Avoid calls to strlen in miscellaneous functions.

* buffer.c (init_buffer): Use precalculated len, adjust if needed.
* font.c (Ffont_xlfd_name): Likewise.  Change to call make_string.
* lread.c (openp): Likewise.

4 files changed, 28 insertions, 15 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index de0f729f915..5815c83ae1e 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,11 +1,18 @@
 2012-07-10  Dmitry Antipov  <dmantipov@yandex.ru>
 
+        Avoid calls to strlen in miscellaneous functions.
+        * buffer.c (init_buffer): Use precalculated len, adjust if needed.
+        * font.c (Ffont_xlfd_name): Likewise.  Change to call make_string.
+        * lread.c (openp): Likewise.
+
+2012-07-10  Dmitry Antipov  <dmantipov@yandex.ru>
+
         Avoid calls to strlen in path processing functions.
         * fileio.c (file_name_as_directory): Add comment.  Change to add
         srclen argument and return the length of result.  Adjust users
         accordingly.
         (directory_file_name): Fix comment.  Change to add srclen argument,
-        swap 1nd and 2st arguments to obey the common convention.  Adjust
+        swap 1st and 2nd arguments to obey the common convention.  Adjust
         users accordingly.
         * filelock.c (fill_in_lock_file_name): Avoid calls to strlen.
 
diff --git a/src/buffer.c b/src/buffer.c
index 28cede3916c..4999639128d 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -5091,9 +5091,10 @@ init_buffer (void)
         fatal ("`get_current_dir_name' failed: %s\n", strerror (errno));
       pwd[len] = DIRECTORY_SEP;
       pwd[len + 1] = '\0';
+      len++;
     }
 
-  BVAR (current_buffer, directory) = make_unibyte_string (pwd, strlen (pwd));
+  BVAR (current_buffer, directory) = make_unibyte_string (pwd, len);
   if (! NILP (BVAR (&buffer_defaults, enable_multibyte_characters)))
     /* At this moment, we still don't know how to decode the
        directory name.  So, we keep the bytes in multibyte form so
diff --git a/src/font.c b/src/font.c
index 4f0f814a583..1eca1c2eb29 100644
--- a/src/font.c
+++ b/src/font.c
@@ -4218,7 +4218,7 @@ the consecutive wildcards are folded into one.  */)
   (Lisp_Object font, Lisp_Object fold_wildcards)
 {
   char name[256];
-  int pixel_size = 0;
+  int namelen, pixel_size = 0;
 
   CHECK_FONT (font);
 
@@ -4232,11 +4232,13 @@ the consecutive wildcards are folded into one.  */)
           if (NILP (fold_wildcards))
             return font_name;
           strcpy (name, SSDATA (font_name));
+          namelen = SBYTES (font_name);
           goto done;
         }
       pixel_size = XFONT_OBJECT (font)->pixel_size;
     }
-  if (font_unparse_xlfd (font, pixel_size, name, 256) < 0)
+  namelen = font_unparse_xlfd (font, pixel_size, name, 256);
+  if (namelen < 0)
     return Qnil;
  done:
   if (! NILP (fold_wildcards))
@@ -4246,11 +4248,12 @@ the consecutive wildcards are folded into one.  */)
       while ((p1 = strstr (p0, "-*-*")))
         {
           strcpy (p1, p1 + 2);
+          namelen -= 2;
           p0 = p1;
         }
     }
 
-  return build_string (name);
+  return make_string (name, namelen);
 }
 
 DEFUN ("clear-font-cache", Fclear_font_cache, Sclear_font_cache, 0, 0, 0,
diff --git a/src/lread.c b/src/lread.c
index c69190c37b6..900a25372d8 100644
--- a/src/lread.c
+++ b/src/lread.c
@@ -1489,7 +1489,7 @@ openp (Lisp_Object path, Lisp_Object str, Lisp_Object suffixes, Lisp_Object *sto
       for (tail = NILP (suffixes) ? Fcons (empty_unibyte_string, Qnil) : suffixes;
            CONSP (tail); tail = XCDR (tail))
         {
-          ptrdiff_t lsuffix = SBYTES (XCAR (tail));
+          ptrdiff_t fnlen, lsuffix = SBYTES (XCAR (tail));
           Lisp_Object handler;
           int exists;
 
@@ -1499,20 +1499,22 @@ openp (Lisp_Object path, Lisp_Object str, Lisp_Object suffixes, Lisp_Object *sto
               && SREF (filename, 0) == '/'
               && SREF (filename, 1) == ':')
             {
-              strncpy (fn, SSDATA (filename) + 2,
-                       SBYTES (filename) - 2);
-              fn[SBYTES (filename) - 2] = 0;
+              fnlen = SBYTES (filename) - 2;
+              strncpy (fn, SSDATA (filename) + 2, fnlen);
+              fn[fnlen] = '\0';
             }
           else
             {
-              strncpy (fn, SSDATA (filename),
-                       SBYTES (filename));
-              fn[SBYTES (filename)] = 0;
+              fnlen = SBYTES (filename);
+              strncpy (fn, SSDATA (filename), fnlen);
+              fn[fnlen] = '\0';
             }
 
           if (lsuffix != 0)  /* Bug happens on CCI if lsuffix is 0.  */
-            strncat (fn, SSDATA (XCAR (tail)), lsuffix);
-
+            {
+              strncat (fn, SSDATA (XCAR (tail)), lsuffix);
+              fnlen += lsuffix;
+            }
           /* Check that the file exists and is not a directory.  */
           /* We used to only check for handlers on non-absolute file names:
                 if (absolute)
@@ -1521,7 +1523,7 @@ openp (Lisp_Object path, Lisp_Object str, Lisp_Object suffixes, Lisp_Object *sto
                   handler = Ffind_file_name_handler (filename, Qfile_exists_p);
              It's not clear why that was the case and it breaks things like
              (load "/bar.el") where the file is actually "/bar.el.gz".  */
-          string = build_string (fn);
+          string = make_string (fn, fnlen);
           handler = Ffind_file_name_handler (string, Qfile_exists_p);
           if ((!NILP (handler) || !NILP (predicate)) && !NATNUMP (predicate))
             {