From 7021192af5af6b6a65a2a708da0a88bb968898e6 Mon Sep 17 00:00:00 2001
From: Joyee Cheung <joyeec9h3@gmail.com>
Date: Mon, 16 Dec 2024 22:10:24 +0100
Subject: [PATCH] build: build v8 with -fvisibility=hidden

V8 should be built with -fvisibility=hidden, otherwise
the resulting binary would contain unnecessary symbols. In
particular, on macOS, this leads to 5000+ weak symbols
resolved at runtime, leading to a startup regression.

On macOS this also reduces the binary size about ~10MB.
On Linux the size reduction is around 8MB.
---
 tools/v8_gypfiles/v8.gyp | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/tools/v8_gypfiles/v8.gyp b/tools/v8_gypfiles/v8.gyp
index 9acad07d966a35..19e490167fc0dc 100644
--- a/tools/v8_gypfiles/v8.gyp
+++ b/tools/v8_gypfiles/v8.gyp
@@ -41,6 +41,14 @@
         'AdditionalOptions': ['/utf-8']
       }
     },
+    # Hide symbols that are not explicitly exported with V8_EXPORT.
+    'cflags': ['-fvisibility=hidden'],
+    'xcode_settings': {
+      'GCC_SYMBOLS_PRIVATE_EXTERN': 'YES',  # -fvisibility=hidden
+    },
+    'defines': [
+      'BUILDING_V8_SHARED',  # Make V8_EXPORT visible.
+    ],
   },
   'targets': [
     {