Re: [PATCH v3 6/8] Create xml from target descriptions

[Philipp Rudo <prudo at linux dot vnet dot ibm dot com>]

Hi Alan,

On Thu, 1 Mar 2018 11:41:04 +0000
Alan Hayward <Alan.Hayward@arm.com> wrote:

[...]

> diff --git a/gdb/common/tdesc.c b/gdb/common/tdesc.c
> index 115e7cd77942b86dedced946773d1d71950e2bb3..ce5b89045c48c65ac4c6c48f6646f8d5c6ce9d8b 100644
> --- a/gdb/common/tdesc.c
> +++ b/gdb/common/tdesc.c
> @@ -288,4 +288,158 @@ tdesc_add_enum_value (tdesc_type_with_fields *type, int value,

[...]

> +void print_xml_feature::visit (const tdesc_reg *reg)
> +{
> +  *m_buffer += "<reg name=\"";
> +  *m_buffer += reg->name;
> +  *m_buffer += "\" bitsize=\"";
> +  *m_buffer += std::to_string (reg->bitsize);
> +  *m_buffer += "\" type=\"";
> +  *m_buffer += reg->type;
> +  *m_buffer += "\" regnum=\"";
> +  *m_buffer += std::to_string (reg->target_regnum);
> +  if (reg->group.length () > 0)
> +    {
> +      *m_buffer += "\" group=\"";
> +      *m_buffer += reg->group;
> +    }
> +  *m_buffer += "\"/>\n";
> +}

in the xml you can also set if an register is gets save_resore, i.e 

if (!reg->save_restore)
  *m_buffer += "\" save-restore=\"no";

[...]

> diff --git a/gdb/regformats/regdat.sh b/gdb/regformats/regdat.sh
> index 8c6e191596350fb4e983f8736985d9832f41e2d3..e6e06bdab0bdecc579686f3525e9f93555e0dd83 100755
> --- a/gdb/regformats/regdat.sh
> +++ b/gdb/regformats/regdat.sh
> @@ -180,7 +180,6 @@ echo
>  cat <<EOF
>  #ifndef IN_PROCESS_AGENT
>    result->expedite_regs = expedite_regs_${name};
> -  result->xmltarget = xmltarget_${name};
>  #endif
> 
>    init_target_desc (result);

This hunk caused all the test cases in gdb.server to fail.  Removing it 'fixed'
it for me.  Although i cannot tell you what went wrong.

Thanks
Philipp


> diff --git a/gdb/target-descriptions.c b/gdb/target-descriptions.c
> index da2c1ce34531c1b23281c42f2dacbc85444ef544..93e73571177c980b4cd1975256c89e8ffb9fcdd6 100644
> --- a/gdb/target-descriptions.c
> +++ b/gdb/target-descriptions.c
> @@ -333,6 +333,8 @@ struct target_desc : tdesc_element
>    /* The features associated with this target.  */
>    std::vector<tdesc_feature_up> features;
> 
> +  char *xmltarget = nullptr;
> +
>    void accept (tdesc_element_visitor &v) const override
>    {
>      v.visit_pre (this);
> @@ -1667,6 +1669,21 @@ private:
>    int m_next_regnum = 0;
>  };
> 
> +/* See common/tdesc.h.  */
> +
> +const char *
> +tdesc_get_features_xml (target_desc *tdesc)
> +{
> +  if (tdesc->xmltarget == nullptr)
> +    {
> +      std::string buffer ("@");
> +      print_xml_feature v (&buffer);
> +      tdesc->accept (v);
> +      tdesc->xmltarget = xstrdup (buffer.c_str ());
> +    }
> +  return tdesc->xmltarget;
> +}
> +
>  static void
>  maint_print_c_tdesc_cmd (const char *args, int from_tty)
>  {
> @@ -1760,7 +1777,36 @@ maintenance_check_xml_descriptions (const char *dir, int from_tty)
>  	= file_read_description_xml (tdesc_xml.data ());
> 
>        if (tdesc == NULL || *tdesc != *e.second)
> -	failed++;
> +	{
> +	  printf_filtered ( _("Descriptions for %s do not match\n"), e.first);
> +	  failed++;
> +	  continue;
> +	}
> +
> +      /* Convert both descriptions to xml, and then back again.  Confirm all
> +	 descriptions are identical.  */
> +
> +      const char *xml = tdesc_get_features_xml ((target_desc *) tdesc);
> +      const char *xml2 = tdesc_get_features_xml ((target_desc *) e.second);
> +      gdb_assert (*xml == '@');
> +      gdb_assert (*xml2 == '@');
> +      const target_desc *t_trans = target_read_description_xml_string (xml+1);
> +      const target_desc *t_trans2 = target_read_description_xml_string (xml2+1);
> +
> +      if (t_trans == NULL || t_trans2 == NULL)
> +	{
> +	  printf_filtered (
> +	    _("Could not convert descriptions for %s back to xml (%p %p)\n"),
> +	    e.first, t_trans, t_trans2);
> +	  failed++;
> +	}
> +      else if (*tdesc != *t_trans || *tdesc != *t_trans2)
> +	{
> +	  printf_filtered
> +	    (_("Translated descriptions for %s do not match (%d %d)\n"),
> +	    e.first, *tdesc == *t_trans, *tdesc == *t_trans2);
> +	  failed++;
> +	}
>      }
>    printf_filtered (_("Tested %lu XML files, %d failed\n"),
>  		   (long) selftests::xml_tdesc.size (), failed);
> diff --git a/gdb/xml-tdesc.h b/gdb/xml-tdesc.h
> index 8f0679707ad0f1e04d803f955f7fb98b4cc0c8c8..fee60e86dd10e1543b935c3cebce505d4dc828e2 100644
> --- a/gdb/xml-tdesc.h
> +++ b/gdb/xml-tdesc.h
> @@ -44,5 +44,10 @@ const struct target_desc *target_read_description_xml (struct target_ops *);
>     otherwise.  */
>  gdb::optional<std::string> target_fetch_description_xml (target_ops *ops);
> 
> +/* Take an xml string, parse it, and return the parsed description.  Does not
> +   handle a string containing includes.  */
> +
> +const struct target_desc *target_read_description_xml_string (const char *);
> +
>  #endif /* XML_TDESC_H */
> 
> diff --git a/gdb/xml-tdesc.c b/gdb/xml-tdesc.c
> index 9190d5f3c64ffdc6d7987d651527f597d695c5a6..f793f07c96847a3d61188fff1c5d63952cc37565 100644
> --- a/gdb/xml-tdesc.c
> +++ b/gdb/xml-tdesc.c
> @@ -752,3 +752,12 @@ target_fetch_description_xml (struct target_ops *ops)
>    return output;
>  #endif
>  }
> +
> +/* Take an xml string, parse it, and return the parsed description.  Does not
> +   handle a string containing includes.  */
> +
> +const struct target_desc *
> +target_read_description_xml_string (const char *xml_str)
> +{
> +  return tdesc_parse_xml (xml_str, nullptr, nullptr);
> +}
>