
     }
+  }
   return false;
 }