[PATCH + 12.1] Silence -Wmaybe-uninitialized warning from target_waitstatus

[PATCH + 12.1] Silence -Wmaybe-uninitialized warning from target_waitstatus

[Tom Tromey]

Currently, one use of target_waitstatus yields a warning:

     target/waitstatus.h: In function 'void stop_all_threads()':
     target/waitstatus.h:175:13: warning: 'ws.target_waitstatus::m_value' may be used uninitialized in this function [-Wmaybe-uninitialized]
       175 |     m_value = other.m_value;
	   |     ~~~~~~~~^~~~~~~~~~~~~~~

This patch silences the warning.  I tried the "volatile member"
approach that was used for gdb::optional, but that didn't work, so
this patch simply initializes the member.
---
 gdb/target/waitstatus.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gdb/target/waitstatus.h b/gdb/target/waitstatus.h
index 7b5faed83c7..63bbd737749 100644
--- a/gdb/target/waitstatus.h
+++ b/gdb/target/waitstatus.h
@@ -418,7 +418,7 @@ struct target_waitstatus
       char *execd_pathname;
       /* Syscall number */
       int syscall_number;
-    } m_value;
+    } m_value {};
 };
 
 /* Extended reasons that can explain why a target/thread stopped for a
-- 
2.34.1

Re: [PATCH + 12.1] Silence -Wmaybe-uninitialized warning from target_waitstatus

[Eli Zaretskii]

> Date: Thu,  7 Apr 2022 10:22:05 -0600
> From: Tom Tromey via Gdb-patches <gdb-patches@sourceware.org>
> Cc: Tom Tromey <tromey@adacore.com>
> 
> Currently, one use of target_waitstatus yields a warning:
> 
>      target/waitstatus.h: In function 'void stop_all_threads()':
>      target/waitstatus.h:175:13: warning: 'ws.target_waitstatus::m_value' may be used uninitialized in this function [-Wmaybe-uninitialized]
>        175 |     m_value = other.m_value;
> 	   |     ~~~~~~~~^~~~~~~~~~~~~~~
> 
> This patch silences the warning.  I tried the "volatile member"
> approach that was used for gdb::optional, but that didn't work, so
> this patch simply initializes the member.
> ---
>  gdb/target/waitstatus.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

I can confirm that the warning is gone after applying this patch.

Thanks.

Re: [PATCH + 12.1] Silence -Wmaybe-uninitialized warning from target_waitstatus

[Tom Tromey]

>>>>> "Tom" == Tom Tromey via Gdb-patches <gdb-patches@sourceware.org> writes:

Tom> Currently, one use of target_waitstatus yields a warning:
Tom>      target/waitstatus.h: In function 'void stop_all_threads()':
Tom>      target/waitstatus.h:175:13: warning: 'ws.target_waitstatus::m_value' may be used uninitialized in this function [-Wmaybe-uninitialized]
Tom>        175 |     m_value = other.m_value;
Tom> 	   |     ~~~~~~~~^~~~~~~~~~~~~~~

Tom> This patch silences the warning.  I tried the "volatile member"
Tom> approach that was used for gdb::optional, but that didn't work, so
Tom> this patch simply initializes the member.

I'm going to push this now.

Tom