dtc: Add code to make diffing trees easier

Grant Likely grant.likely at secretlab.ca
Mon Oct 11 16:52:19 EST 2010


On Mon, Oct 11, 2010 at 11:37:38AM +1100, David Gibson wrote:
> This patch adds a "dtdiff" script to do a useful form diff of two
> device trees.  This automatically converts the tree to dts form (if
> it's not already) and uses a new "-s" option in dtc to "sort" the
> tree.  That is, it sorts the reserve entries, it sorts the properties
> within each node by name, and it sorts nodes by name within their
> parent.
> 
> This gives a pretty sensible diff between the trees, which will ignore
> semantically null internal rearrangements (directly diffing the dts
> files can give a lot of noise due to the order changes).
> 
> Signed-off-by: David Gibson <david at gibson.dropbear.id.au>

Acked-by: Grant Likely <grant.likely at secretlab.ca>

> 
> Index: dtc/dtc.c
> ===================================================================
> --- dtc.orig/dtc.c	2010-10-11 11:11:52.527359928 +1100
> +++ dtc/dtc.c	2010-10-11 11:11:53.675376132 +1100
> @@ -81,6 +81,8 @@ static void  __attribute__ ((noreturn)) 
>  	fprintf(stderr, "\t\tSet the physical boot cpu\n");
>  	fprintf(stderr, "\t-f\n");
>  	fprintf(stderr, "\t\tForce - try to produce output even if the input tree has errors\n");
> +	fprintf(stderr, "\t-s\n");
> +	fprintf(stderr, "\t\tSort nodes and properties before outputting (only useful for\n\t\tcomparing trees)\n");
>  	fprintf(stderr, "\t-v\n");
>  	fprintf(stderr, "\t\tPrint DTC version and exit\n");
>  	fprintf(stderr, "\t-H <phandle format>\n");
> @@ -97,7 +99,7 @@ int main(int argc, char *argv[])
>  	const char *inform = "dts";
>  	const char *outform = "dts";
>  	const char *outname = "-";
> -	int force = 0, check = 0;
> +	int force = 0, check = 0, sort = 0;
>  	const char *arg;
>  	int opt;
>  	FILE *outf = NULL;
> @@ -109,7 +111,7 @@ int main(int argc, char *argv[])
>  	minsize    = 0;
>  	padsize    = 0;
>  
> -	while ((opt = getopt(argc, argv, "hI:O:o:V:R:S:p:fcqb:vH:")) != EOF) {
> +	while ((opt = getopt(argc, argv, "hI:O:o:V:R:S:p:fcqb:vH:s")) != EOF) {
>  		switch (opt) {
>  		case 'I':
>  			inform = optarg;
> @@ -159,6 +161,10 @@ int main(int argc, char *argv[])
>  				    optarg);
>  			break;
>  
> +		case 's':
> +			sort = 1;
> +			break;
> +
>  		case 'h':
>  		default:
>  			usage();
> @@ -197,6 +203,8 @@ int main(int argc, char *argv[])
>  	fill_fullpaths(bi->dt, "");
>  	process_checks(force, bi);
>  
> +	if (sort)
> +		sort_tree(bi);
>  
>  	if (streq(outname, "-")) {
>  		outf = stdout;
> Index: dtc/dtc.h
> ===================================================================
> --- dtc.orig/dtc.h	2010-10-11 11:11:52.555383604 +1100
> +++ dtc/dtc.h	2010-10-11 11:11:53.675376132 +1100
> @@ -220,6 +220,7 @@ struct boot_info {
>  
>  struct boot_info *build_boot_info(struct reserve_info *reservelist,
>  				  struct node *tree, uint32_t boot_cpuid_phys);
> +void sort_tree(struct boot_info *bi);
>  
>  /* Checks */
>  
> Index: dtc/livetree.c
> ===================================================================
> --- dtc.orig/livetree.c	2010-10-11 11:11:52.567361045 +1100
> +++ dtc/livetree.c	2010-10-11 11:11:53.679382348 +1100
> @@ -470,3 +470,140 @@ uint32_t guess_boot_cpuid(struct node *t
>  
>  	return propval_cell(reg);
>  }
> +
> +static int cmp_reserve_info(const void *ax, const void *bx)
> +{
> +	const struct reserve_info *a, *b;
> +
> +	a = *((const struct reserve_info * const *)ax);
> +	b = *((const struct reserve_info * const *)bx);
> +
> +	if (a->re.address < b->re.address)
> +		return -1;
> +	else if (a->re.address > b->re.address)
> +		return 1;
> +	else if (a->re.size < b->re.size)
> +		return -1;
> +	else if (a->re.size > b->re.size)
> +		return 1;
> +	else
> +		return 0;
> +}
> +
> +static void sort_reserve_entries(struct boot_info *bi)
> +{
> +	struct reserve_info *ri, **tbl;
> +	int n = 0, i = 0;
> +
> +	for (ri = bi->reservelist;
> +	     ri;
> +	     ri = ri->next)
> +		n++;
> +
> +	if (n == 0)
> +		return;
> +
> +	tbl = xmalloc(n * sizeof(*tbl));
> +
> +	for (ri = bi->reservelist;
> +	     ri;
> +	     ri = ri->next)
> +		tbl[i++] = ri;
> +
> +	qsort(tbl, n, sizeof(*tbl), cmp_reserve_info);
> +
> +	bi->reservelist = tbl[0];
> +	for (i = 0; i < (n-1); i++)
> +		tbl[i]->next = tbl[i+1];
> +	tbl[n-1]->next = NULL;
> +
> +	free(tbl);
> +}
> +
> +static int cmp_prop(const void *ax, const void *bx)
> +{
> +	const struct property *a, *b;
> +
> +	a = *((const struct property * const *)ax);
> +	b = *((const struct property * const *)bx);
> +
> +	return strcmp(a->name, b->name);
> +}
> +
> +static void sort_properties(struct node *node)
> +{
> +	int n = 0, i = 0;
> +	struct property *prop, **tbl;
> +
> +	for_each_property(node, prop)
> +		n++;
> +
> +	if (n == 0)
> +		return;
> +
> +	tbl = xmalloc(n * sizeof(*tbl));
> +
> +	for_each_property(node, prop)
> +		tbl[i++] = prop;
> +
> +	qsort(tbl, n, sizeof(*tbl), cmp_prop);
> +
> +	node->proplist = tbl[0];
> +	for (i = 0; i < (n-1); i++)
> +		tbl[i]->next = tbl[i+1];
> +	tbl[n-1]->next = NULL;
> +
> +	free(tbl);
> +}
> +
> +static int cmp_subnode(const void *ax, const void *bx)
> +{
> +	const struct node *a, *b;
> +
> +	a = *((const struct node * const *)ax);
> +	b = *((const struct node * const *)bx);
> +
> +	return strcmp(a->name, b->name);
> +}
> +
> +static void sort_subnodes(struct node *node)
> +{
> +	int n = 0, i = 0;
> +	struct node *subnode, **tbl;
> +
> +	for_each_child(node, subnode)
> +		n++;
> +
> +	if (n == 0)
> +		return;
> +
> +	tbl = xmalloc(n * sizeof(*tbl));
> +
> +	for_each_child(node, subnode)
> +		tbl[i++] = subnode;
> +
> +	qsort(tbl, n, sizeof(*tbl), cmp_subnode);
> +
> +	node->children = tbl[0];
> +	for (i = 0; i < (n-1); i++)
> +		tbl[i]->next_sibling = tbl[i+1];
> +	tbl[n-1]->next_sibling = NULL;
> +
> +	free(tbl);
> +}
> +
> +static void sort_node(struct node *node)
> +{
> +	struct node *c;
> +
> +	sort_properties(node);
> +	sort_subnodes(node);
> +	for_each_child(node, c)
> +		sort_node(c);
> +}
> +
> +void sort_tree(struct boot_info *bi)
> +{
> +	sort_reserve_entries(bi);
> +	sort_node(bi->dt);
> +}
> Index: dtc/tests/run_tests.sh
> ===================================================================
> --- dtc.orig/tests/run_tests.sh	2010-10-11 11:11:52.583359649 +1100
> +++ dtc/tests/run_tests.sh	2010-10-11 11:11:53.679382348 +1100
> @@ -368,6 +368,13 @@ cmp_tests () {
>      for tree in $wrongtrees; do
>  	run_test dtbs_equal_unordered -n $basetree $tree
>      done
> +
> +    # now dtc --sort
> +    run_dtc_test -I dtb -O dtb -s -o $basetree.sorted.test.dtb $basetree
> +    run_test dtbs_equal_unordered $basetree $basetree.sorted.test.dtb
> +    run_dtc_test -I dtb -O dtb -s -o $basetree.reversed.sorted.test.dtb $basetree.reversed.test.dtb
> +    run_test dtbs_equal_unordered $basetree.reversed.test.dtb $basetree.reversed.sorted.test.dtb
> +    run_test dtbs_equal_ordered $basetree.sorted.test.dtb $basetree.reversed.sorted.test.dtb
>  }
>  
>  dtbs_equal_tests () {
> Index: dtc/dtdiff
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ dtc/dtdiff	2010-10-11 11:10:57.969901146 +1100
> @@ -0,0 +1,33 @@
> +#! /bin/bash
> +
> +# This script uses the bash <(...) extension.
> +# If you want to change this to work with a generic /bin/sh, make sure
> +# you fix that.
> +
> +
> +DTC=dtc
> +
> +source_and_sort () {
> +    DT="$1"
> +    if [ -d "$DT" ]; then
> +	IFORMAT=fs
> +    elif [ -f "$DT" ]; then
> +	case "$DT" in
> +	    *.dts)
> +		IFORMAT=dts
> +		;;
> +	    *.dtb)
> +		IFORMAT=dtb
> +		;;
> +	esac
> +    fi
> +
> +    if [ -z "$IFORMAT" ]; then
> +	echo "Unrecognized format for $DT" >&2
> +	exit 2
> +    fi
> +
> +    $DTC -I $IFORMAT -O dts -qq -f -s -o - "$DT"
> +}
> +
> +diff -u <(source_and_sort "$1") <(source_and_sort "$2")
> 
> 
> -- 
> 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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