On Tue, 9 Nov 2021, Jason Merrill wrote:
> On 11/9/21 11:02, Patrick Palka wrote:
> > Bootstrapped and regtested on x86_64-pc-linux-gnu, OK for trunk?
>
> OK, though I wonder about using releasing_vec instead of auto_vec; reusing a
> previously allocated vec vs. building one on the stack.
Thanks a lot. And hmm, I think using reusing a previously allocated vec
here would be tricky since cp_parser_template_argument_list can be
called recursively, and so only the outermost call would be able to
benefit from reuse unless we perhaps maintain a freelist of such vecs
IIUC. Seems like that would complicate the code enough to not be worth
it.
> > gcc/cp/ChangeLog:
> >
> > * parser.c (cp_parser_template_argument_list): Use auto_vec
> > instead of manual memory management.
> > ---
> > gcc/cp/parser.c | 35 ++++++++---------------------------
> > 1 file changed, 8 insertions(+), 27 deletions(-)
> >
> > diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
> > index 32de97b08bd..8823399529e 100644
> > --- a/gcc/cp/parser.c
> > +++ b/gcc/cp/parser.c
> > @@ -18558,11 +18558,6 @@ cp_parser_template_name (cp_parser* parser,
> > static tree
> > cp_parser_template_argument_list (cp_parser* parser)
> > {
> > - tree fixed_args[10];
> > - unsigned n_args = 0;
> > - unsigned alloced = 10;
> > - tree *arg_ary = fixed_args;
> > - tree vec;
> > bool saved_in_template_argument_list_p;
> > bool saved_ice_p;
> > bool saved_non_ice_p;
> > @@ -18581,16 +18576,15 @@ cp_parser_template_argument_list (cp_parser*
> > parser)
> > parser->non_integral_constant_expression_p = false;
> > /* Parse the arguments. */
> > + auto_vec<tree, 10> args;
> > do
> > {
> > - tree argument;
> > -
> > - if (n_args)
> > + if (!args.is_empty ())
> > /* Consume the comma. */
> > cp_lexer_consume_token (parser->lexer);
> > /* Parse the template-argument. */
> > - argument = cp_parser_template_argument (parser);
> > + tree argument = cp_parser_template_argument (parser);
> > /* If the next token is an ellipsis, we're expanding a template
> > argument pack. */
> > @@ -18610,29 +18604,16 @@ cp_parser_template_argument_list (cp_parser*
> > parser)
> > argument = make_pack_expansion (argument);
> > }
> > - if (n_args == alloced)
> > - {
> > - alloced *= 2;
> > -
> > - if (arg_ary == fixed_args)
> > - {
> > - arg_ary = XNEWVEC (tree, alloced);
> > - memcpy (arg_ary, fixed_args, sizeof (tree) * n_args);
> > - }
> > - else
> > - arg_ary = XRESIZEVEC (tree, arg_ary, alloced);
> > - }
> > - arg_ary[n_args++] = argument;
> > + args.safe_push (argument);
> > }
> > while (cp_lexer_next_token_is (parser->lexer, CPP_COMMA));
> > - vec = make_tree_vec (n_args);
> > + int n_args = args.length ();
> > + tree vec = make_tree_vec (n_args);
> > - while (n_args--)
> > - TREE_VEC_ELT (vec, n_args) = arg_ary[n_args];
> > + for (int i = 0; i < n_args; i++)
> > + TREE_VEC_ELT (vec, i) = args[i];
> > - if (arg_ary != fixed_args)
> > - free (arg_ary);
> > parser->non_integral_constant_expression_p = saved_non_ice_p;
> > parser->integral_constant_expression_p = saved_ice_p;
> > parser->in_template_argument_list_p = saved_in_template_argument_list_p;
> >
>
>
