Fix Clang resource directory lookup for Fedora with LLVM 17+

src/compile_commands.cpp

@@ -83,15 +83,9 @@ std::vector<std::string> CompileCommands::get_arguments(const boost::filesystem:
     }
   }
 
-  static std::string resource_path = []() -> std::string {
+  static auto find_resource_path = [](const boost::filesystem::path &base_path, std::string version) -> std::string {
-    // Try based on clang_getClangVersion first, even though its format is not guaranteed to be stable.
-    auto clang_version = clangmm::to_string(clang_getClangVersion());
-    std::regex clang_version_regex("([0-9]+\\.[0-9]+\\.[0-9]+)");
-    std::smatch sm;
-    if(std::regex_search(clang_version, sm, clang_version_regex)) {
-      auto version = sm[1].str();
     while(!version.empty() && version.front() != '.' && version.back() != '.') {
-        auto path = boost::filesystem::path(LIBCLANG_LIBRARY_DIR) / "clang" / version;
+      auto path = base_path / "clang" / version;
       boost::system::error_code ec;
       if(boost::filesystem::is_directory(path / "include", ec))
         return path.string();
@@ -100,6 +94,24 @@ std::vector<std::string> CompileCommands::get_arguments(const boost::filesystem:
         break;
       version.erase(pos);
     }
+    return "";
+  };
+
+  static std::string resource_path = []() -> std::string {
+    // Try based on clang_getClangVersion first, even though its format is not guaranteed to be stable.
+    auto clang_version = clangmm::to_string(clang_getClangVersion());
+    std::regex clang_version_regex("([0-9]+\\.[0-9]+\\.[0-9]+)");
+    std::smatch sm;
+    if(std::regex_search(clang_version, sm, clang_version_regex)) {
+      auto version = sm[1].str();
+      auto path = find_resource_path(boost::filesystem::path(LIBCLANG_LIBRARY_DIR), version);
+      if(path.empty()) {
+        // For e.g. Fedora the LibClang is located in /usr/lib64/libclang.so while the resource dir is in /usr/lib/clang/<version>
+        path = find_resource_path(boost::filesystem::path(LIBCLANG_LIBRARY_DIR) / ".." / "lib", version);
+      }
+      if(!path.empty()) {
+        return path;
+      }
     }
 
     boost::system::error_code ec;