bt: Enumerate all threads when symbolizing stacks in the bt utility.

Enumerate tid's from /proc/{pid}/stacks/ and use it to print the
backtrace for all active threads in the specified process.

Userland/Utilities/bt.cpp

@@ -6,6 +6,7 @@
 
 #include <AK/LexicalPath.h>
 #include <LibCore/ArgsParser.h>
+#include <LibCore/DirIterator.h>
 #include <LibCore/EventLoop.h>
 #include <LibCore/File.h>
 #include <LibSymbolClient/Client.h>
@@ -54,31 +55,41 @@ int main(int argc, char** argv)
  args_parser.parse(argc, argv);
  Core::EventLoop loop;
 
- // FIXME: Support multiple threads in the same process!
- auto symbols = SymbolClient::symbolicate_thread(pid, pid);
- for (auto& symbol : symbols) {
- out("{:p} ", symbol.address);
- if (!symbol.name.is_empty())
- out("{} ", symbol.name);
- if (!symbol.filename.is_empty()) {
- bool linked = false;
-
- out("(");
-
- // See if we can find the sources in /usr/src
- // FIXME: I'm sure this can be improved!
- auto full_path = LexicalPath::canonicalized_path(String::formatted("/usr/src/serenity/dummy/dummy/{}", symbol.filename));
- if (access(full_path.characters(), F_OK) == 0) {
- linked = true;
- out("\033]8;;file:https://{}{}?line_number={}\033\\", hostname, full_path, symbol.line_number);
- }
+ Core::DirIterator iterator(String::formatted("/proc/{}/stacks", pid), Core::DirIterator::SkipDots);
+ if (iterator.has_error()) {
+ warnln("Error: pid '{}' doesn't appear to exist.", pid);
+ return 1;
+ }
+
+ while (iterator.has_next()) {
+ pid_t tid = iterator.next_path().to_int().value();
+ outln("tid: {}", tid);
+ auto symbols = SymbolClient::symbolicate_thread(pid, tid);
+ for (auto& symbol : symbols) {
+ out("{:p} ", symbol.address);
+ if (!symbol.name.is_empty())
+ out("{} ", symbol.name);
+ if (!symbol.filename.is_empty()) {
+ bool linked = false;
 
- out("\033[34;1m{}:{}\033[0m", LexicalPath(symbol.filename).basename(), symbol.line_number);
+  out("(");
 
- if (linked)
- out("\033]8;;\033\\");
+ // See if we can find the sources in /usr/src
+ // FIXME: I'm sure this can be improved!
+ auto full_path = LexicalPath::canonicalized_path(String::formatted("/usr/src/serenity/dummy/dummy/{}", symbol.filename));
+ if (access(full_path.characters(), F_OK) == 0) {
+ linked = true;
+ out("\033]8;;file:https://{}{}?line_number={}\033\\", hostname, full_path, symbol.line_number);
+ }
 
- out(")");
+ out("\033[34;1m{}:{}\033[0m", LexicalPath(symbol.filename).basename(), symbol.line_number);
+
+ if (linked)
+ out("\033]8;;\033\\");
+
+ out(")");
+ }
+ outln("");
  }
  outln("");
  }