[RFA] values.c: don't fetch func void return value

[RFA] values.c: don't fetch func void return value

[Elena Zannoni]

While debugging the x86-64 I noticed that there were problems because
gdb was trying to extract a void return value from a function.  It
already has set up the value structure with all the correct fields, it
seems a waste to go and ask the target for a value if we know there
isn't one.

No regressions on x86.

2003-04-16  Elena Zannoni  <ezannoni@redhat.com>

	* values.c (value_being_returned): Don't fetch the return
        value if the return type is void.

Index: values.c
===================================================================
RCS file: /cvs/uberbaum/gdb/values.c,v
retrieving revision 1.47
diff -u -p -r1.47 values.c
--- values.c	20 Feb 2003 00:01:07 -0000	1.47
+++ values.c	16 Apr 2003 21:29:19 -0000
@@ -1240,7 +1240,9 @@ value_being_returned (struct type *valty
 
   val = allocate_value (valtype);
   CHECK_TYPEDEF (valtype);
-  EXTRACT_RETURN_VALUE (valtype, retbuf, VALUE_CONTENTS_RAW (val));
+  /* If the function returns void, don't bother fetching the return value.  */
+  if (TYPE_CODE (valtype) != TYPE_CODE_VOID)
+    EXTRACT_RETURN_VALUE (valtype, retbuf, VALUE_CONTENTS_RAW (val));
 
   return val;
 }

Re: [RFA] values.c: don't fetch func void return value

[Michael Snyder]

Elena Zannoni wrote:
> 
> While debugging the x86-64 I noticed that there were problems because
> gdb was trying to extract a void return value from a function.  It
> already has set up the value structure with all the correct fields,

Meaning the correct fields for a void return?

> it
> seems a waste to go and ask the target for a value if we know there
> isn't one.

Seems reasonable to me...  and I don't see any specific maintainer.
[donning appropriate hat]  Bless you, my child...


> 2003-04-16  Elena Zannoni  <ezannoni@redhat.com>
> 
>         * values.c (value_being_returned): Don't fetch the return
>         value if the return type is void.
> 
> Index: values.c
> ===================================================================
> RCS file: /cvs/uberbaum/gdb/values.c,v
> retrieving revision 1.47
> diff -u -p -r1.47 values.c
> --- values.c    20 Feb 2003 00:01:07 -0000      1.47
> +++ values.c    16 Apr 2003 21:29:19 -0000
> @@ -1240,7 +1240,9 @@ value_being_returned (struct type *valty
> 
>    val = allocate_value (valtype);
>    CHECK_TYPEDEF (valtype);
> -  EXTRACT_RETURN_VALUE (valtype, retbuf, VALUE_CONTENTS_RAW (val));
> +  /* If the function returns void, don't bother fetching the return value.  */
> +  if (TYPE_CODE (valtype) != TYPE_CODE_VOID)
> +    EXTRACT_RETURN_VALUE (valtype, retbuf, VALUE_CONTENTS_RAW (val));
> 
>    return val;
>  }

Re: [RFA] values.c: don't fetch func void return value

[Elena Zannoni]

Michael Snyder writes:
 > Elena Zannoni wrote:
 > > 
 > > While debugging the x86-64 I noticed that there were problems because
 > > gdb was trying to extract a void return value from a function.  It
 > > already has set up the value structure with all the correct fields,
 > 
 > Meaning the correct fields for a void return?
 > 
 > > it
 > > seems a waste to go and ask the target for a value if we know there
 > > isn't one.
 > 
 > Seems reasonable to me...  and I don't see any specific maintainer.
 > [donning appropriate hat]  Bless you, my child...
 > 

Thanks, 
committed

elena


 > 
 > > 2003-04-16  Elena Zannoni  <ezannoni@redhat.com>
 > > 
 > >         * values.c (value_being_returned): Don't fetch the return
 > >         value if the return type is void.
 > > 
 > > Index: values.c
 > > ===================================================================
 > > RCS file: /cvs/uberbaum/gdb/values.c,v
 > > retrieving revision 1.47
 > > diff -u -p -r1.47 values.c
 > > --- values.c    20 Feb 2003 00:01:07 -0000      1.47
 > > +++ values.c    16 Apr 2003 21:29:19 -0000
 > > @@ -1240,7 +1240,9 @@ value_being_returned (struct type *valty
 > > 
 > >    val = allocate_value (valtype);
 > >    CHECK_TYPEDEF (valtype);
 > > -  EXTRACT_RETURN_VALUE (valtype, retbuf, VALUE_CONTENTS_RAW (val));
 > > +  /* If the function returns void, don't bother fetching the return value.  */
 > > +  if (TYPE_CODE (valtype) != TYPE_CODE_VOID)
 > > +    EXTRACT_RETURN_VALUE (valtype, retbuf, VALUE_CONTENTS_RAW (val));
 > > 
 > >    return val;
 > >  }