build: disable ICF for mksnapshot

Refs: https://chromium-review.googlesource.com/c/v8/v8/+/5447267
Co-authored-by: Michaël Zasso <[email protected]>

node.gyp

@@ -1272,6 +1272,7 @@
  'deps/ada/ada.gyp:ada',
  'deps/simdjson/simdjson.gyp:simdjson',
  'deps/simdutf/simdutf.gyp:simdutf',
+ 'disable_icf',
  ],
 
  'includes': [
@@ -1326,6 +1327,21 @@
  }],
  ],
  }, # node_mksnapshot
+ {
+ 'target_name': 'disable_icf',
+ 'type': 'none',
+ 'direct_dependent_settings': {
+ 'conditions': [
+ ['OS=="win"', {
+ 'msvs_settings': {
+ 'VCLinkerTool': {
+ 'EnableCOMDATFolding': '0', # /OPT:NOICF
+ },
+ },
+ }],
+ ],
+ },
+ }, # disable_icf
  ], # end targets
 
  'conditions': [

tools/v8_gypfiles/v8.gyp

@@ -1687,6 +1687,7 @@
  'v8_turboshaft',
  'v8_pch',
  'v8_abseil',
+ 'disable_icf',
  # "build/win:default_exe_manifest",
  ],
  'sources': [
@@ -1702,6 +1703,21 @@
  }],
  ],
  }, # mksnapshot
+ {
+ 'target_name': 'disable_icf',
+ 'type': 'none',
+ 'direct_dependent_settings': {
+ 'conditions': [
+ ['is_win', {
+ 'msvs_settings': {
+ 'VCLinkerTool': {
+ 'EnableCOMDATFolding': '0', # /OPT:NOICF
+ },
+ },
+ }],
+ ],
+ },
+ }, # disable_icf
  {
  'target_name': 'torque',
  'type': 'executable',

unofficial.gni

@@ -235,13 +235,30 @@ template("node_gn_build") {
  if (node_use_node_snapshot) {
  if (current_toolchain == v8_snapshot_toolchain) {
  executable("node_mksnapshot") {
- configs += [ ":node_internal_config" ]
+ configs += [ ":node_internal_config", ":disable_icf" ]
  sources = [
  "src/node_snapshot_stub.cc",
  "tools/snapshot/node_mksnapshot.cc",
  ]
  deps = [ ":libnode" ]
  }
+
+ # This config disables a link time optimization "ICF", which may merge
+ # different functions into one if the function signature and body of them are
+ # identical.
+ #
+ # ICF breaks 1:1 mappings of the external references for V8 snapshot, so we
+ # disable it while taking a V8 snapshot.
+ config("disable_icf") {
+ visibility = [ ":*" ] # Only targets in this file can depend on this.
+ if (is_win) {
+ ldflags = [ "/OPT:NOICF" ] # link.exe, but also lld-link.exe.
+ } else if (is_apple && !use_lld) {
+ ldflags = [ "-Wl,-no_deduplicate" ] # ld64.
+ } else if (use_gold || use_lld) {
+ ldflags = [ "-Wl,--icf=none" ]
+ }
+ }
  }
 
  action("run_node_mksnapshot") {