Re: [PATCH] Cygwin: Suppress a warning generated with w32api >= 12.0.0

[Jon Turney]

On 08/06/2024 17:43, Takashi Yano wrote:

On Fri,  7 Jun 2024 17:37:24 +0100
Jon Turney wrote:

w32api 12.0.0 adds the returns_twice attribute to RtlCaptureContext().
There's some data-flow interaction with using it inside a while loop
which causes a maybe-uninitialized warning.

../../../../winsup/cygwin/exceptions.cc: In member function 'int 
_cygtls::call_signal_handler()':
│
../../../../winsup/cygwin/exceptions.cc:1720:33: error: '' may be 
used uninitialized in this function [-Werror=maybe-uninitialized] 
  │

[...]


It seems that the commit message include non UTF-8 chars.


Thanks for pointing that out. Hopefully, I fixed it before applying.

Re: [PATCH] Cygwin: Suppress a warning generated with w32api >= 12.0.0

[Takashi Yano]

On Fri,  7 Jun 2024 17:37:24 +0100
Jon Turney wrote:
> w32api 12.0.0 adds the returns_twice attribute to RtlCaptureContext().
> There's some data-flow interaction with using it inside a while loop
> which causes a maybe-uninitialized warning.
> 
> ../../../../winsup/cygwin/exceptions.cc: In member function 'int 
> _cygtls::call_signal_handler()':  
>   │
> ../../../../winsup/cygwin/exceptions.cc:1720:33: error: '' may be 
> used uninitialized in this function [-Werror=maybe-uninitialized] 
>   │
> ---
>  winsup/cygwin/exceptions.cc | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/winsup/cygwin/exceptions.cc b/winsup/cygwin/exceptions.cc
> index a2a6f9d4c..28d0431d5 100644
> --- a/winsup/cygwin/exceptions.cc
> +++ b/winsup/cygwin/exceptions.cc
> @@ -1717,7 +1717,10 @@ _cygtls::call_signal_handler ()
>context, unwind to the caller and in case we're called
>from sigdelayed, fix the instruction pointer accordingly. */
> context.uc_mcontext.ctxflags = CONTEXT_FULL;
> +#pragma GCC diagnostic push
> +#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
> RtlCaptureContext ((PCONTEXT) _mcontext);
> +#pragma GCC diagnostic pop
> __unwind_single_frame ((PCONTEXT) _mcontext);
> if (stackptr > stack)
>   {
> -- 
> 2.45.1

It seems that the commit message include non UTF-8 chars.

-- 
Takashi Yano 

[PATCH] Cygwin: Suppress a warning generated with w32api >= 12.0.0

[Jon Turney]

w32api 12.0.0 adds the returns_twice attribute to RtlCaptureContext().
There's some data-flow interaction with using it inside a while loop
which causes a maybe-uninitialized warning.

../../../../winsup/cygwin/exceptions.cc: In member function 'int 
_cygtls::call_signal_handler()':
│
../../../../winsup/cygwin/exceptions.cc:1720:33: error: '' may be 
used uninitialized in this function [-Werror=maybe-uninitialized]   
│
---
 winsup/cygwin/exceptions.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/winsup/cygwin/exceptions.cc b/winsup/cygwin/exceptions.cc
index a2a6f9d4c..28d0431d5 100644
--- a/winsup/cygwin/exceptions.cc
+++ b/winsup/cygwin/exceptions.cc
@@ -1717,7 +1717,10 @@ _cygtls::call_signal_handler ()
 context, unwind to the caller and in case we're called
 from sigdelayed, fix the instruction pointer accordingly. */
  context.uc_mcontext.ctxflags = CONTEXT_FULL;
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
  RtlCaptureContext ((PCONTEXT) _mcontext);
+#pragma GCC diagnostic pop
  __unwind_single_frame ((PCONTEXT) _mcontext);
  if (stackptr > stack)
{
-- 
2.45.1