Mercurial > hg > octave-kai > gnulib-hg
changeset 13919:09a24a6c8f31
Update internal documentation.
* m4/README: Document new idioms for AC_RUN_IFELSE invocations.
author | Bruno Haible <bruno@clisp.org> |
---|---|
date | Mon, 06 Dec 2010 23:17:12 +0100 |
parents | d5a74c6ec06b |
children | 5667703dedaa |
files | ChangeLog m4/README |
diffstat | 2 files changed, 46 insertions(+), 0 deletions(-) [+] |
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--- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,8 @@ +2010-12-06 Bruno Haible <bruno@clisp.org> + + Update internal documentation. + * m4/README: Document new idioms for AC_RUN_IFELSE invocations. + 2010-12-04 Bruno Haible <bruno@clisp.org> Put more information about failed tests into the test return codes.
--- a/m4/README +++ b/m4/README @@ -73,6 +73,47 @@ be the autoconf macro that provides it. This is only an approximation; in general you should look at all preprocessor directives in lib/foo.c. +- In AC_RUN_IFELSE invocations, try to put as much information about failed + tests as possible in the exit code. The exit code is 0 for success and any + value between 1 and 127 for failure. The exit code is printed in config.log; + therefore when an AC_RUN_IFELSE invocation failed, it is possible to analyze + the failure immediately if sufficient information is contained in the exit + code. + + For a program that performs a single test, the typical idiom is: + + if (do_test1 ()) + return 1; + return 0; + + For a test that performs a test with some preparation, the typical idiom is + to return an enumerated value: + + if (prep1 ()) + return 1; + else if (prep2 ()) + return 2; + else if (prep3 ()) + return 3; + else if (do_test1 ()) + return 4; + return 0; + + For multiple independent tests in a single program, you can return a bit + mask with up to 7 bits: + + int result = 0; + if (do_test1 ()) + result |= 1; + if (do_test2 ()) + result |= 2; + if (do_test3 ()) + result |= 4; + return result; + + For more than 7 independent tests, you have to map some possible test + failures to same bit. + - After ANY modifications of an m4 file, you should increment its serial number (in the first line). Also, if this first line features a particular release, _remove_ this release stamp. Example: Change