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.

1 files changed, 4 insertions, 8 deletions

diff --git a/sql/item_func.cc b/sql/item_func.cc
index 6193ab285f2..3c1e2126008 100644
--- a/sql/item_func.cc
+++ b/sql/item_func.cc
@@ -2275,9 +2275,8 @@ void Item_func_min_max::fix_length_and_dec()
 
 uint Item_func_min_max::cmp_datetimes(ulonglong *value)
 {
-  longlong min_max;
+  longlong UNINIT_VAR(min_max);
   uint min_max_idx= 0;
-  LINT_INIT(min_max);
 
   for (uint i=0; i < arg_count ; i++)
   {
@@ -2345,8 +2344,7 @@ String *Item_func_min_max::val_str(String *str)
   }
   case STRING_RESULT:
   {
-    String *res;
-    LINT_INIT(res);
+    String *UNINIT_VAR(res);
     for (uint i=0; i < arg_count ; i++)
     {
       if (i == 0)
@@ -2435,8 +2433,7 @@ longlong Item_func_min_max::val_int()
 my_decimal *Item_func_min_max::val_decimal(my_decimal *dec)
 {
   DBUG_ASSERT(fixed == 1);
-  my_decimal tmp_buf, *tmp, *res;
-  LINT_INIT(res);
+  my_decimal tmp_buf, *tmp, *UNINIT_VAR(res);
 
   if (compare_as_dates)
   {
@@ -4974,8 +4971,7 @@ void Item_func_match::init_search(bool no_order)
 bool Item_func_match::fix_fields(THD *thd, Item **ref)
 {
   DBUG_ASSERT(fixed == 0);
-  Item *item;
-  LINT_INIT(item);				// Safe as arg_count is > 1
+  Item *UNINIT_VAR(item);                        // Safe as arg_count is > 1
 
   maybe_null=1;
   join_key=0;