From 3c3bb0580be0027a1c7187b78c747af74dcfa884 Mon Sep 17 00:00:00 2001 From: Andrew Burgess Date: Fri, 13 Jul 2018 12:01:16 +0100 Subject: gdb: Add switch to disable DWARF stack unwinders Add a maintenance command to disable the DWARF stack unwinders. Normal users would not need this feature, but it is useful to allow extended testing of fallback stack unwinding strategies, for example, prologue scanners. This is a partial implementation of the idea discussed in pr gdb/8434, which talks about a generic ability to disable any frame unwinder. Being able to arbitrarily disable any frame unwinder would be a more complex patch, and I was unsure how useful such a feature would really be, however, I can see (and have) a real need to disable DWARF unwinders. That's why this patch only targets that specific set of unwinders. If in the future we find ourselves adding more switches to disable different unwinders, then we should probably move to a more generic solution, and remove this patch. gdb/ChangeLog: * dwarf2-frame-tailcall.c (tailcall_frame_sniffer): Exit early if DWARF unwinders are disabled. * dwarf2-frame.c: Add dwarf2read.h include. (dwarf2_frame_sniffer): Exit early if DWARF unwinders are disabled. (dwarf2_frame_unwinders_enabled_p): Define. (show_dwarf_unwinders_enabled_p): New function. (_initialize_dwarf2_frame): Register switch to control DWARF unwinder use. * dwarf2-frame.h (dwarf2_frame_unwinders_enabled_p): Declare. * dwarf2read.c (set_dwarf_cmdlist): Remove static keyword. (show_dwarf_cmdlist): Remove static keyword. * dwarf2read.h (set_dwarf_cmdlist): Declare. (show_dwarf_cmdlist): Declare. * NEWS: Document new feature. gdb/doc/ChangeLog: * gdb.texinfo (Maintenance Commands): Add description of maintenance command to control dwarf unwinders. gdb/testsuite/ChangeLog: * gdb.base/maint.exp: Add check that dwarf unwinders control flag is visible. --- gdb/NEWS | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'gdb/NEWS') diff --git a/gdb/NEWS b/gdb/NEWS index 76b963e..669ed2d 100644 --- a/gdb/NEWS +++ b/gdb/NEWS @@ -27,6 +27,10 @@ tfaas COMMAND output). Shortcut for 'thread apply all -s frame apply all -s COMMAND'. +maint set dwarf unwinders (on|off) +maint show dwarf unwinders + Control whether DWARF unwinders can be used. + * Changed commands thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND -- cgit v1.1