git: 2fc4a84ed828 - main - sh: introduce a function to iterate over all aliases

The branch main has been updated by pstef:

URL: https://cgit.FreeBSD.org/src/commit/?id=2fc4a84ed8288bd25be3de35d756f46ec7785030

commit 2fc4a84ed8288bd25be3de35d756f46ec7785030
Author:     Piotr Pawel Stefaniak <pstef@FreeBSD.org>
AuthorDate: 2023-04-29 20:23:59 +0000
Commit:     Piotr Pawel Stefaniak <pstef@FreeBSD.org>
CommitDate: 2023-09-12 16:39:20 +0000

    sh: introduce a function to iterate over all aliases
    
    Currently the data structure holding alias information is opaque for
    consumers outside alias.c and there is no way to iterate over all
    aliases, which will become needed by a future commit.
    
    The new function "iteralias" takes a null pointer to return the first
    alias or an existing alias to return the next one, unless there is
    no alias to return, in which case it returns a null pointer.
    
    I slightly changed the static function hashalias so that it returns the
    index into the array holding link heads, and not the link head directly.
    In this form it's easier to use by iteralias and the slight adjustment
    in the three existing callers doesn't look too bad.
    
    Differential Revision:  https://reviews.freebsd.org/D40619
---
 bin/sh/alias.c | 29 +++++++++++++++++++++++------
 bin/sh/alias.h |  1 +
 2 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/bin/sh/alias.c b/bin/sh/alias.c
index 4bac525e2678..da860be704b6 100644
--- a/bin/sh/alias.c
+++ b/bin/sh/alias.c
@@ -53,7 +53,7 @@ static int aliases;
 
 static void setalias(const char *, const char *);
 static int unalias(const char *);
-static struct alias **hashalias(const char *);
+static size_t hashalias(const char *);
 
 static
 void
@@ -62,7 +62,7 @@ setalias(const char *name, const char *val)
 	struct alias *ap, **app;
 
 	unalias(name);
-	app = hashalias(name);
+	app = &atab[hashalias(name)];
 	INTOFF;
 	ap = ckmalloc(sizeof (struct alias));
 	ap->name = savestr(name);
@@ -87,7 +87,7 @@ unalias(const char *name)
 {
 	struct alias *ap, **app;
 
-	app = hashalias(name);
+	app = &atab[hashalias(name)];
 
 	for (ap = *app; ap; app = &(ap->next), ap = ap->next) {
 		if (equal(name, ap->name)) {
@@ -145,7 +145,7 @@ lookupalias(const char *name, int check)
 
 	if (aliases == 0)
 		return (NULL);
-	for (ap = *hashalias(name); ap; ap = ap->next) {
+	for (ap = atab[hashalias(name)]; ap; ap = ap->next) {
 		if (equal(name, ap->name)) {
 			if (check && (ap->flag & ALIASINUSE))
 				return (NULL);
@@ -242,7 +242,7 @@ unaliascmd(int argc __unused, char **argv __unused)
 	return (i);
 }
 
-static struct alias **
+static size_t
 hashalias(const char *p)
 {
 	unsigned int hashval;
@@ -250,5 +250,22 @@ hashalias(const char *p)
 	hashval = (unsigned char)*p << 4;
 	while (*p)
 		hashval+= *p++;
-	return &atab[hashval % ATABSIZE];
+	return (hashval % ATABSIZE);
+}
+
+const struct alias *
+iteralias(const struct alias *index)
+{
+	size_t i = 0;
+
+	if (index != NULL) {
+		if (index->next != NULL)
+			return (index->next);
+		i = hashalias(index->name) + 1;
+	}
+	for (; i < ATABSIZE; i++)
+		if (atab[i] != NULL)
+			return (atab[i]);
+
+	return (NULL);
 }
diff --git a/bin/sh/alias.h b/bin/sh/alias.h
index 0c6ea99e8b60..a8108d44be2d 100644
--- a/bin/sh/alias.h
+++ b/bin/sh/alias.h
@@ -42,3 +42,4 @@ struct alias {
 };
 
 struct alias *lookupalias(const char *, int);
+const struct alias *iteralias(const struct alias *);