On Fri, Feb 02, 2018 at 09:41:49PM +0100, Julia Lawall wrote:
> The parser is extended to record positions, in build_node,
> build_node_delete, and build_property.
>
> srcpos structures are added to the property and node types, and to the
> parameter lists of the above functions that construct these types.
> Nodes and properties that are created by the compiler rather than from
> parsing source code have NULL as the srcpos value.
>
> merge_nodes, defined in livetree.c uses srcpos_extend to combine
> multiple positions, resulting in a list of positions. srcpos_extend is
> defined in srcpos.c and removes duplicates. As srcpos_extend is
> performing a union, it is O(n^2). The recursion serves to copy the new
> list and then add it to the front of the old one. Using recursion keeps
> the positions in order from newer to older. On each recursive call, the
> current element is compared against each element in the proposed new
> tail, to avoid duplicates. Since the list of positions is only extended
> in srcpos_extend, and srcpos_extend does not produce lists with
> duplicates, it is not necessary to check for the current element in the
> tail of its own list.
>
> Another change to srcpos.c is to make srcpos_copy always do a full copy,
> including a copy of the file substructure. This is required because
> when dtc is used on the output of cpp, the successive detected file
> names overwrite the file name in the file structure. The next field
> does not need to be deep copied, because it is only updated in newly
> copied positions and the positions to which it points have also been
> copied. File names are only updated in uncopied position structures.
>
> Signed-off-by: Julia Lawall <Julia.Lawall@xxxxxxx>
> Signed-off-by: Frank Rowand <frank.rowand@xxxxxxxx>
Sorry I've taken so long to look at this properly.
This looks pretty good overall. Couple of nits noted below..
[snip]
> diff --git a/srcpos.c b/srcpos.c
> index 9dd3297..c6688e7 100644
> --- a/srcpos.c
> +++ b/srcpos.c
> @@ -207,6 +207,7 @@ struct srcpos srcpos_empty = {
> .last_line = 0,
> .last_column = 0,
> .file = NULL,
> + .next = NULL,
> };
>
> void srcpos_update(struct srcpos *pos, const char *text, int len)
> @@ -234,13 +235,52 @@ struct srcpos *
> srcpos_copy(struct srcpos *pos)
> {
> struct srcpos *pos_new;
> + struct srcfile_state *srcfile_state;
> +
> + if (!pos)
> + return NULL;
>
> pos_new = xmalloc(sizeof(struct srcpos));
> memcpy(pos_new, pos, sizeof(struct srcpos));
>
> + if (pos_new) {
No need for the if - that's what xmalloc is for (plus we've already
written to the pointer in the memcpy().
> + /* allocate without free */
> + srcfile_state = xmalloc(sizeof(struct srcfile_state));
> + memcpy(srcfile_state, pos->file, sizeof(struct srcfile_state));
> +
> + pos_new->file = srcfile_state;
> + }
> +
> return pos_new;
> }
>
> +static bool same_pos(struct srcpos *p1, struct srcpos *p2)
> +{
> + return (p1->first_line == p2->first_line &&
> + p1->first_column == p2->first_column &&
> + p1->last_line == p2->last_line &&
> + p1->last_column == p2->last_column &&
> + !strcmp(p1->file->name, p2->file->name));
> +}
> +
> +struct srcpos *srcpos_extend(struct srcpos *pos, struct srcpos *newtail)
> +{
> + struct srcpos *next, *p;
> +
> + if (!pos)
> + return newtail;
> +
> + next = srcpos_extend(pos->next, newtail);
> +
> + for (p = newtail; p != NULL; p = p->next)
> + if (same_pos(pos, p))
> + return next;
> +
> + pos = srcpos_copy(pos);
> + pos->next = next;
> + return pos;
This copies pos and doesn't free the original - and the caller doesn't
free the original either, so there's a leak here.
> +}
> +
> char *
> srcpos_string(struct srcpos *pos)
> {
> diff --git a/srcpos.h b/srcpos.h
> index 9ded12a..d88e7cb 100644
> --- a/srcpos.h
> +++ b/srcpos.h
> @@ -74,6 +74,7 @@ struct srcpos {
> int last_line;
> int last_column;
> struct srcfile_state *file;
> + struct srcpos *next;
> };
>
> #define YYLTYPE struct srcpos
> @@ -105,6 +106,8 @@ extern struct srcpos srcpos_empty;
>
> extern void srcpos_update(struct srcpos *pos, const char *text, int len);
> extern struct srcpos *srcpos_copy(struct srcpos *pos);
> +extern struct srcpos *srcpos_extend(struct srcpos *new_srcpos,
> + struct srcpos *old_srcpos);
> extern char *srcpos_string(struct srcpos *pos);
>
> extern void PRINTF(3, 0) srcpos_verror(struct srcpos *pos, const char *prefix,
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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