[PATCH] s3: Remove check of constant condition in loop

[Swen Schillig]

Hi Timur
On Wed, 2018-03-07 at 00:05 +0100, Timur I. Bakeyev wrote:
> Hi, Swen!
> 
> On 6 March 2018 at 11:46, Swen Schillig via samba-technical <samba-te
> chnical at lists.samba.org> wrote:
> > Please review ...and push.
> 
> Not sure which compiler did you use for testing, but Clang isn't
> happy with nested function declaration:
> 
> +	bool (*str_eq)(const char *, const char *) = NULL;
> +	bool strequal_cs(const char *s1, const char *s2)
> +		{ return (strcmp(s1, s2) == 0); }
> +
> +	str_eq = (conn->case_sensitive) ? strequal_cs : strequal;
> 
> And just refuses to compile. I had to move strequal_cs() outside the
> function and declare it static:
> 
> + static bool strequal_cs(const char *s1, const char *s2)
> + {
> +         return (strcmp(s1, s2) == 0); 
> + }
> Please, consider such a change.
Believe it or not, but that was the first version of my patch :-)
But I thought the gcc-ism'ed version (you were right Jeremy) looks far
better.
Anyhow, if it's not working everywhere it's useless.

So, please find the updated version attached.

Thanks !

Cheers Swen
-------------- next part --------------
From 0f7a357ac509b146e009e852d73753195a881ade Mon Sep 17 00:00:00 2001
From: Swen Schillig <swen at vnet.ibm.com>
Date: Tue, 6 Mar 2018 08:43:46 +0100
Subject: [PATCH] s3: Remove check of constant condition in loop

The function SearchDir contains three loops which check,
for each iteration, whether a string comparison is to be performed
case sesitive or not.
But this condition does not change between loop iterations.
Therefore, introduce a function pointer which is set at the beginning
according to the case sesitivity setting and executes the correct
string comparison in the succeeding code paths.

Signed-off-by: Swen Schillig <swen at vnet.ibm.com>
---
 source3/smbd/dir.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/source3/smbd/dir.c b/source3/smbd/dir.c
index 803cb431740..33dc9ff8892 100644
--- a/source3/smbd/dir.c
+++ b/source3/smbd/dir.c
@@ -1949,6 +1949,11 @@ static void DirCacheAdd(struct smb_Dir *dirp, const char *name, long offset)
 	e->offset = offset;
 }
 
+static bool strequal_cs(const char *s1, const char *s2)
+{
+	return (strcmp(s1, s2) == 0);
+}
+
 /*******************************************************************
  Find an entry by name. Leave us at the offset after it.
  Don't check for veto or invisible files.
@@ -1960,12 +1965,15 @@ bool SearchDir(struct smb_Dir *dirp, const char *name, long *poffset)
 	const char *entry = NULL;
 	char *talloced = NULL;
 	connection_struct *conn = dirp->conn;
+	bool (*str_eq)(const char *, const char *) = NULL;
+
+	str_eq = (conn->case_sensitive) ? strequal_cs : strequal;
 
 	/* Search back in the name cache. */
 	if (dirp->name_cache_size && dirp->name_cache) {
 		for (i = dirp->name_cache_index; i >= 0; i--) {
 			struct name_cache_entry *e = &dirp->name_cache[i];
-			if (e->name && (conn->case_sensitive ? (strcmp(e->name, name) == 0) : strequal(e->name, name))) {
+			if (e->name && str_eq(e->name, name)) {
 				*poffset = e->offset;
 				SeekDir(dirp, e->offset);
 				return True;
@@ -1973,7 +1981,7 @@ bool SearchDir(struct smb_Dir *dirp, const char *name, long *poffset)
 		}
 		for (i = dirp->name_cache_size - 1; i > dirp->name_cache_index; i--) {
 			struct name_cache_entry *e = &dirp->name_cache[i];
-			if (e->name && (conn->case_sensitive ? (strcmp(e->name, name) == 0) : strequal(e->name, name))) {
+			if (e->name && str_eq(e->name, name)) {
 				*poffset = e->offset;
 				SeekDir(dirp, e->offset);
 				return True;
@@ -1986,7 +1994,7 @@ bool SearchDir(struct smb_Dir *dirp, const char *name, long *poffset)
 	dirp->file_number = 0;
 	*poffset = START_OF_DIRECTORY_OFFSET;
 	while ((entry = ReadDirName(dirp, poffset, NULL, &talloced))) {
-		if (conn->case_sensitive ? (strcmp(entry, name) == 0) : strequal(entry, name)) {
+		if (str_eq(entry, name)) {
 			TALLOC_FREE(talloced);
 			return True;
 		}
-- 
2.14.3