Write the magic number 0xf5f5dcdc into a script snapshot file and use this to distinguish whether a…

sdk/bin/dart2js

Index: sdk/bin/dart2js
===================================================================
--- sdk/bin/dart2js	(revision 20251)
+++ sdk/bin/dart2js	(working copy)
@@ -39,12 +39,6 @@
 unset EXTRA_VM_OPTIONS
 declare -a EXTRA_VM_OPTIONS
 
-if test -f "$SNAPSHOT"; then
-  # TODO(ahe): Remove the following line when we are relatively sure it works.
-  echo Using snapshot "$SNAPSHOT" 1>&2

[ahe, 2013/03/20 06:59:28]

Could you retain this for now?

[siva, 2013/03/20 20:57:20]

Done.

-  EXTRA_VM_OPTIONS[${#EXTRA_VM_OPTIONS[@]}]="--use-script-snapshot=$SNAPSHOT"
-fi
-
 # Tell the VM to grow the heap more aggressively. This should only
 # be necessary temporarily until the VM is better at detecting how
 # applications use memory.
@@ -57,4 +51,8 @@
     ;;
 esac
 
-exec "$DART" "${EXTRA_VM_OPTIONS[@]}" "$DART2JS" "${EXTRA_OPTIONS[@]}" "$@"
+if test -f "$SNAPSHOT"; then
+  exec "$DART" "${EXTRA_VM_OPTIONS[@]}" "$SNAPSHOT" "${EXTRA_OPTIONS[@]}" "$@"
+else
+  exec "$DART" "${EXTRA_VM_OPTIONS[@]}" "$DART2JS" "${EXTRA_OPTIONS[@]}" "$@"
+fi