Re: [coreboot] Ouch: romcc "x[0] |= something" patch causes another crash

[Stefan Reinauer]

On 3/15/10 10:59 AM, Patrick Georgi wrote:
> Am 15.03.2010 03:32, schrieb Keith Hui:
> > > Hi all,
> > >
> > > I regret to report that the romcc patch circulated earlier to fix the
> > > segfault I reported, is now causing another segfault. This also seems to
> > > be triggered by something in the 440BX code, as it didn't segfault when
> > > I compile for any mainboards that isn't 440BX. As of now I don't know
> > > what this new segfault is. I'll report back with more findings.
>
> It seems the problem was that copy_triple() isn't supposed to be used on
> flattened (and simple) nodes.
> I built a simple test case that failed:
> void main(void) {
>         int c = 0;
>         c |= 4;
> }
>
> With the attached patch, this testcase, your testcase, and a full abuild
> run work.
>
> Signed-off-by: Patrick Georgi

I can't really verify if this is the correct thing to do, but since it
fixes abuild...

Acked-by: Stefan Reinauer
> 20100315-2-romcc
> Index: util/romcc/romcc.c
>
> --- util/romcc/romcc.c	(Revision 5210)
> +++ util/romcc/romcc.c	(Arbeitskopie)
> @@ -11557,7 +11557,7 @@
>
> static struct triple *assignment_expr(struct compile_state *state)
>  {
> struct triple *def, *left, *right;
> struct triple *def, *left, *left2, *right;
> int tok, op, sign;
> /* The C grammer in K&R shows assignment expressions
> only taking unary expressions as input on their
>
> @@ -11578,6 +11578,9 @@
>     */
>    def = conditional_expr(state);
>    left = def;
> left2 = left;
> if (!(left2->id & TRIPLE_FLAG_FLATTENED))
> left2 = copy_triple(state, left2);
> switch((tok = peek(state))) {
> case TOK_EQ:
> lvalue(state, left);
>
> @@ -11603,19 +11606,19 @@
>    	}
>    	def = write_expr(state, left,
>    		triple(state, op, left->type,
> 		read_expr(state, copy_triple(state, left)), right));
> 		read_expr(state, left2), right));
> break;
> case TOK_PLUSEQ:
> lvalue(state, left);
> eat(state, TOK_PLUSEQ);
> def = write_expr(state, left,
> 	mk_add_expr(state, copy_triple(state, left), assignment_expr(state)));
> 	mk_add_expr(state, left2, assignment_expr(state)));
> break;
> case TOK_MINUSEQ:
> lvalue(state, left);
> eat(state, TOK_MINUSEQ);
> def = write_expr(state, left,
> 	mk_sub_expr(state, copy_triple(state, left), assignment_expr(state)));
> 	mk_sub_expr(state, left2, assignment_expr(state)));
> break;
> case TOK_SLEQ:
> case TOK_SREQ:
>
> @@ -11639,7 +11642,7 @@
>    	}
>    	def = write_expr(state, left,
>    		triple(state, op, left->type,
> 		read_expr(state, copy_triple(state,left)), right));
> 		read_expr(state, left2), right));
> break;
> }
> return def;
>
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