Re: Ping: frozen variable objects

[Vladimir Prus <vladimir at codesourcery dot com>]

On Sunday 15 April 2007 02:53, Nick Roberts wrote:
>  > >  The range of values for fields with specified values, e.g.,
>  > > -@code{in_scope} (@pxref{-var-update}) may be extended.
>  > > +@code{in_scope} (@pxref{-var-update-fields}) may be extended.
>  > 
>  > Doesn't that read a little odd to you?  I'd think '-var-update fields'
>  > at least.
> 
> Also the name that is displayed shouldn't change, so pxref needs to be
> called with two arguments:
> 
> 
> @code{in_scope} (@pxref{-var-update fields, -var-update}) may be extended.
> 
> and
> 
> @anchor{-var-update fields}
> The field in_scope may take three values:
> 
> Here are some other observations about the documentation:
> 
> frozenness (not a common word) has two ns.
> 
> In the description for -var-set-frozen:
> 
>   parameter should be either `1' to make the variable frozen or `0' to
>   make it unfozen.  If a variable object is frozen, then neither itself,
>           ^^^^^^^
> 
> In the description for -var-update:
> 
>   If `*' is used as the variable object names, all existing variable objects
>   are updated.
> 
> Since frozen variables aren't updated implicitly, I would move some
> of the description of them from -var-set-frozen to here.

I think cross-reference will be fine.

>   @c The format of field's content e.g type prefix, may change so parse it
>    @c   at your own risk.  Yes, in general?
>   @@ -19536,7 +19536,10 @@ that corresponds to a composite type, su
>    a number of child variable objects, for example corresponding to each
>    element of a structure.  A child variable object can itself have 
>    children, recursively.  Recursion ends when we reach 
>   -leaf variable objects, which always have built-in types.
>   +leaf variable objects, which always have built-in types.  Child variable
>   +objects are created only by explicit request, so if a frontend 
>   +is not interested in the children of a particular variable object, no
>   +child will be created.
>  
>    For a leaf variable object it is possible to obtain its value as a
>    string, or set the value from a string.  String value can be also
>   @@ -19548,7 +19551,19 @@ A frontend does not need to read the val
>    the program stops.  Instead, MI provides an update command that lists all
>    variable objects whose values has changed since the last update
>    operation.  This considerably reduces the amount of data that must
>   -be transferred to the frontend.
>   +be transferred to the frontend.  As noted above, children variable
>   +objects are created on demand, and only leaf variable objects have a
>   +real value.  As result, gdb will read target memory only for leaf
>   +variables that frontend has created.
> 
> Why not just:
> 
>   @c The format of field's content e.g type prefix, may change so parse it
>    @c   at your own risk.  Yes, in general?
>   @@ -19536,7 +19536,10 @@ that corresponds to a composite type, su
>    a number of child variable objects, for example corresponding to each
>    element of a structure.  A child variable object can itself have 
>    children, recursively.  Recursion ends when we reach 
>   -leaf variable objects, which always have built-in types.
>   +leaf variable objects, which always have built-in types.  Child variable
>   +objects are created only by explicit request, so if a frontend 
>   +is not interested in the children of a particular variable object, no
>   +child will be created.   As result, gdb will read target memory only for
>   +leaf variables that frontend has created.

Because I wanted to say that -var-update specifically does not read memory
for entire structures.

- Volodya