bpo-46430: Intern strings in deep-frozen modules (GH-30683)

Author: kumaraditya303

Include/internal/pycore_code.h

@@ -279,6 +279,8 @@ void _Py_Specialize_CompareOp(PyObject *lhs, PyObject *rhs, _Py_CODEUNIT *instr,
 
 /* Deallocator function for static codeobjects used in deepfreeze.py */
 void _PyStaticCode_Dealloc(PyCodeObject *co);
+/* Function to intern strings of codeobjects */
+void _PyStaticCode_InternStrings(PyCodeObject *co);
 
 #ifdef Py_STATS
 

Misc/NEWS.d/next/Build/2022-01-19-11-08-32.bpo-46430.k403m_.rst

@@ -0,0 +1 @@
+Intern strings in deep-frozen modules. Patch by Kumar Aditya.

Objects/codeobject.c

@@ -1924,3 +1924,15 @@ _PyStaticCode_Dealloc(PyCodeObject *co)
         co->co_weakreflist = NULL;
     }
 }
+
+void
+_PyStaticCode_InternStrings(PyCodeObject *co) 
+{
+    int res = intern_strings(co->co_names);
+    assert(res == 0);
+    res = intern_string_constants(co->co_consts, NULL);
+    assert(res == 0);
+    res = intern_strings(co->co_localsplusnames);
+    assert(res == 0);
+    (void)res;
+}

Tools/scripts/deepfreeze.py

@@ -279,6 +279,7 @@ def generate_code(self, name: str, code: types.CodeType) -> str:
             self.write(f".co_cellvars = {co_cellvars},")
             self.write(f".co_freevars = {co_freevars},")
         self.deallocs.append(f"_PyStaticCode_Dealloc(&{name});")
+        self.patchups.append(f"_PyStaticCode_InternStrings(&{name});")
         return f"& {name}.ob_base"
 
     def generate_tuple(self, name: str, t: Tuple[object, ...]) -> str: