runtime: set $sp before $pc in gdb python script
When setting $pc, gdb does a backtrace using the current value of $sp,
and it may complain if $sp does not match that $pc (although the
assignment went through successfully).
This happens with ARM SSA backend: when setting $pc it prints
> Cannot access memory at address 0x0
As well as occasionally on MIPS64:
> warning: GDB can't find the start of the function at 0xc82003fe07.
> ...
Setting $sp before setting $pc makes it happy.
Change-Id: Idd96dbef3e9b698829da553c6d71d5b4c6d492db
Reviewed-on: https://go-review.googlesource.com/23940
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
diff --git a/src/runtime/runtime-gdb.py b/src/runtime/runtime-gdb.py
index e57fa00..5c9b2a0 100644
--- a/src/runtime/runtime-gdb.py
+++ b/src/runtime/runtime-gdb.py
@@ -448,15 +448,15 @@
except gdb.error:
pc = int(str(pc).split(None, 1)[0], 16)
save_frame = gdb.selected_frame()
- gdb.parse_and_eval('$save_pc = $pc')
gdb.parse_and_eval('$save_sp = $sp')
- gdb.parse_and_eval('$pc = {0}'.format(str(pc)))
+ gdb.parse_and_eval('$save_pc = $pc')
gdb.parse_and_eval('$sp = {0}'.format(str(sp)))
+ gdb.parse_and_eval('$pc = {0}'.format(str(pc)))
try:
gdb.execute(cmd)
finally:
- gdb.parse_and_eval('$pc = $save_pc')
gdb.parse_and_eval('$sp = $save_sp')
+ gdb.parse_and_eval('$pc = $save_pc')
save_frame.select()
