[Python-checkins] bpo-46289: Make conversion of FormattedValue not optional on ASDL (GH-30467)

[miss-islington]

https://github.com/python/cpython/commit/bea3f42bb7c360921f864949ef7472a7ecb02cd3
commit: bea3f42bb7c360921f864949ef7472a7ecb02cd3
branch: 3.10
author: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
committer: miss-islington <31488909+miss-islington at users.noreply.github.com>
date: 2022-01-07T14:30:18-08:00
summary:

bpo-46289: Make conversion of FormattedValue not optional on ASDL (GH-30467)


Automerge-Triggered-By: GH:isidentical
(cherry picked from commit d382f7ee0b98e4ab6ade9384268f25c06be462ad)

Co-authored-by: Batuhan Taskaya <batuhan at python.org>

files:
A Misc/NEWS.d/next/Core and Builtins/2022-01-07-23-32-03.bpo-46289.NnjpVc.rst
M Parser/Python.asdl
M Python/Python-ast.c

diff --git a/Misc/NEWS.d/next/Core and Builtins/2022-01-07-23-32-03.bpo-46289.NnjpVc.rst b/Misc/NEWS.d/next/Core and Builtins/2022-01-07-23-32-03.bpo-46289.NnjpVc.rst
new file mode 100644
index 0000000000000..816ff585f14e6
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2022-01-07-23-32-03.bpo-46289.NnjpVc.rst	
@@ -0,0 +1,2 @@
+ASDL declaration of ``FormattedValue`` has changed to reflect ``conversion``
+field is not optional.
diff --git a/Parser/Python.asdl b/Parser/Python.asdl
index 85225fc88c5a5..32fdc01a7e0e6 100644
--- a/Parser/Python.asdl
+++ b/Parser/Python.asdl
@@ -74,7 +74,7 @@ module Python
          -- x < 4 < 3 and (x < 4) < 3
          | Compare(expr left, cmpop* ops, expr* comparators)
          | Call(expr func, expr* args, keyword* keywords)
-         | FormattedValue(expr value, int? conversion, expr? format_spec)
+         | FormattedValue(expr value, int conversion, expr? format_spec)
          | JoinedStr(expr* values)
          | Constant(constant value, string? kind)
 
diff --git a/Python/Python-ast.c b/Python/Python-ast.c
index ce6e6a93ea70f..2f84cad7749dd 100644
--- a/Python/Python-ast.c
+++ b/Python/Python-ast.c
@@ -1312,7 +1312,7 @@ init_types(struct ast_state *state)
         "     | YieldFrom(expr value)\n"
         "     | Compare(expr left, cmpop* ops, expr* comparators)\n"
         "     | Call(expr func, expr* args, keyword* keywords)\n"
-        "     | FormattedValue(expr value, int? conversion, expr? format_spec)\n"
+        "     | FormattedValue(expr value, int conversion, expr? format_spec)\n"
         "     | JoinedStr(expr* values)\n"
         "     | Constant(constant value, string? kind)\n"
         "     | Attribute(expr value, identifier attr, expr_context ctx)\n"
@@ -1402,11 +1402,8 @@ init_types(struct ast_state *state)
     state->FormattedValue_type = make_type(state, "FormattedValue",
                                            state->expr_type,
                                            FormattedValue_fields, 3,
-        "FormattedValue(expr value, int? conversion, expr? format_spec)");
+        "FormattedValue(expr value, int conversion, expr? format_spec)");
     if (!state->FormattedValue_type) return 0;
-    if (PyObject_SetAttr(state->FormattedValue_type, state->conversion,
-        Py_None) == -1)
-        return 0;
     if (PyObject_SetAttr(state->FormattedValue_type, state->format_spec,
         Py_None) == -1)
         return 0;
@@ -9023,9 +9020,9 @@ obj2ast_expr(struct ast_state *state, PyObject* obj, expr_ty* out, PyArena*
         if (_PyObject_LookupAttr(obj, state->conversion, &tmp) < 0) {
             return 1;
         }
-        if (tmp == NULL || tmp == Py_None) {
-            Py_CLEAR(tmp);
-            conversion = 0;
+        if (tmp == NULL) {
+            PyErr_SetString(PyExc_TypeError, "required field \"conversion\" missing from FormattedValue");
+            return 1;
         }
         else {
             int res;