On 7/17/21 2:36 PM, Jan-Benedict Glaw wrote:
Hi Martin!
On Fri, 2021-06-04 15:27:04 -0600, Martin Sebor <mse...@gmail.com> wrote:
This is a revised patch series to add warning control by group and
location, updated based on feedback on the initial series.
[...]
My automated checking (in this case: Using Debian's "gcc-snapshot"
package) indicates that between versions 1:20210527-1 and
1:20210630-1, building GDB breaks. Your patch is a likely candidate.
It's a case where a method asks for a nonnull argument and later on
checks for NULLness again. The build log is currently available at
(http://wolf.lug-owl.de:8080/jobs/gdb-vax-linux/5), though obviously
breaks for any target:
configure --target=vax-linux --prefix=/tmp/gdb-vax-linux
make all-gdb
[...]
[all 2021-07-16 19:19:25] CXX compile/compile.o
[all 2021-07-16 19:19:30] In file included from
./../gdbsupport/common-defs.h:126,
[all 2021-07-16 19:19:30] from ./defs.h:28,
[all 2021-07-16 19:19:30] from compile/compile.c:20:
[all 2021-07-16 19:19:30] ./../gdbsupport/gdb_unlinker.h: In constructor
'gdb::unlinker::unlinker(const char*)':
[all 2021-07-16 19:19:30] ./../gdbsupport/gdb_assert.h:35:4: error: 'nonnull'
argument 'filename' compared to NULL [-Werror=nonnull-compare]
[all 2021-07-16 19:19:30] 35 | ((void) ((expr) ? 0 :
\
[all 2021-07-16 19:19:30] |
~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[all 2021-07-16 19:19:30] 36 | (gdb_assert_fail (#expr, __FILE__,
__LINE__, FUNCTION_NAME), 0)))
[all 2021-07-16 19:19:30] |
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[all 2021-07-16 19:19:30] ./../gdbsupport/gdb_unlinker.h:38:5: note: in
expansion of macro 'gdb_assert'
[all 2021-07-16 19:19:30] 38 | gdb_assert (filename != NULL);
[all 2021-07-16 19:19:30] | ^~~~~~~~~~
[all 2021-07-16 19:19:31] cc1plus: all warnings being treated as errors
[all 2021-07-16 19:19:31] make[1]: *** [Makefile:1641: compile/compile.o] Error
1
[all 2021-07-16 19:19:31] make[1]: Leaving directory
'/var/lib/laminar/run/gdb-vax-linux/5/binutils-gdb/gdb'
[all 2021-07-16 19:19:31] make: *** [Makefile:11410: all-gdb] Error 2
Code is this:
31 class unlinker
32 {
33 public:
34
35 unlinker (const char *filename) ATTRIBUTE_NONNULL (2)
36 : m_filename (filename)
37 {
38 gdb_assert (filename != NULL);
39 }
I'm quite undecided whether this is bad behavior of GCC or bad coding
style in Binutils/GDB, or both.
A warning should be expected in this case. Before the recent GCC
change it was inadvertently suppressed in gdb_assert macros by its
operand being enclosed in parentheses.
Martin
Thanks,
Jan-Benedict
