#cmakedefine01 does not seem to work with checks

[francoisk]

I may be missing something obvious but #cmakedefine01 does not appear to work with checks.

For example adding the following test to libbuild2-autoconf-tests/module/testscript results in the following failure:

: basics-cmakedefine01-with-check
:
mkdir build;
ln -s ../../bootstrap.build ../../root.build build/;
cat <<EOI >=config.h.cmake;
  #cmakedefine01 zzz_TEST_DUMMY1_H
  EOI
$* <<EOI &config.h &config.h.d;
  ./: h{config}: in{config.h.cmake}
  EOI
cat config.h >>EOO
  #define zzz_TEST_DUMMY1_H 1
  EOO

test libbuild2-autoconf-tests/module/testscript{testscript}
libbuild2-autoconf-tests/module/testscript:229:1: error: process b exited with code 1
  info: command line: b --no-default-options --serial-stop --silent --buildfile -
  info: stderr: libbuild2-autoconf-tests/module/test/basics-cmakedefine01-with-check/stderr-n4
  info: stdin: libbuild2-autoconf-tests/module/test/basics-cmakedefine01-with-check/stdin-n4
config.h.cmake:1: error: variable zzz_TEST_DUMMY1_H should be false/0 or true/1
  info: test id: basics-cmakedefine01-with-check
  info: while testing libbuild2-autoconf-tests/dir{module/}
  info: while testing dir{libbuild2-autoconf-tests/}
info: failed to test dir{libbuild2-autoconf-tests/}

[boris-kolpackov]

Yes, look like it.

The problem with this combination is that our checks use the standard "undefined or defined to 1" protocol rather than the "defined to 0 or defined to 1" expected by #cmakedefine01. We could probably automatically inject translation code after the check body, something along these lines:

#ifndef zzz_TEST_DUMMY1_H
#  define zzz_TEST_DUMMY1_H 0
#elif zzz_TEST_DUMMY1_H != 1
#  error ...
#endif

But that would break any subsequent check that reuse this check. So a bit of a dilemma... Maybe we should insert all the translations at the end of the file, after all the checks..?

[boris-kolpackov]

Thinking some more on this, the "translate at the end" idea also has an issue, if someone writes something like this:

#cmakedefine01 HAVE_FOO

#if HAVE_FOO == 0
...
#endif

Another option would be to translate immediately but mark the name as poisoned so that it could not be used as a base for further checks. Which would be a limitation, but probably acceptable (in practice, there is not much check reuse except for base stuff like BUILD2_AUTOCONF_LIBC_VERSION).