On Wed, Nov 22, 2023 at 01:21:12PM +0100, Jakub Jelinek wrote:
> So, pedantically perhaps just assuming TRY_CATCH_EXPR where second argument
> is not STATEMENT_LIST to be the CATCH_EXPR/EH_FILTER_EXPR case could work
> for C++, but there are other FEs and it would be fragile (and weird, given
> that STATEMENT_LIST with single stmt in it vs. that stmt ought to be
> generally interchangeable).
Looking at other FE, e.g. go/go-gcc.cc clearly has:
stat_tree = build2_loc(location.gcc_location(), TRY_CATCH_EXPR,
void_type_node, stat_tree,
build2_loc(location.gcc_location(), CATCH_EXPR,
void_type_node, NULL, except_tree));
so CATCH_EXPR is immediately the second operand of TRY_CATCH_EXPR.
d/toir.cc has:
/* Back-end expects all catches in a TRY_CATCH_EXPR to be enclosed in a
statement list, however pop_stmt_list may optimize away the list
if there is only a single catch to push. */
if (TREE_CODE (catches) != STATEMENT_LIST)
{
tree stmt_list = alloc_stmt_list ();
append_to_statement_list_force (catches, &stmt_list);
catches = stmt_list;
}
add_stmt (build2 (TRY_CATCH_EXPR, void_type_node, trybody, catches));
so I assume it run into the try_catch_may_fallthru issue (because gimplifier
clearly doesn't require that).
rust/rust-gcc.cc copies go-gcc.cc and also creates CATCH_EXPR directly in
TRY_CATCH_EXPR's operand.
Note, the only time one runs into the ICE is when the first operand (i.e.
try body) doesn't fall thru, otherwise the function returns true early.
Jakub
