Silence some false positive warnings for gcc 4.7

Message ID	1453327970-4275-1-git-send-email-cmetcalf@ezchip.com
State	Committed
Headers	Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk Sender: libc-alpha-owner@sourceware.org Received-SPF: Fail (protection.outlook.com: domain of ezchip.com does not designate 12.216.194.146 as permitted sender) receiver=protection.outlook.com; client-ip=12.216.194.146; helo=ld-1.internal.tilera.com; From: Chris Metcalf <cmetcalf@ezchip.com> To: <libc-alpha@sourceware.org>, Adhemerval Zanella <adhemerval.zanella@linaro.org> CC: Chris Metcalf <cmetcalf@ezchip.com> Subject: [PATCH] Silence some false positive warnings for gcc 4.7 Date: Wed, 20 Jan 2016 17:12:50 -0500 Message-ID: <1453327970-4275-1-git-send-email-cmetcalf@ezchip.com> In-Reply-To: <569FD245.3080107@linaro.org> MIME-Version: 1.0 Content-Type: text/plain X-Microsoft-Exchange-Diagnostics: 1; AM3PR02MB116; 2:x/6EH89f3lr57Tfhut3TsnUs4vESAPA2EUf72IzNaN+0Ri6hCxvAbL/kBEL1DURdYaG8MZBj+cTtjbOIqdw+JmVdmWQ+714uJQ4ysm/dMG74ER6cSTPzT63qp91QaNLmzdEBjDZKV3yI4QfG6LObiA==; 3:SqXjtvg8Sx5G5vTegENTEDj49EL9gDtwhuGz5TAXDmaoHXlF2Sdwf9jqmbqLE47MSCc7J6QI/nkDMm/4a/MLmP32eaoNl7D++6IRm3lxoxCPk1MQT2A8haMombGlis7WJ76mwq4bdPbVs+xv85xqSreJBTuiiiZ4E61kCQ8zloJ8xm/o9xjgzJc6MRF5uoux+7VNqIvbkt4jDUQsgSn44arrr67Trjqrumn2s4gyb6w=; 25:X8F3dcbO9AydTJ/FXi7KkHdvCi1R8PVYowOrFO6r2XP47kNMsfN0qat+iVJyq4UvVNxb1E8DRI913DZ8H+pfwku/0uGBq3Q6UWraetVJ9KvvkC5amDRU73ODqfVtSP5FkPjpmdf2fBDD0efw+pUDLlPClWKFm971MhfQbyoxu39EKqAvEN3zUgve+0aamr9+Gbul6Dg31HvwLLKpUmzikoyPrn61iOOyOnnhP8rVV8nvL/dWMjW9+U6sWtvpnIyI; 20:jOXIl+Gl6+fAsu8XOmo2Val+wskZ7iYXv/Oz+4UYEFYQLnt+sJMSEiOGFBjt+3VlxO+nTAmbd5Yfw01vpRTSIXlUI4TNiLWXjqBJvzehkDoBBN8HUV29zORah4O7TtSvS5bowhSKROrggTCT5Qv79im5Ni8k90MzM6DqUCevJe0= SpamDiagnosticOutput: 1:23 SpamDiagnosticMetadata: NSPM

Message ID

1453327970-4275-1-git-send-email-cmetcalf@ezchip.com

State

Committed

Headers

Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm
Precedence: bulk
Sender: libc-alpha-owner@sourceware.org
Received-SPF: Fail (protection.outlook.com: domain of ezchip.com does not
	designate 12.216.194.146 as permitted sender)
	receiver=protection.outlook.com; client-ip=12.216.194.146;
	helo=ld-1.internal.tilera.com;
From: Chris Metcalf <cmetcalf@ezchip.com>
To: <libc-alpha@sourceware.org>, Adhemerval Zanella
	<adhemerval.zanella@linaro.org>
CC: Chris Metcalf <cmetcalf@ezchip.com>
Subject: [PATCH] Silence some false positive warnings for gcc 4.7
Date: Wed, 20 Jan 2016 17:12:50 -0500
Message-ID: <1453327970-4275-1-git-send-email-cmetcalf@ezchip.com>
In-Reply-To: <569FD245.3080107@linaro.org>
MIME-Version: 1.0
Content-Type: text/plain
SpamDiagnosticOutput: 1:23
SpamDiagnosticMetadata: NSPM
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 20 Jan 2016 22:12:56.4768
	(UTC)
X-MS-Exchange-CrossTenant-Id: 0fc16e0a-3cd3-4092-8b2f-0a42cff122c3
X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=0fc16e0a-3cd3-4092-8b2f-0a42cff122c3;
	Ip=[12.216.194.146]; Helo=[ld-1.internal.tilera.com]
X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem
X-MS-Exchange-Transport-CrossTenantHeadersStamped: AM3PR02MB116

Commit Message

Chris Metcalf Jan. 20, 2016, 10:12 p.m. UTC

  Good to push to master?

2016-01-20  Chris Metcalf  <cmetcalf@ezchip.com>

	* nis/nis_table.c (__follow_path): Disable diagnostic for
	uninitialized variable that is a false positive for gcc 4.7.
	* stdio-common/vfscanf.c (_IO_vfwscanf): Likewise.

Comments

Stefan Liebler Jan. 21, 2016, 8:11 a.m. UTC | #1

Hi,

I got the same werrors when building with a gcc 4.7.4 on s390x.
After applying the patch, glibc builds without an werror.

Bye
Stefan

On 01/20/2016 11:12 PM, Chris Metcalf wrote:
> Good to push to master?
>
> 2016-01-20  Chris Metcalf  <cmetcalf@ezchip.com>
>
> 	* nis/nis_table.c (__follow_path): Disable diagnostic for
> 	uninitialized variable that is a false positive for gcc 4.7.
> 	* stdio-common/vfscanf.c (_IO_vfwscanf): Likewise.
>
> diff --git a/nis/nis_table.c b/nis/nis_table.c
> index 2831164a191b..1d607a49c4e9 100644
> --- a/nis/nis_table.c
> +++ b/nis/nis_table.c
> @@ -19,6 +19,7 @@
>   #include <assert.h>
>   #include <string.h>
>   #include <rpcsvc/nis.h>
> +#include <libc-internal.h>
>
>   #include "nis_xdr.h"
>   #include "nis_intern.h"
> @@ -175,6 +176,12 @@ __follow_path (char **tablepath, char **tableptr, struct ib_request *ibreq,
>
>         *tableptr = *tablepath;
>       }
> +
> +  /* Since tableptr is only set here, and it's set when tablepath is NULL,
> +     which it is initially defined as, we know it will always be set here.  */
> +  DIAG_PUSH_NEEDS_COMMENT;
> +  DIAG_IGNORE_NEEDS_COMMENT (4.7, "-Wmaybe-uninitialized");
> +
>     if (*tableptr == NULL)
>       return NIS_NOTFOUND;
>
> @@ -182,6 +189,8 @@ __follow_path (char **tablepath, char **tableptr, struct ib_request *ibreq,
>     if (newname[0] == '\0')
>       return NIS_NOTFOUND;
>
> +  DIAG_POP_NEEDS_COMMENT;
> +
>     newname = strdup (newname);
>     if (newname == NULL)
>       return NIS_NOMEMORY;
> diff --git a/stdio-common/vfscanf.c b/stdio-common/vfscanf.c
> index f8f97cd1d2cd..8cd59557a698 100644
> --- a/stdio-common/vfscanf.c
> +++ b/stdio-common/vfscanf.c
> @@ -27,6 +27,7 @@
>   #include <string.h>
>   #include <wchar.h>
>   #include <wctype.h>
> +#include <libc-internal.h>
>   #include <libc-lock.h>
>   #include <locale/localeinfo.h>
>   #include <scratch_buffer.h>
> @@ -1535,6 +1536,13 @@ _IO_vfscanf_internal (_IO_FILE *s, const char *format, _IO_va_list argptr,
>   		    {
>   		      /* Get the string for the digits with value N.  */
>   #ifdef COMPILE_WSCANF
> +
> +		      /* wcdigits_extended[] is fully set in the loop
> +			 above, but the test for "map != NULL" is done
> +			 inside the loop here and outside the loop there.  */
> +		      DIAG_PUSH_NEEDS_COMMENT;
> +		      DIAG_IGNORE_NEEDS_COMMENT (4.7, "-Wmaybe-uninitialized");
> +
>   		      if (__glibc_unlikely (map != NULL))
>   			wcdigits[n] = wcdigits_extended[n];
>   		      else
> @@ -1542,6 +1550,8 @@ _IO_vfscanf_internal (_IO_FILE *s, const char *format, _IO_va_list argptr,
>   			  _NL_CURRENT (LC_CTYPE, _NL_CTYPE_INDIGITS0_WC + n);
>   		      wcdigits[n] += from_level;
>
> +		      DIAG_POP_NEEDS_COMMENT;
> +
>   		      if (c == (wint_t) *wcdigits[n])
>   			{
>   			  to_level = from_level;
>

Adhemerval Zanella Netto Jan. 21, 2016, 1:48 p.m. UTC | #2

LGTM, thanks.

On 20-01-2016 20:12, Chris Metcalf wrote:
> Good to push to master?
> 
> 2016-01-20  Chris Metcalf  <cmetcalf@ezchip.com>
> 
> 	* nis/nis_table.c (__follow_path): Disable diagnostic for
> 	uninitialized variable that is a false positive for gcc 4.7.
> 	* stdio-common/vfscanf.c (_IO_vfwscanf): Likewise.
> 
> diff --git a/nis/nis_table.c b/nis/nis_table.c
> index 2831164a191b..1d607a49c4e9 100644
> --- a/nis/nis_table.c
> +++ b/nis/nis_table.c
> @@ -19,6 +19,7 @@
>  #include <assert.h>
>  #include <string.h>
>  #include <rpcsvc/nis.h>
> +#include <libc-internal.h>
>  
>  #include "nis_xdr.h"
>  #include "nis_intern.h"
> @@ -175,6 +176,12 @@ __follow_path (char **tablepath, char **tableptr, struct ib_request *ibreq,
>  
>        *tableptr = *tablepath;
>      }
> +
> +  /* Since tableptr is only set here, and it's set when tablepath is NULL,
> +     which it is initially defined as, we know it will always be set here.  */
> +  DIAG_PUSH_NEEDS_COMMENT;
> +  DIAG_IGNORE_NEEDS_COMMENT (4.7, "-Wmaybe-uninitialized");
> +
>    if (*tableptr == NULL)
>      return NIS_NOTFOUND;
>  
> @@ -182,6 +189,8 @@ __follow_path (char **tablepath, char **tableptr, struct ib_request *ibreq,
>    if (newname[0] == '\0')
>      return NIS_NOTFOUND;
>  
> +  DIAG_POP_NEEDS_COMMENT;
> +
>    newname = strdup (newname);
>    if (newname == NULL)
>      return NIS_NOMEMORY;
> diff --git a/stdio-common/vfscanf.c b/stdio-common/vfscanf.c
> index f8f97cd1d2cd..8cd59557a698 100644
> --- a/stdio-common/vfscanf.c
> +++ b/stdio-common/vfscanf.c
> @@ -27,6 +27,7 @@
>  #include <string.h>
>  #include <wchar.h>
>  #include <wctype.h>
> +#include <libc-internal.h>
>  #include <libc-lock.h>
>  #include <locale/localeinfo.h>
>  #include <scratch_buffer.h>
> @@ -1535,6 +1536,13 @@ _IO_vfscanf_internal (_IO_FILE *s, const char *format, _IO_va_list argptr,
>  		    {
>  		      /* Get the string for the digits with value N.  */
>  #ifdef COMPILE_WSCANF
> +
> +		      /* wcdigits_extended[] is fully set in the loop
> +			 above, but the test for "map != NULL" is done
> +			 inside the loop here and outside the loop there.  */
> +		      DIAG_PUSH_NEEDS_COMMENT;
> +		      DIAG_IGNORE_NEEDS_COMMENT (4.7, "-Wmaybe-uninitialized");
> +
>  		      if (__glibc_unlikely (map != NULL))
>  			wcdigits[n] = wcdigits_extended[n];
>  		      else
> @@ -1542,6 +1550,8 @@ _IO_vfscanf_internal (_IO_FILE *s, const char *format, _IO_va_list argptr,
>  			  _NL_CURRENT (LC_CTYPE, _NL_CTYPE_INDIGITS0_WC + n);
>  		      wcdigits[n] += from_level;
>  
> +		      DIAG_POP_NEEDS_COMMENT;
> +
>  		      if (c == (wint_t) *wcdigits[n])
>  			{
>  			  to_level = from_level;
>

diff mbox

Patch

diff --git a/nis/nis_table.c b/nis/nis_table.c
index 2831164a191b..1d607a49c4e9 100644
--- a/nis/nis_table.c
+++ b/nis/nis_table.c
@@ -19,6 +19,7 @@ 
 #include <assert.h>
 #include <string.h>
 #include <rpcsvc/nis.h>
+#include <libc-internal.h>
 
 #include "nis_xdr.h"
 #include "nis_intern.h"
@@ -175,6 +176,12 @@  __follow_path (char **tablepath, char **tableptr, struct ib_request *ibreq,
 
       *tableptr = *tablepath;
     }
+
+  /* Since tableptr is only set here, and it's set when tablepath is NULL,
+     which it is initially defined as, we know it will always be set here.  */
+  DIAG_PUSH_NEEDS_COMMENT;
+  DIAG_IGNORE_NEEDS_COMMENT (4.7, "-Wmaybe-uninitialized");
+
   if (*tableptr == NULL)
     return NIS_NOTFOUND;
 
@@ -182,6 +189,8 @@  __follow_path (char **tablepath, char **tableptr, struct ib_request *ibreq,
   if (newname[0] == '\0')
     return NIS_NOTFOUND;
 
+  DIAG_POP_NEEDS_COMMENT;
+
   newname = strdup (newname);
   if (newname == NULL)
     return NIS_NOMEMORY;
diff --git a/stdio-common/vfscanf.c b/stdio-common/vfscanf.c
index f8f97cd1d2cd..8cd59557a698 100644
--- a/stdio-common/vfscanf.c
+++ b/stdio-common/vfscanf.c
@@ -27,6 +27,7 @@ 
 #include <string.h>
 #include <wchar.h>
 #include <wctype.h>
+#include <libc-internal.h>
 #include <libc-lock.h>
 #include <locale/localeinfo.h>
 #include <scratch_buffer.h>
@@ -1535,6 +1536,13 @@  _IO_vfscanf_internal (_IO_FILE *s, const char *format, _IO_va_list argptr,
 		    {
 		      /* Get the string for the digits with value N.  */
 #ifdef COMPILE_WSCANF
+
+		      /* wcdigits_extended[] is fully set in the loop
+			 above, but the test for "map != NULL" is done
+			 inside the loop here and outside the loop there.  */
+		      DIAG_PUSH_NEEDS_COMMENT;
+		      DIAG_IGNORE_NEEDS_COMMENT (4.7, "-Wmaybe-uninitialized");
+
 		      if (__glibc_unlikely (map != NULL))
 			wcdigits[n] = wcdigits_extended[n];
 		      else
@@ -1542,6 +1550,8 @@  _IO_vfscanf_internal (_IO_FILE *s, const char *format, _IO_va_list argptr,
 			  _NL_CURRENT (LC_CTYPE, _NL_CTYPE_INDIGITS0_WC + n);
 		      wcdigits[n] += from_level;
 
+		      DIAG_POP_NEEDS_COMMENT;
+
 		      if (c == (wint_t) *wcdigits[n])
 			{
 			  to_level = from_level;