Bug #43414 Parenthesis (and other) warnings compiling MySQL

with gcc 4.3.2
      
This patch fixes a number of GCC warnings about variables used
before initialized. A new macro UNINIT_VAR() is introduced for
use in the variable declaration, and LINT_INIT() usage will be
gradually deprecated. (A workaround is used for g++, pending a
patch for a g++ bug.)
      
GCC warnings for unused results (attribute warn_unused_result)
for a number of system calls (present at least in later
Ubuntus, where the usual void cast trick doesn't work) are
also fixed.


client/mysqlmanager-pwgen.c:
  A fix for warn_unused_result, adding fallback to use of
  srand()/rand() if /dev/random cannot be used. Also actually
  adds calls to rand() in the second branch so that it actually
  creates a random password.

10 files changed, 20 insertions, 33 deletions

diff --git a/myisam/ft_boolean_search.c b/myisam/ft_boolean_search.c
index 255c51fd33a..50f2cd52b3d 100644
--- a/myisam/ft_boolean_search.c
+++ b/myisam/ft_boolean_search.c
@@ -218,11 +218,9 @@ static int _ft2_search(FTB *ftb, FTB_WORD *ftbw, my_bool init_search)
   int subkeys=1;
   my_bool can_go_down;
   MI_INFO *info=ftb->info;
-  uint off, extra=HA_FT_WLEN+info->s->base.rec_reflength;
+  uint UNINIT_VAR(off), extra=HA_FT_WLEN+info->s->base.rec_reflength;
   byte *lastkey_buf=ftbw->word+ftbw->off;
-  LINT_INIT(off);
 
-  LINT_INIT(off);
   if (ftbw->flags & FTB_FLAG_TRUNC)
     lastkey_buf+=ftbw->len;
 
diff --git a/myisam/mi_check.c b/myisam/mi_check.c
index 285a31d34c6..80a90977609 100644
--- a/myisam/mi_check.c
+++ b/myisam/mi_check.c
@@ -140,11 +140,10 @@ int chk_del(MI_CHECK *param, register MI_INFO *info, uint test_flag)
 {
   reg2 ha_rows i;
   uint delete_link_length;
-  my_off_t empty,next_link,old_link;
+  my_off_t empty,next_link,UNINIT_VAR(old_link);
   char buff[22],buff2[22];
   DBUG_ENTER("chk_del");
 
-  LINT_INIT(old_link);
   param->record_checksum=0;
   delete_link_length=((info->s->options & HA_OPTION_PACK_RECORD) ? 20 :
 		      info->s->rec_reflength+1);
@@ -936,11 +935,11 @@ static uint isam_key_length(MI_INFO *info, register MI_KEYDEF *keyinfo)
 int chk_data_link(MI_CHECK *param, MI_INFO *info,int extend)
 {
   int	error,got_error,flag;
-  uint	key,left_length,b_type,field;
+  uint	key,UNINIT_VAR(left_length),b_type,field;
   ha_rows records,del_blocks;
-  my_off_t used,empty,pos,splits,start_recpos,
+  my_off_t used,empty,pos,splits,UNINIT_VAR(start_recpos),
 	   del_length,link_used,start_block;
-  byte	*record= 0, *to;
+  byte	*record= 0, *UNINIT_VAR(to);
   char llbuff[22],llbuff2[22],llbuff3[22];
   ha_checksum intern_record_checksum;
   ha_checksum key_checksum[MI_MAX_POSSIBLE_KEY];
@@ -965,7 +964,6 @@ int chk_data_link(MI_CHECK *param, MI_INFO *info,int extend)
   records=del_blocks=0;
   used=link_used=splits=del_length=0;
   intern_record_checksum=param->glob_crc=0;
-  LINT_INIT(left_length);  LINT_INIT(start_recpos);  LINT_INIT(to);
   got_error=error=0;
   empty=info->s->pack.header_length;
 
@@ -2222,9 +2220,8 @@ int mi_repair_by_sort(MI_CHECK *param, register MI_INFO *info,
   ulong   *rec_per_key_part;
   char llbuff[22];
   SORT_INFO sort_info;
-  ulonglong key_map;
+  ulonglong UNINIT_VAR(key_map);
   DBUG_ENTER("mi_repair_by_sort");
-  LINT_INIT(key_map);
 
   start_records=info->state->records;
   got_error=1;
@@ -2620,11 +2617,10 @@ int mi_repair_parallel(MI_CHECK *param, register MI_INFO *info,
   IO_CACHE new_data_cache; /* For non-quick repair. */
   IO_CACHE_SHARE io_share;
   SORT_INFO sort_info;
-  ulonglong key_map;
+  ulonglong UNINIT_VAR(key_map);
   pthread_attr_t thr_attr;
   ulong max_pack_reclength;
   DBUG_ENTER("mi_repair_parallel");
-  LINT_INIT(key_map);
 
   start_records=info->state->records;
   got_error=1;
@@ -3206,7 +3202,7 @@ static int sort_get_next_record(MI_SORT_PARAM *sort_param)
   int parallel_flag;
   uint found_record,b_type,left_length;
   my_off_t pos;
-  byte *to;
+  byte *UNINIT_VAR(to);
   MI_BLOCK_INFO block_info;
   SORT_INFO *sort_info=sort_param->sort_info;
   MI_CHECK *param=sort_info->param;
diff --git a/myisam/mi_create.c b/myisam/mi_create.c
index bb53393c345..43639409014 100644
--- a/myisam/mi_create.c
+++ b/myisam/mi_create.c
@@ -37,7 +37,7 @@ int mi_create(const char *name,uint keys,MI_KEYDEF *keydefs,
 	      MI_CREATE_INFO *ci,uint flags)
 {
   register uint i,j;
-  File dfile,file;
+  File UNINIT_VAR(dfile),file;
   int errpos,save_errno, create_mode= O_RDWR | O_TRUNC;
   myf create_flag;
   uint fields,length,max_key_length,packed,pointer,real_length_diff,
diff --git a/myisam/mi_delete.c b/myisam/mi_delete.c
index e08e5097e33..327a977dcca 100644
--- a/myisam/mi_delete.c
+++ b/myisam/mi_delete.c
@@ -220,7 +220,7 @@ static int d_search(register MI_INFO *info, register MI_KEYDEF *keyinfo,
   uint length,nod_flag,search_key_length;
   my_bool last_key;
   uchar *leaf_buff,*keypos;
-  my_off_t leaf_page,next_block;
+  my_off_t UNINIT_VAR(leaf_page),next_block;
   uchar lastkey[MI_MAX_KEY_BUFF];
   DBUG_ENTER("d_search");
   DBUG_DUMP("page",(uchar*) anc_buff,mi_getint(anc_buff));
diff --git a/myisam/mi_dynrec.c b/myisam/mi_dynrec.c
index 3542a82be59..af911428d11 100644
--- a/myisam/mi_dynrec.c
+++ b/myisam/mi_dynrec.c
@@ -1234,16 +1234,14 @@ void _my_store_blob_length(byte *pos,uint pack_length,uint length)
 int _mi_read_dynamic_record(MI_INFO *info, my_off_t filepos, byte *buf)
 {
   int block_of_record;
-  uint b_type,left_length;
-  byte *to;
+  uint b_type,UNINIT_VAR(left_length);
+  byte *UNINIT_VAR(to);
   MI_BLOCK_INFO block_info;
   File file;
   DBUG_ENTER("mi_read_dynamic_record");
 
   if (filepos != HA_OFFSET_ERROR)
   {
-    LINT_INIT(to);
-    LINT_INIT(left_length);
     file=info->dfile;
     block_of_record= 0;   /* First block of record is numbered as zero. */
     block_info.second_read= 0;
@@ -1506,13 +1504,12 @@ int _mi_read_rnd_dynamic_record(MI_INFO *info, byte *buf,
 {
   int block_of_record, info_read, save_errno;
   uint left_len,b_type;
-  byte *to;
+  byte *UNINIT_VAR(to);
   MI_BLOCK_INFO block_info;
   MYISAM_SHARE *share=info->s;
   DBUG_ENTER("_mi_read_rnd_dynamic_record");
 
   info_read=0;
-  LINT_INIT(to);
 
   if (info->lock_type == F_UNLCK)
   {
diff --git a/myisam/mi_open.c b/myisam/mi_open.c
index d9b7f6453db..285e295d999 100644
--- a/myisam/mi_open.c
+++ b/myisam/mi_open.c
@@ -678,7 +678,7 @@ err:
 byte *mi_alloc_rec_buff(MI_INFO *info, ulong length, byte **buf)
 {
   uint extra;
-  uint32 old_length;
+  uint32 UNINIT_VAR(old_length);
   LINT_INIT(old_length);
 
   if (! *buf || length > (old_length=mi_get_rec_buff_len(info, *buf)))
diff --git a/myisam/mi_packrec.c b/myisam/mi_packrec.c
index 68911d7f129..75cf45d5434 100644
--- a/myisam/mi_packrec.c
+++ b/myisam/mi_packrec.c
@@ -1362,7 +1362,7 @@ uint _mi_pack_get_block_info(MI_INFO *myisam, MI_BIT_BUFF *bit_buff,
                              File file, my_off_t filepos)
 {
   uchar *header=info->header;
-  uint head_length,ref_length;
+  uint head_length, UNINIT_VAR(ref_length);
   LINT_INIT(ref_length);
 
   if (file >= 0)
diff --git a/myisam/mi_search.c b/myisam/mi_search.c
index 795c7ee55c3..3b1cd6158f2 100644
--- a/myisam/mi_search.c
+++ b/myisam/mi_search.c
@@ -240,12 +240,11 @@ int _mi_seq_search(MI_INFO *info, register MI_KEYDEF *keyinfo, uchar *page,
                    uchar *key, uint key_len, uint comp_flag, uchar **ret_pos,
                    uchar *buff, my_bool *last_key)
 {
-  int flag;
-  uint nod_flag,length,not_used[2];
+  int UNINIT_VAR(flag);
+  uint nod_flag,UNINIT_VAR(length),not_used[2];
   uchar t_buff[MI_MAX_KEY_BUFF],*end;
   DBUG_ENTER("_mi_seq_search");
 
-  LINT_INIT(flag); LINT_INIT(length);
   end= page+mi_getint(page);
   nod_flag=mi_test_if_nod(page);
   page+=2+nod_flag;
diff --git a/myisam/mi_update.c b/myisam/mi_update.c
index bea457d2e9a..fa0797b1d61 100644
--- a/myisam/mi_update.c
+++ b/myisam/mi_update.c
@@ -27,11 +27,8 @@ int mi_update(register MI_INFO *info, const byte *oldrec, byte *newrec)
   bool auto_key_changed=0;
   ulonglong changed;
   MYISAM_SHARE *share=info->s;
-  ha_checksum old_checksum;
+  ha_checksum UNINIT_VAR(old_checksum);
   DBUG_ENTER("mi_update");
-  LINT_INIT(new_key);
-  LINT_INIT(changed);
-  LINT_INIT(old_checksum);
 
   DBUG_EXECUTE_IF("myisam_pretend_crashed_table_on_usage",
                   mi_print_error(info->s, HA_ERR_CRASHED);
diff --git a/myisam/sort.c b/myisam/sort.c
index 2465227a449..f418be6a72d 100644
--- a/myisam/sort.c
+++ b/myisam/sort.c
@@ -489,7 +489,7 @@ int thr_write_keys(MI_SORT_PARAM *sort_param)
 {
   SORT_INFO *sort_info=sort_param->sort_info;
   MI_CHECK *param=sort_info->param;
-  ulong length, keys;
+  ulong UNINIT_VAR(length), keys;
   ulong *rec_per_key_part=param->rec_per_key_part;
   int got_error=sort_info->got_error;
   uint i;
@@ -896,7 +896,7 @@ merge_buffers(MI_SORT_PARAM *info, uint keys, IO_CACHE *from_file,
   int error;
   uint sort_length,maxcount;
   ha_rows count;
-  my_off_t to_start_filepos;
+  my_off_t UNINIT_VAR(to_start_filepos);
   uchar *strpos;
   BUFFPEK *buffpek,**refpek;
   QUEUE queue;