build: add --v8-enable-wasm-gdb-remote-debugging configure option

This patch adds `--v8-enable-wasm-gdb-remote-debugging` &
`--v8-disable-wasm-gdb-remote-debugging` configure options, enabled by
default on linux/mac/win when wasm is enabled. The `--wasm-gdb-remote`
& `--wasm-gdb-remote-port` v8 options are exposed and allows one to
attach lldb to node and debug wasm modules with dwarf info.

Assisted-by: Codex <codex@openai.com>
Signed-off-by: Cheng Shao <terrorjack@type.dance>

Author: TerrorJack

configure.py

@@ -1203,6 +1203,20 @@
     help='Enable V8 transparent hugepage support. This feature is only '+
          'available on Linux platform.')
 
+parser.add_argument('--v8-enable-wasm-gdb-remote-debugging',
+    action='store_true',
+    dest='v8_enable_wasm_gdb_remote_debugging',
+    default=None,
+    help='Enable V8 WebAssembly debugging via the GDB-remote protocol. ' +
+         'Enabled by default on Linux, macOS, and Windows when WebAssembly ' +
+         'is enabled.')
+
+parser.add_argument('--v8-disable-wasm-gdb-remote-debugging',
+    action='store_false',
+    dest='v8_enable_wasm_gdb_remote_debugging',
+    default=None,
+    help='Disable V8 WebAssembly debugging via the GDB-remote protocol.')
+
 maglev_enabled_by_default_help = f"(Maglev is enabled by default on {','.join(maglev_enabled_architectures)})"
 
 parser.add_argument('--v8-disable-maglev',
@@ -2179,6 +2193,18 @@ def configure_v8(o, configs):
   set_configuration_variable(configs, 'v8_enable_v8_checks', release=0, debug=1)
 
   o['variables']['v8_enable_webassembly'] = 0 if options.v8_lite_mode else 1
+  if all(opt in sys.argv for opt in [
+      '--v8-enable-wasm-gdb-remote-debugging',
+      '--v8-disable-wasm-gdb-remote-debugging',
+  ]):
+    raise Exception(
+        'Only one of the --v8-enable-wasm-gdb-remote-debugging or '
+        '--v8-disable-wasm-gdb-remote-debugging options can be specified at a time.')
+  wasm_gdb = options.v8_enable_wasm_gdb_remote_debugging
+  if wasm_gdb is None:
+    wasm_gdb = (o['variables']['v8_enable_webassembly'] and
+                flavor in ('linux', 'mac', 'win'))
+  o['variables']['v8_enable_wasm_gdb_remote_debugging'] = B(wasm_gdb)
   o['variables']['v8_enable_javascript_promise_hooks'] = 1
   o['variables']['v8_enable_lite_mode'] = 1 if options.v8_lite_mode else 0
   is_gdbjit_supported_arch = (

tools/v8_gypfiles/features.gypi

@@ -321,6 +321,10 @@
     # Sets -dV8_ENABLE_WEBASSEMBLY.
     'v8_enable_webassembly%': 1,
 
+    # Enable WebAssembly debugging via GDB-remote protocol.
+    # Sets -dV8_ENABLE_WASM_GDB_REMOTE_DEBUGGING.
+    'v8_enable_wasm_gdb_remote_debugging%': 0,
+
     # Enable advanced BigInt algorithms, costing about 10-30 KiB binary size
     # depending on platform.
     'v8_advanced_bigint_algorithms%': 1,
@@ -524,6 +528,9 @@
       ['v8_enable_webassembly==1', {
         'defines': ['V8_ENABLE_WEBASSEMBLY',],
       }],
+      ['v8_enable_wasm_gdb_remote_debugging==1', {
+        'defines': ['V8_ENABLE_WASM_GDB_REMOTE_DEBUGGING',],
+      }],
       ['v8_dict_property_const_tracking==1', {
         'defines': ['V8_DICT_PROPERTY_CONST_TRACKING',],
       }],

tools/v8_gypfiles/v8.gyp

@@ -709,6 +709,11 @@
               '<!@pymod_do_main(GN-scraper "<(V8_ROOT)/BUILD.gn"  "v8_header_set.\\"v8_internal_headers\\".*?v8_enable_webassembly.*?sources \\+= ")',
             ],
           }],
+          ['v8_enable_wasm_gdb_remote_debugging==1', {
+            'sources': [
+              '<!@pymod_do_main(GN-scraper "<(V8_ROOT)/BUILD.gn"  "v8_header_set.\\"v8_internal_headers\\".*?v8_enable_wasm_gdb_remote_debugging.*?sources \\+= ")',
+            ],
+          }],
           ['v8_enable_wasm_simd256_revec==1', {
             'sources': [
               '<!@pymod_do_main(GN-scraper "<(V8_ROOT)/BUILD.gn"  "v8_header_set.\\"v8_internal_headers\\".*?v8_enable_wasm_simd256_revec.*?sources \\+= ")',
@@ -1193,6 +1198,11 @@
             '<!@pymod_do_main(GN-scraper "<(V8_ROOT)/BUILD.gn"  "\\"v8_base_without_compiler.*?v8_enable_webassembly.*?sources \\+= ")',
           ],
         }],
+        ['v8_enable_wasm_gdb_remote_debugging==1', {
+          'sources': [
+            '<!@pymod_do_main(GN-scraper "<(V8_ROOT)/BUILD.gn"  "\\"v8_base_without_compiler.*?v8_enable_wasm_gdb_remote_debugging.*?sources \\+= ")',
+          ],
+        }],
         ['v8_enable_heap_snapshot_verify==1', {
           'sources': [
             '<!@pymod_do_main(GN-scraper "<(V8_ROOT)/BUILD.gn"  "\\"v8_base_without_compiler.*?v8_enable_heap_snapshot_verify.*?sources \\+= ")',