Re: [PATCH] Remove unwanted spaces when looking up builtin types

[Siva Chandra <sivachandra at google dot com>]

On Fri, Nov 7, 2014 at 5:49 AM, Siva Chandra <sivachandra@google.com> wrote:
> On Wed, Oct 29, 2014 at 11:50 AM, Siva Chandra <sivachandra@google.com> wrote:
>> Currently, if we do something like gdb.lookup_type(" unsigned long "),
>> GDB errors out because of the leading and trailing spaces.  The
>> attached patch fixes this problem.
>>
>> A practical situation where this problem is hit is when invoking
>> template methods. Its not uncommon to do things like this:
>>
>> (gdb) p foo.bar< unsigned long >()
>>
>> If "bar" happens to be an xmethod, then its implementation will
>> typically need to parse the name of the method ("bar< unsigned long >"
>> in the above example) to get the template argument and lookup the
>> type. GDB currently fails for such cases. One could of course
>> sanitize/fix such inputs in Python before calling lookup_type, but I
>> think it is better done on the GDB side as having white spaces is
>> valid syntax.
>>
>> For non-builtin types, lookup_type goes through the symbol lookup
>> path. AFAIU, that path already ignores whitespaces.
>

Ping.
This is not super critical, but I see that an xmethod test fails after
I have upgraded to gcc-4.8.2 from gcc-4.6. The essential difference I
have found is that looking up a symbol for "  unsigned int  " works
when the test is compiled with gcc-4.6 and it does not when compiled
with 4.8.2. And, when it does not, the type is looked up via
"language_lookup_primitive_type_by_name" which errors out as it does
an exact string match.

[I have not yet looked into why there is a difference between gcc-4.6
and gcc-4.8.2 as I think that the proposed fix is not inappropriate
and does fix the problem.]

>
> gdb/ChangeLog:
>
> 2014-11-07  Siva Chandra Reddy  <sivachandra@google.com>
>
>         * language.c (language_lookup_primitive_type_by_name): Remove
>         unwanted space in the type name before looking it up.
>         (whitespace_p): New function.
>
> gdb/testsuite/ChangeLog:
>
> 2014-11-07  Siva Chandra Reddy  <sivachandra@google.com>
>
>         * gdb.python/py-type.exp: Add new tests.