Bug#53445: Build with -Wall and fix warnings that it generates

Apart strict-aliasing warnings, fix the remaining warnings
generated by GCC 4.4.4 -Wall and -Wextra flags.

One major source of warnings was the in-house function my_bcmp
which (unconventionally) took pointers to unsigned characters
as the byte sequences to be compared. Since my_bcmp and bcmp
are deprecated functions whose only difference with memcmp is
the return value, every use of the function is replaced with
memcmp as the special return value wasn't actually being used
by any caller.

There were also various other warnings, mostly due to type
mismatches, missing return values, missing prototypes, dead
code (unreachable) and ignored return values.

1 files changed, 17 insertions, 14 deletions

diff --git a/sql/mysqld.cc b/sql/mysqld.cc
index 5514c356bd1..99f16b36dfa 100644
--- a/sql/mysqld.cc
+++ b/sql/mysqld.cc
@@ -559,7 +559,7 @@ ulong query_buff_size, slow_launch_time, slave_open_temp_tables;
 ulong open_files_limit, max_binlog_size, max_relay_log_size;
 ulong slave_net_timeout, slave_trans_retries;
 ulong slave_exec_mode_options;
-const char *slave_exec_mode_str= "STRICT";
+static const char *slave_exec_mode_str= "STRICT";
 ulong thread_cache_size=0, thread_pool_size= 0;
 ulong binlog_cache_size=0;
 ulonglong  max_binlog_cache_size=0;
@@ -2464,7 +2464,6 @@ extern "C" sig_handler handle_segfault(int sig)
 {
   time_t curr_time;
   struct tm tm;
-  THD *thd=current_thd;
 
   /*
     Strictly speaking, one needs a mutex here
@@ -2523,13 +2522,15 @@ the thread stack. Please read http://dev.mysql.com/doc/mysql/en/linux.html\n\n",
 #endif /* HAVE_LINUXTHREADS */
 
 #ifdef HAVE_STACKTRACE
+  THD *thd=current_thd;
+
   if (!(test_flags & TEST_NO_STACKTRACE))
   {
-    fprintf(stderr,"thd: 0x%lx\n",(long) thd);
-    fprintf(stderr,"\
-Attempting backtrace. You can use the following information to find out\n\
-where mysqld died. If you see no messages after this, something went\n\
-terribly wrong...\n");  
+    fprintf(stderr, "thd: 0x%lx\n",(long) thd);
+    fprintf(stderr, "Attempting backtrace. You can use the following "
+                    "information to find out\nwhere mysqld died. If "
+                    "you see no messages after this, something went\n"
+                    "terribly wrong...\n");
     my_print_stacktrace(thd ? (uchar*) thd->thread_stack : NULL,
                         my_thread_stack_size);
   }
@@ -7879,10 +7880,11 @@ static int mysql_init_variables(void)
 
   /* Things with default values that are not zero */
   delay_key_write_options= (uint) DELAY_KEY_WRITE_ON;
-  slave_exec_mode_options= 0;
-  slave_exec_mode_options= (uint)
-    find_bit_type_or_exit(slave_exec_mode_str, &slave_exec_mode_typelib, NULL,
-                          &error);
+  slave_exec_mode_options= find_bit_type_or_exit(slave_exec_mode_str,
+                                                 &slave_exec_mode_typelib,
+                                                 NULL, &error);
+  /* Default mode string must not yield a error. */
+  DBUG_ASSERT(!error);
   if (error)
     return 1;
   opt_specialflag= SPECIAL_ENGLISH;
@@ -8118,8 +8120,9 @@ mysqld_get_one_option(int optid,
     init_slave_skip_errors(argument);
     break;
   case OPT_SLAVE_EXEC_MODE:
-    slave_exec_mode_options= (uint)
-      find_bit_type_or_exit(argument, &slave_exec_mode_typelib, "", &error);
+    slave_exec_mode_options= find_bit_type_or_exit(argument,
+                                                   &slave_exec_mode_typelib,
+                                                   "", &error);
     if (error)
       return 1;
     break;
@@ -8773,7 +8776,7 @@ static int get_options(int *argc,char **argv)
   /* Set global MyISAM variables from delay_key_write_options */
   fix_delay_key_write((THD*) 0, OPT_GLOBAL);
   /* Set global slave_exec_mode from its option */
-  fix_slave_exec_mode(OPT_GLOBAL);
+  fix_slave_exec_mode();
 
 #ifndef EMBEDDED_LIBRARY
   if (mysqld_chroot)