From: Glenn Morris Date: Wed, 16 May 2012 06:15:52 +0000 (-0700) Subject: Try to fix building with gcc >= 4.6 on Darwin. X-Git-Tag: emacs-24.2.90~471^2~65 X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=27cb7be27d1ee87665bd497af42e142e41a00765;p=emacs.git Try to fix building with gcc >= 4.6 on Darwin. Eg, hydra builds have been failing for some time because (?) of this. In gcc < 4.6, unrecognized -no-fo options just cause a warning. In 4.6 and later, they cause an error. * configure.in: (CPP): Do not unconditionally set it on Darwin. Instead, try to test if -no-cpp-precomp is accepted. (CPP_TEST_OPTIONS, SPECIFIED_CPP): New. Fixes: debbugs:9755 --- diff --git a/ChangeLog b/ChangeLog index 9bf19a1ee57..0495e917f21 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,10 @@ +2012-05-16 Glenn Morris + + * configure.in: Try to fix building with gcc >= 4.6 on Darwin. + (CPP): Do not unconditionally set it on Darwin. + Instead, try to test if -no-cpp-precomp is accepted. + (CPP_TEST_OPTIONS, SPECIFIED_CPP): New. (Bug#9755) + 2012-05-15 Glenn Morris * Makefile.in (install-arch-dep): Replace use of MV_DIRS. diff --git a/configure.in b/configure.in index 46909d75f9e..5dfcc921e4f 100644 --- a/configure.in +++ b/configure.in @@ -492,12 +492,11 @@ case "${canonical}" in * ) unported=yes ;; esac opsys=darwin - # Define CPP as follows to make autoconf work correctly. - CPP="${CC-cc} -E -no-cpp-precomp" # Use fink packages if available. + # FIXME? Is it really our business to decide this for the user? if test -d /sw/include && test -d /sw/lib; then GCC_TEST_OPTIONS="-I/sw/include -L/sw/lib" - CPP="${CPP} ${GCC_TEST_OPTIONS}" + CPP_TEST_OPTIONS=${GCC_TEST_OPTIONS} NON_GCC_TEST_OPTIONS=${GCC_TEST_OPTIONS} fi ;; @@ -581,9 +580,7 @@ case "${canonical}" in machine=intel386 case "${canonical}" in *-cygwin ) opsys=cygwin ;; - *-darwin* ) opsys=darwin - CPP="${CC-cc} -E -no-cpp-precomp" - ;; + *-darwin* ) opsys=darwin ;; *-sysv4.2uw* ) opsys=unixware; NON_GNU_CPP=/lib/cpp ;; *-sysv5uw* ) opsys=unixware; NON_GNU_CPP=/lib/cpp ;; *-sysv5OpenUNIX* ) opsys=unixware; NON_GNU_CPP=/lib/cpp ;; @@ -633,13 +630,18 @@ test -n "$CC" && cc_specified=yes # Save the value of CFLAGS that the user specified. SPECIFIED_CFLAGS="$CFLAGS" +# Save specified CPP (if any), before AC_PROG_CPP runs. +SPECIFIED_CPP="$CPP" + dnl Sets GCC=yes if using gcc. AC_PROG_CC AM_PROG_CC_C_O # Initialize gnulib right after verifying that the C compiler works. +# Note: this ends up setting CPP. gl_EARLY +dnl Note: looks like gl_EARLY has already done this (via AC_PROG_CPP). # On Suns, sometimes $CPP names a directory. if test -n "$CPP" && test -d "$CPP"; then CPP= @@ -663,6 +665,46 @@ fail; fi fi +## If using gcc, and on darwin, see if using Apple's gcc, where old +## (pre gcc 3.3?) versions need -no-cpp-precomp to workaround some +## (unrecorded) issue. +## Frankly, I suspect this option is no longer needed on any system +## still in use today. It is at best a no-op since Apple's version +## of gcc 3.3 (?), which corresponds (?) to Xcode 1.5 from 2004. +## This was for OS X 10.3, and the nextstep port (for example) +## only supports 10.4 or later (although you could be building a +## non-ns version on some older OS X I guess). +if test x"$opsys" = xdarwin && test x"$GCC" = xyes; then + AC_MSG_CHECKING([whether we are using an Apple version of GCC]) + AC_CACHE_VAL(emacs_cv_apple_gcc, + [AC_LINK_IFELSE([AC_LANG_PROGRAM([[]], +[[#ifndef __APPLE_CC__ +fail; +#endif +]])], emacs_cv_apple_gcc=yes, emacs_cv_apple_gcc=no)]) + AC_MSG_RESULT($emacs_cv_apple_gcc) + + ## This only tests that adding the option does not cause an error. + ## FIXME It may still cause "unrecognized option" + ## (in gcc < 4.6 --no-foo does that; newer versions throw an error). + ## The message appears on stderr, so AC_EGREP_CPP is no use. + ## It would be better to test if it is actually needed. + ## For that, someone would have actually had to document what the + ## issues it worked around were, so we could test for them. + if test $emacs_cv_apple_gcc = yes; then + AC_MSG_CHECKING([whether preprocessor accepts -no-cpp-precomp]) + save_CPP="$CPP" + test x$SPECIFIED_CPP = x && CPP="${CC-cc} -E" + CPP="$CPP -no-cpp-precomp" + dnl NB this will run AC_PROG_CPP first if it has not already happened. + AC_CACHE_VAL(emacs_cv_precomp, + [AC_PREPROC_IFELSE([AC_LANG_PROGRAM([[]],[[]])], emacs_cv_precomp=yes, emacs_cv_precomp=no)]) + AC_MSG_RESULT($emacs_cv_precomp) + + test $emacs_cv_precomp = no && CPP="$save_CPP" + fi +fi + #### Some systems specify a CPP to use unless we are using GCC. #### Now that we know whether we are using GCC, we can decide whether #### to use that one. @@ -671,6 +713,8 @@ then CPP="$NON_GNU_CPP" fi +test "x$CPP_TEST_OPTIONS" != x && CPP="$CPP $CPP_TEST_OPTIONS" + #### Some systems specify a CC to use unless we are using GCC. #### Now that we know whether we are using GCC, we can decide whether #### to use that one. @@ -805,12 +849,16 @@ fi #### Some other nice autoconf tests. -dnl checks for programs +dnl Note: looks like gl_EARLY has already done this. AC_PROG_CPP AC_PROG_INSTALL + +dnl Note: looks like configure does this very early on anyway. AC_PROG_MKDIR_P + +dnl Note: looks like gl_EARLY has already done this. if test "x$RANLIB" = x; then - AC_PROG_RANLIB + AC_PROG_RANLIB fi ## Although we're running on an amd64 kernel, we're actually compiling for