[Bug target/100603] New: csky: config/csky/csky.h:402:13: error: comparison of unsigned expression in '>= 0' is always true [-Werror=type-limits]

["jbglaw@lug-owl.de" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100603

            Bug ID: 100603
           Summary: csky: config/csky/csky.h:402:13: error: comparison of
                    unsigned expression in '>= 0' is always true
                    [-Werror=type-limits]
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jbglaw@lug-owl.de
  Target Milestone: ---

Hi!

I've started doing CI builds for numerous targets again and stumbled over this
(as of 5e0236d3b0e0d7ad98bcee36128433fa755b5558) using Debian's "gcc-snapshot":

$ g++ --version
g++ (Debian 20210320-1) 11.0.1 20210320 (experimental) [master revision
3279a9a5a9a:6526c452d22:5f256a70a05fcfc5a1caf56678ceb12b4f87f781]

$ ./configure --target=csky-linux-gnu --enable-werror-always
--enable-languages=all --prefix=/tmp/gcc-csky-linux-gnu

$ make all-gcc
[...]
/usr/lib/gcc-snapshot/bin/g++  -fno-PIE -c   -g -O2 -DIN_GCC 
-DCROSS_DIRECTORY_STRUCTURE   -fno-exceptions -fno-rtti
-fasynchronous-unwind-tables -W -Wall -Wno-narrowing -Wwrite-strings
-Wcast-qual -Wno-error=format-diag -Wmissing-format-attribute
-Woverloaded-virtual -pedantic -Wno-long-long -Wno-variadic-macros
-Wno-overlength-strings -Werror -fno-common  -DHAVE_CONFIG_H -I. -I.
-I../.././gcc -I../.././gcc/. -I../.././gcc/../include
-I../.././gcc/../libcpp/include -I../.././gcc/../libcody 
-I../.././gcc/../libdecnumber -I../.././gcc/../libdecnumber/dpd
-I../libdecnumber -I../.././gcc/../libbacktrace   -o builtins.o -MT builtins.o
-MMD -MP -MF ./.deps/builtins.TPo ../.././gcc/builtins.c
[all 2021-05-13 15:48:27.392703] In file included from ./tm.h:32,
[all 2021-05-13 15:48:27.392897]                  from
../.././gcc/backend.h:28,
[all 2021-05-13 15:48:27.392981]                  from
../.././gcc/builtins.c:27:
[all 2021-05-13 15:48:27.393053] ../.././gcc/builtins.c: In function 'int
apply_args_size()':
[all 2021-05-13 15:48:27.393128] ../.././gcc/config/csky/csky.h:402:13: error:
comparison of unsigned expression in '>= 0' is always true
[-Werror=type-limits]
[all 2021-05-13 15:48:27.393204]   402 |   (((REGNO) >= CSKY_FIRST_PARM_REGNUM 
                      \
[all 2021-05-13 15:48:27.393279] ../.././gcc/builtins.c:2187:13: note: in
expansion of macro 'FUNCTION_ARG_REGNO_P'
[all 2021-05-13 15:48:27.393350]  2187 |         if (FUNCTION_ARG_REGNO_P
(regno))
[all 2021-05-13 15:48:27.393420]       |             ^~~~~~~~~~~~~~~~~~~~
[all 2021-05-13 15:49:14.430002] cc1plus: all warnings being treated as errors
[all 2021-05-13 15:49:14.463549] make[1]: *** [Makefile:1142: builtins.o] Error
1
[all 2021-05-13 15:49:14.464381] make[1]: Leaving directory
'/var/lib/laminar/run/gcc-csky-linux-gnu/1/gcc/host-x86_64-pc-linux-gnu/gcc'
[all 2021-05-13 15:49:14.469285] make: *** [Makefile:4432: all-gcc] Error 2