1. 17 Apr, 2020 1 commit
  2. 20 Feb, 2020 1 commit
    • Paolo Severini's avatar
      Add initial support for Wasm debugging with LLDB: implements a GDB-remote stub · 03fc4149
      Paolo Severini authored
      This is the first piece of the wasm debugging prototype (besides the changes to
      add/remove breakpoints in WasmModuleObject made with
      https://chromium.googlesource.com/v8/v8.git/+/e699f39caed9a23f8e20bd3a0386a3236e272737).
      
      This changelist adds the infrastructure for a GDB-remote stub that will be used
      to manage debugging sessions via the gdb-remote protocol.
      It enables the creation and termination of debugging sessions over TCP
      connections that are managed in a separate thread.
      The logic to actually send, receive and decode GDB-remote packets will be part
      of a future changelist.
      
      Build with: v8_enable_wasm_gdb_remote_debugging = true
      Run with:
        --wasm-gdb-remote                  Enables Wasm debugging with LLDB
                                           (default: false)
        --wasm-gdb-remote-port             TCP port to be used for debugging
                                           (default: 8765)
        --wasm-pause-waiting-for-debugger  Pauses the execution of Wasm code waiting
                                           for a debugger (default: false)
        --trace-wasm-gdb-remote            Enables tracing of Gdb-remote packets
                                           (default: false)
      
      Note that most of this code is "borrowed" from the code of the Chromium NaCL
      GDB-remote stub (located in Chromium in src\native_client\src\trusted\debug_stub).
      
      Implementation details:
      - class GdbServer acts as a singleton manager for the gdb-remote stub. It is
        instantiated as soon as the first Wasm module is loaded in the Wasm engine.
      - class GdbServerThread spawns the worker thread for the TCP connection.
      - class Transport manages the socket connection, in a portable way.
      - class Session represents a remote debugging session.
      - class Target represents a debugging target and it’s the place where the
        debugging packets will be processed and will implement the logic to debug
        a Wasm engine.
      
      Bug: chromium:1010467
      Change-Id: Ib2324e5901f5ae1d855b96b99ef0995d407322b6
      Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1923407Reviewed-by: 's avatarClemens Backes <clemensb@chromium.org>
      Reviewed-by: 's avatarBenedikt Meurer <bmeurer@chromium.org>
      Reviewed-by: 's avatarMichael Achenbach <machenbach@chromium.org>
      Commit-Queue: Paolo Severini <paolosev@microsoft.com>
      Cr-Commit-Position: refs/heads/master@{#66379}
      03fc4149