Commit 912fed3380

Alex Rønne Petersen <alex@alexrp.com>
2025-10-14 09:52:10
std.debug: use the SP as the initial FP on SPARC
The FP would point to the register save area for the previous frame, while the SP points to the register save area for the current frame. So use the latter.
1 parent 6de2d61
Changed files (1)
lib
lib/std/debug.zig
@@ -825,8 +825,19 @@ const StackIterator = union(enum) {
             // in our caller's frame and above.
             return .{ .di = .init(&.current()) };
         }
-        flushSparcWindows();
-        return .{ .fp = @frameAddress() };
+        return .{
+            // On SPARC, the frame pointer will point to the previous frame's save area,
+            // meaning we will read the previous return address and thus miss a frame.
+            // Instead, start at the stack pointer so we get the return address from the
+            // current frame's save area. The addition of the stack bias cannot fail here
+            // since we know we have a valid stack pointer.
+            .fp = if (native_arch.isSPARC()) sp: {
+                flushSparcWindows();
+                break :sp asm (""
+                    : [_] "={o6}" (-> usize),
+                ) + stack_bias;
+            } else @frameAddress(),
+        };
     }
     fn deinit(si: *StackIterator) void {
         switch (si.*) {