From 60f987d8d5f7272793a40290d060b8f50933f825 Mon Sep 17 00:00:00 2001
From: Takuto Ikuta <tikuta@chromium.org>
Date: Mon, 08 Jun 2026 19:43:20 -0700
Subject: [PATCH] build: Omit ar from inputs when resolved via $PATH

The GN build configuration previously added the `ar` tool to the inputs
list unconditionally. However, if the `ar` tool is specified simply by
its filename and is resolved via the system `$PATH`, it should not be
tracked as a direct input dependency.

This change adds a condition to verify if `ar` is an explicit path
rather than just a filename. It only includes `ar` in the action's
inputs list when it is not resolved from `$PATH`.

This is to address
https://crrev.com/c/7835150/8/build/toolchain/gcc_toolchain.gni#406

Bug: 358521078
Change-Id: I096ac4aa7f3b697c58c94af1349159b9c87f4201
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7904982
Commit-Queue: Takuto Ikuta <tikuta@chromium.org>
Reviewed-by: Matt Stark <msta@google.com>
Auto-Submit: Takuto Ikuta <tikuta@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1643634}
---

diff --git a/build/toolchain/gcc_toolchain.gni b/build/toolchain/gcc_toolchain.gni
index 51433d4..ec66ab3 100644
--- a/build/toolchain/gcc_toolchain.gni
+++ b/build/toolchain/gcc_toolchain.gni
@@ -408,8 +408,12 @@
         command = "cmd /s /c \"\"$python_path\" $tool_wrapper_path delete-file {{output}} && $command\""
       } else {
         command = "rm -f {{output}} && $command"
-        inputs =
-            [ get_path_info(rebase_path(ar, ".", root_out_dir), "abspath") ]
+
+        # Add ar to inputs if it's not from $PATH.
+        if (get_path_info(ar, "file") != ar) {
+          inputs =
+              [ get_path_info(rebase_path(ar, ".", root_out_dir), "abspath") ]
+        }
       }
 
       # Almost all targets build with //build/config/compiler:thin_archive which