build: disable ICF for mksnapshot

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

node.gyp

@@ -1319,6 +1319,11 @@
  'winmm.lib',
  'Ws2_32.lib',
  ],
+ 'msbuild_settings': {
+ 'Link': {
+ 'EnableCOMDATFolding': 'false', # /OPT:NOICF
+ },
+ },
  }],
  # Avoid excessive LTO
  ['enable_lto=="true"', {

tools/v8_gypfiles/v8.gyp

@@ -1700,6 +1700,13 @@
  ['enable_lto=="true"', {
  'ldflags': [ '-fno-lto' ],
  }],
+ ['OS=="win"', {
+ 'msbuild_settings': {
+ 'Link': {
+ 'EnableCOMDATFolding': 'false', # /OPT:NOICF
+ },
+ },
+ }],
  ],
  }, # mksnapshot
  {

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") {