[Bug target/102683] [12 Regression] ICE in set_min_and_max_values_for_integral_type, at stor-layout.c:2851

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102683

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jason at gcc dot gnu.org

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
Now, for some reason we initialize 'y' which is clearly not necessary:

      y = .DEFERRED_INIT (32, 2, 0);
      if (n == 1) goto <D.1920>; else goto <D.1921>;
      <D.1920>:
      y = x;
      goto <D.1922>;
      <D.1921>:
      y = *.LC1;
      <D.1922>:

and the suggested patch fixes the ICE during expansion.  But we should avoid
the .DEFERRED_INIT here.  The GENERIC is

    struct C y;
  <<cleanup_point <<< Unknown tree: expr_stmt
  (void) (y = n == 1 ? TARGET_EXPR <D.1917, x> : TARGET_EXPR <D.1916,
{.c=__complex__ (3.0e+0, 3.0e+0)}>) >>>>>;

so we have first

        stmt <decl_expr 0x7ffff6666da0 type <void_type 0x7ffff6558f18 void>
            side-effects arg:0 <var_decl 0x7ffff7ff52d0 y>
            t.i:10:5 start: t.i:10:5 finish: t.i:10:5>

and then

        stmt <cleanup_point_expr 0x7ffff6666e00 type <void_type 0x7ffff6558f18
void>
            side-effects
            arg:0 <expr_stmt 0x7ffff6666de0 type <void_type 0x7ffff6558f18
void>
                side-effects
                arg:0 <convert_expr 0x7ffff6666dc0 type <void_type
0x7ffff6558f18 void>
                    side-effects
                    arg:0 <init_expr 0x7ffff66810a0 type <record_type
0x7ffff6663d20 C>
                        side-effects arg:0 <var_decl 0x7ffff7ff52d0 y>
                        arg:1 <cond_expr 0x7ffff66772d0 type <record_type
0x7ffff6663d20 C>
...

so this is an INIT_EXPR which never(?) requires .DEFERRED_INIT?  Of course
we're instrumenting the DECL_EXPR, not the INIT_EXPR and at that point
we didn't see the INIT_EXPR.

I wonder if we want a bit on DECL_EXPR denoting whether the decl is
fully initialized?