[GR-24201] Make imp.get_magic() as written into the pyc files derived from SerializationUtils.VERSION.

PullRequest: graalpython/1036

Author: ppisl

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/modules/ImpModuleBuiltins.java

@@ -78,6 +78,7 @@
 import com.oracle.graal.python.nodes.function.PythonBuiltinBaseNode;
 import com.oracle.graal.python.nodes.function.PythonBuiltinNode;
 import com.oracle.graal.python.nodes.function.builtins.PythonBinaryBuiltinNode;
+import com.oracle.graal.python.parser.sst.SerializationUtils;
 import com.oracle.graal.python.runtime.ExecutionContext.ForeignCallContext;
 import com.oracle.graal.python.runtime.PythonContext;
 import com.oracle.graal.python.runtime.PythonOptions;
@@ -151,6 +152,25 @@ public boolean run() {
         }
     }
 
+    @Builtin(name = "get_magic")
+    @GenerateNodeFactory
+    public abstract static class GetMagic extends PythonBuiltinNode {
+        // it's b'\x0c\xaf\xaf\xe1', original magic number of GraalPython
+        private static int BASE_MAGIC_NUMBER = 212840417;
+
+        @Specialization
+        public PBytes run() {
+            // The magic number in CPython is usually increased by 10.
+            int number = BASE_MAGIC_NUMBER + 10 * SerializationUtils.VERSION;
+            byte[] magicNumber = new byte[4];
+            magicNumber[0] = (byte) (number >>> 24);
+            magicNumber[1] = (byte) (number >>> 16);
+            magicNumber[2] = (byte) (number >>> 8);
+            magicNumber[3] = (byte) (number);
+            return factory().createBytes(magicNumber);
+        }
+    }
+
     @Builtin(name = "__create_dynamic__", minNumOfPositionalArgs = 2)
     @GenerateNodeFactory
     public abstract static class CreateDynamic extends PythonBuiltinNode {

graalpython/lib-graalpython/_imp.py

@@ -40,12 +40,6 @@
 # Package context -- the full module name for package imports
 _py_package_context = None
 
-
-@__graalpython__.builtin
-def get_magic():
-    return b'\x0c\xaf\xaf\xe1'
-
-
 @__graalpython__.builtin
 def create_dynamic(module_spec, filename=None):
     global _py_package_context