# Process this file with autoconf to produce a configure script.

AC_INIT([libatomic_ops],[7.6.2],https://github.com/ivmai/libatomic_ops/issues)

AC_PREREQ(2.61)

AC_CANONICAL_TARGET([])

AC_CONFIG_SRCDIR(src/atomic_ops.c)

AC_CONFIG_MACRO_DIR([m4])

AM_INIT_AUTOMAKE([foreign nostdinc])

AM_MAINTAINER_MODE

AC_CONFIG_HEADERS([src/config.h])

# Checks for programs.

AM_PROG_CC_C_O

AM_PROG_AS

LT_INIT([disable-shared])

# Checks for functions.

AC_FUNC_MMAP

# Determine PIC flag.

need_asm=false

PICFLAG=

AC_MSG_CHECKING(for PIC compiler flag)

if test "$GCC" = yes; then

  old_CC="$CC"

  if test -n "$CROSS_CC"; then

    CC="$CROSS_CC"

  fi

  case "$host" in

    *-*-cygwin* | *-*-mingw*)

      # Cygwin and Mingw[-w32/64] do not need -fPIC.

      AC_MSG_RESULT([not needed])

      ;;

    *)

      AC_MSG_RESULT(-fPIC)

      PICFLAG=-fPIC

      AC_MSG_CHECKING(whether -fPIC compiler option causes __PIC__ definition)

      # Workaround: at least GCC 3.4.6 (Solaris) does not define this macro.

      old_CFLAGS="$CFLAGS"

      CFLAGS="$PICFLAG $CFLAGS"

      AC_TRY_COMPILE([],[

 #ifndef __PIC__

 # error

 #endif

      ], [ac_cv_pic_macro=yes], [ac_cv_pic_macro=no])

      CFLAGS="$old_CFLAGS"

      AC_MSG_RESULT($ac_cv_pic_macro)

      AS_IF([test "$ac_cv_pic_macro" = yes], [],

            [PICFLAG="-D__PIC__=1 $PICFLAG"])

      ;;

  esac

  # Output all warnings.

  AC_MSG_CHECKING([whether compiler supports -Wextra])

  old_CFLAGS="$CFLAGS"

  CFLAGS="-Wextra $CFLAGS"

  AC_TRY_COMPILE([],[], [ac_cv_cc_wextra=yes], [ac_cv_cc_wextra=no])

  CFLAGS="$old_CFLAGS"

  AC_MSG_RESULT($ac_cv_cc_wextra)

  AS_IF([test "$ac_cv_cc_wextra" = yes], [WEXTRA="-Wextra"], [WEXTRA="-W"])

  AC_MSG_CHECKING([whether compiler supports -Wpedantic])

  CFLAGS="-Wpedantic -Wno-long-long $CFLAGS"

  AC_TRY_COMPILE([],[

extern int quiet;

  ], [ac_cv_cc_pedantic=yes], [ac_cv_cc_pedantic=no])

  CFLAGS="$old_CFLAGS"

  AC_MSG_RESULT($ac_cv_cc_pedantic)

  WPEDANTIC=

  AS_IF([test "$ac_cv_cc_pedantic" = yes],

        [WPEDANTIC="-Wpedantic -Wno-long-long"])

  CFLAGS="-Wall $WEXTRA $WPEDANTIC $CFLAGS"

  AC_ARG_ENABLE(werror, [AC_HELP_STRING([--enable-werror],

                            [Pass -Werror to the C compiler])])

  if test "$enable_werror" = yes; then

    CFLAGS="-Werror $CFLAGS"

  fi

  CC="$old_CC"

else

  case "$host" in

    *-*-hpux*)

      AC_MSG_RESULT([+Z])

      PICFLAG="+Z"

      CFLAGS="+O2 -mt $CFLAGS"

      ;;

    *-*-solaris*)

      AC_MSG_RESULT(-Kpic)

      PICFLAG=-Kpic

      CFLAGS="-O $CFLAGS"

      need_asm=true

      ;;

    *-*-linux*)

      AC_MSG_RESULT(-fPIC)

      PICFLAG=-fPIC

      # Any Linux compiler had better be gcc compatible.

      ;;

    *)

      AC_MSG_RESULT([none])

      ;;

  esac

fi

AC_ARG_ENABLE(assertions,

        [AC_HELP_STRING([--enable-assertions], [Assertion checking])])

if test "$enable_assertions" != yes; then

  AC_DEFINE([NDEBUG], 1, [Define to disable assertion checking.])

fi

AC_ARG_ENABLE(atomic-intrinsics,

        [AC_HELP_STRING([--disable-atomic-intrinsics],

                        [Do not use C11 atomic intrinsics])])

if test "$enable_atomic_intrinsics" = no; then

  AC_DEFINE([AO_DISABLE_GCC_ATOMICS], 1,

            [Define to avoid C11 atomic intrinsics even if available.])

fi

AC_ARG_ENABLE(gcov, AC_HELP_STRING([--enable-gcov],

                                   [Turn on code coverage analysis]))

if test "$enable_gcov" = "yes"; then

  CFLAGS="$CFLAGS --coverage"

  # Turn off code optimization to get accurate line numbers.

  CFLAGS=`echo "$CFLAGS" | sed -e 's/-O\(1\|2\|3\|4\|s\|fast\)\?//g'`

fi

AC_ARG_ENABLE(docs,

        [AC_HELP_STRING([--disable-docs],

                        [Do not build and install documentation])])

AM_CONDITIONAL(ENABLE_DOCS, test x$enable_docs != xno)

AC_SUBST(PICFLAG)

AC_SUBST(DEFS)

# Extra user-defined C flags.

AC_SUBST([CFLAGS_EXTRA])

AH_TEMPLATE([_PTHREADS], [Indicates the use of pthreads (NetBSD).])

AH_TEMPLATE([AO_USE_NANOSLEEP],

        [Use nanosleep() instead of select() (only if atomic operations \

         are emulated)])

AH_TEMPLATE([AO_USE_NO_SIGNALS],

        [Do not block signals in compare_and_swap (only if atomic operations \

         are emulated)])

AH_TEMPLATE([AO_USE_WIN32_PTHREADS],

        [Use Win32 Sleep() instead of select() (only if atomic operations \

         are emulated)])

AH_TEMPLATE([AO_TRACE_MALLOC], [Trace AO_malloc/free calls (for debug only)])

# These macros are tested in public headers

AH_TEMPLATE([AO_GENERALIZE_ASM_BOOL_CAS],

        [Force compare_and_swap definition via fetch_compare_and_swap])

AH_TEMPLATE([AO_PREFER_GENERALIZED],

        [Prefer generalized definitions to direct assembly-based ones])

AH_TEMPLATE([AO_USE_PTHREAD_DEFS],

        [Emulate atomic operations via slow and async-signal-unsafe \

         pthread locking])

AH_TEMPLATE([AO_ASM_X64_AVAILABLE],

        [Inline assembly available (only VC/x86_64)])

AH_TEMPLATE([AO_ASSUME_VISTA],

        [Assume Windows Server 2003, Vista or later target (only VC/x86)])

AH_TEMPLATE([AO_CMPXCHG16B_AVAILABLE],

        [Assume target is not old AMD Opteron chip (only x86_64)])

AH_TEMPLATE([AO_FORCE_USE_SWP],

        [Force test_and_set to use SWP instruction instead of LDREX/STREX \

         (only arm v6+)])

AH_TEMPLATE([AO_NO_SPARC_V9], [Assume target is not sparc v9+ (only sparc)])

AH_TEMPLATE([AO_OLD_STYLE_INTERLOCKED_COMPARE_EXCHANGE],

        [Assume ancient MS VS Win32 headers (only VC/arm v6+, VC/x86)])

AH_TEMPLATE([AO_UNIPROCESSOR], [Assume single-core target (only arm v6+)])

AH_TEMPLATE([AO_USE_INTERLOCKED_INTRINSICS],

        [Assume Win32 _Interlocked primitives available as intrinsics \

         (only VC/arm)])

AH_TEMPLATE([AO_USE_PENTIUM4_INSTRS],

        [Use Pentium 4 'mfence' instruction (only x86)])

AH_TEMPLATE([AO_USE_SYNC_CAS_BUILTIN],

        [Prefer GCC built-in CAS intrinsics in favor of inline assembly \

         (only gcc/x86, gcc/x86_64)])

AH_TEMPLATE([AO_WEAK_DOUBLE_CAS_EMULATION],

        [Emulate double-width CAS via pthread locking in case of no hardware \

         support (only gcc/x86_64, the emulation is unsafe)])

AH_TEMPLATE([AO_PREFER_BUILTIN_ATOMICS],

        [Prefer C11 atomic intrinsics over assembly-based implementation \

        even in case of inefficient implementation (do not use assembly for \

        any atomic_ops primitive if C11/GCC atomic intrinsics available)])

AC_DEFINE(_REENTRANT, 1, [Required define if using POSIX threads.])

# Libraries needed to support threads (if any).

have_pthreads=false

AC_CHECK_LIB(pthread, pthread_self, have_pthreads=true)

if test x$have_pthreads = xtrue; then

  THREADDLLIBS=-lpthread

  case "$host" in

    *-*-netbsd*)

      # Indicates the use of pthreads.

      AC_DEFINE(_PTHREADS)

      ;;

    *-*-openbsd* | *-*-kfreebsd*-gnu | *-*-dgux*)

      THREADDLLIBS=-pthread

      ;;

    *-*-cygwin* | *-*-darwin*)

      # Cygwin does not have a real libpthread, so Libtool cannot link

      # against it.

      THREADDLLIBS=

      ;;

    *-*-mingw*)

      # Use Win32 threads for tests anyway.

      THREADDLLIBS=

      # Skip test_atomic_pthreads.

      have_pthreads=false

      ;;

  esac

else

  AC_DEFINE([AO_NO_PTHREADS], 1, [No pthreads library available])

  # Assume VxWorks or Win32.

  THREADDLLIBS=

fi

AC_SUBST(THREADDLLIBS)

AM_CONDITIONAL(HAVE_PTHREAD_H, test x$have_pthreads = xtrue)

AM_CONDITIONAL(NEED_ASM, test x$need_asm = xtrue)

AC_CONFIG_FILES([

        Makefile

        doc/Makefile

        src/Makefile

        tests/Makefile

        pkgconfig/atomic_ops.pc

        pkgconfig/atomic_ops-uninstalled.pc ])

AC_CONFIG_COMMANDS([default],[[]],[[

PICFLAG="${PICFLAG}"

CC="${CC}"

DEFS="${DEFS}"

]])

AC_OUTPUT