From ac793232eeeca87378b6b6cf4bec6e610859b5b1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alex=20R=C3=B8nne=20Petersen?= <alex@alexrp.com>
Date: Thu, 15 Jan 2026 07:55:47 +0100
Subject: [PATCH] test: skip non-libc module tests for targets that require or
 default to libc

We were just creating duplicate work and breaking -Dskip-libc.
---
 test/tests.zig | 32 ++++++++++++++++++++++----------
 1 file changed, 22 insertions(+), 10 deletions(-)

diff --git a/test/tests.zig b/test/tests.zig
index 52b2fe6621..7873774c2a 100644
--- a/test/tests.zig
+++ b/test/tests.zig
@@ -2345,27 +2345,39 @@ pub fn addModuleTests(b: *std.Build, options: ModuleTestOptions) *Step {
             }
         }
 
+        const resolved_target = b.resolveTargetQuery(test_target.target);
+        const target = &resolved_target.result;
+
+        if (test_target.link_libc == false and target.requiresLibC()) continue;
+        // If the target requires libc, there's no point building the cases that
+        // don't explicitly link libc as they'll just end up actually linking
+        // libc anyway, thus creating duplicate work and making -Dskip-libc not
+        // work as expected.
+        if (test_target.link_libc == null and target.requiresLibC()) continue;
+        // These targets don't strictly require libc, but we don't yet have a
+        // syscall layer for them, so the compiler links libc by default. They
+        // therefore get the same treatment here.
+        if (test_target.link_libc == null and (target.os.tag == .freebsd or target.os.tag == .netbsd)) continue;
+
         if (!options.test_extra_targets and test_target.extra_target) continue;
 
         if (options.skip_non_native and !test_target.target.isNative())
             continue;
 
-        if (options.skip_spirv and test_target.target.cpu_arch != null and test_target.target.cpu_arch.?.isSpirV()) continue;
-        if (options.skip_wasm and test_target.target.cpu_arch != null and test_target.target.cpu_arch.?.isWasm()) continue;
+        if (options.skip_spirv and target.cpu.arch.isSpirV()) continue;
+        if (options.skip_wasm and target.cpu.arch.isWasm()) continue;
 
-        if (options.skip_freebsd and test_target.target.os_tag == .freebsd) continue;
-        if (options.skip_netbsd and test_target.target.os_tag == .netbsd) continue;
-        if (options.skip_openbsd and test_target.target.os_tag == .openbsd) continue;
-        if (options.skip_windows and test_target.target.os_tag == .windows) continue;
-        if (options.skip_darwin and test_target.target.os_tag != null and test_target.target.os_tag.?.isDarwin()) continue;
-        if (options.skip_linux and test_target.target.os_tag == .linux) continue;
+        if (options.skip_freebsd and target.os.tag == .freebsd) continue;
+        if (options.skip_netbsd and target.os.tag == .netbsd) continue;
+        if (options.skip_openbsd and target.os.tag == .openbsd) continue;
+        if (options.skip_windows and target.os.tag == .windows) continue;
+        if (options.skip_darwin and target.os.tag.isDarwin()) continue;
+        if (options.skip_linux and target.os.tag == .linux) continue;
 
         const would_use_llvm = wouldUseLlvm(test_target.use_llvm, test_target.target, test_target.optimize_mode);
         if (options.skip_llvm and would_use_llvm) continue;
 
-        const resolved_target = b.resolveTargetQuery(test_target.target);
         const triple_txt = resolved_target.query.zigTriple(b.allocator) catch @panic("OOM");
-        const target = &resolved_target.result;
 
         if (options.test_target_filters.len > 0) {
             for (options.test_target_filters) |filter| {