From 39e9ad1d29bd4eb074374dd29a89952a0a2c2bb7 Mon Sep 17 00:00:00 2001
From: Jordan Petridis <jordan@centricular.com>
Date: Mon, 18 Nov 2024 15:46:10 +0200
Subject: [PATCH] cargo: Default to thin lto for the release profile

Normal "fat" lto is quite resource heavy and requires
a lot of ram at compile time. Thinlto is a
much lighter alternative that produces comparable results
performance but it scales much better. [1] [2] [3]

All browser engines also compile with thinlto exclusively,
as it's almost as fast and saves considerable amount of
link time in the build.

[1]: https://doc.rust-lang.org/cargo/reference/profiles.html#lto
[2]: https://clang.llvm.org/docs/ThinLTO.html
[3]: https://blog.llvm.org/2016/06/thinlto-scalable-and-incremental-lto.html

In a test build on a windows machine, this brings down
the from scratch compile time from 7m30s to roughly 5m.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-rs/-/merge_requests/1922>
---
 Cargo.toml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Cargo.toml b/Cargo.toml
index 59de4982..28e608e4 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -117,7 +117,7 @@ default-members = [
 ]
 
 [profile.release]
-lto = true
+lto = "thin"
 opt-level = 3
 debug = true
 panic = 'unwind'