Skip to content

auto approve #42

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom
Open
wants to merge 2 commits into
base: sycl
Choose a base branch
from
Open

auto approve #42

wants to merge 2 commits into from

Conversation

DoyleLi
Copy link
Owner

@DoyleLi DoyleLi commented Sep 13, 2021

Signed-off-by: Xiaodong Li [email protected]

DoyleLi pushed a commit that referenced this pull request Nov 8, 2021
@0x1eaf @sam-mccall
[clangd] Print current request context along with the stack trace
045695f 
Motivation:

At the moment it is hard to attribute a clangd crash to a specific request out of all in-flight requests that might be processed concurrently. So before we can act on production clangd crashes, we have to do quite some digging through the log tables populated by our in-house VSCode extension or sometimes even directly reach out to the affected developer. Having all the details needed to reproduce a crash printed alongside its stack trace has a potential to save us quite some time, that could better be spent on fixing the actual problems.

Implementation approach:

* introduce `ThreadCrashReporter` class that allows to set a temporary signal handler for the current thread
* follow RAII pattern to simplify printing context for crashes occurring within a particular scope
* hold `std::function` as a handler to allow capturing context to print
* set local `ThreadCrashReporter` within `JSONTransport::loop()` to print request JSON for main thread crashes, and in `ASTWorker::run()` to print the file paths, arguments and contents for worker thread crashes

`ThreadCrashReporter` currently allows only one active handler per thread, but the approach can be extended to support stacked handlers printing context incrementally.

Example output for main thread crashes:

  ```
  ...
  #15 0x00007f7ddc819493 __libc_start_main (/lib64/libc.so.6+0x23493)
  #16 0x000000000249775e _start (/home/emmablink/local/llvm-project/build/bin/clangd+0x249775e)
  Signalled while processing message:
  {"jsonrpc": "2.0", "method": "textDocument/didOpen", "params": {"textDocument": {"uri": "file:///home/emmablink/test.cpp", "languageId": "cpp", "version": 1, "text": "template <typename>\nclass Bar {\n  Bar<int> *variables_to_modify;\n  foo() {\n    for (auto *c : *variables_to_modify)\n      delete c;\n  }\n};\n"}}}
  ```

Example output for AST worker crashes:

  ```
  ...
  #41 0x00007fb18304c14a start_thread pthread_create.c:0:0
  #42 0x00007fb181bfcdc3 clone (/lib64/libc.so.6+0xfcdc3)
  Signalled during AST action:
  Filename: test.cpp
  Directory: /home/emmablink
  Command Line: /usr/bin/clang -resource-dir=/data/users/emmablink/llvm-project/build/lib/clang/14.0.0 -- /home/emmablink/test.cpp
  Version: 1
  Contents:
  template <typename>
  class Bar {
    Bar<int> *variables_to_modify;
    foo() {
      for (auto *c : *variables_to_modify)
        delete c;
    }
  };
  ```

Testing:

The unit test covers the thread-localitity and nesting aspects of `ThreadCrashReporter`. There might be way to set up a lit-based integration test that would spawn clangd, send a message to it, signal it immediately and check the standard output, but this might be prone to raceconditions.

Reviewed By: sammccall

Differential Revision: https://reviews.llvm.org/D109506
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Reviewers

@bb-sycl bb-sycl bb-sycl approved these changes

Assignees
No one assigned
Labels
None yet
Projects
None yet
Milestone
No milestone
Development

Successfully merging this pull request may close these issues.
2 participants
@DoyleLi @bb-sycl