zig

commit 80f6b8c4b3a6dcb17dcd9bb3ecaf528b3da9c54e (tree)
parent c383cd50d5eb3b677493ab0058d860a9177a2679
Author: mlugg <mlugg@mlugg.co.uk>
Date:   Thu,  9 Oct 2025 14:14:19 +0100

std.debug: fix incorrect FP unwinding on RISC-V and SPARC

I broke this when porting this logic for the `std.debug` rework in
https://github.com/ziglang/zig/pull/25227. The offset that I copied was
actually being treated as relative to the address of the *saved* base
pointer. I think it makes more sense to do what I did and just treat all
offsets as relative to this frame's base.

Diffstat:
M
lib/std/debug.zig
 | 
2
++

1 file changed, 2 insertions(+), 0 deletions(-)
diff --git a/lib/std/debug.zig b/lib/std/debug.zig
@@ -993,6 +993,8 @@ const StackIterator = union(enum) {
 
     /// Offset of the saved return address wrt the frame pointer.
     const ra_offset = off: {
+        if (native_arch.isRISCV()) break :off -1 * @sizeOf(usize);
+        if (native_arch.isSPARC()) break :off 15 * @sizeOf(usize);
         if (native_arch.isPowerPC64()) break :off 2 * @sizeOf(usize);
         // On s390x, r14 is the link register and we need to grab it from its customary slot in the
         // register save area (ELF ABI s390x Supplement §1.2.2.2).