#!/bin/bash
# Copyright 2019 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

#### CATEGORY=Run, inspect and debug
### run fidlcat on given target.

## Runs fidlcat in the given configuration; currently, fidlcat logs all FIDL
## chatter from the given target executable.  Starts the debug agent on the
## proposed target, and closes the debug agent on exit.
##
## CAUTION: This support is experimental, and invocation strategy is likely to
## change.  The component launching configuration is *especially* likely to go
## away over time.
##
## TROUBLESHOOTING TIPS:
##
## - Remember to use "fx set-device" when working with multiple devices.
## - This scripts by default will mute the SSH connection stdout/stderr, so any
##   errors triggered by it won't appear. Use the --debug-mode flag to see
##   the debug log's from the debug agent and fidlcat.
## - This scripts uses the tool "nc" for testing TCP connections. Check that it
##   is in $PATH and that it works.
##
## Usage: fx fidlcat [--debug-mode] [(--port|-p) <PORT>] [--with-symbol-server]
##                   [--with-process-info] [--stack=<value>]
##                   [--syscalls=<regexp>] [--exclude-syscalls=<regexp>] [--dump-messages]
##                   [--verbose=<value> | --quiet=<value>] [--log-file <path>]
##                   [--remote-pid=<pid> | --remote-name=<name> | run <component specification>]
##
##    --port                Port the debug agent will be listening on. Will use 2345
##                          by default.
##    --with-symbol-server  Connect to the symbol server. The first time you use this option,
##                          fidlcat will give you a link to an authentication page.
##                          You then have to use the generated key to authenticate.
##    --debug-mode          Whether the debug agent's debug logs should be shown.
##    --with-process-info   Display the process name, process id and thread id on
##                          each line (useful for grep).
##    --stack=<value>       Define the amount of stack frame to display
##                          0: none (default value)
##                          1: call site (1 to 4 levels)
##                          2: full stack frame (adds some overhead)
##    --syscalls            A regular expression which selects the syscalls to decode and display.
##                          Can be passed multiple times.
##                          By default, only zx_channel_.* syscalls are displayed.
##                          To display all the syscalls, use: --syscalls ".*"
##    --exclude-syscalls    A regular expression which selects the syscalls to not decode and
##                          display.
##                          Can be passed multiple times.
##                          To be displayed, a syscall must verify --syscalls and not verify
##                          --exclude-syscalls.
##                          To display all the syscalls but the zx_handle syscalls, use:
##                          --syscalls ".*" --exclude-syscalls "zx_handle_.*"
##    --dump-messages       Always does a hexadecimal dump of the messages even if we can
##                          decode them.
##    --verbose=<value>     The log verbosity.  Legal values are "info", "warning",
##                          "error", "fatal", or a number, starting from 0. Extra
##                          verbosity comes with higher levels.
##    --quiet=<value>       The log verbosity.  Legal values are "info", "warning",
##                          "error", "fatal", or a number, starting from 0. Extra
##                          verbosity comes with lower levels.
##    --log-file=<path>     The log file destination.
##    --remote-pid          The koid of the remote process to trace
##    --remote-name         A set of comma-separated regexes. Fidlcat will monitor all existing
##                          and future processes whose names match one of the regexes.
##                          Can be provided multiple times for multiple regexes.
##    --symbol-path=<path>  An extra location where fildcat can find debug symbols.      
##    --fidl-ir-path=<path> An extra location where fidlcat can find FIDL compiled files.
##    --gdb                 Launch fidlcat using gdb. This is only useful to be able to debug
##                          fidlcat. When this option is used, the string you have to type within
##                          gdb to launch fidlcat is printed and then, gdb is launched.
##                          This option only works if you have the unstripped version of fidlcat.
##    run                   A token indicating that you want to invoke and trace
##                          the following component. The component is specified
##                          with either a bash regex that matches a component URL
##                          known to the build, or a full component URL not known
##                          to your build, but available to your target.
##
## Flags after -- are parsed by fidlcat.  Example usage:
##
## # Attaches to the process with the given pid on the target:
## fx fidlcat --remote-pid=4755
##
## # Launches the echo client, and monitors its FIDL chatter:
## fx fidlcat run fuchsia-pkg://fuchsia.com/echo_client_cpp#meta/echo_client_cpp.cmx
##
## # Also launches the echo client, and monitors its FIDL chatter:
## fx fidlcat run echo_client_cpp.cmx
##
## # Will trace existing and future processes whose name contains "echo_client"
## fx fidlcat --remote-name=echo_client
##
## All three options --remote-pid, --remote-name and run can be used together.
## However, run must always be the last one.
## When --remote-name and run are used together, only processes which match
## --remote-name are monitored.
##
## Examples (echo_server is launched by echo_client):
##
## # run and monitor echo_client.
## fx fidlcat run echo_client_cpp.cmx
##
## # run and monitor echo_client.
## fx fidlcat --remote-name=echo_client run echo_client_cpp.cmx
##
## # run echo_client and monitor echo_server.
## fx fidlcat --remote-name=echo_server run echo_client_cpp.cmx
##
## # run echo_client and monitor echo_client and echo_server.
## fx fidlcat --remote-name=echo run echo_client_cpp.cmx
##
## # run echo_client and monitor echo_client and echo_server.
## fx fidlcat --remote-name=echo_client --remote-name=echo_server run echo_client_cpp.cmx

source "$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null 2>&1 && pwd)"/../lib/vars.sh || exit $?
fx-config-read
source "$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null 2>&1 && pwd)"/../contrib/lib/debug-agent.sh || exit $?

action=

arguments=()

use_gdb=0

# Options for the zxdb client.
agent_out="/dev/null"
debug_mode=

while [[ $# -gt 0 ]]; do
  case "$1" in
    --help|-h)
      fx-command-help
      exit 0
      ;;
    --port|-p)
      shift
      port="$1"
      ;;
    --with-symbol-server)
      arguments+=("--symbol-server")
      arguments+=("gs://fuchsia-artifacts-release/debug")
      ;;
    --debug-mode)
      agent_out="/dev/stdout"
      debug_mode="--debug-mode"
      ;;
    --with-process-info)
      arguments+=("--with-process-info")
      ;;
    --dump-messages)
      arguments+=("--dump-messages")
      ;;
    --stack=*)
      arguments+=("$1")
      ;;
    --syscalls=*)
      arguments+=("$1")
      ;;
    --exclude-syscalls=*)
      arguments+=("$1")
      ;;
    --verbose=*)
      arguments+=("$1")
      ;;
    --quiet=*)
      arguments+=("$1")
      ;;
    --log-file=*)
      arguments+=("$1")
      ;;
    --remote-pid=*)
      arguments+=("$1")
      ;;
    --remote-name=*)
      arguments+=("$1")
      ;;
    --symbol-path=*)
      arguments+=("$1")
      ;;
    --fidl-ir-path=*)
      arguments+=("$1")
      ;;
    --gdb)
      use_gdb=1
      ;;
    run)
      action="$1"
      shift
      break # Remaining flags are passed to fidlcat, with processing below
      ;;
    --)
      shift
      break # Remaining flags are passed to fidlcat
      ;;
    *)
      echo "Invalid flag $1"
      exit 1
  esac
  shift
done

# Infer the package URL from a regex-specified name.
package_file="${FUCHSIA_BUILD_DIR}/component_index_metadata"
if [[ "${action}" == "run" ]]; then
  component=$1
  components=()
  all_pkgs="$(cat "${package_file}")"
  if [[ -n "${all_pkgs}" ]]; then
    for pkg in ${all_pkgs}; do
      if [[ "${pkg}" =~ ${component} ]]; then
        components+=("${pkg}")
      fi
    done
  else
    # If there aren't any packages in the component_index_metadata file, then
    # assume the users know what they are doing. fidlcat should complain.
    components+=("${component}")
  fi

  if [[ ${#components[@]} = 0 ]]; then
    fx-error "Package $component is not known to the current build configuration."
    fx-error "Check \`fx list-packages\` for the correct name,"
    fx-error "or adjust the build configuration with \`fx set\`."
    exit 1
  elif [[ ${#components[@]} -gt 1 ]]; then
    fx-error "Ambiguous match: $component matches the following ${#components[@]} packages:"
    for component in "${components[@]}"; do
      fx-error "  $component"
    done
    exit 1
  fi
  component="${components[0]}"
  shift
  # We have now removed "run <partial component URL regex>" from the remaining
  # positional parameters.  The following set command replaces them with "run
  # <full component URL>".
  set - "$@" "run" "${component}"
fi

if [[ -z "${port}" ]]; then
  port=2345
fi

if launch_debug_agent "${port}" "" "${agent_out}"; then
  arguments+=("--connect" "$(get-device-addr-resource):${port}")
  arguments+=("--fidl-ir-path" @"${FUCHSIA_BUILD_DIR}"/all_fidl_json.txt)
  arguments+=("-s" "${FUCHSIA_BUILD_DIR}")
  arguments+=("-s" "${ZIRCON_BUILDROOT}")
  arguments+=("-s" "${PREBUILT_CLANG_DIR}/lib/debug")
  arguments+=("--symbol-cache" "~")
  arguments+=("--pretty-print")
  arguments+=("$@")

  if [[ ${use_gdb} -eq 1 ]]; then
    # Starts gdb.
    gdb --args ${FUCHSIA_BUILD_DIR}/host_x64/exe.unstripped/fidlcat ${arguments[@]}
  else
    # Now that the debug agent is launched, starts fidlcat.
    "${FUCHSIA_BUILD_DIR}/host-tools/fidlcat" ${arguments[@]}
  fi

  # launch_debug_agent starts an agent in the background. Note: killing
  # the ssh session as below generally won't terminate the agent, but
  # it prevents us ending up with a zobmie on the host.
  pids=$(jobs -p)
  if [[ -n "${pids}" ]]; then
    kill "${pids}" > /dev/null >&2
    wait
  fi
else
  fx-error "Could not launch debug agent. Exiting. Make sure you're running 'fx serve'."
  exit 1
fi