[PATCH v2 5/7] fixdep: refactor hash table lookup

From: Masahiro Yamada
Date: Sat Jan 07 2023 - 04:19:27 EST


Change the hash table code so it will be easier to add the second table.

Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
Reviewed-by: Miguel Ojeda <ojeda@xxxxxxxxxx>
Tested-by: Miguel Ojeda <ojeda@xxxxxxxxxx>
---

(no changes since v1)

scripts/basic/fixdep.c | 47 ++++++++++++++++++++++--------------------
1 file changed, 25 insertions(+), 22 deletions(-)

diff --git a/scripts/basic/fixdep.c b/scripts/basic/fixdep.c
index f5a51770eb74..74f90a0deeb9 100644
--- a/scripts/basic/fixdep.c
+++ b/scripts/basic/fixdep.c
@@ -113,7 +113,7 @@ struct item {
};

#define HASHSZ 256
-static struct item *hashtab[HASHSZ];
+static struct item *config_hashtab[HASHSZ];

static unsigned int strhash(const char *str, unsigned int sz)
{
@@ -125,25 +125,11 @@ static unsigned int strhash(const char *str, unsigned int sz)
return hash;
}

-/*
- * Lookup a value in the configuration string.
- */
-static int is_defined_config(const char *name, int len, unsigned int hash)
-{
- struct item *aux;
-
- for (aux = hashtab[hash % HASHSZ]; aux; aux = aux->next) {
- if (aux->hash == hash && aux->len == len &&
- memcmp(aux->name, name, len) == 0)
- return 1;
- }
- return 0;
-}
-
/*
* Add a new value to the configuration string.
*/
-static void define_config(const char *name, int len, unsigned int hash)
+static void add_to_hashtable(const char *name, int len, unsigned int hash,
+ struct item *hashtab[])
{
struct item *aux = malloc(sizeof(*aux) + len);

@@ -158,17 +144,34 @@ static void define_config(const char *name, int len, unsigned int hash)
hashtab[hash % HASHSZ] = aux;
}

+/*
+ * Lookup a string in the hash table. If found, just return true.
+ * If not, add it to the hashtable and return false.
+ */
+static bool in_hashtable(const char *name, int len, struct item *hashtab[])
+{
+ struct item *aux;
+ unsigned int hash = strhash(name, len);
+
+ for (aux = hashtab[hash % HASHSZ]; aux; aux = aux->next) {
+ if (aux->hash == hash && aux->len == len &&
+ memcmp(aux->name, name, len) == 0)
+ return true;
+ }
+
+ add_to_hashtable(name, len, hash, hashtab);
+
+ return false;
+}
+
/*
* Record the use of a CONFIG_* word.
*/
static void use_config(const char *m, int slen)
{
- unsigned int hash = strhash(m, slen);
-
- if (is_defined_config(m, slen, hash))
- return;
+ if (in_hashtable(m, slen, config_hashtab))
+ return;

- define_config(m, slen, hash);
/* Print out a dependency path from a symbol name. */
printf(" $(wildcard include/config/%.*s) \\\n", slen, m);
}
--
2.34.1