[PATCH 08/19] bootwrapper: Rename p and pp to anchor and anchorptr.

[PATCH 08/19] bootwrapper: Rename p and pp to anchor and anchorptr.

[Scott Wood]

This makes the meaning of "p" clearer, and increases the visual
difference between the two to avoid bugs such as the one fixed in
"Modify *pp, not *p, in ft_shuffle()".

Signed-off-by: Scott Wood <scottwood@freescale.com>
---
 arch/powerpc/boot/flatdevtree.c |   44 +++++++++++++++++++++-----------------
 1 files changed, 24 insertions(+), 20 deletions(-)

diff --git a/arch/powerpc/boot/flatdevtree.c b/arch/powerpc/boot/flatdevtree.c
index f2a29ca..0c8970e 100644
--- a/arch/powerpc/boot/flatdevtree.c
+++ b/arch/powerpc/boot/flatdevtree.c
@@ -215,23 +215,25 @@ static inline char *next_start(struct ft_cxt *cxt, enum ft_rgn_id r)
  * See if we can expand region rgn by nextra bytes by using up
  * free space after or before the region.
  */
-static int ft_shuffle(struct ft_cxt *cxt, char **pp, enum ft_rgn_id rgn,
-		int nextra)
+static int ft_shuffle(struct ft_cxt *cxt, char **anchorptr,
+                      enum ft_rgn_id rgn, int nextra)
 {
-	char *p = *pp;
+	char *anchor = *anchorptr;
 	char *rgn_start, *rgn_end;
 
 	rgn_start = cxt->rgn[rgn].start;
 	rgn_end = rgn_start + cxt->rgn[rgn].size;
 	if (nextra <= 0 || rgn_end + nextra <= next_start(cxt, rgn)) {
 		/* move following stuff */
-		if (p < rgn_end) {
+		if (anchor < rgn_end) {
 			if (nextra < 0)
-				memmove(p, p - nextra, rgn_end - p + nextra);
+				memmove(anchor, anchor - nextra,
+				        rgn_end - anchor + nextra);
 			else
-				memmove(p + nextra, p, rgn_end - p);
+				memmove(anchor + nextra, anchor,
+				        rgn_end - anchor);
 			if (rgn == FT_STRUCT)
-				ft_node_update_after(cxt, p, nextra);
+				ft_node_update_after(cxt, anchor, nextra);
 		}
 		cxt->rgn[rgn].size += nextra;
 		if (rgn == FT_STRINGS)
@@ -241,12 +243,13 @@ static int ft_shuffle(struct ft_cxt *cxt, char **pp, enum ft_rgn_id rgn,
 	}
 	if (prev_end(cxt, rgn) <= rgn_start - nextra) {
 		/* move preceding stuff */
-		if (p > rgn_start) {
-			memmove(rgn_start - nextra, rgn_start, p - rgn_start);
+		if (anchor > rgn_start) {
+			memmove(rgn_start - nextra, rgn_start,
+			        anchor - rgn_start);
 			if (rgn == FT_STRUCT)
-				ft_node_update_before(cxt, p, -nextra);
+				ft_node_update_before(cxt, anchor, -nextra);
 		}
-		*pp -= nextra;
+		*anchorptr -= nextra;
 		cxt->rgn[rgn].start -= nextra;
 		cxt->rgn[rgn].size += nextra;
 		return 1;
@@ -254,22 +257,22 @@ static int ft_shuffle(struct ft_cxt *cxt, char **pp, enum ft_rgn_id rgn,
 	return 0;
 }
 
-static int ft_make_space(struct ft_cxt *cxt, char **pp, enum ft_rgn_id rgn,
-			 int nextra)
+static int ft_make_space(struct ft_cxt *cxt, char **anchorptr,
+                         enum ft_rgn_id rgn, int nextra)
 {
 	unsigned long size, ssize, tot;
 	char *str, *next;
 	enum ft_rgn_id r;
 
 	if (!cxt->isordered) {
-		unsigned long rgn_off = *pp - cxt->rgn[rgn].start;
+		unsigned long rgn_off = *anchorptr - cxt->rgn[rgn].start;
 
 		if (!ft_reorder(cxt, nextra))
 			return 0;
 
-		*pp = cxt->rgn[rgn].start + rgn_off;
+		*anchorptr = cxt->rgn[rgn].start + rgn_off;
 	}
-	if (ft_shuffle(cxt, pp, rgn, nextra))
+	if (ft_shuffle(cxt, anchorptr, rgn, nextra))
 		return 1;
 
 	/* See if there is space after the strings section */
@@ -282,7 +285,8 @@ static int ft_make_space(struct ft_cxt *cxt, char **pp, enum ft_rgn_id rgn,
 		memmove(str, cxt->rgn[FT_STRINGS].start, ssize);
 		cxt->rgn[FT_STRINGS].start = str;
 		/* enough space now? */
-		if (rgn >= FT_STRUCT && ft_shuffle(cxt, pp, rgn, nextra))
+		if (rgn >= FT_STRUCT &&
+		    ft_shuffle(cxt, anchorptr, rgn, nextra))
 			return 1;
 	}
 
@@ -316,7 +320,7 @@ static int ft_make_space(struct ft_cxt *cxt, char **pp, enum ft_rgn_id rgn,
 				new_start = cxt->rgn[r].start + shift;
 				cxt->rgn[r].start = new_start;
 			}
-			*pp += shift;
+			*anchorptr += shift;
 			cxt->str_anchor += shift;
 		}
 
@@ -326,7 +330,7 @@ static int ft_make_space(struct ft_cxt *cxt, char **pp, enum ft_rgn_id rgn,
 		memmove(str, cxt->rgn[FT_STRINGS].start, ssize);
 		cxt->rgn[FT_STRINGS].start = str;
 
-		if (ft_shuffle(cxt, pp, rgn, nextra))
+		if (ft_shuffle(cxt, anchorptr, rgn, nextra))
 			return 1;
 	}
 
@@ -341,7 +345,7 @@ static int ft_make_space(struct ft_cxt *cxt, char **pp, enum ft_rgn_id rgn,
 		ft_node_update_after(cxt, cxt->rgn[FT_STRUCT].start, nextra);
 		cxt->rgn[FT_STRUCT].start = next;
 
-		if (ft_shuffle(cxt, pp, rgn, nextra))
+		if (ft_shuffle(cxt, anchorptr, rgn, nextra))
 			return 1;
 	}
 
-- 
1.5.0.3

Re: [PATCH 08/19] bootwrapper: Rename p and pp to anchor and anchorptr.

[David Gibson]

On Mon, Mar 12, 2007 at 02:41:50PM -0600, Scott Wood wrote:
> This makes the meaning of "p" clearer, and increases the visual
> difference between the two to avoid bugs such as the one fixed in
> "Modify *pp, not *p, in ft_shuffle()".

Hrm.  This does increase the visual difference, but honestly the
meaning of "anchor" is not notably more obvious to me than "p".

-- 
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

Re: [PATCH 08/19] bootwrapper: Rename p and pp to anchor and anchorptr.

[Mark A. Greer]

On Tue, Mar 13, 2007 at 01:19:55PM +1100, David Gibson wrote:
> On Mon, Mar 12, 2007 at 02:41:50PM -0600, Scott Wood wrote:
> > This makes the meaning of "p" clearer, and increases the visual
> > difference between the two to avoid bugs such as the one fixed in
> > "Modify *pp, not *p, in ft_shuffle()".
> 
> Hrm.  This does increase the visual difference, but honestly the
> meaning of "anchor" is not notably more obvious to me than "p".

Ditto :)

Re: [PATCH 08/19] bootwrapper: Rename p and pp to anchor and anchorptr.

[Scott Wood]

On Tue, Mar 13, 2007 at 01:19:55PM +1100, David Gibson wrote:
> On Mon, Mar 12, 2007 at 02:41:50PM -0600, Scott Wood wrote:
> > This makes the meaning of "p" clearer, and increases the visual
> > difference between the two to avoid bugs such as the one fixed in
> > "Modify *pp, not *p, in ft_shuffle()".
> 
> Hrm.  This does increase the visual difference, but honestly the
> meaning of "anchor" is not notably more obvious to me than "p".

The idea was that it's where the caller holds on to when the data gets
moved around.  I agree that it's not a great name, but I couldn't think
of anything better (and previously, someone requested that I change the
name from p).  Any suggestions?

-Scott