On 11/9/21 13:42, Patrick Palka wrote:
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.
We do maintain such a freelist, in make_tree_vector/release_tree_vector,
which releasing_vec is a wrapper class for.
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;
