AC_PREREQ([2.60])
AC_INIT([libsecp256k1],[0.1])
AC_CONFIG_AUX_DIR([build-aux])
AC_CONFIG_MACRO_DIR([build-aux/m4])
AC_CANONICAL_HOST
AH_TOP([#ifndef LIBSECP256K1_CONFIG_H])
AH_TOP([#define LIBSECP256K1_CONFIG_H])
AH_BOTTOM([#endif /*LIBSECP256K1_CONFIG_H*/])
AM_INIT_AUTOMAKE([foreign subdir-objects])

# Set -g if CFLAGS are not already set, which matches the default autoconf
# behavior (see PROG_CC in the Autoconf manual) with the exception that we don't
# set -O2 here because we set it in any case (see further down).
: ${CFLAGS="-g"}
LT_INIT

dnl make the compilation flags quiet unless V=1 is used
m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])

PKG_PROG_PKG_CONFIG

AC_PATH_TOOL(AR, ar)
AC_PATH_TOOL(RANLIB, ranlib)
AC_PATH_TOOL(STRIP, strip)
AX_PROG_CC_FOR_BUILD

AM_PROG_CC_C_O

AC_PROG_CC_C89
if test x"$ac_cv_prog_cc_c89" = x"no"; then
  AC_MSG_ERROR([c89 compiler support required])
fi
AM_PROG_AS

case $host_os in
  *darwin*)
     if  test x$cross_compiling != xyes; then
       AC_PATH_PROG([BREW],brew,)
       if test x$BREW != x; then
         dnl These Homebrew packages may be keg-only, meaning that they won't be found
         dnl in expected paths because they may conflict with system files. Ask
         dnl Homebrew where each one is located, then adjust paths accordingly.

         openssl_prefix=`$BREW --prefix openssl 2>/dev/null`
         gmp_prefix=`$BREW --prefix gmp 2>/dev/null`
         if test x$openssl_prefix != x; then
           PKG_CONFIG_PATH="$openssl_prefix/lib/pkgconfig:$PKG_CONFIG_PATH"
           export PKG_CONFIG_PATH
           CRYPTO_CPPFLAGS="-I$openssl_prefix/include"
         fi
         if test x$gmp_prefix != x; then
           GMP_CPPFLAGS="-I$gmp_prefix/include"
           GMP_LIBS="-L$gmp_prefix/lib"
         fi
       else
         AC_PATH_PROG([PORT],port,)
         dnl if homebrew isn't installed and macports is, add the macports default paths
         dnl as a last resort.
         if test x$PORT != x; then
           CPPFLAGS="$CPPFLAGS -isystem /opt/local/include"
           LDFLAGS="$LDFLAGS -L/opt/local/lib"
         fi
       fi
     fi
   ;;
esac

CFLAGS="-W $CFLAGS"

warn_CFLAGS="-std=c89 -pedantic -Wall -Wextra -Wcast-align -Wnested-externs -Wshadow -Wstrict-prototypes -Wno-unused-function -Wno-long-long -Wno-overlength-strings"
saved_CFLAGS="$CFLAGS"
CFLAGS="$warn_CFLAGS $CFLAGS"
AC_MSG_CHECKING([if ${CC} supports ${warn_CFLAGS}])
AC_COMPILE_IFELSE([AC_LANG_SOURCE([[char foo;]])],
    [ AC_MSG_RESULT([yes]) ],
    [ AC_MSG_RESULT([no])
      CFLAGS="$saved_CFLAGS"
    ])

saved_CFLAGS="$CFLAGS"
CFLAGS="-fvisibility=hidden $CFLAGS"
AC_MSG_CHECKING([if ${CC} supports -fvisibility=hidden])
AC_COMPILE_IFELSE([AC_LANG_SOURCE([[char foo;]])],
    [ AC_MSG_RESULT([yes]) ],
    [ AC_MSG_RESULT([no])
      CFLAGS="$saved_CFLAGS"
    ])

AC_ARG_ENABLE(benchmark,
    AS_HELP_STRING([--enable-benchmark],[compile benchmark [default=yes]]),
    [use_benchmark=$enableval],
    [use_benchmark=yes])

AC_ARG_ENABLE(coverage,
    AS_HELP_STRING([--enable-coverage],[enable compiler flags to support kcov coverage analysis [default=no]]),
    [enable_coverage=$enableval],
    [enable_coverage=no])

AC_ARG_ENABLE(tests,
    AS_HELP_STRING([--enable-tests],[compile tests [default=yes]]),
    [use_tests=$enableval],
    [use_tests=yes])

AC_ARG_ENABLE(openssl_tests,
    AS_HELP_STRING([--enable-openssl-tests],[enable OpenSSL tests [default=auto]]),
    [enable_openssl_tests=$enableval],
    [enable_openssl_tests=auto])

AC_ARG_ENABLE(experimental,
    AS_HELP_STRING([--enable-experimental],[allow experimental configure options [default=no]]),
    [use_experimental=$enableval],
    [use_experimental=no])

AC_ARG_ENABLE(exhaustive_tests,
    AS_HELP_STRING([--enable-exhaustive-tests],[compile exhaustive tests [default=yes]]),
    [use_exhaustive_tests=$enableval],
    [use_exhaustive_tests=yes])

AC_ARG_ENABLE(endomorphism,
    AS_HELP_STRING([--enable-endomorphism],[enable endomorphism [default=no]]),
    [use_endomorphism=$enableval],
    [use_endomorphism=no])

AC_ARG_ENABLE(ecmult_static_precomputation,
    AS_HELP_STRING([--enable-ecmult-static-precomputation],[enable precomputed ecmult table for signing [default=auto]]),
    [use_ecmult_static_precomputation=$enableval],
    [use_ecmult_static_precomputation=auto])

AC_ARG_ENABLE(module_ecdh,
    AS_HELP_STRING([--enable-module-ecdh],[enable ECDH shared secret computation (experimental)]),
    [enable_module_ecdh=$enableval],
    [enable_module_ecdh=no])

AC_ARG_ENABLE(module_recovery,
    AS_HELP_STRING([--enable-module-recovery],[enable ECDSA pubkey recovery module [default=no]]),
    [enable_module_recovery=$enableval],
    [enable_module_recovery=no])

AC_ARG_ENABLE(external_default_callbacks,
    AS_HELP_STRING([--enable-external-default-callbacks],[enable external default callback functions [default=no]]),
    [use_external_default_callbacks=$enableval],
    [use_external_default_callbacks=no])

AC_ARG_WITH([field], [AS_HELP_STRING([--with-field=64bit|32bit|auto],
[finite field implementation to use [default=auto]])],[req_field=$withval], [req_field=auto])

AC_ARG_WITH([bignum], [AS_HELP_STRING([--with-bignum=gmp|no|auto],
[bignum implementation to use [default=auto]])],[req_bignum=$withval], [req_bignum=auto])

AC_ARG_WITH([scalar], [AS_HELP_STRING([--with-scalar=64bit|32bit|auto],
[scalar implementation to use [default=auto]])],[req_scalar=$withval], [req_scalar=auto])

AC_ARG_WITH([asm], [AS_HELP_STRING([--with-asm=x86_64|arm|no|auto],
[assembly optimizations to use (experimental: arm) [default=auto]])],[req_asm=$withval], [req_asm=auto])

AC_ARG_WITH([ecmult-window], [AS_HELP_STRING([--with-ecmult-window=SIZE|auto],
[window size for ecmult precomputation for verification, specified as integer in range [2..24].]
[Larger values result in possibly better performance at the cost of an exponentially larger precomputed table.]
[The table will store 2^(SIZE-2) * 64 bytes of data but can be larger in memory due to platform-specific padding and alignment.]
[If the endomorphism optimization is enabled, two tables of this size are used instead of only one.]
["auto" is a reasonable setting for desktop machines (currently 15). [default=auto]]
)],
[req_ecmult_window=$withval], [req_ecmult_window=auto])

AC_ARG_WITH([ecmult-gen-precision], [AS_HELP_STRING([--with-ecmult-gen-precision=2|4|8|auto],
[Precision bits to tune the precomputed table size for signing.]
[The size of the table is 32kB for 2 bits, 64kB for 4 bits, 512kB for 8 bits of precision.]
[A larger table size usually results in possible faster signing.]
["auto" is a reasonable setting for desktop machines (currently 4). [default=auto]]
)],
[req_ecmult_gen_precision=$withval], [req_ecmult_gen_precision=auto])

AC_CHECK_TYPES([__int128])

AC_CHECK_HEADER([valgrind/memcheck.h], [enable_valgrind=yes], [enable_valgrind=no], [])
AM_CONDITIONAL([VALGRIND_ENABLED],[test "$enable_valgrind" = "yes"])

if test x"$enable_coverage" = x"yes"; then
    AC_DEFINE(COVERAGE, 1, [Define this symbol to compile out all VERIFY code])
    CFLAGS="-O0 --coverage $CFLAGS"
    LDFLAGS="--coverage $LDFLAGS"
else
    CFLAGS="-O2 $CFLAGS"
fi

if test x"$use_ecmult_static_precomputation" != x"no"; then
  # Temporarily switch to an environment for the native compiler
  save_cross_compiling=$cross_compiling
  cross_compiling=no
  SAVE_CC="$CC"
  CC="$CC_FOR_BUILD"
  SAVE_CFLAGS="$CFLAGS"
  CFLAGS="$CFLAGS_FOR_BUILD"
  SAVE_CPPFLAGS="$CPPFLAGS"
  CPPFLAGS="$CPPFLAGS_FOR_BUILD"
  SAVE_LDFLAGS="$LDFLAGS"
  LDFLAGS="$LDFLAGS_FOR_BUILD"

  warn_CFLAGS_FOR_BUILD="-Wall -Wextra -Wno-unused-function"
  saved_CFLAGS="$CFLAGS"
  CFLAGS="$warn_CFLAGS_FOR_BUILD $CFLAGS"
  AC_MSG_CHECKING([if native ${CC_FOR_BUILD} supports ${warn_CFLAGS_FOR_BUILD}])
  AC_COMPILE_IFELSE([AC_LANG_SOURCE([[char foo;]])],
      [ AC_MSG_RESULT([yes]) ],
      [ AC_MSG_RESULT([no])
        CFLAGS="$saved_CFLAGS"
      ])

  AC_MSG_CHECKING([for working native compiler: ${CC_FOR_BUILD}])
  AC_RUN_IFELSE(
    [AC_LANG_PROGRAM([], [])],
    [working_native_cc=yes],
    [working_native_cc=no],[:])

  CFLAGS_FOR_BUILD="$CFLAGS"

  # Restore the environment
  cross_compiling=$save_cross_compiling
  CC="$SAVE_CC"
  CFLAGS="$SAVE_CFLAGS"
  CPPFLAGS="$SAVE_CPPFLAGS"
  LDFLAGS="$SAVE_LDFLAGS"

  if test x"$working_native_cc" = x"no"; then
    AC_MSG_RESULT([no])
    set_precomp=no
    m4_define([please_set_for_build], [Please set CC_FOR_BUILD, CFLAGS_FOR_BUILD, CPPFLAGS_FOR_BUILD, and/or LDFLAGS_FOR_BUILD.])
    if test x"$use_ecmult_static_precomputation" = x"yes";  then
      AC_MSG_ERROR([native compiler ${CC_FOR_BUILD} does not produce working binaries. please_set_for_build])
    else
      AC_MSG_WARN([Disabling statically generated ecmult table because the native compiler ${CC_FOR_BUILD} does not produce working binaries. please_set_for_build])
    fi
  else
    AC_MSG_RESULT([yes])
    set_precomp=yes
  fi
else
  set_precomp=no
fi

if test x"$req_asm" = x"auto"; then
  SECP_64BIT_ASM_CHECK
  if test x"$has_64bit_asm" = x"yes"; then
    set_asm=x86_64
  fi
  if test x"$set_asm" = x; then
    set_asm=no
  fi
else
  set_asm=$req_asm
  case $set_asm in
  x86_64)
    SECP_64BIT_ASM_CHECK
    if test x"$has_64bit_asm" != x"yes"; then
      AC_MSG_ERROR([x86_64 assembly optimization requested but not available])
    fi
    ;;
  arm)
    ;;
  no)
    ;;
  *)
    AC_MSG_ERROR([invalid assembly optimization selection])
    ;;
  esac
fi

if test x"$req_field" = x"auto"; then
  if test x"set_asm" = x"x86_64"; then
    set_field=64bit
  fi
  if test x"$set_field" = x; then
    SECP_INT128_CHECK
    if test x"$has_int128" = x"yes"; then
      set_field=64bit
    fi
  fi
  if test x"$set_field" = x; then
    set_field=32bit
  fi
else
  set_field=$req_field
  case $set_field in
  64bit)
    if test x"$set_asm" != x"x86_64"; then
      SECP_INT128_CHECK
      if test x"$has_int128" != x"yes"; then
        AC_MSG_ERROR([64bit field explicitly requested but neither __int128 support or x86_64 assembly available])
      fi
    fi
    ;;
  32bit)
    ;;
  *)
    AC_MSG_ERROR([invalid field implementation selection])
    ;;
  esac
fi

if test x"$req_scalar" = x"auto"; then
  SECP_INT128_CHECK
  if test x"$has_int128" = x"yes"; then
    set_scalar=64bit
  fi
  if test x"$set_scalar" = x; then
    set_scalar=32bit
  fi
else
  set_scalar=$req_scalar
  case $set_scalar in
  64bit)
    SECP_INT128_CHECK
    if test x"$has_int128" != x"yes"; then
      AC_MSG_ERROR([64bit scalar explicitly requested but __int128 support not available])
    fi
    ;;
  32bit)
    ;;
  *)
    AC_MSG_ERROR([invalid scalar implementation selected])
    ;;
  esac
fi

if test x"$req_bignum" = x"auto"; then
  SECP_GMP_CHECK
  if test x"$has_gmp" = x"yes"; then
    set_bignum=gmp
  fi

  if test x"$set_bignum" = x; then
    set_bignum=no
  fi
else
  set_bignum=$req_bignum
  case $set_bignum in
  gmp)
    SECP_GMP_CHECK
    if test x"$has_gmp" != x"yes"; then
      AC_MSG_ERROR([gmp bignum explicitly requested but libgmp not available])
    fi
    ;;
  no)
    ;;
  *)
    AC_MSG_ERROR([invalid bignum implementation selection])
    ;;
  esac
fi

# select assembly optimization
use_external_asm=no

case $set_asm in
x86_64)
  AC_DEFINE(USE_ASM_X86_64, 1, [Define this symbol to enable x86_64 assembly optimizations])
  ;;
arm)
  use_external_asm=yes
  ;;
no)
  ;;
*)
  AC_MSG_ERROR([invalid assembly optimizations])
  ;;
esac

# select field implementation
case $set_field in
64bit)
  AC_DEFINE(USE_FIELD_5X52, 1, [Define this symbol to use the FIELD_5X52 implementation])
  ;;
32bit)
  AC_DEFINE(USE_FIELD_10X26, 1, [Define this symbol to use the FIELD_10X26 implementation])
  ;;
*)
  AC_MSG_ERROR([invalid field implementation])
  ;;
esac

# select bignum implementation
case $set_bignum in
gmp)
  AC_DEFINE(HAVE_LIBGMP, 1, [Define this symbol if libgmp is installed])
  AC_DEFINE(USE_NUM_GMP, 1, [Define this symbol to use the gmp implementation for num])
  AC_DEFINE(USE_FIELD_INV_NUM, 1, [Define this symbol to use the num-based field inverse implementation])
  AC_DEFINE(USE_SCALAR_INV_NUM, 1, [Define this symbol to use the num-based scalar inverse implementation])
  ;;
no)
  AC_DEFINE(USE_NUM_NONE, 1, [Define this symbol to use no num implementation])
  AC_DEFINE(USE_FIELD_INV_BUILTIN, 1, [Define this symbol to use the native field inverse implementation])
  AC_DEFINE(USE_SCALAR_INV_BUILTIN, 1, [Define this symbol to use the native scalar inverse implementation])
  ;;
*)
  AC_MSG_ERROR([invalid bignum implementation])
  ;;
esac

#select scalar implementation
case $set_scalar in
64bit)
  AC_DEFINE(USE_SCALAR_4X64, 1, [Define this symbol to use the 4x64 scalar implementation])
  ;;
32bit)
  AC_DEFINE(USE_SCALAR_8X32, 1, [Define this symbol to use the 8x32 scalar implementation])
  ;;
*)
  AC_MSG_ERROR([invalid scalar implementation])
  ;;
esac

#set ecmult window size
if test x"$req_ecmult_window" = x"auto"; then
  set_ecmult_window=15
else
  set_ecmult_window=$req_ecmult_window
fi

error_window_size=['window size for ecmult precomputation not an integer in range [2..24] or "auto"']
case $set_ecmult_window in
''|*[[!0-9]]*)
  # no valid integer
  AC_MSG_ERROR($error_window_size)
  ;;
*)
  if test "$set_ecmult_window" -lt 2 -o "$set_ecmult_window" -gt 24 ; then
    # not in range
    AC_MSG_ERROR($error_window_size)
  fi
  AC_DEFINE_UNQUOTED(ECMULT_WINDOW_SIZE, $set_ecmult_window, [Set window size for ecmult precomputation])
  ;;
esac

#set ecmult gen precision
if test x"$req_ecmult_gen_precision" = x"auto"; then
  set_ecmult_gen_precision=4
else
  set_ecmult_gen_precision=$req_ecmult_gen_precision
fi

case $set_ecmult_gen_precision in
2|4|8)
  AC_DEFINE_UNQUOTED(ECMULT_GEN_PREC_BITS, $set_ecmult_gen_precision, [Set ecmult gen precision bits])
  ;;
*)
  AC_MSG_ERROR(['ecmult gen precision not 2, 4, 8 or "auto"'])
  ;;
esac

if test x"$use_tests" = x"yes"; then
  SECP_OPENSSL_CHECK
  if test x"$has_openssl_ec" = x"yes"; then
    if test x"$enable_openssl_tests" != x"no"; then
      AC_DEFINE(ENABLE_OPENSSL_TESTS, 1, [Define this symbol if OpenSSL EC functions are available])
      SECP_TEST_INCLUDES="$SSL_CFLAGS $CRYPTO_CFLAGS $CRYPTO_CPPFLAGS"
      SECP_TEST_LIBS="$CRYPTO_LIBS"

      case $host in
      *mingw*)
        SECP_TEST_LIBS="$SECP_TEST_LIBS -lgdi32"
        ;;
      esac
    fi
  else
    if test x"$enable_openssl_tests" = x"yes"; then
      AC_MSG_ERROR([OpenSSL tests requested but OpenSSL with EC support is not available])
    fi
  fi
else
  if test x"$enable_openssl_tests" = x"yes"; then
    AC_MSG_ERROR([OpenSSL tests requested but tests are not enabled])
  fi
fi

if test x"$set_bignum" = x"gmp"; then
  SECP_LIBS="$SECP_LIBS $GMP_LIBS"
  SECP_INCLUDES="$SECP_INCLUDES $GMP_CPPFLAGS"
fi

if test x"$use_endomorphism" = x"yes"; then
  AC_DEFINE(USE_ENDOMORPHISM, 1, [Define this symbol to use endomorphism optimization])
fi

if test x"$set_precomp" = x"yes"; then
  AC_DEFINE(USE_ECMULT_STATIC_PRECOMPUTATION, 1, [Define this symbol to use a statically generated ecmult table])
fi

if test x"$enable_module_ecdh" = x"yes"; then
  AC_DEFINE(ENABLE_MODULE_ECDH, 1, [Define this symbol to enable the ECDH module])
fi

if test x"$enable_module_recovery" = x"yes"; then
  AC_DEFINE(ENABLE_MODULE_RECOVERY, 1, [Define this symbol to enable the ECDSA pubkey recovery module])
fi

AC_C_BIGENDIAN()

if test x"$use_external_asm" = x"yes"; then
  AC_DEFINE(USE_EXTERNAL_ASM, 1, [Define this symbol if an external (non-inline) assembly implementation is used])
fi

if test x"$use_external_default_callbacks" = x"yes"; then
  AC_DEFINE(USE_EXTERNAL_DEFAULT_CALLBACKS, 1, [Define this symbol if an external implementation of the default callbacks is used])
fi

if test x"$enable_experimental" = x"yes"; then
  AC_MSG_NOTICE([******])
  AC_MSG_NOTICE([WARNING: experimental build])
  AC_MSG_NOTICE([Experimental features do not have stable APIs or properties, and may not be safe for production use.])
  AC_MSG_NOTICE([Building ECDH module: $enable_module_ecdh])
  AC_MSG_NOTICE([******])
else
  if test x"$enable_module_ecdh" = x"yes"; then
    AC_MSG_ERROR([ECDH module is experimental. Use --enable-experimental to allow.])
  fi
  if test x"$set_asm" = x"arm"; then
    AC_MSG_ERROR([ARM assembly optimization is experimental. Use --enable-experimental to allow.])
  fi
fi

AC_CONFIG_HEADERS([src/libsecp256k1-config.h])
AC_CONFIG_FILES([Makefile libsecp256k1.pc])
AC_SUBST(SECP_INCLUDES)
AC_SUBST(SECP_LIBS)
AC_SUBST(SECP_TEST_LIBS)
AC_SUBST(SECP_TEST_INCLUDES)
AM_CONDITIONAL([ENABLE_COVERAGE], [test x"$enable_coverage" = x"yes"])
AM_CONDITIONAL([USE_TESTS], [test x"$use_tests" != x"no"])
AM_CONDITIONAL([USE_EXHAUSTIVE_TESTS], [test x"$use_exhaustive_tests" != x"no"])
AM_CONDITIONAL([USE_BENCHMARK], [test x"$use_benchmark" = x"yes"])
AM_CONDITIONAL([USE_ECMULT_STATIC_PRECOMPUTATION], [test x"$set_precomp" = x"yes"])
AM_CONDITIONAL([ENABLE_MODULE_ECDH], [test x"$enable_module_ecdh" = x"yes"])
AM_CONDITIONAL([ENABLE_MODULE_RECOVERY], [test x"$enable_module_recovery" = x"yes"])
AM_CONDITIONAL([USE_EXTERNAL_ASM], [test x"$use_external_asm" = x"yes"])
AM_CONDITIONAL([USE_ASM_ARM], [test x"$set_asm" = x"arm"])

dnl make sure nothing new is exported so that we don't break the cache
PKGCONFIG_PATH_TEMP="$PKG_CONFIG_PATH"
unset PKG_CONFIG_PATH
PKG_CONFIG_PATH="$PKGCONFIG_PATH_TEMP"

AC_OUTPUT

echo
echo "Build Options:"
echo "  with endomorphism       = $use_endomorphism"
echo "  with ecmult precomp     = $set_precomp"
echo "  with external callbacks = $use_external_default_callbacks"
echo "  with benchmarks         = $use_benchmark"
echo "  with coverage           = $enable_coverage"
echo "  module ecdh             = $enable_module_ecdh"
echo "  module recovery         = $enable_module_recovery"
echo
echo "  asm                     = $set_asm"
echo "  bignum                  = $set_bignum"
echo "  field                   = $set_field"
echo "  scalar                  = $set_scalar"
echo "  ecmult window size      = $set_ecmult_window"
echo "  ecmult gen prec. bits   = $set_ecmult_gen_precision"
echo
echo "  valgrind                = $enable_valgrind"
echo "  CC                      = $CC"
echo "  CFLAGS                  = $CFLAGS"
echo "  CPPFLAGS                = $CPPFLAGS"
echo "  LDFLAGS                 = $LDFLAGS"
echo
