Further improve the debugger scripts (#111)

Author: rockbruno

Example/.bazelrc

@@ -1,5 +1,12 @@
 common --ios_simulator_device="iPhone 16 Pro"
-common --ios_simulator_version="18.4"
+common --ios_simulator_version="18.6"
+
+# rules_swift flags migration
+# --swiftcopt and --host_swiftcopt are deprecated
+common --flag_alias=swiftcopt=@build_bazel_rules_swift//swift:copt
+common --flag_alias=host_swiftcopt=@build_bazel_rules_swift//swift:exec_copt
+common --swiftcopt=-whole-module-optimization
+common --host_swiftcopt=-whole-module-optimization
 
 # All of the following are Debug/Index setup configs inspired by the default rules_xcodeproj template
 

Example/README.md

@@ -21,7 +21,7 @@ After performing these steps, you should already be able to see the basic indexi
 
 - To run a regular build: Cmd+Shift+B -> `Build HelloWorld`
 - To run a debug build, launch the simulator and attach `lldb`: Cmd+Shift+D -> `Debug HelloWorld (Example)`
-  - This requires a **iOS 18.4 iPhone 16 Pro** simulator installed as this is what the example project is currently configured for. Make sure you have one available, as otherwise the build will fail.
+  - This requires a **iOS 18.6 iPhone 16 Pro** simulator installed as this is what the example project is currently configured for. Make sure you have one available, as otherwise the build will fail.
 - To test: Cmd+Shift+P -> `Run Test Task` -> `Test HelloWorldTests`
 
 ## Considerations

Example/scripts/lldb_attach.py

@@ -1,8 +1,11 @@
-
-from lldb_common import load_launch_info, load_output_base, run_command
+from lldb_common import load_launch_info, load_bazel_info, run_command
+import os
 
 launch_info = load_launch_info()
-output_base = load_output_base()
+bazel_info = load_bazel_info()
+output_base = bazel_info["output_base"]
+execution_root = bazel_info["execution_root"]
+workspace_root = os.getcwd()
 device_platform = launch_info["platform"]
 device_udid = launch_info["udid"]
 debug_pid = str(launch_info["pid"])
@@ -12,21 +15,25 @@
 # This is needed because we use the `oso_prefix_is_pwd` feature, which makes the
 # paths to archives relative to the exec root.
 run_command(
-    f'platform settings -w "{output_base}/execroot/_main"',
+    f'platform settings -w "{execution_root}"',
 )
 
 # Adjust the source map.
 #
-# The source map will be initialized to the workspace. Need to resolve external
-# paths to the stable external directory. Then need to resolve generated files
-# to the execution root. We set it for `./` instead of `./bazel-out/` to allow
-# the convenience symlink to be used if it exists.
+# By default, breakpoints will move the IDE to the file within the execution root.
+# We need to map them to their real location in the workspace root to fix that.
+# The only exception is the the `external` folder, which only exists within the execution root.
+run_command(
+    'settings append target.source-map "." "{}"'.format(workspace_root),
+)
 run_command(
     'settings insert-before target.source-map 0 "./external/" '
     f'"{output_base}/external/"',
 )
+
+# Helps lldb to not timeout on large projects
 run_command(
-    f'settings append target.source-map "./" "{output_base}/execroot/_main/"',
+    'settings set plugin.process.gdb-remote.packet-timeout 300',
 )
 
 if device_platform == "device":

Example/scripts/lldb_common.py

@@ -11,33 +11,27 @@
 
 # These files are generated by the lldb_launch_and_debug.sh script.
 LAUNCH_INFO_PATH = pathlib.Path(".bsp/skbsp_generated/lldb.json")
-OUTPUT_BASE_PATH = pathlib.Path(".bsp/skbsp_generated/output_base.txt")
+BAZEL_INFO_PATH = pathlib.Path(".bsp/skbsp_generated/bazel_info.json")
 
 
-def load_launch_info() -> dict[str, Any]:
+def _load_file(path: pathlib.Path) -> str:
     # We exit cleanly as a way to not throw a bunch of
     # errors when the `preLaunchTask` fails. Ideally we wouldn't get here, but
     # `lldb-dap` has a bug where background tasks don't prevent debugging from
     # starting.
-    if not LAUNCH_INFO_PATH.exists():
-        print("Launch info file not found. Exiting.", file=sys.stderr, flush=True)
+    if not path.exists():
+        print(f"File not found: {path}. Exiting.", file=sys.stderr, flush=True)
         lldb.SBDebugger.Terminate()
         os._exit(0)
+    return path.read_text()
 
-    return json.loads(LAUNCH_INFO_PATH.read_text())
 
+def load_launch_info() -> dict[str, Any]:
+    return json.loads(_load_file(LAUNCH_INFO_PATH))
 
-def load_output_base() -> str:
-    # We exit cleanly as a way to not throw a bunch of
-    # errors when the `preLaunchTask` fails. Ideally we wouldn't get here, but
-    # `lldb-dap` has a bug where background tasks don't prevent debugging from
-    # starting.
-    if not OUTPUT_BASE_PATH.exists():
-        print("Output base file not found. Exiting.", file=sys.stderr, flush=True)
-        lldb.SBDebugger.Terminate()
-        os._exit(0)
 
-    return OUTPUT_BASE_PATH.read_text().strip()
+def load_bazel_info() -> dict[str, Any]:
+    return json.loads(_load_file(BAZEL_INFO_PATH))
 
 
 def run_command(command: str) -> None:

Example/scripts/lldb_launch_and_debug.sh

@@ -9,26 +9,39 @@ WORKSPACE_ROOT=$(pwd)
 # When asking Bazel to launch a simulator, we need to intercept
 # the launched process' PID to be able to debug it later on.
 # We do this by asking it to write this info to a file.
-# These two paths are also hardcoded in the lldb_attach.py and lldb_kill_app.py scripts.
-INFO_JSON=${WORKSPACE_ROOT}/.bsp/skbsp_generated/lldb.json
-rm -f ${INFO_JSON} || true
+# These paths are also hardcoded in the lldb_attach.py and lldb_kill_app.py scripts.
+LAUNCH_INFO_JSON=${WORKSPACE_ROOT}/.bsp/skbsp_generated/lldb.json
+rm -f ${LAUNCH_INFO_JSON} || true
 OUTPUT_BASE=$(bazelisk info output_base)
-OUTPUT_BASE_INFO_PATH=${WORKSPACE_ROOT}/.bsp/skbsp_generated/output_base.txt
-rm -f ${OUTPUT_BASE_INFO_PATH} || true
+EXECUTION_ROOT=$(bazelisk info execution_root)
+BAZEL_INFO_JSON=${WORKSPACE_ROOT}/.bsp/skbsp_generated/bazel_info.json
+rm -f ${BAZEL_INFO_JSON} || true
 mkdir -p ${WORKSPACE_ROOT}/.bsp/skbsp_generated
-echo "${OUTPUT_BASE}" > ${OUTPUT_BASE_INFO_PATH}
+cat > ${BAZEL_INFO_JSON} <<EOF
+{
+  "output_base": "${OUTPUT_BASE}",
+  "execution_root": "${EXECUTION_ROOT}"
+}
+EOF
+
+ADDITIONAL_FLAGS=()
+ADDITIONAL_FLAGS+=("--keep_going")
+ADDITIONAL_FLAGS+=("--color=yes")
+# We need --remote_download_regex because the files that lldb needs won't usually be downloaded by Bazel
+# when using flags like --remote_download_toplevel and the such.
+ADDITIONAL_FLAGS+=("--remote_download_regex=.*\.indexstore/.*|.*\.(a|cfg|c|C|cc|cl|cpp|cu|cxx|c++|def|h|H|hh|hpp|hxx|h++|hmap|ilc|inc|inl|ipp|tcc|tlh|tli|tpp|m|modulemap|mm|pch|swift|swiftdoc|swiftmodule|swiftsourceinfo|yaml)$")
 
-# FIXME: Could not figure out how to make the output show up on the dedicated
-# debug console. So we need to keep this script alive and display it here in the meantime.
 BAZEL_APPLE_PREFER_PERSISTENT_SIMS=1 \
-BAZEL_APPLE_LAUNCH_INFO_PATH=${INFO_JSON} \
+BAZEL_APPLE_LAUNCH_INFO_PATH=${LAUNCH_INFO_JSON} \
 BAZEL_SIMCTL_LAUNCH_FLAGS="--wait-for-debugger --stdout=$(tty) --stderr=$(tty)" \
-bazelisk run "${BAZEL_LABEL_TO_RUN}"
+bazelisk run "${BAZEL_LABEL_TO_RUN}" "${ADDITIONAL_FLAGS[@]}"
 
-PID=$(jq -r '.pid' "${INFO_JSON}")
+PID=$(jq -r '.pid' "${LAUNCH_INFO_JSON}")
 
 echo "Launched with PID: ${PID}"
 
 # Keep the terminal alive until the app is killed.
-# FIXME: Only necessary because of the stdout-related FIXME mentioned above
+# FIXME: This is only necessary because I couldn't figure out how to make the app's output
+# show up on the dedicated debug console. So we need to keep this script alive and
+# display it here in the meantime.
 lsof -p ${PID} +r 1 &>/dev/null