From 5b09384f0126f4270109bcee72bc63e70be2596d Mon Sep 17 00:00:00 2001
From: Dylan Conway <35280289+dylan-conway@users.noreply.github.com>
Date: Thu, 6 Jun 2024 22:01:28 -0700
Subject: [PATCH] add `memrchr` to `strings.lastIndexOfChar` on linux (#11671)

---
 src/linux_c.zig          | 1 +
 src/string_immutable.zig | 8 ++++++++
 2 files changed, 9 insertions(+)

diff --git a/src/linux_c.zig b/src/linux_c.zig
index bc7c1917f1..601b77ac4e 100644
--- a/src/linux_c.zig
+++ b/src/linux_c.zig
@@ -676,3 +676,4 @@ pub const RENAME_EXCHANGE = 1 << 1;
 pub const RENAME_WHITEOUT = 1 << 2;
 
 pub extern "C" fn quick_exit(code: c_int) noreturn;
+pub extern "C" fn memrchr(ptr: [*]const u8, val: c_int, len: usize) ?[*]const u8;
diff --git a/src/string_immutable.zig b/src/string_immutable.zig
index e36a9a0e32..3cb523a902 100644
--- a/src/string_immutable.zig
+++ b/src/string_immutable.zig
@@ -272,6 +272,14 @@ pub fn indexOfSigned(self: string, str: string) i32 {
 }
 
 pub inline fn lastIndexOfChar(self: []const u8, char: u8) ?usize {
+    if (comptime Environment.isLinux) {
+        if (@inComptime()) {
+            return lastIndexOfCharT(u8, self, char);
+        }
+        const start = bun.C.memrchr(self.ptr, char, self.len) orelse return null;
+        const i = @intFromPtr(start) - @intFromPtr(self.ptr);
+        return @intCast(i);
+    }
     return lastIndexOfCharT(u8, self, char);
 }