Avoid spurious rebuilds of the dynamic lookups Makefile.

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

diff --git a/src/scripts/lookups-Makefile b/src/scripts/lookups-Makefile
index dd0472b8d914503fb7f4964a36c2c3770ba98f25..e7aeaa08aaa0f818936dfabbc4d28c1a635f17e1 100755 (executable)
--- a/src/scripts/lookups-Makefile
+++ b/src/scripts/lookups-Makefile
@@ -2,44 +2,78 @@
 
 # We turn the configure-built build-$foo/lookups/Makefile.predynamic into Makefile
 
-if [ -x /usr/xpg4/bin/sh ] && [ -z "$EXIM_BLOCK_XPG4_LOOP" ]
+# We always re-exec ourselves at least once, because it's the cleanest and
+# most portable way to turn on various features we expect of POSIX sh.
+if [ -z "$EXIM_LOOKUP_MAKEFILE_ADJUSTED" ]
 then
-  EXIM_BLOCK_XPG4_LOOP=yes
-  export EXIM_BLOCK_XPG4_LOOP
-  PATH="/usr/xpg4/bin:$PATH"
-  export PATH
-  exec /usr/xpg4/bin/sh "$0" "$@"
+  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
-defs_source=Makefile
+target=lookups/Makefile.postdynamic
+defs_source=Makefile-t
 tag_marker='MAGIC-TAG-MODS-OBJ-RULES-GO-HERE'
 
 tab='  '
 
-# 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.
-
-if grep -q "^CFLAGS_DYNAMIC[ $tab]*=" "$defs_source"
+# 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 "Missing CFLAGS_DYNAMIC inhibits building dynamic module lookup"
+  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
 
-tmp="$target.t"
+# 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="$1"
-  grep -q "^LOOKUP_${dyn_name}[ $tab]*=[ $tab]*2" "$defs_source"
+  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="$1"
-  grep -q "^LOOKUP_${want_name}[ $tab]*=[ $tab]*." "$defs_source"
+  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.
@@ -49,7 +83,7 @@ OBJ=""
 
 emit_module_rule() {
   local lookup_name="$1"
-  local mod_name
+  local mod_name pkgconf
   if [ "${lookup_name%:*}" = "$lookup_name" ]
   then
     mod_name=$(echo $lookup_name | tr A-Z a-z)
@@ -61,21 +95,29 @@ emit_module_rule() {
   if want_dynamic "$lookup_name"
   then
     if [ -z "$enable_dynamic" ]; then
-      echo >&2 "Inhibited dynamic modules prevents building dynamic $lookup_name"
+      echo >&2 "Missing CFLAGS_DYNAMIC prevents building dynamic $lookup_name"
       exit 1
     fi
     MODS="${MODS} ${mod_name}.so"
-    grep "^LOOKUP_${lookup_name}_" "$defs_source"
-    echo "LOOKUP_${mod_name}_INCLUDE = \$(LOOKUP_${lookup_name}_INCLUDE)"
-    echo "LOOKUP_${mod_name}_LIBS = \$(LOOKUP_${lookup_name}_LIBS)"
+    pkgconf=$(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 "$target"
 exec 5>&1
-exec > "$tmp"
+exec > "$target"
 
 sed -n "1,/$tag_marker/p" < "$input"
 
@@ -103,7 +145,7 @@ echo "OBJ = $OBJ"
 sed -n "/$tag_marker/,\$p" < "$input"
 
 exec >&5
-mv "$tmp" "$target"
 
+# Configure-Makefile will move $target into place
 
 # vim: set ft=sh sw=2 :