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From:Mats Kindahl Date:June 23 2009 9:03am
Subject:Re: MySql coding style: Request for deprecation of UPPERCASE typedefs
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Tor Didriksen wrote:
> On Mon, 22 Jun 2009 19:12:08 +0200, Roy Lyseng <Roy.Lyseng@stripped> wrote:
> 
>>
>>
>> Konstantin Osipov wrote:
>>> * Tor Didriksen <Tor.Didriksen@stripped> [09/06/22 17:23]:
>>>
>>>> "Structure types are typedef'ed to an all-upper-case identifier."
>>>> Can someone explain the reasoning behind this?
>>>> ALL_UPPERCASE_NAME says DANGEROUS_THIS_IS_A_MACRO to me, rather than
>>>> struct/class.
>>>>
>>>> typedef struct foo { ... } FOO;
>>>> Is legacy C-style, and does not belong in a C++ style guide (imho).
>>>>
>>>> Roy had an email about this:
>>>> http://lists.mysql.com/internals/36570
>>>> I could find no objections to his mail, the thread simply died.
>>>>
>>>
>>> This is an obsolete convention, but it is still widely used in the
>>> optimizer and semantic analysis code, even in new parts of it. It
>>> was difficult for me to involve some optimizer engineers into
>>> discussion about the coding style.
>>>
>>> In runtime, I find it largely irrelevant: I advocate against
>>> introduction of new struct objects into the code base, classes
>>> should be used instead, and for classes we use a different naming
>>> rule.
>>>
>>> We also have a lot of legacy code that follows this old guideline.
>>> typedef's are really a pain to maintain, since they obfuscate
>>> tags-jumping, make forward declarations more difficult.
>>>
>>> I guess updating the old code could be a task for reengineering
>>> team. Drizle did it one of the first things. I would gladly review
>>> any patch that removes unnecessary typedefs
>>> from the code, and submit such patches myself once in a while.
>>> Nobody else, however,  seem to have done much about it instead of
>>> talking :-<.
>>>
>>> Please submit a change request to the coding style group to remove
>>> that rule (unless this mail is already a change request).
>>>
>>>
>>> As Tor said, there is already a proposal:
>>> http://lists.mysql.com/internals/36570.
>>
>> When it is accepted, I will be more than happy to start removing old
>> typedefs. But I consider it a waste of time unless we have a clear rule.
>>
>> Thanks,
>> Roy
> 
> Please note that I am not suggesting a major rewrite of existing code.
> I don't think that is productive use of engineer time.

Actually, I think that is a productive use of engineer time. I tried to work out
the dependencies of lex.h (to make it self-sufficient), and this is what I got:

class Table_ident;       /* Need to be before include of sql_yacc.h */
class Item_num;
class String;
class Key_part_spec;
struct TABLE_LIST;
typedef struct st_udf_func udf_func;
typedef struct st_lex_user LEX_USER;
#include "sql_list.h"                 /* Pull in List<> */
#include "set_var.h"                  /* Pull in sys_var_with_base */
#include "sql_yacc.h"                 /* Pull in symbol definitions */

For each line, I had to do a symbol search to find the definition of it and see
how and where it was defined. Most other files have similar dependencies...

/Matz

> 
> -- didrik
> 
> 
> 
> 

-- 
Mats Kindahl
Senior Software Engineer
Database Technology Group
Sun Microsystems
Thread
MySql coding style: Request for deprecation of UPPERCASE typedefsTor Didriksen22 Jun
  • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsMats Kindahl22 Jun
    • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsMichael Widenius24 Jun
      • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsTor Didriksen25 Jun
        • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsMichael Widenius27 Jun
      • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsMats Kindahl25 Jun
        • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsMichael Widenius27 Jun
          • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsJay Pipes27 Jun
          • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsTor Didriksen29 Jun
          • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsMats Kindahl29 Jun
            • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsKristian Nielsen29 Jun
              • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsTor Didriksen30 Jun
                • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsMats Kindahl30 Jun
                • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsKristian Nielsen30 Jun
                  • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsTor Didriksen1 Jul
                    • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsKristian Nielsen1 Jul
                  • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsKonstantin Osipov1 Jul
              • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsKonstantin Osipov1 Jul
                • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsKristian Nielsen2 Jul
  • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsKonstantin Osipov22 Jun
    • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsRoy Lyseng22 Jun
      • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsTor Didriksen23 Jun
        • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsMats Kindahl23 Jun
          • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsTor Didriksen23 Jun
            • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsMats Kindahl23 Jun
              • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsMichael Widenius27 Jun
                • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsMats Kindahl30 Jun
            • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsMichael Widenius24 Jun
              • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsTor Didriksen25 Jun
                • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsJonas Oreland25 Jun
                  • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsDavi Arnaut25 Jun
                    • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsMichael Widenius27 Jun
                  • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsMichael Widenius27 Jun
                • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsJay Pipes25 Jun
                  • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsMats Kindahl25 Jun
                  • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsMichael Widenius27 Jun
                • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsMichael Widenius27 Jun
                  • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsMats Kindahl30 Jun
              • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsMats Kindahl25 Jun
                • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsMichael Widenius27 Jun
                  • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsJay Pipes27 Jun
                    • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsMichael Widenius30 Jun
                  • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsJay Pipes27 Jun
                    • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsMichael Widenius1 Jul
    • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsTor Didriksen23 Jun
  • Re: MySql coding style: Request for deprecation of UPPERCASEtypedefsSergei Golubchik22 Jun
    • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsTor Didriksen23 Jun
      • Re: MySql coding style: Request for deprecation of UPPERCASEtypedefsSergei Golubchik23 Jun
        • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsTor Didriksen23 Jun
  • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsAlex Esterkin1 Jul
    • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsTor Didriksen1 Jul
    • Re: MySql coding style: Request for deprecation of UPPERCASE typedefsKonstantin Osipov1 Jul