gdb-gdb.py: strip typedefs in intrusive_list printer assertion

  When debugging gdb itself and trying to print a intrusive_list that has
more than one element, I get:

    File "/home/simark/build/binutils-gdb-all-targets/gdb/gdb-gdb.py", line 365, in _children_generator
      node_ptr = self._as_node_ptr(elem_ptr)
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
    File "/home/simark/build/binutils-gdb-all-targets/gdb/gdb-gdb.py", line 345, in _as_node_ptr
      assert elem_ptr.type.code == gdb.TYPE_CODE_PTR
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    AssertionError

This is because node_ptr is a typedef
(intrusive_list_base_iterator::pointer).  Add a call to strip_typedefs
to get to the real type.

Enhance gdb.gdb/python-helper.exp with a test that would have caught
this bug.

Change-Id: I3eaca8de5ed06d05756ed979332b6a431e15b700
---
 gdb/gdb-gdb.py.in                       |  2 +-
 gdb/testsuite/gdb.gdb/python-helper.exp | 15 +++++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)


base-commit: 0ed152c5c6b3c72fc505b331ed77e08b438d643a
  

Simon Marchi <simon.marchi@polymtl.ca> writes:

> When debugging gdb itself and trying to print a intrusive_list that has
> more than one element, I get:
>
>     File "/home/simark/build/binutils-gdb-all-targets/gdb/gdb-gdb.py", line 365, in _children_generator
>       node_ptr = self._as_node_ptr(elem_ptr)
>                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^
>     File "/home/simark/build/binutils-gdb-all-targets/gdb/gdb-gdb.py", line 345, in _as_node_ptr
>       assert elem_ptr.type.code == gdb.TYPE_CODE_PTR
>              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>     AssertionError
>
> This is because node_ptr is a typedef
> (intrusive_list_base_iterator::pointer).  Add a call to strip_typedefs
> to get to the real type.
>
> Enhance gdb.gdb/python-helper.exp with a test that would have caught
> this bug.

Thanks for extending the test case.

This LGTM.

Approved-By: Andrew Burgess <aburgess@redhat.com>

Thanks,
Andrew


>
> Change-Id: I3eaca8de5ed06d05756ed979332b6a431e15b700
> ---
>  gdb/gdb-gdb.py.in                       |  2 +-
>  gdb/testsuite/gdb.gdb/python-helper.exp | 15 +++++++++++++++
>  2 files changed, 16 insertions(+), 1 deletion(-)
>
> diff --git a/gdb/gdb-gdb.py.in b/gdb/gdb-gdb.py.in
> index b5a7fa4f3903..7cab6941f02c 100644
> --- a/gdb/gdb-gdb.py.in
> +++ b/gdb/gdb-gdb.py.in
> @@ -342,7 +342,7 @@ class IntrusiveListPrinter:
>          corresponding intrusive_list_node.
>          """
>  
> -        assert elem_ptr.type.code == gdb.TYPE_CODE_PTR
> +        assert elem_ptr.type.strip_typedefs().code == gdb.TYPE_CODE_PTR
>  
>          if self._uses_member_node():
>              # Node as a member: add the member node offset from to the element's
> diff --git a/gdb/testsuite/gdb.gdb/python-helper.exp b/gdb/testsuite/gdb.gdb/python-helper.exp
> index 8a8afb12257b..4589edc388fd 100644
> --- a/gdb/testsuite/gdb.gdb/python-helper.exp
> +++ b/gdb/testsuite/gdb.gdb/python-helper.exp
> @@ -111,6 +111,16 @@ proc test_python_helper {} {
>  	}
>      }
>  
> +    # Add a second inferior, useful to the intrusive_list pretty-printer test
> +    # below.
> +    send_inferior "add-inferior\n"
> +    gdb_test_multiple "" "add second inferior in inner GDB" {
> +	-i "$inferior_spawn_id"
> +	-re "Added inferior 2\r\n$gdb_prompt $" {
> +	    pass $gdb_test_name
> +	}
> +    }
> +
>      # Send Ctrl-C to the inner GDB, this should kick us back to the
>      # prompt of the outer GDB.
>      send_inferior "\003"
> @@ -253,6 +263,11 @@ proc test_python_helper {} {
>      # Test the htab_t pretty-printer.
>      gdb_test -prompt $outer_prompt_re "print all_bfds" "htab_t with ${::decimal} elements = \\{${::hex}.*\\}"
>  
> +    # Test the intrusive_list pretty-printer.  A bug occured in the
> +    # pretty-printer for lists with more than one element.  Verify that
> +    # we see both elements of the inferior_list list being printed.
> +    gdb_test -prompt $outer_prompt_re "print inferior_list" "intrusive list of inferior = {.*, num = 1,.*, num = 2,.*}"
> +
>      return 0
>  }
>  
>
> base-commit: 0ed152c5c6b3c72fc505b331ed77e08b438d643a
> -- 
> 2.45.2
  

On 2024-07-19 07:42, Andrew Burgess wrote:
> Simon Marchi <simon.marchi@polymtl.ca> writes:
> 
>> When debugging gdb itself and trying to print a intrusive_list that has
>> more than one element, I get:
>>
>>     File "/home/simark/build/binutils-gdb-all-targets/gdb/gdb-gdb.py", line 365, in _children_generator
>>       node_ptr = self._as_node_ptr(elem_ptr)
>>                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>     File "/home/simark/build/binutils-gdb-all-targets/gdb/gdb-gdb.py", line 345, in _as_node_ptr
>>       assert elem_ptr.type.code == gdb.TYPE_CODE_PTR
>>              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>     AssertionError
>>
>> This is because node_ptr is a typedef
>> (intrusive_list_base_iterator::pointer).  Add a call to strip_typedefs
>> to get to the real type.
>>
>> Enhance gdb.gdb/python-helper.exp with a test that would have caught
>> this bug.
> 
> Thanks for extending the test case.
> 
> This LGTM.
> 
> Approved-By: Andrew Burgess <aburgess@redhat.com>
> 
> Thanks,
> Andrew

Thanks, pushed.

Simon