Re: [PATCH 1/3] dtc: Keep type information from DTS

[Stephen Warren <swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>]

On 12/13/2013 09:49 AM, Tomasz Figa wrote:
> Currently dtc loses information about data types when parsing DTS,
> because it flattens all the parsed property data into a flat stream of
> bytes. The only saved metadata is for references to other nodes inside
> cell arrays. This makes it impossible to do any checks on data types on
> livetree representation.
> 
> This patch makes dtc store type information inside data struct by using
> marker infrastructure. A new type of marker is introduced that holds
> type enum as its ref member. Such markers are then inserted wherever
> data of given type starts, so information about type of each property
> data section is preserved.

> diff --git a/dtc-parser.y b/dtc-parser.y

>  	| propdataprefix DT_REF
>  		{
> -			$$ = data_add_marker($1, REF_PATH, $2);
> +			struct data d;
> +			d = data_add_marker($1, TYPE, (char *)TYPE_STRING);
> +			$$ = data_add_marker(d, REF_PATH, $2);
>  		}

I guess here, the lexer does give us a string that's the target of the
reference, so this is correct. However, I wonder if semantically we
shouldn't call this a TYPE_REFERENCE, so we can distinguish between
references and regular strings?

> diff --git a/livetree.c b/livetree.c

> @@ -530,16 +530,24 @@ cell_t get_node_phandle(struct node *root, struct node *node)
>  	node->phandle = phandle;
>  
>  	if (!get_property(node, "linux,phandle")
> -	    && (phandle_format & PHANDLE_LEGACY))
> +	    && (phandle_format & PHANDLE_LEGACY)) {
> +		struct data d;
> +
> +		d = data_add_marker(empty_data, TYPE, (char *)TYPE_ARRAY_INT32);

Similarly here, can we encode as e.g. TYPE_PHANDLE or something like
that, so we keep the semantic information?

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