#!/bin/sh

#--------------------------------------------------------------------------#

# Run './configure' to produce a 'makefile' in the 'build' sub-directory or
# in any immediate sub-directory different from the 'src', 'scripts' and
# 'test' directories.

#--------------------------------------------------------------------------#

rm -f configure.log

#--------------------------------------------------------------------------#

# Common default options.

all=no
debug=no
libs=""
logging=no
check=no
closefrom=yes
competition=no
coverage=no
flexible=yes
profile=no
memory_fuzzing=no
contracts=yes
tracing=yes
unlocked=yes
pedantic=no
options=""
quiet=no
m32=no
contrib=yes
ipasir=yes

#--------------------------------------------------------------------------#

if [ -f ./scripts/colors.sh ]
then
  . ./scripts/colors.sh
elif [ -f ../scripts/colors.sh ]
then
  . ../scripts/colors.sh
else
  BAD=""
  HILITE=""
  BOLD=""
  NORMAL=""
fi

die () {
  if [ -f configure.log ]
  then
    checklog=" (check also 'configure.log')"
  else
    checklog=""
  fi
  cecho "${BOLD}configure:${NORMAL} ${BAD}error:${NORMAL} $*${checklog}"
  exit 1
}

rm -f configure.log

msg () {
  cecho "${BOLD}configure:${NORMAL} $*"
}

# if we can find the 'color.sh' script source it and overwrite color codes

for dir in . ..
do
  [ -f $dir/scripts/colors.sh ] || continue
  . $dir/scripts/colors.sh || exit 1
  break
done

#--------------------------------------------------------------------------#

# Parse and handle command line options.

usage () {
cat << EOF
usage: configure [ <option> ... ]

where '<option>' is one of the following

-h|--help          print this command line summary
-g|--debug         compile with debugging information
-c|--check         compile with assertion checking (default for '-g')
-l|--log[ging]     include logging code (but disabled by default)
-a|--all           short cut for all above, e.g., '-g -l' (thus also '-c')
-q|--quiet         exclude message and profiling code (logging too)
-p|--pedantic      add '--pedantic' and '-Werror' compilation flag
-s|--symbols       add '-ggdb3' (even for optimized compilation)

--coverage         compile with '-ftest-coverage -fprofile-arcs' for 'gcov'
--profile          compile with '-pg' to profile with 'gprof'
--memory-fuzzing   compile with '-rdynamic -fno-omit-frame-pointer' and
                   '-DMOBICAL_MEMORY' to fuzz for bad memory allocation handling

--no-contracts     compile without API contract checking code
--no-tracing       compile without API call tracing code
--no-contrib       compile without contributed code
--no-ipasir        compile without ipasir interface

--competition      configure for the competition
                   ('--quiet', '--no-contracts', '--no-tracing')

-f...              pass '-f<option>[=<val>]' options to the makefile
-W...              pass '-W<warning>' options to the makefile
-m32               pass '-m32' to the compiler (compile for 32 bit)
-ggdb3             pass '-ggdb3' to makefile (like '-s')
-O|-O[123]         pass '-O' or '-O[123]' to the makefile
-static...         pass '-static...' option to makefile

The environment variable CXX can be used to set a different C++
compiler than the default 'g++'.  Similarly you can add additional
compilation options by setting CXXFLAGS.  For example

  CXX=clang++ CXXFLAGS=-fPIC ./configure

will enforce to use 'clang++' as C++ compiler and also produce
position independent code.  In order to be shell independent we also
allow to have the following form.  Thus for instance

  ./configure CXX="g++-8" CXXFLAGS="-fPIC -fsanitize=address"

will have the same effect as

  CXX="g++-8" ./configure -fPIC -fsanitize=address

The following configuration options might be usefull during porting the
code to a new platform and are usually not necessary to change.

--no-closefrom     use our own 'closefrom' replacement
--no-flexible      do not use flexible array members
--no-unlocked      force compilation without unlocked IO
EOF
exit 0
}

#--------------------------------------------------------------------------#

while [ $# -gt 0 ]
do
  case $1 in

    -h|--help) usage;;

    -a|--all) all=yes;;

    -g|--debug) debug=yes;;
    -c|--check) check=yes;;
    -l|--log|--logging) logging=yes;;

    -l*) libs="$libs $1";;

    -p|--pedantic) pedantic=yes;;
    -q|--quiet) quiet=yes;;

    --no-contracts | --no-contract) contracts=no;;
    --no-tracing | --no-trace) tracing=no;;
    --no-contrib) contrib=no;;
    --no-ipasir) ipasir=no;;

    --coverage) coverage=yes;;
    --profile) profile=yes;;
    --memory-fuzzing) memory_fuzzing=yes;;

    --competition) competition=yes;;

    --no-closefrom) closefrom=no;;
    --no-flexible) flexible=no;;
    --no-unlocked) unlocked=no;;

    -m32) options="$options $1";m32=yes;;
    -f*|-W*|-ggdb3|-O|-O1|-O2|-O3) options="$options $1";;
    -s|--symbols) options="$options -ggdb3";;
    -static*) options="$options $1";;

    CXX=*)
      CXX="`expr \"$1\" : 'CXX=\(.*\)'`"
      ;;

    CXXFLAGS=*)
      CXXFLAGS="`expr \"$1\" : 'CXXFLAGS=\(.*\)'`"
      ;;

    *) die "invalid option '$1' (try '-h')";;

  esac
  shift
done

#--------------------------------------------------------------------------#

if [ $quiet = yes ]
then
  [ $logging = yes ] && die "can not combine '-q' with '-l'"
fi

if [ $all = yes ]
then
  [ $check = yes ] && die "'-a' subsumes '-c'"
  [ $debug = yes ] && die "'-a' subsumes '-g'"
  [ $logging = yes ] && die "'-a' subsumes '-l'"
  check=yes
  debug=yes
  logging=yes
elif [ $debug = yes ]
then
  [ $check = yes ] && die "'-g' subsumes '-c'"
  check=yes
fi

#--------------------------------------------------------------------------#

# Generate and enter 'build' directory if not already in sub-directory.

build_in_default_build_sub_directory () {
  if [ -d build ]
  then
    msg "reusing default 'build' directory"
  else
    mkdir build 2>/dev/null || \
    die "failed to generate 'build' directory"
    msg "making default 'build' directory"
  fi
  cd build
  msg "building in default ${HILITE}'`pwd`'${NORMAL}"
  build=build
}

if [ -f configure -a -f makefile.in -a -d src ]
then
  root="`pwd`"
  build_in_default_build_sub_directory
elif [ -f ../configure -a -f ../makefile.in -a -d ../src ]
then
  cwd="`pwd`"
  build=`basename "$cwd"`
  root=`dirname "$cwd"`
  case x"$build" in
    xsrc|xtest|xscripts)
      cd ..
      build_in_default_build_sub_directory
      ;;
    *)
      msg "building in ${HILITE}'$build'${NORMAL} sub-directory"
      ;;
  esac
else
  die "call 'configure' from root of CaDiCaL source or a sub-directory"
fi

msg "root directory '$root'"

#--------------------------------------------------------------------------#

src="$root/src"

if [ -d "$src" ]
then
  msg "source directory '$src'"
else
  die "could not find source director '$src'"
fi

#--------------------------------------------------------------------------#

# Prepare '@CXX@' and '@CXXFLAGS@' parameters for 'makefile.in'

[ x"$CXX" = x ] && CXX=g++
[ x"$CXXFLAGS" = x ] || CXXFLAGS="$CXXFLAGS "
[ x"$CPPFLAGS" = x ] || CPPFLAGS="$CPPFLAGS "
[ x"$LDFLAGS" = x ] || LDFLAGS="$LDFLAGS "

case x"$CXX" in
  x*g++*|x*clang++*) CXXFLAGS="${CXXFLAGS}-Wall -Wextra";;
  *) CXXFLAGS="${CXXFLAGS}-W";;
esac

if [ $debug = yes ]
then
  CXXFLAGS="$CXXFLAGS -g"
else
  case x"$CXX" in
    x*g++*|x*clang++*) CXXFLAGS="$CXXFLAGS -O3";;
    *) CXXFLAGS="$CXXFLAGS -O";;
  esac
fi

if [ $m32 = yes ]
then
  case x"$CXX" in
    x*g++*)
      options="$options -mpc64"
      msg "forcing portable 64-bit FPU mode ('-mpc64') for '$CXX'"
      ;;
  esac
fi

if [ $competition = yes ]
then
  quiet=yes
  contracts=no
  tracing=no
  contrib=no
fi

[ $check = no ] && CXXFLAGS="$CXXFLAGS -DNDEBUG"
[ $logging = yes ] && CXXFLAGS="$CXXFLAGS -DLOGGING"
[ $quiet = yes ] && CXXFLAGS="$CXXFLAGS -DQUIET"
[ $profile = yes ] && CXXFLAGS="$CXXFLAGS -pg"
[ $coverage = yes ] && CXXFLAGS="$CXXFLAGS -ftest-coverage -fprofile-arcs"
[ $memory_fuzzing = yes ] && CXXFLAGS="$CXXFLAGS -rdynamic -fno-omit-frame-pointer -DMOBICAL_MEMORY"
if [ $pedantic = yes ]
then
  CXXFLAGS="$CXXFLAGS --pedantic -Werror -std=c++11"
  case x"$CXX" in
    x*g++*|x*clang++*) CXXFLAGS="${CXXFLAGS} -Wp,-D_GLIBCXX_ASSERTIONS"
    ;;
  esac
fi
[ $contracts = no ] && CXXFLAGS="$CXXFLAGS -DNCONTRACTS"
[ $tracing = no ] && CXXFLAGS="$CXXFLAGS -DNTRACING"
[ $contrib = no ] && CXXFLAGS="$CXXFLAGS -DNCONTRIB"
[ $ipasir = no ] && CXXFLAGS="$CXXFLAGS -DNIPASIR"

CXXFLAGS="$CXXFLAGS$options"

#--------------------------------------------------------------------------#

case x"$CXX" in
  x*g++* | x*clang++*) WERROR="-Werror -pedantic";;
  *) WERROR="";;
esac

# Check that compilation flags work.

feature=./configure-hello-world
cat <<EOF > $feature.cpp
#include <iostream>
int main () { std::cout << "hello world" << std::endl; }
EOF
if $CXX $CXXFLAGS $WERROR -o $feature.exe $feature.cpp 2>>configure.log
then
  if [ ! "`$feature.exe 2>>configure.log|tr -d '\r'`" = "hello world" ]
  then
    die "execution of '$feature.exe' failed"
  fi
else
  die "test compilation '$feature.cpp'"
fi

#--------------------------------------------------------------------------#

# Since C99/C++11 is becoming the standard newer versions of 'g++' (7.3 for
# instance) discourage certain GCC extensions, particularly the GCC version
# of variadic macros, if the same concept exists in the standard.  This
# forced us to replace all GCC style 'ARGS...' macros with '...' and
# '__VA_ARGS__'.  Otherwise compiling the library with '--pedantic -Werror'
# would fail (configuration flag '-p').  However, older versions of 'gcc'
# (such as 4.8) would disallow these new forms of macros unless we
# explicitly enforce the new standard with '-std=c++11'.  Here we try to
# figure out whether we need that flag.  In earlier versions we used
# '-std=c++0x' but due to issues with older MacOS builds we switched to
# '-std=c++11' instead.

feature=./configure-requires-c++11
cat <<EOF > $feature.cpp
#include <cstdio>
#include <vector>

// old variadic macro usage 'ARGS...' / '#ARGS' discouraged in g++-7...
// new variadic macro usage '...' / '__VA_ARGS__' available in C99/C++11
//
#define MACRO(FMT, ...) printf (FMT "\n", __VA_ARGS__)

// we use ranged for loops which became available in gcc 4.6 and for
// the gcc 4.6 as well as 4.8 requires '-std=c++11' too.
//
unsigned f (const std::vector<unsigned> & a) {
  unsigned res = 0;
  for (auto i : a) res += i;
  return res;
}

int main () { MACRO ("%d", 42); return 0; }
EOF
if $CXX $CXXFLAGS $WERROR -o $feature.exe $feature.cpp 2>>configure.log
then
  if [ "`$feature.exe 2>>configure.log|tr -d '\r'`" = 42 ]
  then
    msg "compiler supports all required C99/C++11 extensions"
  else
    die "checking compilation without '-std=c++11' failed"
  fi
else
  CXXFLAGS="$CXXFLAGS -std=c++11"
  if $CXX $CXXFLAGS -o $feature.exe $feature.cpp 2>>configure.log
  then
    if [ "`$feature.exe 2>>configure.log|tr -d '\r'`" = 42 ]
    then
      msg "using '-std=c++11' for all required C99/C++11 extensions"
    else
      die "checking compilation with '-std=c++11' failed"
    fi
  else
    die "compiler does not support C99/C++11 even with '-std=c++11'"
  fi
fi

#--------------------------------------------------------------------------#

# Flexible array members are in C99 but not in C++11 but essential.  Thus
# with pedantic compilation we have to fake them which in turn might produce
# warnings.  To control those build variances with respect to warnings
# we check the support of flexible array members explicitly.

if [ $flexible = yes ]
then
  feature=./configure-have-flexible-array-members
cat <<EOF > $feature.cpp
#include <cstdlib>
struct S {
  int size;
  int flexible_array_member[];
};
int main () {
  struct S * s = (struct S*) malloc (12);
  s->size = 2;
  s->flexible_array_member[0] = 1;
  s->flexible_array_member[1] = -1;
  int res = 0;
  for (int i = 0; i != s->size; i++)
    res += s->flexible_array_member[i];
  return res;
}
EOF
  if $CXX $CXXFLAGS -o $feature.exe $feature.cpp 2>>configure.log
  then
    if $feature.exe
    then
      msg "compiler configuration supports flexible array members"
    else
      msg "no support for flexible array members (non zero exit code)"
      flexible=no
    fi
  else
    msg "no support for flexible array members (compilation failed)"
    flexible=no
  fi
else
  msg "not using flexible array members (since '--no-flexible' specified)"
fi

[ $flexible = no ] && CXXFLAGS="$CXXFLAGS -DNFLEXIBLE"

#--------------------------------------------------------------------------#

# Unlocked IO is much faster but not necessarily supported.

if [ $unlocked = yes ]
then
  feature=./configure-have-unlocked-io
cat <<EOF > $feature.cpp
#include <cstdio>
int main () {
  const char * path = "$feature.log";
  FILE * file = fopen (path, "w");
  if (!file) return 1;
  if (putc_unlocked (42, file) != 42) return 1;
  if (fclose (file)) return 1;
  file = fopen (path, "r");
  if (!file) return 1;
  if (getc_unlocked (file) != 42) return 1;
  if (fclose (file)) return 1;
  return 0;
}
EOF
  if $CXX $CXXFLAGS -o $feature.exe $feature.cpp 2>>configure.log
  then
    if $feature.exe
    then
      msg "unlocked IO with '{putc,getc}_unlocked' seems to work"
    else
      msg "not using unlocked IO (running '$feature.exe' failed)"
      unlocked=no
    fi
  else
    msg "not using unlocked IO (failed to compile '$feature.cpp')"
    unlocked=no
  fi
else
  msg "not using unlocked IO (since '--no-unlocked' specified)"
fi

[ $unlocked = no ] && CXXFLAGS="$CXXFLAGS -DNUNLOCKED"

#--------------------------------------------------------------------------#

# We need 'closefrom' to avoid a race in reentrant multi-threaded writing of
# compressed files.  This is due to copying filedescriptors during fork,
# which is needed to support safe writing of compressed files through a pipe
# and the help of an external compression utility (such as 'gzip').

if [ $closefrom = yes ]
then
  feature=./configure-have-closefrom
cat <<EOF > $feature.cpp
extern "C" {
#include <unistd.h>
};
int main () {
  closefrom (0);
  return 0;
}
EOF
  if $CXX $CXXFLAGS -o $feature.exe $feature.cpp 2>>configure.log
  then
    if $feature.exe
    then
      msg "'closefrom' seems to be working"
    else
      msg "'closefrom' does not seem to be working"
      closefrom=no
    fi
  else
    msg "can not use 'closefrom' (failed to compile '$feature.cpp')"
    closefrom=no
  fi
else
  msg "not using 'closefrom' (since '--no-closefrom' specified)"
fi

[ $closefrom = no ] && CXXFLAGS="$CXXFLAGS -DNCLOSEFROM"

#--------------------------------------------------------------------------#

# Instantiate '../makefile.in' template to produce 'makefile' in 'build'.

msg "compiling with ${HILITE}'$CXX $CXXFLAGS'${NORMAL}"

rm -f makefile
sed \
-e "2c\\
# This 'makefile' is generated from '../makefile.in'." \
-e "s,@CXX@,$CXX," \
-e "s#@CXXFLAGS@#$CXXFLAGS#" \
-e "s#@CPPFLAGS@#$CPPFLAGS#" \
-e "s#@LDFLAGS@#$LDFLAGS#" \
-e "s#@LIBS@#$libs#" \
-e "s#@CONTRIB@#$contrib#" \
-e "s#@IPASIR@#$ipasir#" \
-e "s#@ROOT@#$root#" \
../makefile.in > makefile

msg "generated '$build/makefile' from '../makefile.in'"

#--------------------------------------------------------------------------#

build="`pwd`"
makefile="`dirname "$build"`/makefile"
cat <<EOF > "$makefile"
CADICALBUILD=$build
all:
	\$(MAKE) -C "\$(CADICALBUILD)"
clean:
	@if [ -d "\$(CADICALBUILD)" ]; \\
	then \\
	  if [ -f "\$(CADICALBUILD)"/makefile ]; \\
	  then \\
	     touch "\$(CADICALBUILD)"/build.hpp; \\
	     \$(MAKE) -C "\$(CADICALBUILD)" clean; \\
	  fi; \\
	  rm -rf "\$(CADICALBUILD)"; \\
	fi
	rm -f "$src/makefile"
	rm -f "$makefile"
test:
	\$(MAKE) -C "\$(CADICALBUILD)" test
cadical:
	\$(MAKE) -C "\$(CADICALBUILD)" cadical
mobical:
	\$(MAKE) -C "\$(CADICALBUILD)" mobical
update:
	\$(MAKE) -C "\$(CADICALBUILD)" update
format:
	\$(MAKE) -C "\$(CADICALBUILD)" format
.PHONY: all cadical clean mobical test format
EOF

msg "generated '../makefile' as proxy to ..."
msg "... '$build/makefile'"

#--------------------------------------------------------------------------#

if [ -f $src/makefile ]
then
  msg "removing '$src/makefile'"
  rm -f $src/makefile
fi

msg "linking '$root/makefile'"
ln -s $root/makefile $src/makefile

#--------------------------------------------------------------------------#

msg "now run ${HILITE}'make'${NORMAL} to compile CaDiCaL"
msg "optionally run 'make test'"