[PATCH 3/7] meson: use precompiled headers for our test-helper

From: Patrick Steinhardt <ps@pks.im>
Date: Sep 24, 2026, 14:09 UTC
Message-ID: <20260924-pks-meson-improvements-v1-3-90b7f79f1c4e@pks.im>
In-Reply-To: <20260924-pks-meson-improvements-v1-0-90b7f79f1c4e@pks.im>

In 671df48df8 (meson: precompile "git-compat-util.h", 2026-03-19) we have introduced support for precompiled headers into Meson. At that time though we only converted "libgit.a" to make use of those.

Nowadays though, our test-helper also consists of a bunch of code files, and all of these include "git-compat-util.h" via "test-tool.h" as the first header. So they're a natural target to also use precompiled headers.

Adapt the test-tool executable to make use of them, which results in a surprisingly large speedup for clean builds:

  Benchmark 1: meson compile (version = HEAD~)
    Time (mean ± σ):      6.363 s ±  0.033 s    [User: 92.858 s, System: 22.500 s]
    Range (min … max):    6.311 s …  6.418 s    10 runs

  Benchmark 2: meson compile (version = HEAD)
    Time (mean ± σ):      5.327 s ±  0.021 s    [User: 75.135 s, System: 20.373 s]
    Range (min … max):    5.299 s …  5.362 s    10 runs

  Summary
    meson compile (version = HEAD) ran
      1.19 ± 0.01 times faster than meson compile (version = HEAD~)

Signed-off-by: Patrick Steinhardt <ps@pks.im>
---
 t/helper/meson.build | 1 +
 1 file changed, 1 insertion(+)

diff --git a/t/helper/meson.build b/t/helper/meson.build
index 3235f10ab8..ae513b4cdc 100644
--- a/t/helper/meson.build
+++ b/t/helper/meson.build
@@ -83,6 +83,7 @@ test_tool_sources = [
 
 test_tool = executable('test-tool',
   sources: test_tool_sources,
+  c_pch: '../../tools/precompiled.h',
   dependencies: [libgit_commonmain],
 )
 bin_wrappers += test_tool

-- 
2.56.0.rc2.329.gd58861e689.dirty