[DTrace-devel] [PATCH 15/20] Add support for string constants in compiled D programs

[Eugene Loh]

Oops.  Here's another one:

On 6/2/21 1:48 AM, Kris Van Hees wrote:
> diff --git a/libdtrace/dt_cg.c b/libdtrace/dt_cg.c
> @@ -1935,8 +1927,27 @@ dt_cg_store_var(dt_node_t *src, dt_irlist_t *dlp, dt_regset_t *drp,
>   
>   		/* store by value or by reference */
>   		if (src->dn_flags & DT_NF_REF) {
> +			size_t	size;
> +
>   			emit(dlp, BPF_ALU64_IMM(BPF_ADD, reg, idp->di_offset));
> -			dt_cg_memcpy(dlp, drp, reg, src->dn_reg, idp->di_size);
> +
> +			/*
> +			 * Determine the amount of data to be copied.  It is
> +			 * usually the size of the identifier, except for
> +			 * string constants where it is the size of the string
> +			 * constant (adjusted for the variable-width length
> +			 * prefix).  An assignment of a string constant is a
> +			 * store of type 'string' with a RHS of type
> +			 * DT_TOK_STRING.
> +			 */
> +			if (dt_node_is_string(src) &&
> +			    src->dn_right->dn_op == DT_TOK_STRING) {
> +				size = dt_node_type_size(src->dn_right);
> +				size += dt_vint_size(size) + 1;

dt_node_type_size() already includes a byte for the terminating NULL.  
So the size+= line should not include the +1.

> +			} else
> +				size = idp->di_size;
> +
> +			dt_cg_memcpy(dlp, drp, reg, src->dn_reg, size);
>   		} else {
>   			size_t	size = idp->di_size;
>