[PATCH] Update FAQ question and answer about gdb and signals

[PATCH] Update FAQ question and answer about gdb and signals

[Jon Turney]

Signed-off-by: Jon Turney <jon.turney@dronecode.org.uk>
---
 winsup/doc/faq-programming.xml | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/winsup/doc/faq-programming.xml b/winsup/doc/faq-programming.xml
index af6102a..7f1ffd9 100644
--- a/winsup/doc/faq-programming.xml
+++ b/winsup/doc/faq-programming.xml
@@ -859,15 +859,22 @@ on using <literal>strace</literal>, see the Cygwin User's Guide.
 </answer></qandaentry>
 
 <qandaentry id="faq.programming.gdb-signals">
-<question><para>Why doesn't gdb handle signals?</para></question>
+<question><para>How does gdb handle signals?</para></question>
 <answer>
 
-<para>Unfortunately, there is only minimal signal handling support in gdb
-currently.  Signal handling only works with Windows-type signals.
-SIGINT may work, SIGFPE may work, SIGSEGV definitely does.  You cannot
-'stop', 'print' or 'nopass' signals like SIGUSR1 or SIGHUP to the
-process being debugged.
+<para>
+gdb maps known Windows exceptions to signals such as SIGSEGV, SIGFPE, SIGTRAP,
+SIGINT and SIGILL.  Other Windows exceptions are passed on to the handler (if
+any), and reported as an unknown signal if an unhandled (second chance)
+exception occurs.
 </para>
+
+<para>
+There is also an experimental feature to notify gdb of purely Cygwin signals
+like SIGABRT, SIGHUP or SIGUSR1.  This currently has some known problems, for
+example, single-stepping from these signals may not work as expected.
+</para>
+
 </answer></qandaentry>
 
 <qandaentry id="faq.programming.linker">
-- 
2.6.2

Re: [PATCH] Update FAQ question and answer about gdb and signals

[Corinna Vinschen]

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On Jan 14 18:05, Jon Turney wrote:
> Signed-off-by: Jon Turney <jon.turney@dronecode.org.uk>
> ---
>  winsup/doc/faq-programming.xml | 19 +++++++++++++------
>  1 file changed, 13 insertions(+), 6 deletions(-)
> 
> diff --git a/winsup/doc/faq-programming.xml b/winsup/doc/faq-programming.xml
> index af6102a..7f1ffd9 100644
> --- a/winsup/doc/faq-programming.xml
> +++ b/winsup/doc/faq-programming.xml
> @@ -859,15 +859,22 @@ on using <literal>strace</literal>, see the Cygwin User's Guide.
>  </answer></qandaentry>
>  
>  <qandaentry id="faq.programming.gdb-signals">
> -<question><para>Why doesn't gdb handle signals?</para></question>
> +<question><para>How does gdb handle signals?</para></question>
>  <answer>
>  
> -<para>Unfortunately, there is only minimal signal handling support in gdb
> -currently.  Signal handling only works with Windows-type signals.
> -SIGINT may work, SIGFPE may work, SIGSEGV definitely does.  You cannot
> -'stop', 'print' or 'nopass' signals like SIGUSR1 or SIGHUP to the
> -process being debugged.
> +<para>
> +gdb maps known Windows exceptions to signals such as SIGSEGV, SIGFPE, SIGTRAP,
> +SIGINT and SIGILL.  Other Windows exceptions are passed on to the handler (if
> +any), and reported as an unknown signal if an unhandled (second chance)
> +exception occurs.
>  </para>
> +
> +<para>
> +There is also an experimental feature to notify gdb of purely Cygwin signals
> +like SIGABRT, SIGHUP or SIGUSR1.  This currently has some known problems, for
> +example, single-stepping from these signals may not work as expected.
> +</para>
> +
>  </answer></qandaentry>
>  
>  <qandaentry id="faq.programming.linker">
> -- 
> 2.6.2

ACK


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat

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