From 34001a987a6defdb70f6f3c17cce9d9c665fe6e8 Mon Sep 17 00:00:00 2001 From: Stefano Lattarini Date: Wed, 9 Jan 2013 23:16:53 +0100 Subject: compile: use 'compile' script when "-c -o" is used with losing compilers Do so seen when only source files in the "current" directory are present. This commit is part of a series of related changes addressing automake bug#13378 (see also the plan 'PLANS/subdir-objects.txt'). Before this change, Automake-generated C compilation rules mistakenly passed the "-c -o" options combination unconditionally (even to losing compiler) when the 'subdir-objects' was used but sources were only present in the top-level directory. Issue spotted by Nick Bowler: We fix this by having Automake redefine AC_PROG_CC to take over the role of AM_PROG_CC_C_O and to require the 'compile' script unconditionally (albeit that will continue to be invoked only when inferior compilers are detected). Among other things, this means AM_PROG_CC_C_O explicitly is no longer required; that macro is still supported for backward-compatibility, but calling it is basically a no-op now. This change has some pros and some cons (obviously, we believe the former outweighs the latter). Here are the most relevant ones: + Pros 1: Some logic in the Automake script has been simplified. + Pros 2: That simplification has automatically fixed an actual bug (see Nick's mails referenced above; admittedly, that was present only in corner-case situations, but still); the test 't/ccnoco4.sh', which demonstrated the bug and has been failing so far, now passes. + Pros 3: Things works more "automagically" now (no need to manually add the AM_PROG_CC_C_O macro to configure.ac anymore). * Cons 1: The 'compile' script will be required in all projects using C compilation; this will only be a problem for packages not using '--add-missing'. However, such packages are definitely more rare than the ones using '--add-missing', and adjusting them will be trivial -- just copy the compile script over from the new Automake installation. * Cons 2: The copy & paste of autoconf internals hack this change has introduced in our "rewrite" of AC_PROG_CC is really an egregious abomination. It can only be justified with the fact that we expect future versions of autoconf to implement the semantics we need directly in AC_PROG_CC, so that we'll be able to leverage that (since Automake 1.14 will require the latest Autoconf version released). Now, the detailed list of file-by-file changes ... * automake.in ($seen_cc_c_o): Remove this global variable. (scan_autoconf_traces): Don't set it, and do not trace the 'AM_PROG_CC_C_O' m4 macro. (lang_c_rewrite): Remove, no longer needed. * doc/automake.texi: Adjust expected "autoreconf --install" output in the amhello example. Remove statements about the need for the AM_PROG_CC_C_O macro. Report it is obsolete now. * m4/init.m4: Re-write AC_PROG_CC to append checks about whether the C compiler supports "-c -o" together. These checks have basically been ripped out (with adaptations) from the 'AC_PROG_CC_C_O' macro of Autoconf and ... * m4/minuso.m4 (AM_PROG_CC_C_O): ... this macro of ours, which has thus basically become a no-op. * t/ax/am-test-lib.sh (am_setup_testdir): Also copy the 'compile' script in the test directory; if we don't do so, every test using AC_PROG_CC should call automake with the "--add-missing" option, or copy the 'compile' script itself. * t/cond11.sh: No need to create a dummy 'compile' script: that is already brought in by 'am_setup_testdir()', that is automatically invoked when 'test-lib.sh' is sourced. * t/add-missing.tap: Adjust: we expect the 'compile' script to be required by a mere AC_PROG_CC call now. * t/dist-auxdir-many-subdirs.sh: Likewise. * t/specflg6.sh: Likewise. * t/subobj4.sh: Likewise. * t/cxx-lt-demo.sh: Likewise, and update comments to match. * t/distcom2.sh: Enhance a little. * t/dollarvar2.sh: Adjust. * t/extra-portability.sh: Likewise. * t/libobj19.sh: Likewise. * t/per-target-flags.sh: Likewise. * t/repeated-options.sh: Likewise. * t/subobj.sh: Likewise, and enhance a little. * t/ccnoco2.sh: Remove as obsolete. * t/list-of-tests.mk (handwritten_TESTS): Adjust. (XFAIL_TESTS): Remove 't/ccnoco4.sh'. * NEWS: Update. Signed-off-by: Stefano Lattarini --- t/dollarvar2.sh | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) (limited to 't/dollarvar2.sh') diff --git a/t/dollarvar2.sh b/t/dollarvar2.sh index 718374370..ef2dd06af 100755 --- a/t/dollarvar2.sh +++ b/t/dollarvar2.sh @@ -65,27 +65,22 @@ grep 'recursive variable expansion' stderr cat >Makefile.am <<'EOF' x = 1 bla = $(foo$(x)) -noinst_PROGRAMS = foo -foo_CPPFLAGS = -Dwhatever +oops = $(var-with-dash) EOF -echo AC_PROG_CC >> configure.ac - -$ACLOCAL --force - # Can disable both 'portability' and 'portability-recursive' warnings. $AUTOMAKE -Wno-portability # Disabling 'portability-recursive' warnings should not disable # 'portability' warnings. AUTOMAKE_fails -Wportability -Wno-portability-recursive -grep AM_PROG_CC_C_O stderr +grep 'var-with-dash' stderr grep 'recursive variable expansion' stderr && exit 1 # Enabling 'portability-recursive' warnings should not enable # all the 'portability' warning. AUTOMAKE_fails -Wno-portability -Wportability-recursive -grep AM_PROG_CC_C_O stderr && exit 1 +grep 'var-with-dash' stderr && exit 1 grep 'recursive variable expansion' stderr : -- cgit v1.2.1