From d0a1a9e82f0ab77c2acb76f07a731a617d26a79e Mon Sep 17 00:00:00 2001
From: Werner Almesberger <werner@openmoko.org>
Date: Sun, 21 Nov 2010 08:12:14 -0300
Subject: [PATCH] qpkg: rearrange things in prereq.c to free the stack paradigm
 for other uses

- prereq.c (stack, epoch, push, pop, resolve, prereq): renamed to
  "installs"
- prereq.c (n_stack, stack_max, push, pop, resolve, prereq): changed
  "stack" to "install"
- prereq.c (push): renamed "push" to "append_install"
- prereq.c (pop): renamed "pop" to "backtrack"
---
 qpkg/prereq.c | 48 ++++++++++++++++++++++++------------------------
 1 file changed, 24 insertions(+), 24 deletions(-)

diff --git a/qpkg/prereq.c b/qpkg/prereq.c
index b12f2d6..69e3b19 100644
--- a/qpkg/prereq.c
+++ b/qpkg/prereq.c
@@ -30,10 +30,10 @@ struct list {
 
 
 static struct pkg **best = NULL;
-static struct pkg **stack = NULL;
+static struct pkg **installs = NULL;
 static int n_best;	/* undefined if best == NULL */
-static int n_stack = 0;
-static int stack_max = 0;
+static int n_install = 0;
+static int install_max = 0;
 
 
 static int epoch(const char **s, const struct id *id)
@@ -98,40 +98,40 @@ static void done(void)
 {
 	int size;
 
-	if (best && n_best <= n_stack)
+	if (best && n_best <= n_install)
 		return;
 	free(best);
-	size = sizeof(*stack)*(n_stack+1);
+	size = sizeof(*installs)*(n_install+1);
 	best = alloc_size(size);
-	memcpy(best, stack, sizeof(*stack)*n_stack);
-	n_best = n_stack;
+	memcpy(best, installs, sizeof(*installs)*n_install);
+	n_best = n_install;
 	best[n_best] = NULL;
 }
 
 
-static void push(struct pkg *pkg)
+static void append_install(struct pkg *pkg)
 {
 //fprintf(stderr, "push %.*s\n", ID2PF(pkg->id));
-	if (n_stack == stack_max) {
-		stack_max = (stack_max+1)*2;
-		stack = realloc(stack, sizeof(*stack)*stack_max);
-		if (!stack) {
+	if (n_install == install_max) {
+		install_max = (install_max+1)*2;
+		installs = realloc(installs, sizeof(*installs)*install_max);
+		if (!installs) {
 			perror("realloc");
 			exit(1);
 		}
 		
 	}
-	stack[n_stack++] = pkg;
+	installs[n_install++] = pkg;
 	assert(!pkg->mark && !(pkg->flags & QPKG_INSTALLED));
 	pkg->mark = 1;
 }
 
 
-static void pop(void)
+static void backtrack(void)
 {
-	assert(n_stack);
-	n_stack--;
-	stack[n_stack]->mark = 0;
+	assert(n_install);
+	n_install--;
+	installs[n_install]->mark = 0;
 }
 
 
@@ -186,7 +186,7 @@ static int level = 0;
 		next_dep = next_dep->next;
 	}
 	for (pkg = dep->pkg->jrb->val; pkg; pkg = pkg->more) {
-		if (best && n_stack == n_best)
+		if (best && n_install == n_best)
 			return;
 #if 0
 fprintf(stderr, "%*s", level, "");
@@ -207,14 +207,14 @@ fprintf(stderr, "\n");
 		if (conflicts(pkg, conf))
 			continue;
 level++;
-		push(pkg);
+		append_install(pkg);
 		more_deps.refs = pkg->depends;
 		more_deps.next = next_dep;
 		more_conf.refs = pkg->conflicts;
 		more_conf.next = conf;
 		resolve(&more_deps, dep->next, &more_conf);
 		next_dep = more_deps.next;
-		pop();
+		backtrack();
 level--;
 	}
 }
@@ -229,13 +229,13 @@ struct pkg **prereq(struct pkg *pkg)
 
 #if 0
 	/* make sure we don't return NULL if all dependencies are met */
-	if (!stack) {
-		stack = alloc_type(struct pkg *);
-		stack_max = 1;
+	if (!installs) {
+		installs = alloc_type(struct pkg *);
+		install_max = 1;
 	}
 #endif
 	/* @@@ make list of pre-existing conflicts */
 	resolve(&deps, NULL, NULL);
-	free(stack);
+	free(installs);
 	return best;
 }