c-ares/m4/cares-compilers.m4

#***************************************************************************
# $Id$
#
# Copyright (C) 2008 by Daniel Stenberg et al
#
# Permission to use, copy, modify, and distribute this software and its
# documentation for any purpose and without fee is hereby granted, provided
# that the above copyright notice appear in all copies and that both that
# copyright notice and this permission notice appear in supporting
# documentation, and that the name of M.I.T. not be used in advertising or
# publicity pertaining to distribution of the software without specific,
# written prior permission.  M.I.T. makes no representations about the
# suitability of this software for any purpose.  It is provided "as is"
# without express or implied warranty.
#
#***************************************************************************

# File version for 'aclocal' use. Keep it a single number.
# serial 6


dnl CARES_CHECK_COMPILER
dnl -------------------------------------------------
dnl Verify if the C compiler being used is known.

AC_DEFUN([CARES_CHECK_COMPILER], [
  #
  compiler_id="unknown"
  compiler_num="0"
  #
  flags_dbg_all="unknown"
  flags_dbg_yes="unknown"
  flags_dbg_off="unknown"
  flags_opt_all="unknown"
  flags_opt_yes="unknown"
  flags_opt_off="unknown"
  #
  CARES_CHECK_COMPILER_DEC
  CARES_CHECK_COMPILER_HP
  CARES_CHECK_COMPILER_IBM
  CARES_CHECK_COMPILER_INTEL
  CARES_CHECK_COMPILER_GNU
  CARES_CHECK_COMPILER_SUN
  #
  if test "$compiler_id" = "unknown"; then
  cat <<_EOF 1>&2
***
*** Warning: This configure script does not have information about the
*** compiler you are using, relative to the flags required to enable or
*** disable generation of debug info, optimization options or warnings.
***
*** Whatever settings are present in CFLAGS will be used for this run.
***
*** If you wish to help the c-ares project to better support your compiler
*** you can report this and the required info on the c-ares development
*** mailing list: http://cool.haxx.se/mailman/listinfo/c-ares/
***
_EOF
  fi
])


dnl CARES_CHECK_COMPILER_DEC
dnl -------------------------------------------------
dnl Verify if the C compiler being used is DEC's.

AC_DEFUN([CARES_CHECK_COMPILER_DEC], [
  AC_MSG_CHECKING([whether we are using the DEC/Compaq C compiler])
  CURL_CHECK_DEF([__DECC], [], [silent])
  CURL_CHECK_DEF([__DECC_VER], [], [silent])
  if test "$curl_cv_have_def___DECC" = "yes" &&
    test "$curl_cv_have_def___DECC_VER" = "yes"; then
    AC_MSG_RESULT([yes])
    compiler_id="DECC"
    flags_dbg_all="-g -g0 -g1 -g2 -g3"
    flags_dbg_yes="-g2"
    flags_dbg_off="-g0"
    flags_opt_all="-O -O0 -O1 -O2 -O3 -O4"
    flags_opt_yes="-O1"
    flags_opt_off="-O0"
  else
    AC_MSG_RESULT([no])
  fi
])


dnl CARES_CHECK_COMPILER_GNU
dnl -------------------------------------------------
dnl Verify if the C compiler being used is GNU's.

AC_DEFUN([CARES_CHECK_COMPILER_GNU], [
  AC_REQUIRE([CARES_CHECK_COMPILER_INTEL])dnl
  #
  AC_MSG_CHECKING([whether we are using the GNU C compiler])
  CURL_CHECK_DEF([__GNUC__], [], [silent])
  if test "$curl_cv_have_def___GNUC__" = "yes" &&
    test "$compiler_id" = "unknown"; then
    AC_MSG_RESULT([yes])
    compiler_id="GNUC"
    gccver=`$CC -dumpversion`
    gccvhi=`echo $gccver | cut -d . -f1`
    gccvlo=`echo $gccver | cut -d . -f2`
    compiler_num=`(expr $gccvhi "*" 100 + $gccvlo) 2>/dev/null`
    flags_dbg_all="-g -g0 -g1 -g2 -g3"
    flags_dbg_all="$flags_dbg_all -ggdb"
    flags_dbg_all="$flags_dbg_all -gstabs"
    flags_dbg_all="$flags_dbg_all -gstabs+"
    flags_dbg_all="$flags_dbg_all -gcoff"
    flags_dbg_all="$flags_dbg_all -gxcoff"
    flags_dbg_all="$flags_dbg_all -gdwarf-2"
    flags_dbg_all="$flags_dbg_all -gvms"
    flags_dbg_yes="-g"
    flags_dbg_off="-g0"
    flags_opt_all="-O -O0 -O1 -O2 -O3 -Os"
    flags_opt_yes="-O2"
    flags_opt_off="-O0"
  else
    AC_MSG_RESULT([no])
  fi
])


dnl CARES_CHECK_COMPILER_HP
dnl -------------------------------------------------
dnl Verify if the C compiler being used is HP's.

AC_DEFUN([CARES_CHECK_COMPILER_HP], [
  AC_MSG_CHECKING([whether we are using the HP C compiler])
  CURL_CHECK_DEF([__HP_cc], [], [silent])
  if test "$curl_cv_have_def___HP_cc" = "yes"; then
    AC_MSG_RESULT([yes])
    compiler_id="HPC"
    flags_dbg_all="-g -s"
    flags_dbg_yes="-g"
    flags_dbg_off="-s"
    flags_opt_all="-O +O0 +O1 +O2 +O3 +O4"
    flags_opt_yes="+O2"
    flags_opt_off="+O0"
  else
    AC_MSG_RESULT([no])
  fi
])


dnl CARES_CHECK_COMPILER_IBM
dnl -------------------------------------------------
dnl Verify if the C compiler being used is IBM's.

AC_DEFUN([CARES_CHECK_COMPILER_IBM], [
  AC_MSG_CHECKING([whether we are using the IBM C compiler])
  CURL_CHECK_DEF([__IBMC__], [], [silent])
  if test "$curl_cv_have_def___IBMC__" = "yes"; then
    AC_MSG_RESULT([yes])
    compiler_id="IBMC"
    flags_dbg_all="-g -g0 -g1 -g2 -g3"
    flags_dbg_yes="-g"
    flags_dbg_off=""
    flags_opt_all="-O -O0 -O1 -O2 -O3 -O4 -O5"
    flags_opt_all="$flags_opt_all -qnooptimize"
    flags_opt_all="$flags_opt_all -qoptimize=0"
    flags_opt_all="$flags_opt_all -qoptimize=1"
    flags_opt_all="$flags_opt_all -qoptimize=2"
    flags_opt_all="$flags_opt_all -qoptimize=3"
    flags_opt_all="$flags_opt_all -qoptimize=4"
    flags_opt_all="$flags_opt_all -qoptimize=5"
    flags_opt_yes="-O2"
    flags_opt_off="-qnooptimize"
  else
    AC_MSG_RESULT([no])
  fi
])


dnl CARES_CHECK_COMPILER_INTEL
dnl -------------------------------------------------
dnl Verify if the C compiler being used is Intel's.

AC_DEFUN([CARES_CHECK_COMPILER_INTEL], [
  AC_BEFORE([$0],[CARES_CHECK_COMPILER_GNU])dnl
  AC_MSG_CHECKING([whether we are using the Intel C compiler])
  CURL_CHECK_DEF([__INTEL_COMPILER], [], [silent])
  if test "$curl_cv_have_def___INTEL_COMPILER" = "yes"; then
    AC_MSG_RESULT([yes])
    CURL_CHECK_DEF([__unix__], [], [silent])
    if test "$curl_cv_have_def___unix__" = "yes"; then
      compiler_id="ICC_unix"
      flags_dbg_all="-g -g0"
      flags_dbg_yes="-g"
      flags_dbg_off="-g0"
      flags_opt_all="-O -O0 -O1 -O2 -O3 -Os"
      flags_opt_yes="-O2"
      flags_opt_off="-O0"
    else
      compiler_id="ICC_windows"
      flags_dbg_all="/ZI /Zi /zI /zi /ZD /Zd /zD /zd /Z7 /z7 /Oy /Oy-"
      flags_dbg_all="$flags_dbg_all /debug"
      flags_dbg_all="$flags_dbg_all /debug:none"
      flags_dbg_all="$flags_dbg_all /debug:minimal"
      flags_dbg_all="$flags_dbg_all /debug:partial"
      flags_dbg_all="$flags_dbg_all /debug:full"
      flags_dbg_all="$flags_dbg_all /debug:semantic_stepping"
      flags_dbg_all="$flags_dbg_all /debug:extended"
      flags_dbg_yes="/Zi /Oy-"
      flags_dbg_off="/debug:none /Oy-"
      flags_opt_all="/O /O0 /O1 /O2 /O3 /Od /Og /Og- /Oi /Oi-"
      flags_opt_yes="/O2"
      flags_opt_off="/Od"
    fi
    compiler_num="$curl_cv_def___INTEL_COMPILER"
  else
    AC_MSG_RESULT([no])
  fi
])


dnl CARES_CHECK_COMPILER_SUN
dnl -------------------------------------------------
dnl Verify if the C compiler being used is SUN's.

AC_DEFUN([CARES_CHECK_COMPILER_SUN], [
  AC_MSG_CHECKING([whether we are using the SUN C compiler])
  CURL_CHECK_DEF([__SUNPRO_C], [], [silent])
  if test "$curl_cv_have_def___SUNPRO_C" = "yes"; then
    AC_MSG_RESULT([yes])
    compiler_id="SUNC"
    flags_dbg_all="-g -s"
    flags_dbg_yes="-g"
    flags_dbg_off="-s"
    flags_opt_all="-O -xO1 -xO2 -xO3 -xO4 -xO5"
    flags_opt_yes="-xO2"
    flags_opt_off=""
  else
    AC_MSG_RESULT([no])
  fi
])


dnl CARES_SET_COMPILER_BASIC_OPTS
dnl -------------------------------------------------
dnl Sets compiler specific options/flags which do not
dnl depend on configure's debug, optimize or warnings
dnl options.

AC_DEFUN([CARES_SET_COMPILER_BASIC_OPTS], [
  AC_REQUIRE([CARES_CHECK_COMPILER])dnl
  #
  if test "$compiler_id" = "DECC"; then
    dnl Select strict ANSI C compiler mode
    CFLAGS="$CFLAGS -std1"
    dnl Turn off optimizer ANSI C aliasing rules
    CFLAGS="$CFLAGS -noansi_alias"
    dnl Generate warnings for missing function prototypes
    CFLAGS="$CFLAGS -warnprotos"
    dnl Change some warnings into fatal errors
    CFLAGS="$CFLAGS -msg_fatal toofewargs,toomanyargs"
  fi
  #
  if test "$compiler_id" = "HPC"; then
    dnl Disallow run-time dereferencing of null pointers
    CFLAGS="$CFLAGS -z"
  fi
  #
  if test "$compiler_id" = "IBMC"; then
    dnl Ensure that compiler optimizations are always thread-safe.
    CFLAGS="$CFLAGS -qthreaded"
    dnl Disable type based strict aliasing optimizations, using worst
    dnl case aliasing assumptions when compiling. Type based aliasing
    dnl would restrict the lvalues that could be safely used to access
    dnl a data object.
    CFLAGS="$CFLAGS -qnoansialias"
    dnl Force compiler to stop after the compilation phase, without
    dnl generating an object code file when compilation has errors.
    CFLAGS="$CFLAGS -qhalt=e"
  fi
  #
  if test "$compiler_id" = "ICC_unix"; then
    dnl On unix this compiler uses gcc's header files, so
    dnl we select ANSI C89 dialect plus GNU extensions.
    CPPFLAGS="$CPPFLAGS -std=gnu89"
    dnl Change some warnings into errors
    dnl #140: too many arguments in function call
    dnl #147: declaration is incompatible with 'previous one'
    dnl #165: too few arguments in function call
    dnl #266: function declared implicitly
    CPPFLAGS="$CPPFLAGS -we 140,147,165,266"
    dnl Disable some remarks
    dnl #279: controlling expression is constant
    dnl #981: operands are evaluated in unspecified order
    dnl #1469: "cc" clobber ignored
    if test "$compiler_num" -lt "910"; then
      CPPFLAGS="$CPPFLAGS -wd 279"
    fi
    CPPFLAGS="$CPPFLAGS -wd 981,1469"
    dnl Disable use of ANSI C aliasing rules in optimizations
    CFLAGS="$CFLAGS -no-ansi-alias"
    dnl Disable floating point optimizations
    CFLAGS="$CFLAGS -fp-model precise"
  fi
])


dnl CARES_SET_COMPILER_DEBUG_OPTS
dnl -------------------------------------------------
dnl Sets compiler specific options/flags which depend
dnl on configure's debug option.

AC_DEFUN([CARES_SET_COMPILER_DEBUG_OPTS], [
  AC_REQUIRE([CARES_CHECK_OPTION_DEBUG])dnl
  AC_REQUIRE([CARES_CHECK_COMPILER])dnl
  #
  if test "$compiler_id" != "unknown"; then
    #
    ac_save_CFLAGS="$CFLAGS"
    ac_save_CPPFLAGS="$CPPFLAGS"
    #
    honor_debug_option="yes"
    CARES_VAR_STRIP([CFLAGS],[${flags_dbg_all}])
    CARES_VAR_STRIP([CPPFLAGS],[${flags_dbg_all}])
    if test "$want_debug" = "yes"; then
      CFLAGS="$CFLAGS $flags_dbg_yes"
      AC_MSG_CHECKING([if compiler accepts debug enabling flags $flags_dbg_yes])
    fi
    if test "$want_debug" = "no"; then
      CFLAGS="$CFLAGS $flags_dbg_off"
      AC_MSG_CHECKING([if compiler accepts debug disabling flags $flags_dbg_off])
    fi
    AC_COMPILE_IFELSE([
      AC_LANG_PROGRAM([[
      ]],[[
        int i = 1;
        return i;
      ]])
    ],[
      AC_MSG_RESULT([yes])
    ],[
      AC_MSG_RESULT([no])
      honor_debug_option="no"
    ])
    #
    if test "$honor_debug_option" = "no"; then
      CFLAGS="$ac_save_CFLAGS"
      CPPFLAGS="$ac_save_CPPFLAGS"
    fi
    #
  fi
])


dnl CARES_SET_COMPILER_OPTIMIZE_OPTS
dnl -------------------------------------------------
dnl Sets compiler specific options/flags which depend
dnl on configure's optimize option.

AC_DEFUN([CARES_SET_COMPILER_OPTIMIZE_OPTS], [
  AC_REQUIRE([CARES_CHECK_OPTION_OPTIMIZE])dnl
  AC_REQUIRE([CARES_CHECK_COMPILER])dnl
  #
  if test "$compiler_id" != "unknown"; then
    #
    ac_save_CFLAGS="$CFLAGS"
    ac_save_CPPFLAGS="$CPPFLAGS"
    #
    dnl If optimization request setting has not been explicitly specified,
    dnl it has been derived from the debug setting and initially assumed.
    dnl This initially assumed optimizer setting will finally be ignored
    dnl if CFLAGS or CPPFLAGS already hold optimizer flags. This implies
    dnl that an initially assumed optimizer setting might not be honored.
    #
    honor_optimize_option="yes"
    if test "$want_optimize" = "assume_no" ||
       test "$want_optimize" = "assume_yes"; then
      AC_MSG_CHECKING([if compiler optimizer assumed setting might be used])
      CARES_VAR_MATCH_IFELSE([CFLAGS],[${flags_opt_all}],[
        honor_optimize_option="no"
      ])
      CARES_VAR_MATCH_IFELSE([CPPFLAGS],[${flags_opt_all}],[
        honor_optimize_option="no"
      ])
      AC_MSG_RESULT([$honor_optimize_option])
      if test "$honor_optimize_option" = "yes"; then
        if test "$want_optimize" = "assume_yes"; then
          want_optimize="yes"
        fi
        if test "$want_optimize" = "assume_no"; then
          want_optimize="no"
        fi
      fi
    fi
    #
    if test "$honor_optimize_option" = "yes"; then
      CARES_VAR_STRIP([CFLAGS],[${flags_opt_all}])
      CARES_VAR_STRIP([CPPFLAGS],[${flags_opt_all}])
      if test "$want_optimize" = "yes"; then
        CFLAGS="$CFLAGS $flags_opt_yes"
        AC_MSG_CHECKING([if compiler accepts optimizer enabling flags $flags_opt_yes])
      fi
      if test "$want_optimize" = "no"; then
        CFLAGS="$CFLAGS $flags_opt_off"
        AC_MSG_CHECKING([if compiler accepts optimizer disabling flags $flags_opt_off])
      fi
      AC_COMPILE_IFELSE([
        AC_LANG_PROGRAM([[
        ]],[[
          int i = 1;
          return i;
        ]])
      ],[
        AC_MSG_RESULT([yes])
      ],[
        AC_MSG_RESULT([no])
        honor_optimize_option="no"
      ])
    fi
    #
    if test "$honor_optimize_option" = "no"; then
      CFLAGS="$ac_save_CFLAGS"
      CPPFLAGS="$ac_save_CPPFLAGS"
    fi
    #
  fi
])


dnl CARES_SET_COMPILER_WARNING_OPTS
dnl -------------------------------------------------
dnl Sets compiler options/flags which depend on
dnl configure's warnings given option.

AC_DEFUN([CARES_SET_COMPILER_WARNING_OPTS], [
  AC_REQUIRE([CARES_CHECK_OPTION_WARNINGS])dnl
  AC_REQUIRE([CARES_CHECK_COMPILER])dnl
  #
  if test "$compiler_id" = "DECC"; then
    if test "$want_warnings" = "yes"; then
      dnl Select a higher warning level than default level2
      CFLAGS="$CFLAGS -msg_enable level3"
    fi
  fi
  #
  if test "$compiler_id" = "GNUC"; then
    #
    # FIXME: Some of these warnings should be changed into errors
    #        and moved to CARES-SET-COMPILER-BASIC-OPTS
    #
    if test "$want_warnings" = "yes"; then
      dnl this is a set of options we believe *ALL* gcc versions support:
      WARN="-W -Wall -Wwrite-strings -pedantic -Wpointer-arith -Wnested-externs -Winline -Wmissing-prototypes"
      dnl -Wcast-align is a bit too annoying on all gcc versions ;-)
      if test "$compiler_num" -ge "207"; then
        dnl gcc 2.7 or later
        WARN="$WARN -Wmissing-declarations"
      fi
      if test "$compiler_num" -gt "295"; then
        dnl only if the compiler is newer than 2.95 since we got lots of
        dnl "`_POSIX_C_SOURCE' is not defined" in system headers with
        dnl gcc 2.95.4 on FreeBSD 4.9!
        WARN="$WARN -Wundef -Wno-long-long -Wsign-compare -Wshadow -Wno-multichar"
      fi
      if test "$compiler_num" -ge "296"; then
        dnl gcc 2.96 or later
        WARN="$WARN -Wfloat-equal"
      fi
      if test "$compiler_num" -gt "296"; then
        dnl this option does not exist in 2.96
        WARN="$WARN -Wno-format-nonliteral"
      fi
      dnl -Wunreachable-code seems totally unreliable on my gcc 3.3.2 on
      dnl on i686-Linux as it gives us heaps with false positives.
      dnl Also, on gcc 4.0.X it is totally unbearable and complains all
      dnl over making it unusable for generic purposes. Let's not use it.
      if test "$compiler_num" -ge "303"; then
        dnl gcc 3.3 and later
        WARN="$WARN -Wendif-labels -Wstrict-prototypes"
      fi
      if test "$compiler_num" -ge "304"; then
        # try these on gcc 3.4
        WARN="$WARN -Wdeclaration-after-statement"
      fi
      for flag in $CPPFLAGS; do
        case "$flag" in
          -I*)
            dnl Include path, provide a -isystem option for the same dir
            dnl to prevent warnings in those dirs. The -isystem was not very
            dnl reliable on earlier gcc versions.
            add=`echo $flag | sed 's/^-I/-isystem /g'`
            WARN="$WARN $add"
            ;;
        esac
      done
      CFLAGS="$CFLAGS $WARN"
      AC_MSG_NOTICE([Added this set of compiler options: $WARN])
    fi
  fi
  #
  if test "$compiler_id" = "HPC"; then
    if test "$want_warnings" = "yes"; then
      dnl Issue all warnings
      CFLAGS="$CFLAGS +w1"
    fi
  fi
  #
  if test "$compiler_id" = "ICC_unix"; then
    if test "$want_warnings" = "yes"; then
      if test "$compiler_num" -gt "600"; then
        dnl Show errors, warnings, and remarks
        CPPFLAGS="$CPPFLAGS -Wall"
        dnl Perform extra compile-time code checking
        CPPFLAGS="$CPPFLAGS -Wcheck"
      fi
    fi
  fi
  #
  if test "$compiler_id" = "SUNC"; then
    if test "$want_warnings" = "yes"; then
      dnl Perform stricter semantic and lint-like checks
      CFLAGS="$CFLAGS -v"
    fi
  fi
  #
])


dnl CARES_PROCESS_DEBUG_BUILD_OPTS
dnl -------------------------------------------------
dnl Settings which depend on configure's debug given
dnl option, and further configure the build process.
dnl Don't use this macro for compiler dependant stuff.

AC_DEFUN([CARES_PROCESS_DEBUG_BUILD_OPTS], [
  AC_REQUIRE([CARES_CHECK_OPTION_DEBUG])dnl
  AC_BEFORE([$0],[AC_PROG_LIBTOOL])dnl
  #
  if test "$want_debug" = "yes"; then

    dnl when doing the debug stuff, use static library only
    AC_DISABLE_SHARED

    debugbuild="yes"

    dnl the entire --enable-debug is a hack that lives and runs on top of
    dnl libcurl stuff so this BUILDING_LIBCURL is not THAT much uglier
    AC_DEFINE(BUILDING_LIBCURL, 1, [when building as static part of libcurl])

    CPPFLAGS="$CPPFLAGS -DCURLDEBUG"

    dnl CHECKME: Do we still need so specify this include path here?
    CPPFLAGS="$CPPFLAGS -I$srcdir/../include"

  fi
  #
])


dnl CARES_CHECK_PROG_CC
dnl -------------------------------------------------
dnl Check for compiler program, preventing CFLAGS and
dnl CPPFLAGS from being unexpectedly changed.

AC_DEFUN([CARES_CHECK_PROG_CC], [
  ac_save_CFLAGS="$CFLAGS"
  ac_save_CPPFLAGS="$CPPFLAGS"
  AC_PROG_CC
  CFLAGS="$ac_save_CFLAGS"
  CPPFLAGS="$ac_save_CPPFLAGS"
])


dnl CARES_VAR_MATCH (VARNAME, VALUE)
dnl -------------------------------------------------
dnl Verifies if shell variable VARNAME contains VALUE.
dnl Contents of variable VARNAME and VALUE are handled
dnl as whitespace separated lists of words. If at least
dnl one word of VALUE is present in VARNAME the match
dnl is considered positive, otherwise false.

AC_DEFUN([CARES_VAR_MATCH], [
  ac_var_match_word="no"
  for word1 in "${[$1]}"; do
    for word2 in "[$2]"; do
      if test "$word1" = "$word2"; then
        ac_var_match_word="yes"
      fi
    done
  done
])


dnl CARES_VAR_MATCH_IFELSE (VARNAME, VALUE,
dnl                        [ACTION-IF-MATCH], [ACTION-IF-NOT-MATCH])
dnl -------------------------------------------------
dnl This performs a CURL_VAR_MATCH check and executes
dnl first branch if the match is positive, otherwise
dnl the second branch is executed.

AC_DEFUN([CARES_VAR_MATCH_IFELSE], [
  CARES_VAR_MATCH([$1],[$2])
  if test "$ac_var_match_word" = "yes"; then
  ifelse($3,,:,[$3])
  ifelse($4,,,[else
    [$4]])
  fi
])


dnl CARES_VAR_STRIP (VARNAME, VALUE)
dnl -------------------------------------------------
dnl Contents of variable VARNAME and VALUE are handled
dnl as whitespace separated lists of words. Each word
dnl from VALUE is removed from VARNAME when present.

AC_DEFUN([CARES_VAR_STRIP], [
  ac_var_stripped=""
  for word1 in "${[$1]}"; do
    ac_var_strip_word="no"
    for word2 in "[$2]"; do
      if test "$word1" = "$word2"; then
        ac_var_strip_word="yes"
      fi
    done
    if test "$ac_var_strip_word" = "no"; then
      ac_var_stripped="$ac_var_stripped $word1"
    fi
  done
  dnl squeeze whitespace out of result
  [$1]=`eval echo $ac_var_stripped`
])