Re: [PATCH] c++: don't leak 'arglist' in build_new_op

[Jason Merrill <jason@redhat.com>]

On 12/10/21 11:21, Patrick Palka wrote:
> 'arglist' can be captured by a conversion within 'candidates', but if we
> use a releasing_vec then we'll be sure to free it only after
> 'candidates' is freed by obstack_free.
> 
> Bootstrapped and regtested in x86_64-pc-linux-gnu, does this look OK for
> trunk?

OK.

> gcc/cp/ChangeLog:
> 
> 	* call.c (build_new_op): Use releasing_vec for arglist.  Declare
> 	conv in the scope it's used.
> ---
>   gcc/cp/call.c | 6 ++----
>   1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/gcc/cp/call.c b/gcc/cp/call.c
> index 28bd8e0c260..347df5da35d 100644
> --- a/gcc/cp/call.c
> +++ b/gcc/cp/call.c
> @@ -6461,13 +6461,12 @@ build_new_op (const op_location_t &loc, enum tree_code code, int flags,
>   	      tsubst_flags_t complain)
>   {
>     struct z_candidate *candidates = 0, *cand;
> -  vec<tree, va_gc> *arglist;
> +  releasing_vec arglist;
>     tree result = NULL_TREE;
>     bool result_valid_p = false;
>     enum tree_code code2 = ERROR_MARK;
>     enum tree_code code_orig_arg1 = ERROR_MARK;
>     enum tree_code code_orig_arg2 = ERROR_MARK;
> -  conversion *conv;
>     void *p;
>     bool strict_p;
>     bool any_viable_p;
> @@ -6543,7 +6542,6 @@ build_new_op (const op_location_t &loc, enum tree_code code, int flags,
>         arg2_type = integer_type_node;
>       }
>   
> -  vec_alloc (arglist, 3);
>     arglist->quick_push (arg1);
>     if (arg2 != NULL_TREE)
>       arglist->quick_push (arg2);
> @@ -6814,7 +6812,7 @@ build_new_op (const op_location_t &loc, enum tree_code code, int flags,
>   	     corresponding parameters of the selected operation function,
>   	     except that the second standard conversion sequence of a
>   	     user-defined conversion sequence (12.3.3.1.2) is not applied."  */
> -	  conv = cand->convs[0];
> +	  conversion *conv = cand->convs[0];
>   	  if (conv->user_conv_p)
>   	    {
>   	      conv = strip_standard_conversion (conv);