Hi!
Andrew P. mentioned earlier he'd like to see in the dump files a note
whether it was a failed must tail call or not.
We already print that on the tailc/musttail pass side, because
print_gimple_stmt prints [must tail call] after the musttail calls.
The first hunk below does it for GENERIC CALL_EXPRs too (which is needed
for the expand diagnostics). That isn't enough though, because the
error on it was done first and then CALL_EXPR_MUST_TAIL_CALL flag was
cleared, so the dump didn't have it anymore. I've reordered the
dump printing with error, so that it works properly.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2025-04-14 Jakub Jelinek <ja...@redhat.com>
PR tree-optimization/119718
* tree-pretty-print.cc (dump_generic_node) <case CALL_EXPR>: Dump
also CALL_EXPR_MUST_TAIL_CALL flag.
* calls.cc (maybe_complain_about_tail_call): Emit error about
CALL_EXPR_MUST_TAIL_CALL only after emitting dump message, not before
it.
--- gcc/tree-pretty-print.cc.jj 2025-04-12 13:09:55.367024475 +0200
+++ gcc/tree-pretty-print.cc 2025-04-14 08:58:21.480256810 +0200
@@ -3201,6 +3201,8 @@ dump_generic_node (pretty_printer *pp, t
pp_string (pp, " [return slot optimization]");
if (CALL_EXPR_TAILCALL (node))
pp_string (pp, " [tail call]");
+ if (CALL_EXPR_MUST_TAIL_CALL (node))
+ pp_string (pp, " [must tail call]");
break;
case WITH_CLEANUP_EXPR:
--- gcc/calls.cc.jj 2025-04-12 13:12:53.788557966 +0200
+++ gcc/calls.cc 2025-04-14 09:00:00.939905377 +0200
@@ -1273,11 +1273,6 @@ void
maybe_complain_about_tail_call (tree call_expr, const char *reason)
{
gcc_assert (TREE_CODE (call_expr) == CALL_EXPR);
- if (CALL_EXPR_MUST_TAIL_CALL (call_expr))
- {
- error_at (EXPR_LOCATION (call_expr), "cannot tail-call: %s", reason);
- CALL_EXPR_MUST_TAIL_CALL (call_expr) = 0;
- }
if (CALL_EXPR_TAILCALL (call_expr)
&& dump_file
&& (dump_flags & TDF_DETAILS))
@@ -1286,6 +1281,11 @@ maybe_complain_about_tail_call (tree cal
print_generic_expr (dump_file, call_expr, TDF_SLIM);
fprintf (dump_file, "\n");
}
+ if (CALL_EXPR_MUST_TAIL_CALL (call_expr))
+ {
+ error_at (EXPR_LOCATION (call_expr), "cannot tail-call: %s", reason);
+ CALL_EXPR_MUST_TAIL_CALL (call_expr) = 0;
+ }
}
/* Fill in ARGS_SIZE and ARGS array based on the parameters found in
Jakub
