From 2e2d6d2c3dcaccb101c97cf81e7a5f2afdf1ed49 Mon Sep 17 00:00:00 2001
From: kcbanner <kcbanner@gmail.com>
Date: Sun, 27 Aug 2023 19:50:57 -0400
Subject: [PATCH] linux: fixup for platforms that don't support extern
 functions yet

---
 lib/std/os/linux.zig | 23 +++++++++++++++--------
 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/lib/std/os/linux.zig b/lib/std/os/linux.zig
index c967c1dd7b..9d3dcac559 100644
--- a/lib/std/os/linux.zig
+++ b/lib/std/os/linux.zig
@@ -154,9 +154,21 @@ pub usingnamespace @import("linux/io_uring.zig");
 /// Set by startup code, used by `getauxval`.
 pub var elf_aux_maybe: ?[*]std.elf.Auxv = null;
 
-/// See `std.elf` for the constants.
-/// This matches the libc getauxval function.
-pub extern fn getauxval(index: usize) usize;
+pub usingnamespace if (switch (builtin.zig_backend) {
+    // Calling extern functions is not yet supported with these backends
+    .stage2_x86_64, .stage2_aarch64, .stage2_arm, .stage2_riscv64, .stage2_sparc64 => false,
+    else => !builtin.link_libc,
+}) struct {
+    /// See `std.elf` for the constants.
+    /// This matches the libc getauxval function.
+    pub extern fn getauxval(index: usize) usize;
+    comptime {
+        @export(getauxvalImpl, .{ .name = "getauxval", .linkage = .Weak });
+    }
+} else struct {
+    pub const getauxval = getauxvalImpl;
+};
+
 fn getauxvalImpl(index: usize) callconv(.C) usize {
     const auxv = elf_aux_maybe orelse return 0;
     var i: usize = 0;
@@ -166,11 +178,6 @@ fn getauxvalImpl(index: usize) callconv(.C) usize {
     }
     return 0;
 }
-comptime {
-    if (!builtin.link_libc) {
-        @export(getauxvalImpl, .{ .name = "getauxval", .linkage = .Weak });
-    }
-}
 
 // Some architectures (and some syscalls) require 64bit parameters to be passed
 // in a even-aligned register pair.