[Bug bootstrap/88721] New: [9 regression] -Wmaybe-uninitialized warnings in sparc.c

[ro at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88721

            Bug ID: 88721
           Summary: [9 regression] -Wmaybe-uninitialized warnings in
                    sparc.c
           Product: gcc
           Version: 9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: bootstrap
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ro at gcc dot gnu.org
                CC: ebotcazou at gcc dot gnu.org
  Target Milestone: ---
              Host: sparc-sun-solaris2.11
            Target: sparc-sun-solaris2.11
             Build: sparc-sun-solaris2.11

Between 20190104 (r267571) and 20190105 (r267602), Solaris/SPARC bootstrap
began
to fail:

/vol/gcc/src/hg/trunk/local/gcc/config/sparc/sparc.c: In function 'rtx_def*
sparc_function_incoming_arg(cumulative_args_t, machine_mode, const_tree,
bool)':
/vol/gcc/src/hg/trunk/local/gcc/config/sparc/sparc.c:7417:39: error: 'regno'
may be used uninitialized in this function [-Werror=maybe-uninitialized]
 7417 |       return function_arg_union_value (size, mode, slotno, regno);
      |              ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
/vol/gcc/src/hg/trunk/local/gcc/config/sparc/sparc.c:7386:15: note: 'regno' was
declared here
 7386 |   int slotno, regno, padding;
      |               ^~~~~

/vol/gcc/src/hg/trunk/local/gcc/config/sparc/sparc.c: In function 'void
sparc_function_arg_advance(cumulative_args_t, machine_mode, const_tree, bool)':
/vol/gcc/src/hg/trunk/local/gcc/config/sparc/sparc.c:7603:14: error: 'padding'
may be used uninitialized in this function [-Werror=maybe-uninitialized]
 7603 |   cum->words += padding;
      |   ~~~~~~~~~~~^~~~~~~~~~