Re: awk for config headers

[Benoit SIGOURE]

On Sep 30, 2007, at 8:34 PM, Ralf Wildenhues wrote:

Following up on
<http://lists.gnu.org/archive/html/autoconf/2007-09/msg00075.html>,
here's a rewrite using awk instead of sed to generate config headers.

Notes:
- backslash-newline are retained in config.h, flattened for @DEFS@,
- should be portable to old awk,
- the length limits for define values should be lifted now (for config
  headers, not for DEFS): the per line limit is still that of sed and
  the shell, but for awk, long values are split into several literal
  strings (and over several lines in the script).

  D defines and L "active" config header lines, i.e., those with
  `#define' or `#undef' in the header input file,
- still needs testing on all kinds of systems.

The absolute impact of the speedup is rather small: for OpenMPI, on a

this change, even though the relative improvement is nice.

configure size increases by a few hundred bytes, config.status size
decreases for more than a few defines (from 180K to 160K in the above
example).

In the patch below, I've not changed the XFAILing test `Define a
newline' as that would clash with Eric's proposed patch; likewise a
manual change is still missing.

What do you think?

- formally, this is a work complexity reduction from D * L to D + L for modern GNU/Linux x86, creating 5 config headers with roughly 520 defines takes 0.68 sec over previously 1.32 sec. So speedup is no reason to do

Great thing overall.

I do hope that the length of the awk script is due to the severe
limitations of portable awk rather than my inability to write concise

there.  ;-)

programs in that language, but of course would happy to be proven wrong

Looks fine to me.

FreeBSD 6.2, GNU/Linux.

Tested with plain awk on Solaris 2.6, HP-UX 10.20, AIX 4.3, Tru64 4.0D,

  - Saving the raw message with your favorite mail client.
  - Adding a line that contains `---' before the actual patch
  - Invoking git am /path/to/raw_mail


ERROR: 301 tests were run,
7 failed (4 expected failures).
9 tests were skipped.
[...]
testsuite: 103 156 158 failed

Hmm so I just checked without your patch:
$ git co HEAD~1
$ make -j2 && make check

ERROR: 301 tests were run,
6 failed (4 expected failures).
9 tests were skipped.
[...]
testsuite: 156 158 failed



For the 3 tests, the error is:
.../m4:configure.ac:...: ERROR: end of file in string
autom4te: .../m4 failed with exit status: 1

Tested here (Mac OSX 10.4.10) and I get failures. By the way, with Git, testing the patch is as simple as: git am (apply mailbox) parses the headers of the mail to retain authorship and date of the original commit, looks for `---' in order to delimit the patch and the commit message (read: "it would be great if you guys got in the habit of adding the --- in your mails to be nice with Git users" :D). It does all the unescaping necessary (such as converting `=3D' in `=' etc.) and supports binary patches, type changes etc. So humm it looks like your patch breaks (at least) test #103 [#define header templates] here. testsuite.log @ https://www.tsunanet.net/~tsuna/awk-for-config- headers.log

--
Benoit Sigoure aka Tsuna
EPITA Research and Development Laboratory

I didn't have time to investigate, however please let me know if I can do anything to provide you with more valuable information.

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