Hi,
On Wed, Jul 15 2020, Shuai Wang via Gcc wrote:
> Hello,
>
> I am using the following code to iterate different gimple statements:
>
> ...
> gimple* stmt = gsi_stmt(gsi);
> if (gimple_assign_load_p(stmt)) {
> tree rhs = gimple_assign_rhs1 (stmt);
> if (!rhs) return;
> gimple* def_stmt = SSA_NAME_DEF_STMT(rhs);
The RHS of a gimple load can never be an SSA_NAME (just look at the
source of gimple_assign_load_p), so you cannot use SSA_NAME_DEF_STMT
with it. It's usually a VAR_DECL (or PARM_DECL) or MEM_REF which
however can be buried within arbitrarily complex "handled_component"
(see handled_component_p), i.e. ARRAY_REFs, COMPONENT_REFs and the like.
> if (!def_stmt) return;
>
> switch (gimple_code (def_stmt)) {
> ....
> }
> }
>
> While the above code works smoothly for most of the cases, to my surprise,
> the following statement (pointed by gsi) would cause a crash at
> gimple_code(def_stmt):
>
> stderr.9_1 = stderr;
the RHS is a VAR_DECL here.
Martin
