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.

3 files changed, 9 insertions, 19 deletions

diff --git a/strings/ctype-ucs2.c b/strings/ctype-ucs2.c
index 65e4182d564..6657ef01785 100644
--- a/strings/ctype-ucs2.c
+++ b/strings/ctype-ucs2.c
@@ -202,11 +202,10 @@ static int my_strnncoll_ucs2(CHARSET_INFO *cs,
                              my_bool t_is_prefix)
 {
   int s_res,t_res;
-  my_wc_t s_wc,t_wc;
+  my_wc_t UNINIT_VAR(s_wc),t_wc;
   const uchar *se=s+slen;
   const uchar *te=t+tlen;
   MY_UNICASE_INFO **uni_plane= cs->caseinfo;
-  LINT_INIT(s_wc);
 
   while ( s < se && t < te )
   {
@@ -317,11 +316,10 @@ static int my_strncasecmp_ucs2(CHARSET_INFO *cs,
 			       const char *s, const char *t,  uint len)
 {
   int s_res,t_res;
-  my_wc_t s_wc,t_wc;
+  my_wc_t UNINIT_VAR(s_wc),t_wc;
   const char *se=s+len;
   const char *te=t+len;
   MY_UNICASE_INFO **uni_plane= cs->caseinfo;
-  LINT_INIT(s_wc);
 
   while ( s < se && t < te )
   {
@@ -1385,10 +1383,9 @@ int my_strnncoll_ucs2_bin(CHARSET_INFO *cs,
                           my_bool t_is_prefix)
 {
   int s_res,t_res;
-  my_wc_t s_wc,t_wc;
+  my_wc_t UNINIT_VAR(s_wc),t_wc;
   const uchar *se=s+slen;
   const uchar *te=t+tlen;
-  LINT_INIT(s_wc);
 
   while ( s < se && t < te )
   {
diff --git a/strings/ctype-utf8.c b/strings/ctype-utf8.c
index 4682868562f..3fcde4aca64 100644
--- a/strings/ctype-utf8.c
+++ b/strings/ctype-utf8.c
@@ -2306,11 +2306,10 @@ static int my_strnncoll_utf8(CHARSET_INFO *cs,
                              my_bool t_is_prefix)
 {
   int s_res,t_res;
-  my_wc_t s_wc,t_wc;
+  my_wc_t UNINIT_VAR(s_wc), t_wc;
   const uchar *se=s+slen;
   const uchar *te=t+tlen;
   MY_UNICASE_INFO **uni_plane= cs->caseinfo;
-  LINT_INIT(s_wc);
 
   while ( s < se && t < te )
   {
@@ -2377,10 +2376,9 @@ static int my_strnncollsp_utf8(CHARSET_INFO *cs,
                                my_bool diff_if_only_endspace_difference)
 {
   int s_res, t_res, res;
-  my_wc_t s_wc,t_wc;
+  my_wc_t UNINIT_VAR(s_wc),t_wc;
   const uchar *se= s+slen, *te= t+tlen;
   MY_UNICASE_INFO **uni_plane= cs->caseinfo;
-  LINT_INIT(s_wc);
 
 #ifndef VARCHAR_WITH_DIFF_ENDSPACE_ARE_DIFFERENT_FOR_UNIQUE
   diff_if_only_endspace_difference= 0;
diff --git a/strings/decimal.c b/strings/decimal.c
index c535d0f73dc..7c2c2999fb8 100644
--- a/strings/decimal.c
+++ b/strings/decimal.c
@@ -1359,8 +1359,7 @@ int bin2decimal(char *from, decimal_t *to, int precision, int scale)
   if (intg0x)
   {
     int i=dig2bytes[intg0x];
-    dec1 x;
-    LINT_INIT(x);
+    dec1 UNINIT_VAR(x);
     switch (i)
     {
       case 1: x=mi_sint1korr(from); break;
@@ -1401,8 +1400,7 @@ int bin2decimal(char *from, decimal_t *to, int precision, int scale)
   if (frac0x)
   {
     int i=dig2bytes[frac0x];
-    dec1 x;
-    LINT_INIT(x);
+    dec1 UNINIT_VAR(x);
     switch (i)
     {
       case 1: x=mi_sint1korr(from); break;
@@ -1480,7 +1478,7 @@ decimal_round(decimal_t *from, decimal_t *to, int scale,
               decimal_round_mode mode)
 {
   int frac0=scale>0 ? ROUND_UP(scale) : scale/DIG_PER_DEC1,
-      frac1=ROUND_UP(from->frac), round_digit,
+    frac1=ROUND_UP(from->frac), UNINIT_VAR(round_digit),
       intg0=ROUND_UP(from->intg), error=E_DEC_OK, len=to->len,
       intg1=ROUND_UP(from->intg +
                      (((intg0 + frac0)>0) && (from->buf[0] == DIG_MAX)));
@@ -1489,7 +1487,6 @@ decimal_round(decimal_t *from, decimal_t *to, int scale,
 
   sanity(to);
 
-  LINT_INIT(round_digit);
   switch (mode) {
   case HALF_UP:
   case HALF_EVEN:       round_digit=5; break;
@@ -2117,13 +2114,11 @@ static int do_div_mod(decimal_t *from1, decimal_t *from2,
 {
   int frac1=ROUND_UP(from1->frac)*DIG_PER_DEC1, prec1=from1->intg+frac1,
       frac2=ROUND_UP(from2->frac)*DIG_PER_DEC1, prec2=from2->intg+frac2,
-      error, i, intg0, frac0, len1, len2, dintg, div_mod=(!mod);
+      UNINIT_VAR(error), i, intg0, frac0, len1, len2, dintg, div_mod=(!mod);
   dec1 *buf0, *buf1=from1->buf, *buf2=from2->buf, *tmp1,
        *start2, *stop2, *stop1, *stop0, norm2, carry, *start1, dcarry;
   dec2 norm_factor, x, guess, y;
 
-  LINT_INIT(error);
-
   if (mod)
     to=mod;