Avoid spurious rebuilds of the dynamic lookups Makefile.

[exim.git] / src / scripts / lookups-Makefile

#! /bin/sh

# We turn the configure-built build-$foo/lookups/Makefile.predynamic into Makefile

# We always re-exec ourselves at least once, because it's the cleanest and
# most portable way to turn on various features we expect of POSIX sh.
if [ -z "$EXIM_LOOKUP_MAKEFILE_ADJUSTED" ]
then
  SHELL=/bin/sh
  EXIM_LOOKUP_MAKEFILE_ADJUSTED=yes
  export EXIM_LOOKUP_MAKEFILE_ADJUSTED

  # Solaris sh and tr are problematic until we get xpg4 variants
  if [ -x /usr/xpg4/bin/sh ]
  then
    PATH="/usr/xpg4/bin:$PATH"
    export PATH
    SHELL=/usr/xpg4/bin/sh
    export SHELL
  fi

  # IRIX uses /bin/ksh for sh but in a compatibility mode unless $_XPG == 1,
  # where said compatibility mode disables $(...)
  _XPG=1
  export _XPG

  exec "$SHELL" "$0" "$@"
fi

input=lookups/Makefile.predynamic
target=lookups/Makefile.postdynamic
defs_source=Makefile-t
tag_marker='MAGIC-TAG-MODS-OBJ-RULES-GO-HERE'

tab='	'

# We rely on tr(1) for translating case below.  Some people export
# values of LC_CTYPE and LC_COLLATE which apparently break our assumptions.
# We're a script expecting certain output based on known inputs and not dealing
# with UTF8, so we should be safe doingthis:
LC_ALL=C
export LC_ALL

# nb: do not permit leading whitespace for this, as CFLAGS_DYNAMIC is exported
# to the lookups subdir via a line with leading whitespace which otherwise
# matches
if grep -q "^CFLAGS_DYNAMIC[ $tab?:]*=" "$defs_source"
then
  # we have a definition, we're good to go
  echo >&2 ">>> Creating lookups/Makefile for building dynamic modules"
  enable_dynamic=yes
else
  echo >&2 ">>> Creating lookups/Makefile without dynamic module support"
  enable_dynamic=''
  # We always do something now, since there should always be a lookup,
  # and now we need to run in order to put the OBJ=$(OBJ)+ rules in.  So we
  # continue on.
fi

# For the want_ checks, we need to let the user override values from the make
# command-line, not just check the Makefile.

want_dynamic() {
  local dyn_name="$1"
  local re="LOOKUP_${dyn_name}[ $tab]*=[ $tab]*2"
  env | grep -q "^$re"
  if [ $? -eq 0 ]; then return 0; fi
  grep -q "^[ $tab]*$re" "$defs_source"
}

want_at_all() {
  local want_name="$1"
  local re="LOOKUP_${want_name}[ $tab]*=[ $tab]*."
  env | grep -q "^$re"
  if [ $? -eq 0 ]; then return 0; fi
  grep -q "^[ $tab]*$re" "$defs_source"
}

# The values of these variables will be emitted into the Makefile.

MODS=""
OBJ=""

emit_module_rule() {
  local lookup_name="$1"
  local mod_name pkgconf
  if [ "${lookup_name%:*}" = "$lookup_name" ]
  then
    mod_name=$(echo $lookup_name | tr A-Z a-z)
  else
    mod_name="${lookup_name#*:}"
    lookup_name="${lookup_name%:*}"
  fi

  if want_dynamic "$lookup_name"
  then
    if [ -z "$enable_dynamic" ]; then
      echo >&2 "Missing CFLAGS_DYNAMIC prevents building dynamic $lookup_name"
      exit 1
    fi
    MODS="${MODS} ${mod_name}.so"
    pkgconf=$(grep "^LOOKUP_${lookup_name}_PC" "$defs_source")
    if [ $? -eq 0 ]; then
      pkgconf=$(echo $pkgconf | sed 's/^.*= *//')
      echo "LOOKUP_${mod_name}_INCLUDE = $(pkg-config --cflags $pkgconf)"
      echo "LOOKUP_${mod_name}_LIBS = $(pkg-config --libs $pkgconf)"
    else
      grep "^LOOKUP_${lookup_name}_" "$defs_source"
      echo "LOOKUP_${mod_name}_INCLUDE = \$(LOOKUP_${lookup_name}_INCLUDE)"
      echo "LOOKUP_${mod_name}_LIBS = \$(LOOKUP_${lookup_name}_LIBS)"
    fi
  elif want_at_all "$lookup_name"
  then
    OBJ="${OBJ} ${mod_name}.o"
  fi
}

rm -f "$target"
exec 5>&1
exec > "$target"

sed -n "1,/$tag_marker/p" < "$input"

for name_mod in \
    CDB DBM:dbmdb DNSDB DSEARCH IBASE LSEARCH MYSQL NIS NISPLUS ORACLE \
    PASSWD PGSQL SQLITE TESTDB WHOSON
do
  emit_module_rule $name_mod
done

if want_at_all LDAP
then
  OBJ="${OBJ} ldap.o"
fi

# Because the variable is EXPERIMENTAL_SPF and not LOOKUP_SPF we
# always include spf.o and compile a dummy if EXPERIMENTAL_SPF is not
# defined.

OBJ="${OBJ} spf.o"

echo "MODS = $MODS"
echo "OBJ = $OBJ"

sed -n "/$tag_marker/,\$p" < "$input"

exec >&5

# Configure-Makefile will move $target into place

# vim: set ft=sh sw=2 :