From eea014efb7f19eb160581314e74a899a2efca5c6 Mon Sep 17 00:00:00 2001
From: Xiang Xiao <xiaoxiang@xiaomi.com>
Date: Fri, 18 Mar 2022 15:10:04 +0800
Subject: [PATCH] Fix error: conflicting types for built-in function 'execl';
 expected 'int(const char *, const char *, ...)

Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
---
 include/unistd.h             |  2 +-
 libs/libc/unistd/lib_execl.c | 82 ++++++++++++++++--------------------
 2 files changed, 37 insertions(+), 47 deletions(-)

diff --git a/include/unistd.h b/include/unistd.h
index d158955a98..b383f20553 100644
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -367,7 +367,7 @@ int     lchown(FAR const char *path, uid_t owner, gid_t group);
 /* Execution of programs from files */
 
 #ifdef CONFIG_LIBC_EXECFUNCS
-int     execl(FAR const char *path, ...);
+int     execl(FAR const char *path, FAR const char *arg0, ...);
 int     execv(FAR const char *path, FAR char * const argv[]);
 #endif
 
diff --git a/libs/libc/unistd/lib_execl.c b/libs/libc/unistd/lib_execl.c
index 5caba340cb..54ea688798 100644
--- a/libs/libc/unistd/lib_execl.c
+++ b/libs/libc/unistd/lib_execl.c
@@ -113,10 +113,10 @@
  *
  ****************************************************************************/
 
-int execl(FAR const char *path, ...)
+int execl(FAR const char *path, FAR const char *arg0, ...)
 {
-  FAR char **argv = (FAR char **)NULL;
-  FAR char *arg;
+  FAR char **argv = NULL;
+  FAR char *arg = (FAR char *)arg0;
   size_t nargs;
   va_list ap;
   int argc;
@@ -124,67 +124,57 @@ int execl(FAR const char *path, ...)
 
   /* Count the number of arguments */
 
-  va_start(ap, path);
+  va_start(ap, arg0);
   nargs = 0;
-  do
+
+  while (arg != NULL)
     {
-      /* Check if the next argument is present */
+      /* Yes.. increment the number of arguments.  Here is a sanity
+       * check to prevent running away with an unterminated argv[] list.
+       * MAX_EXECL_ARGS should be sufficiently large that this never
+       * happens in normal usage.
+       */
+
+      if (++nargs > MAX_EXECL_ARGS)
+        {
+          set_errno(E2BIG);
+          va_end(ap);
+          return ERROR;
+        }
 
       arg = va_arg(ap, FAR char *);
-      if (arg)
-        {
-          /* Yes.. increment the number of arguments.  Here is a sanity
-           * check to prevent running away with an unterminated argv[] list.
-           * MAX_EXECL_ARGS should be sufficiently large that this never
-           * happens in normal usage.
-           */
-
-          if (++nargs > MAX_EXECL_ARGS)
-            {
-              set_errno(E2BIG);
-              va_end(ap);
-              return ERROR;
-            }
-        }
     }
-  while (arg);
 
   va_end(ap);
 
   /* Allocate a temporary argv[] array */
 
-  if (nargs > 0)
+  argv = (FAR char **)lib_malloc((nargs + 1) * sizeof(FAR char *));
+  if (argv == NULL)
     {
-      argv = (FAR char **)lib_malloc((nargs + 1) * sizeof(FAR char *));
-      if (argv == (FAR char **)NULL)
-        {
-          set_errno(ENOMEM);
-          return ERROR;
-        }
-
-      /* Collect the arguments into the argv[] array */
-
-      va_start(ap, path);
-      for (argc = 0; argc < nargs; argc++)
-        {
-          argv[argc] = va_arg(ap, FAR char *);
-        }
-
-      argv[nargs] = NULL;
-      va_end(ap);
+      set_errno(ENOMEM);
+      return ERROR;
     }
 
+  argv[0] = (FAR char *)arg0;
+
+  /* Collect the arguments into the argv[] array */
+
+  va_start(ap, arg0);
+  for (argc = 1; argc <= nargs; argc++)
+    {
+      argv[argc] = va_arg(ap, FAR char *);
+    }
+
+  va_end(ap);
+
   /* Then let execv() do the real work */
 
-  ret = execv(path, (FAR char * const *)argv);
+  ret = execv(path, argv);
 
   /* Free the allocated argv[] list */
 
-  if (argv)
-    {
-      lib_free(argv);
-    }
-
+  lib_free(argv);
   return ret;
 }