bpo-40334: PEP 617 implementation: New PEG parser for CPython (GH-19503)

Co-authored-by: Guido van Rossum <guido@python.org>
Co-authored-by: Lysandros Nikolaou <lisandrosnik@gmail.com>

8 files changed, 182 insertions, 57 deletions

diff --git a/Python/ast_opt.c b/Python/ast_opt.c
index 1766321..ff786d6 100644
--- a/Python/ast_opt.c
+++ b/Python/ast_opt.c
@@ -563,7 +563,8 @@ astfold_expr(expr_ty node_, PyArena *ctx_, _PyASTOptimizeState *state)
         CALL(fold_tuple, expr_ty, node_);
         break;
     case Name_kind:
-        if (_PyUnicode_EqualToASCIIString(node_->v.Name.id, "__debug__")) {
+        if (node_->v.Name.ctx == Load &&
+                _PyUnicode_EqualToASCIIString(node_->v.Name.id, "__debug__")) {
             return make_const(node_, PyBool_FromLong(!state->optimize), ctx_);
         }
         break;
diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index 22ee596..1888335 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -816,7 +816,12 @@ builtin_compile_impl(PyObject *module, PyObject *source, PyObject *filename,
     if (str == NULL)
         goto error;
 
+    int current_use_peg = PyInterpreterState_Get()->config.use_peg;
+    if (flags & PyCF_TYPE_COMMENTS || feature_version >= 0) {
+        PyInterpreterState_Get()->config.use_peg = 0;
+    }
     result = Py_CompileStringObject(str, filename, start[compile_mode], &cf, optimize);
+    PyInterpreterState_Get()->config.use_peg = current_use_peg;
     Py_XDECREF(source_copy);
     goto finally;
 
diff --git a/Python/compile.c b/Python/compile.c
index 54e6516..3c21fba 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -2153,6 +2153,55 @@ compiler_default_arguments(struct compiler *c, arguments_ty args)
 }
 
 static int
+forbidden_name(struct compiler *c, identifier name, expr_context_ty ctx)
+{
+
+    if (ctx == Store && _PyUnicode_EqualToASCIIString(name, "__debug__")) {
+        compiler_error(c, "cannot assign to __debug__");
+        return 1;
+    }
+    return 0;
+}
+
+static int
+compiler_check_debug_one_arg(struct compiler *c, arg_ty arg)
+{
+    if (arg != NULL) {
+        if (forbidden_name(c, arg->arg, Store))
+            return 0;
+    }
+    return 1;
+}
+
+static int
+compiler_check_debug_args_seq(struct compiler *c, asdl_seq *args)
+{
+    if (args != NULL) {
+        for (int i = 0, n = asdl_seq_LEN(args); i < n; i++) {
+            if (!compiler_check_debug_one_arg(c, asdl_seq_GET(args, i)))
+                return 0;
+        }
+    }
+    return 1;
+}
+
+static int
+compiler_check_debug_args(struct compiler *c, arguments_ty args)
+{
+    if (!compiler_check_debug_args_seq(c, args->posonlyargs))
+        return 0;
+    if (!compiler_check_debug_args_seq(c, args->args))
+        return 0;
+    if (!compiler_check_debug_one_arg(c, args->vararg))
+        return 0;
+    if (!compiler_check_debug_args_seq(c, args->kwonlyargs))
+        return 0;
+    if (!compiler_check_debug_one_arg(c, args->kwarg))
+        return 0;
+    return 1;
+}
+
+static int
 compiler_function(struct compiler *c, stmt_ty s, int is_async)
 {
     PyCodeObject *co;
@@ -2189,6 +2238,9 @@ compiler_function(struct compiler *c, stmt_ty s, int is_async)
         scope_type = COMPILER_SCOPE_FUNCTION;
     }
 
+    if (!compiler_check_debug_args(c, args))
+        return 0;
+
     if (!compiler_decorators(c, decos))
         return 0;
 
@@ -2596,6 +2648,9 @@ compiler_lambda(struct compiler *c, expr_ty e)
     arguments_ty args = e->v.Lambda.args;
     assert(e->kind == Lambda_kind);
 
+    if (!compiler_check_debug_args(c, args))
+        return 0;
+
     if (!name) {
         name = PyUnicode_InternFromString("<lambda>");
         if (!name)
@@ -3505,6 +3560,9 @@ compiler_nameop(struct compiler *c, identifier name, expr_context_ty ctx)
            !_PyUnicode_EqualToASCIIString(name, "True") &&
            !_PyUnicode_EqualToASCIIString(name, "False"));
 
+    if (forbidden_name(c, name, ctx))
+        return 0;
+
     mangled = _Py_Mangle(c->u->u_private, name);
     if (!mangled)
         return 0;
@@ -4056,6 +4114,9 @@ validate_keywords(struct compiler *c, asdl_seq *keywords)
         if (key->arg == NULL) {
             continue;
         }
+        if (forbidden_name(c, key->arg, Store)) {
+            return -1;
+        }
         for (Py_ssize_t j = i + 1; j < nkeywords; j++) {
             keyword_ty other = ((keyword_ty)asdl_seq_GET(keywords, j));
             if (other->arg && !PyUnicode_Compare(key->arg, other->arg)) {
@@ -5013,6 +5074,8 @@ compiler_visit_expr1(struct compiler *c, expr_ty e)
             ADDOP_NAME(c, LOAD_ATTR, e->v.Attribute.attr, names);
             break;
         case Store:
+            if (forbidden_name(c, e->v.Attribute.attr, e->v.Attribute.ctx))
+                return 0;
             ADDOP_NAME(c, STORE_ATTR, e->v.Attribute.attr, names);
             break;
         case Del:
@@ -5183,6 +5246,8 @@ compiler_annassign(struct compiler *c, stmt_ty s)
     }
     switch (targ->kind) {
     case Name_kind:
+        if (forbidden_name(c, targ->v.Name.id, Store))
+            return 0;
         /* If we have a simple name in a module or class, store annotation. */
         if (s->v.AnnAssign.simple &&
             (c->u->u_scope_type == COMPILER_SCOPE_MODULE ||
@@ -5200,6 +5265,8 @@ compiler_annassign(struct compiler *c, stmt_ty s)
         }
         break;
     case Attribute_kind:
+        if (forbidden_name(c, targ->v.Attribute.attr, Store))
+            return 0;
         if (!s->v.AnnAssign.value &&
             !check_ann_expr(c, targ->v.Attribute.value)) {
             return 0;
diff --git a/Python/importlib.h b/Python/importlib.h
index 4bd8b62..59e0272 100644
--- a/Python/importlib.h
+++ b/Python/importlib.h
@@ -1594,50 +1594,51 @@ const unsigned char _Py_M__importlib_bootstrap[] = {
     0,218,1,120,90,5,119,104,101,114,101,90,9,102,114,111,
     109,95,110,97,109,101,90,3,101,120,99,114,10,0,0,0,
     114,10,0,0,0,114,11,0,0,0,114,215,0,0,0,9,
-    4,0,0,115,44,0,0,0,0,10,8,1,10,1,4,1,
-    12,2,4,1,28,2,8,1,14,1,10,1,2,255,8,2,
-    10,1,14,1,2,1,14,1,14,4,10,1,16,255,2,2,
-    12,1,26,1,114,215,0,0,0,99,1,0,0,0,0,0,
-    0,0,0,0,0,0,3,0,0,0,6,0,0,0,67,0,
-    0,0,115,146,0,0,0,124,0,160,0,100,1,161,1,125,
-    1,124,0,160,0,100,2,161,1,125,2,124,1,100,3,117,
-    1,114,82,124,2,100,3,117,1,114,78,124,1,124,2,106,
-    1,107,3,114,78,116,2,106,3,100,4,124,1,155,2,100,
-    5,124,2,106,1,155,2,100,6,157,5,116,4,100,7,100,
-    8,141,3,1,0,124,1,83,0,124,2,100,3,117,1,114,
-    96,124,2,106,1,83,0,116,2,106,3,100,9,116,4,100,
-    7,100,8,141,3,1,0,124,0,100,10,25,0,125,1,100,
-    11,124,0,118,1,114,142,124,1,160,5,100,12,161,1,100,
-    13,25,0,125,1,124,1,83,0,41,14,122,167,67,97,108,
-    99,117,108,97,116,101,32,119,104,97,116,32,95,95,112,97,
-    99,107,97,103,101,95,95,32,115,104,111,117,108,100,32,98,
-    101,46,10,10,32,32,32,32,95,95,112,97,99,107,97,103,
-    101,95,95,32,105,115,32,110,111,116,32,103,117,97,114,97,
-    110,116,101,101,100,32,116,111,32,98,101,32,100,101,102,105,
-    110,101,100,32,111,114,32,99,111,117,108,100,32,98,101,32,
-    115,101,116,32,116,111,32,78,111,110,101,10,32,32,32,32,
-    116,111,32,114,101,112,114,101,115,101,110,116,32,116,104,97,
-    116,32,105,116,115,32,112,114,111,112,101,114,32,118,97,108,
-    117,101,32,105,115,32,117,110,107,110,111,119,110,46,10,10,
-    32,32,32,32,114,146,0,0,0,114,106,0,0,0,78,122,
-    32,95,95,112,97,99,107,97,103,101,95,95,32,33,61,32,
-    95,95,115,112,101,99,95,95,46,112,97,114,101,110,116,32,
-    40,122,4,32,33,61,32,250,1,41,233,3,0,0,0,41,
-    1,90,10,115,116,97,99,107,108,101,118,101,108,122,89,99,
-    97,110,39,116,32,114,101,115,111,108,118,101,32,112,97,99,
-    107,97,103,101,32,102,114,111,109,32,95,95,115,112,101,99,
-    95,95,32,111,114,32,95,95,112,97,99,107,97,103,101,95,
-    95,44,32,102,97,108,108,105,110,103,32,98,97,99,107,32,
-    111,110,32,95,95,110,97,109,101,95,95,32,97,110,100,32,
-    95,95,112,97,116,104,95,95,114,1,0,0,0,114,142,0,
-    0,0,114,129,0,0,0,114,22,0,0,0,41,6,114,35,
-    0,0,0,114,131,0,0,0,114,193,0,0,0,114,194,0,
-    0,0,114,195,0,0,0,114,130,0,0,0,41,3,218,7,
-    103,108,111,98,97,108,115,114,187,0,0,0,114,96,0,0,
-    0,114,10,0,0,0,114,10,0,0,0,114,11,0,0,0,
-    218,17,95,99,97,108,99,95,95,95,112,97,99,107,97,103,
-    101,95,95,46,4,0,0,115,34,0,0,0,0,7,10,1,
-    10,1,8,1,18,1,22,2,4,254,6,3,4,1,8,1,
+    4,0,0,115,52,0,0,0,0,10,8,1,10,1,4,1,
+    12,2,4,1,4,1,2,255,4,1,8,255,10,2,8,1,
+    14,1,10,1,2,255,8,2,10,1,14,1,2,1,14,1,
+    14,4,10,1,16,255,2,2,12,1,26,1,114,215,0,0,
+    0,99,1,0,0,0,0,0,0,0,0,0,0,0,3,0,
+    0,0,6,0,0,0,67,0,0,0,115,146,0,0,0,124,
+    0,160,0,100,1,161,1,125,1,124,0,160,0,100,2,161,
+    1,125,2,124,1,100,3,117,1,114,82,124,2,100,3,117,
+    1,114,78,124,1,124,2,106,1,107,3,114,78,116,2,106,
+    3,100,4,124,1,155,2,100,5,124,2,106,1,155,2,100,
+    6,157,5,116,4,100,7,100,8,141,3,1,0,124,1,83,
+    0,124,2,100,3,117,1,114,96,124,2,106,1,83,0,116,
+    2,106,3,100,9,116,4,100,7,100,8,141,3,1,0,124,
+    0,100,10,25,0,125,1,100,11,124,0,118,1,114,142,124,
+    1,160,5,100,12,161,1,100,13,25,0,125,1,124,1,83,
+    0,41,14,122,167,67,97,108,99,117,108,97,116,101,32,119,
+    104,97,116,32,95,95,112,97,99,107,97,103,101,95,95,32,
+    115,104,111,117,108,100,32,98,101,46,10,10,32,32,32,32,
+    95,95,112,97,99,107,97,103,101,95,95,32,105,115,32,110,
+    111,116,32,103,117,97,114,97,110,116,101,101,100,32,116,111,
+    32,98,101,32,100,101,102,105,110,101,100,32,111,114,32,99,
+    111,117,108,100,32,98,101,32,115,101,116,32,116,111,32,78,
+    111,110,101,10,32,32,32,32,116,111,32,114,101,112,114,101,
+    115,101,110,116,32,116,104,97,116,32,105,116,115,32,112,114,
+    111,112,101,114,32,118,97,108,117,101,32,105,115,32,117,110,
+    107,110,111,119,110,46,10,10,32,32,32,32,114,146,0,0,
+    0,114,106,0,0,0,78,122,32,95,95,112,97,99,107,97,
+    103,101,95,95,32,33,61,32,95,95,115,112,101,99,95,95,
+    46,112,97,114,101,110,116,32,40,122,4,32,33,61,32,250,
+    1,41,233,3,0,0,0,41,1,90,10,115,116,97,99,107,
+    108,101,118,101,108,122,89,99,97,110,39,116,32,114,101,115,
+    111,108,118,101,32,112,97,99,107,97,103,101,32,102,114,111,
+    109,32,95,95,115,112,101,99,95,95,32,111,114,32,95,95,
+    112,97,99,107,97,103,101,95,95,44,32,102,97,108,108,105,
+    110,103,32,98,97,99,107,32,111,110,32,95,95,110,97,109,
+    101,95,95,32,97,110,100,32,95,95,112,97,116,104,95,95,
+    114,1,0,0,0,114,142,0,0,0,114,129,0,0,0,114,
+    22,0,0,0,41,6,114,35,0,0,0,114,131,0,0,0,
+    114,193,0,0,0,114,194,0,0,0,114,195,0,0,0,114,
+    130,0,0,0,41,3,218,7,103,108,111,98,97,108,115,114,
+    187,0,0,0,114,96,0,0,0,114,10,0,0,0,114,10,
+    0,0,0,114,11,0,0,0,218,17,95,99,97,108,99,95,
+    95,95,112,97,99,107,97,103,101,95,95,46,4,0,0,115,
+    42,0,0,0,0,7,10,1,10,1,8,1,18,1,6,1,
+    2,255,4,1,4,255,6,2,4,254,6,3,4,1,8,1,
     6,2,6,2,4,254,6,3,8,1,8,1,14,1,114,221,
     0,0,0,114,10,0,0,0,99,5,0,0,0,0,0,0,
     0,0,0,0,0,9,0,0,0,5,0,0,0,67,0,0,
diff --git a/Python/importlib_external.h b/Python/importlib_external.h
index 9618f9f..dd23742 100644
--- a/Python/importlib_external.h
+++ b/Python/importlib_external.h
@@ -481,10 +481,11 @@ const unsigned char _Py_M__importlib_bootstrap_external[] = {
     108,101,118,101,108,90,13,98,97,115,101,95,102,105,108,101,
     110,97,109,101,114,5,0,0,0,114,5,0,0,0,114,8,
     0,0,0,218,17,115,111,117,114,99,101,95,102,114,111,109,
-    95,99,97,99,104,101,116,1,0,0,115,52,0,0,0,0,
+    95,99,97,99,104,101,116,1,0,0,115,68,0,0,0,0,
     9,12,1,8,1,10,1,12,1,4,1,10,1,12,1,14,
-    1,16,1,4,1,4,1,12,1,8,1,18,2,10,1,8,
-    1,16,1,10,1,16,1,10,1,14,2,16,1,10,1,16,
+    1,16,1,4,1,4,1,12,1,8,1,2,1,2,255,4,
+    1,2,255,8,2,10,1,8,1,16,1,10,1,16,1,10,
+    1,4,1,2,255,8,2,16,1,10,1,4,1,2,255,10,
     2,14,1,114,102,0,0,0,99,1,0,0,0,0,0,0,
     0,0,0,0,0,5,0,0,0,9,0,0,0,67,0,0,
     0,115,124,0,0,0,116,0,124,0,131,1,100,1,107,2,
diff --git a/Python/initconfig.c b/Python/initconfig.c
index c313d91..7662d61 100644
--- a/Python/initconfig.c
+++ b/Python/initconfig.c
@@ -68,6 +68,7 @@ static const char usage_3[] = "\
 -X opt : set implementation-specific option. The following options are available:\n\
 \n\
          -X faulthandler: enable faulthandler\n\
+         -X oldparser: enable the traditional LL(1) parser; also PYTHONOLDPARSER\n\
          -X showrefcount: output the total reference count and number of used\n\
              memory blocks when the program finishes or after each statement in the\n\
              interactive interpreter. This only works on debug builds\n\
@@ -634,6 +635,7 @@ _PyConfig_InitCompatConfig(PyConfig *config)
 #ifdef MS_WINDOWS
     config->legacy_windows_stdio = -1;
 #endif
+    config->use_peg = 1;
 }
 
 
@@ -791,6 +793,7 @@ _PyConfig_Copy(PyConfig *config, const PyConfig *config2)
     COPY_ATTR(isolated);
     COPY_ATTR(use_environment);
     COPY_ATTR(dev_mode);
+    COPY_ATTR(use_peg);
     COPY_ATTR(install_signal_handlers);
     COPY_ATTR(use_hash_seed);
     COPY_ATTR(hash_seed);
@@ -894,6 +897,7 @@ config_as_dict(const PyConfig *config)
     SET_ITEM_INT(isolated);
     SET_ITEM_INT(use_environment);
     SET_ITEM_INT(dev_mode);
+    SET_ITEM_INT(use_peg);
     SET_ITEM_INT(install_signal_handlers);
     SET_ITEM_INT(use_hash_seed);
     SET_ITEM_UINT(hash_seed);
@@ -1428,6 +1432,11 @@ config_read_complex_options(PyConfig *config)
         config->import_time = 1;
     }
 
+    if (config_get_env(config, "PYTHONOLDPARSER")
+       || config_get_xoption(config, L"oldparser")) {
+        config->use_peg = 0;
+    }
+
     PyStatus status;
     if (config->tracemalloc < 0) {
         status = config_init_tracemalloc(config);
@@ -2507,6 +2516,7 @@ PyConfig_Read(PyConfig *config)
     assert(config->isolated >= 0);
     assert(config->use_environment >= 0);
     assert(config->dev_mode >= 0);
+    assert(config->use_peg >= 0);
     assert(config->install_signal_handlers >= 0);
     assert(config->use_hash_seed >= 0);
     assert(config->faulthandler >= 0);
diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index 0a25ebc..6199f0c 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -29,6 +29,8 @@
 #include "ast.h"                  // PyAST_FromNodeObject()
 #include "marshal.h"              // PyMarshal_ReadLongFromFile()
 
+#include <pegen_interface.h>      // PyPegen_ASTFrom*
+
 #ifdef MS_WINDOWS
 #  include "malloc.h"             // alloca()
 #endif
@@ -183,6 +185,7 @@ PyRun_InteractiveOneObjectEx(FILE *fp, PyObject *filename,
     PyArena *arena;
     const char *ps1 = "", *ps2 = "", *enc = NULL;
     int errcode = 0;
+    int use_peg = _PyInterpreterState_GET()->config.use_peg;
     _Py_IDENTIFIER(encoding);
     _Py_IDENTIFIER(__main__);
 
@@ -235,9 +238,17 @@ PyRun_InteractiveOneObjectEx(FILE *fp, PyObject *filename,
         Py_XDECREF(oenc);
         return -1;
     }
-    mod = PyParser_ASTFromFileObject(fp, filename, enc,
-                                     Py_single_input, ps1, ps2,
-                                     flags, &errcode, arena);
+
+    if (use_peg) {
+        mod = PyPegen_ASTFromFileObject(fp, filename, Py_single_input,
+                                        enc, ps1, ps2, &errcode, arena);
+    }
+    else {
+        mod = PyParser_ASTFromFileObject(fp, filename, enc,
+                                         Py_single_input, ps1, ps2,
+                                         flags, &errcode, arena);
+    }
+
     Py_XDECREF(v);
     Py_XDECREF(w);
     Py_XDECREF(oenc);
@@ -1019,6 +1030,7 @@ PyRun_StringFlags(const char *str, int start, PyObject *globals,
     mod_ty mod;
     PyArena *arena;
     PyObject *filename;
+    int use_peg = _PyInterpreterState_GET()->config.use_peg;
 
     filename = _PyUnicode_FromId(&PyId_string); /* borrowed */
     if (filename == NULL)
@@ -1028,7 +1040,13 @@ PyRun_StringFlags(const char *str, int start, PyObject *globals,
     if (arena == NULL)
         return NULL;
 
-    mod = PyParser_ASTFromStringObject(str, filename, start, flags, arena);
+    if (use_peg) {
+        mod = PyPegen_ASTFromStringObject(str, filename, start, flags, arena);
+    }
+    else {
+        mod = PyParser_ASTFromStringObject(str, filename, start, flags, arena);
+    }
+
     if (mod != NULL)
         ret = run_mod(mod, filename, globals, locals, flags, arena);
     PyArena_Free(arena);
@@ -1043,6 +1061,7 @@ PyRun_FileExFlags(FILE *fp, const char *filename_str, int start, PyObject *globa
     mod_ty mod;
     PyArena *arena = NULL;
     PyObject *filename;
+    int use_peg = _PyInterpreterState_GET()->config.use_peg;
 
     filename = PyUnicode_DecodeFSDefault(filename_str);
     if (filename == NULL)
@@ -1052,8 +1071,15 @@ PyRun_FileExFlags(FILE *fp, const char *filename_str, int start, PyObject *globa
     if (arena == NULL)
         goto exit;
 
-    mod = PyParser_ASTFromFileObject(fp, filename, NULL, start, 0, 0,
-                                     flags, NULL, arena);
+    if (use_peg) {
+        mod = PyPegen_ASTFromFileObject(fp, filename, start, NULL, NULL, NULL,
+                                        NULL, arena);
+    }
+    else {
+        mod = PyParser_ASTFromFileObject(fp, filename, NULL, start, 0, 0,
+                                         flags, NULL, arena);
+    }
+
     if (closeit)
         fclose(fp);
     if (mod == NULL) {
@@ -1196,11 +1222,17 @@ Py_CompileStringObject(const char *str, PyObject *filename, int start,
 {
     PyCodeObject *co;
     mod_ty mod;
+    int use_peg = _PyInterpreterState_GET()->config.use_peg;
     PyArena *arena = PyArena_New();
     if (arena == NULL)
         return NULL;
 
-    mod = PyParser_ASTFromStringObject(str, filename, start, flags, arena);
+    if (use_peg) {
+        mod = PyPegen_ASTFromStringObject(str, filename, start, flags, arena);
+    }
+    else {
+        mod = PyParser_ASTFromStringObject(str, filename, start, flags, arena);
+    }
     if (mod == NULL) {
         PyArena_Free(arena);
         return NULL;
@@ -1297,13 +1329,19 @@ _Py_SymtableStringObjectFlags(const char *str, PyObject *filename, int start, Py
 {
     struct symtable *st;
     mod_ty mod;
+    int use_peg = _PyInterpreterState_GET()->config.use_peg;
     PyArena *arena;
 
     arena = PyArena_New();
     if (arena == NULL)
         return NULL;
 
-    mod = PyParser_ASTFromStringObject(str, filename, start, flags, arena);
+    if (use_peg) {
+        mod = PyPegen_ASTFromStringObject(str, filename, start, flags, arena);
+    }
+    else {
+        mod = PyParser_ASTFromStringObject(str, filename, start, flags, arena);
+    }
     if (mod == NULL) {
         PyArena_Free(arena);
         return NULL;
diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index 92ea5e7..cf3ddff 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -2427,6 +2427,7 @@ static PyStructSequence_Field flags_fields[] = {
     {"inspect",                 "-i"},
     {"interactive",             "-i"},
     {"optimize",                "-O or -OO"},
+    {"use_peg",                 "-p old or -p new"},
     {"dont_write_bytecode",     "-B"},
     {"no_user_site",            "-s"},
     {"no_site",                 "-S"},
@@ -2447,7 +2448,7 @@ static PyStructSequence_Desc flags_desc = {
     "sys.flags",        /* name */
     flags__doc__,       /* doc */
     flags_fields,       /* fields */
-    15
+    16
 };
 
 static PyObject*
@@ -2470,6 +2471,7 @@ make_flags(PyThreadState *tstate)
     SetFlag(config->inspect);
     SetFlag(config->interactive);
     SetFlag(config->optimization_level);
+    SetFlag(config->use_peg);
     SetFlag(!config->write_bytecode);
     SetFlag(!config->user_site_directory);
     SetFlag(!config->site_import);