Horton

Re: ECPG cleanup and fix for clang compile-time problem

Andres Freund <andres@anarazel.de>

View thread View on postgr.es
From: Andres Freund <andres@anarazel.de>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-hackers@lists.postgresql.org, Peter Eisentraut <peter_e@gmx.net>, Michael Paquier <michael.paquier@gmail.com>
Date: 2024-04-19T03:40:22Z
Lists: pgsql-hackers 
On 2024-04-18 23:11:52 -0400, Tom Lane wrote:
> Andres Freund <andres@anarazel.de> writes:
> > On 2024-04-18 22:18:34 -0400, Tom Lane wrote:
> >> (If our code coverage tools worked on bison/flex stuff,
> >> maybe this'd be less scary ... but they don't.)
>
> > For bison coverage seems to work, see e.g.:
>
> Yeah, I'd just noticed that --- I had it in my head that we'd put
> LCOV_EXCL_START/STOP into bison files too, but nope they are only
> in flex files.  That's good for this specific problem, because the
> code I'm worried about is all in the bison file.

At least locally the coverage seems to make sense too, both for the main
grammar and for ecpg's.


> > around the scanner "body".  Without that I get reasonable-looking, albeit not
> > very comforting, coverage for pgc.l as well.
>
> I was just looking locally at what I got by removing that, and sadly
> I don't think I believe it: there are a lot of places where it claims
> we hit lines we don't, and vice versa.  That might be partially
> blamable on old tools on my RHEL8 workstation, but it sure seems
> that flex output confuses lcov to some extent.

Hm. Here it mostly looks reasonable, except that at least things seem off by
1. And sure enough, if I look at pgc.l it has code like

case 2:
YY_RULE_SETUP
#line 465 "/home/andres/src/postgresql/src/interfaces/ecpg/preproc/pgc.l"
{
                                        token_start = yytext;
                                        state_before_str_start = YYSTATE;

However line 465 is actually the "token_start" line.

Further down this seems to get worse, by "<<EOF>>" it's off by 4 lines.


$ apt policy flex
flex:
  Installed: 2.6.4-8.2+b2
  Candidate: 2.6.4-8.2+b2
  Version table:
 *** 2.6.4-8.2+b2 500
        500 http://mirrors.ocf.berkeley.edu/debian unstable/main amd64 Packages
        100 /var/lib/dpkg/status

Greetings,

Andres Freund

Commits

  1. ecpg: clean up some other assorted memory leaks.

  2. ecpg: fix some memory leakage of data-type-related structures.

  3. ecpg: put all string-valued tokens returned by pgc.l in local storage.

  4. ecpg: fix more minor mishandling of bad input in preprocessor.

  5. ecpg: fix some minor mishandling of bad input in preprocessor.

  6. ecpg: avoid breaking the IDENT precedence level in two.

  7. ecpg: improve preprocessor's memory management.

  8. ecpg: move some functions into a new file ecpg/preproc/util.c.

  9. ecpg: re-implement preprocessor's string management.

  10. ecpg: major cleanup, simplification, and documentation of parse.pl.

  11. ecpg: remove check_rules.pl.

  12. ecpg: clean up documentation of parse.pl, and add more input checking.

  13. Clean up indentation and whitespace inconsistencies in ecpg.

  14. Exclude flex-generated code from coverage testing