Commit ecf95343 authored by Daniel Stenberg's avatar Daniel Stenberg
Browse files

configure: use cpp -P when needed 

Since gcc 5, the processor output can get split up on multiple lines
that made the configure script fail to figure out values from
definitions. The fix is to use cpp -P, and this fix now first checks if
cpp -P is necessary and then if cpp -P works before it uses that to
extract defined values.

Fixes #719
parent 7e312bdf

acinclude.m4

+50 −1
Original line number Diff line number Diff line
@@ -20,7 +20,6 @@ 
#

#***************************************************************************





dnl CURL_CHECK_DEF (SYMBOL, [INCLUDES], [SILENT])

dnl -------------------------------------------------

dnl Use the C preprocessor to find out if the given object-style symbol
@@ -31,6 +30,10 @@ dnl result in a set of double-quoted strings the returned expansion will 
dnl actually be a single double-quoted string concatenating all them.



AC_DEFUN([CURL_CHECK_DEF], [

  AC_REQUIRE([CURL_CPP_P])dnl

  OLDCPPFLAGS=$CPPFLAGS

  # CPPPFLAGS comes from CURL_CPP_P

  CPPFLAGS="$CPPPFLAGS"

  AS_VAR_PUSHDEF([ac_HaveDef], [curl_cv_have_def_$1])dnl

  AS_VAR_PUSHDEF([ac_Def], [curl_cv_def_$1])dnl

  if test -z "$SED"; then
@@ -67,6 +70,7 @@ CURL_DEF_TOKEN $1 
  fi

  AS_VAR_POPDEF([ac_Def])dnl

  AS_VAR_POPDEF([ac_HaveDef])dnl

  CPPFLAGS=$OLDCPPFLAGS

])
@@ -3147,3 +3151,48 @@ use vars qw( 
1;

_EOF

])



dnl CURL_CPP_P

dnl

dnl Check if $cpp -P should be used for extract define values due to gcc 5

dnl splitting up strings and defines between line outputs. gcc by default

dnl (without -P) will show TEST EINVAL TEST as

dnl

dnl # 13 "conftest.c"

dnl TEST

dnl # 13 "conftest.c" 3 4

dnl     22

dnl # 13 "conftest.c"

dnl            TEST



AC_DEFUN([CURL_CPP_P], [

  AC_MSG_CHECKING([if cpp -P is needed])

  AC_EGREP_CPP([TEST.*TEST], [

 #include <errno.h>

TEST EINVAL TEST

  ], [cpp=no], [cpp=yes])

  AC_MSG_RESULT([$cpp])



  dnl we need cpp -P so check if it works then

  if test "x$cpp" = "xyes"; then

    AC_MSG_CHECKING([if cpp -P works])

    OLDCPPFLAGS=$CPPFLAGS

    CPPFLAGS="$CPPFLAGS -P"

    AC_EGREP_CPP([TEST.*TEST], [

 #include <errno.h>

TEST EINVAL TEST

    ], [cpp_p=yes], [cpp_p=no])

    AC_MSG_RESULT([$cpp_p])



    if test "x$cpp_p" = "xno"; then

      AC_MSG_WARN([failed to figure out cpp -P alternative])

      # without -P

      CPPPFLAGS=$OLDCPPFLAGS

    else

      # with -P

      CPPPFLAGS=$CPPFLAGS

    fi

    dnl restore CPPFLAGS

    CPPFLAGS=$OLDCPPFLAGS

  fi

])