bpo-32892: Use ast.Constant instead of specific constant AST types. (GH-9445)

6 files changed, 55 insertions, 493 deletions

diff --git a/Python/Python-ast.c b/Python/Python-ast.c
index 6a2f28e..bbe8e69 100644
--- a/Python/Python-ast.c
+++ b/Python/Python-ast.c
@@ -284,16 +284,6 @@ static char *Call_fields[]={
     "args",
     "keywords",
 };
-static PyTypeObject *Num_type;
-_Py_IDENTIFIER(n);
-static char *Num_fields[]={
-    "n",
-};
-static PyTypeObject *Str_type;
-_Py_IDENTIFIER(s);
-static char *Str_fields[]={
-    "s",
-};
 static PyTypeObject *FormattedValue_type;
 _Py_IDENTIFIER(conversion);
 _Py_IDENTIFIER(format_spec);
@@ -306,15 +296,6 @@ static PyTypeObject *JoinedStr_type;
 static char *JoinedStr_fields[]={
     "values",
 };
-static PyTypeObject *Bytes_type;
-static char *Bytes_fields[]={
-    "s",
-};
-static PyTypeObject *NameConstant_type;
-static char *NameConstant_fields[]={
-    "value",
-};
-static PyTypeObject *Ellipsis_type;
 static PyTypeObject *Constant_type;
 static char *Constant_fields[]={
     "value",
@@ -736,17 +717,6 @@ static PyObject* ast2obj_int(long b)
 
 /* Conversion Python -> AST */
 
-static int obj2ast_singleton(PyObject *obj, PyObject** out, PyArena* arena)
-{
-    if (obj != Py_None && obj != Py_True && obj != Py_False) {
-        PyErr_SetString(PyExc_ValueError,
-                        "AST singleton must be True, False, or None");
-        return 1;
-    }
-    *out = obj;
-    return 0;
-}
-
 static int obj2ast_object(PyObject* obj, PyObject** out, PyArena* arena)
 {
     if (obj == Py_None)
@@ -764,13 +734,11 @@ static int obj2ast_object(PyObject* obj, PyObject** out, PyArena* arena)
 
 static int obj2ast_constant(PyObject* obj, PyObject** out, PyArena* arena)
 {
-    if (obj) {
-        if (PyArena_AddPyObject(arena, obj) < 0) {
-            *out = NULL;
-            return -1;
-        }
-        Py_INCREF(obj);
+    if (PyArena_AddPyObject(arena, obj) < 0) {
+        *out = NULL;
+        return -1;
     }
+    Py_INCREF(obj);
     *out = obj;
     return 0;
 }
@@ -784,24 +752,6 @@ static int obj2ast_identifier(PyObject* obj, PyObject** out, PyArena* arena)
     return obj2ast_object(obj, out, arena);
 }
 
-static int obj2ast_string(PyObject* obj, PyObject** out, PyArena* arena)
-{
-    if (!PyUnicode_CheckExact(obj) && !PyBytes_CheckExact(obj)) {
-        PyErr_SetString(PyExc_TypeError, "AST string must be of type str");
-        return 1;
-    }
-    return obj2ast_object(obj, out, arena);
-}
-
-static int obj2ast_bytes(PyObject* obj, PyObject** out, PyArena* arena)
-{
-    if (!PyBytes_CheckExact(obj)) {
-        PyErr_SetString(PyExc_TypeError, "AST bytes must be of type bytes");
-        return 1;
-    }
-    return obj2ast_object(obj, out, arena);
-}
-
 static int obj2ast_int(PyObject* obj, int* out, PyArena* arena)
 {
     int i;
@@ -943,22 +893,11 @@ static int init_types(void)
     if (!Compare_type) return 0;
     Call_type = make_type("Call", expr_type, Call_fields, 3);
     if (!Call_type) return 0;
-    Num_type = make_type("Num", expr_type, Num_fields, 1);
-    if (!Num_type) return 0;
-    Str_type = make_type("Str", expr_type, Str_fields, 1);
-    if (!Str_type) return 0;
     FormattedValue_type = make_type("FormattedValue", expr_type,
                                     FormattedValue_fields, 3);
     if (!FormattedValue_type) return 0;
     JoinedStr_type = make_type("JoinedStr", expr_type, JoinedStr_fields, 1);
     if (!JoinedStr_type) return 0;
-    Bytes_type = make_type("Bytes", expr_type, Bytes_fields, 1);
-    if (!Bytes_type) return 0;
-    NameConstant_type = make_type("NameConstant", expr_type,
-                                  NameConstant_fields, 1);
-    if (!NameConstant_type) return 0;
-    Ellipsis_type = make_type("Ellipsis", expr_type, NULL, 0);
-    if (!Ellipsis_type) return 0;
     Constant_type = make_type("Constant", expr_type, Constant_fields, 1);
     if (!Constant_type) return 0;
     Attribute_type = make_type("Attribute", expr_type, Attribute_fields, 3);
@@ -2090,44 +2029,6 @@ Call(expr_ty func, asdl_seq * args, asdl_seq * keywords, int lineno, int
 }
 
 expr_ty
-Num(object n, int lineno, int col_offset, PyArena *arena)
-{
-    expr_ty p;
-    if (!n) {
-        PyErr_SetString(PyExc_ValueError,
-                        "field n is required for Num");
-        return NULL;
-    }
-    p = (expr_ty)PyArena_Malloc(arena, sizeof(*p));
-    if (!p)
-        return NULL;
-    p->kind = Num_kind;
-    p->v.Num.n = n;
-    p->lineno = lineno;
-    p->col_offset = col_offset;
-    return p;
-}
-
-expr_ty
-Str(string s, int lineno, int col_offset, PyArena *arena)
-{
-    expr_ty p;
-    if (!s) {
-        PyErr_SetString(PyExc_ValueError,
-                        "field s is required for Str");
-        return NULL;
-    }
-    p = (expr_ty)PyArena_Malloc(arena, sizeof(*p));
-    if (!p)
-        return NULL;
-    p->kind = Str_kind;
-    p->v.Str.s = s;
-    p->lineno = lineno;
-    p->col_offset = col_offset;
-    return p;
-}
-
-expr_ty
 FormattedValue(expr_ty value, int conversion, expr_ty format_spec, int lineno,
                int col_offset, PyArena *arena)
 {
@@ -2164,57 +2065,6 @@ JoinedStr(asdl_seq * values, int lineno, int col_offset, PyArena *arena)
 }
 
 expr_ty
-Bytes(bytes s, int lineno, int col_offset, PyArena *arena)
-{
-    expr_ty p;
-    if (!s) {
-        PyErr_SetString(PyExc_ValueError,
-                        "field s is required for Bytes");
-        return NULL;
-    }
-    p = (expr_ty)PyArena_Malloc(arena, sizeof(*p));
-    if (!p)
-        return NULL;
-    p->kind = Bytes_kind;
-    p->v.Bytes.s = s;
-    p->lineno = lineno;
-    p->col_offset = col_offset;
-    return p;
-}
-
-expr_ty
-NameConstant(singleton value, int lineno, int col_offset, PyArena *arena)
-{
-    expr_ty p;
-    if (!value) {
-        PyErr_SetString(PyExc_ValueError,
-                        "field value is required for NameConstant");
-        return NULL;
-    }
-    p = (expr_ty)PyArena_Malloc(arena, sizeof(*p));
-    if (!p)
-        return NULL;
-    p->kind = NameConstant_kind;
-    p->v.NameConstant.value = value;
-    p->lineno = lineno;
-    p->col_offset = col_offset;
-    return p;
-}
-
-expr_ty
-Ellipsis(int lineno, int col_offset, PyArena *arena)
-{
-    expr_ty p;
-    p = (expr_ty)PyArena_Malloc(arena, sizeof(*p));
-    if (!p)
-        return NULL;
-    p->kind = Ellipsis_kind;
-    p->lineno = lineno;
-    p->col_offset = col_offset;
-    return p;
-}
-
-expr_ty
 Constant(constant value, int lineno, int col_offset, PyArena *arena)
 {
     expr_ty p;
@@ -3289,24 +3139,6 @@ ast2obj_expr(void* _o)
             goto failed;
         Py_DECREF(value);
         break;
-    case Num_kind:
-        result = PyType_GenericNew(Num_type, NULL, NULL);
-        if (!result) goto failed;
-        value = ast2obj_object(o->v.Num.n);
-        if (!value) goto failed;
-        if (_PyObject_SetAttrId(result, &PyId_n, value) == -1)
-            goto failed;
-        Py_DECREF(value);
-        break;
-    case Str_kind:
-        result = PyType_GenericNew(Str_type, NULL, NULL);
-        if (!result) goto failed;
-        value = ast2obj_string(o->v.Str.s);
-        if (!value) goto failed;
-        if (_PyObject_SetAttrId(result, &PyId_s, value) == -1)
-            goto failed;
-        Py_DECREF(value);
-        break;
     case FormattedValue_kind:
         result = PyType_GenericNew(FormattedValue_type, NULL, NULL);
         if (!result) goto failed;
@@ -3335,28 +3167,6 @@ ast2obj_expr(void* _o)
             goto failed;
         Py_DECREF(value);
         break;
-    case Bytes_kind:
-        result = PyType_GenericNew(Bytes_type, NULL, NULL);
-        if (!result) goto failed;
-        value = ast2obj_bytes(o->v.Bytes.s);
-        if (!value) goto failed;
-        if (_PyObject_SetAttrId(result, &PyId_s, value) == -1)
-            goto failed;
-        Py_DECREF(value);
-        break;
-    case NameConstant_kind:
-        result = PyType_GenericNew(NameConstant_type, NULL, NULL);
-        if (!result) goto failed;
-        value = ast2obj_singleton(o->v.NameConstant.value);
-        if (!value) goto failed;
-        if (_PyObject_SetAttrId(result, &PyId_value, value) == -1)
-            goto failed;
-        Py_DECREF(value);
-        break;
-    case Ellipsis_kind:
-        result = PyType_GenericNew(Ellipsis_type, NULL, NULL);
-        if (!result) goto failed;
-        break;
     case Constant_kind:
         result = PyType_GenericNew(Constant_type, NULL, NULL);
         if (!result) goto failed;
@@ -6606,54 +6416,6 @@ obj2ast_expr(PyObject* obj, expr_ty* out, PyArena* arena)
         if (*out == NULL) goto failed;
         return 0;
     }
-    isinstance = PyObject_IsInstance(obj, (PyObject*)Num_type);
-    if (isinstance == -1) {
-        return 1;
-    }
-    if (isinstance) {
-        object n;
-
-        if (_PyObject_LookupAttrId(obj, &PyId_n, &tmp) < 0) {
-            return 1;
-        }
-        if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"n\" missing from Num");
-            return 1;
-        }
-        else {
-            int res;
-            res = obj2ast_object(tmp, &n, arena);
-            if (res != 0) goto failed;
-            Py_CLEAR(tmp);
-        }
-        *out = Num(n, lineno, col_offset, arena);
-        if (*out == NULL) goto failed;
-        return 0;
-    }
-    isinstance = PyObject_IsInstance(obj, (PyObject*)Str_type);
-    if (isinstance == -1) {
-        return 1;
-    }
-    if (isinstance) {
-        string s;
-
-        if (_PyObject_LookupAttrId(obj, &PyId_s, &tmp) < 0) {
-            return 1;
-        }
-        if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"s\" missing from Str");
-            return 1;
-        }
-        else {
-            int res;
-            res = obj2ast_string(tmp, &s, arena);
-            if (res != 0) goto failed;
-            Py_CLEAR(tmp);
-        }
-        *out = Str(s, lineno, col_offset, arena);
-        if (*out == NULL) goto failed;
-        return 0;
-    }
     isinstance = PyObject_IsInstance(obj, (PyObject*)FormattedValue_type);
     if (isinstance == -1) {
         return 1;
@@ -6748,64 +6510,6 @@ obj2ast_expr(PyObject* obj, expr_ty* out, PyArena* arena)
         if (*out == NULL) goto failed;
         return 0;
     }
-    isinstance = PyObject_IsInstance(obj, (PyObject*)Bytes_type);
-    if (isinstance == -1) {
-        return 1;
-    }
-    if (isinstance) {
-        bytes s;
-
-        if (_PyObject_LookupAttrId(obj, &PyId_s, &tmp) < 0) {
-            return 1;
-        }
-        if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"s\" missing from Bytes");
-            return 1;
-        }
-        else {
-            int res;
-            res = obj2ast_bytes(tmp, &s, arena);
-            if (res != 0) goto failed;
-            Py_CLEAR(tmp);
-        }
-        *out = Bytes(s, lineno, col_offset, arena);
-        if (*out == NULL) goto failed;
-        return 0;
-    }
-    isinstance = PyObject_IsInstance(obj, (PyObject*)NameConstant_type);
-    if (isinstance == -1) {
-        return 1;
-    }
-    if (isinstance) {
-        singleton value;
-
-        if (_PyObject_LookupAttrId(obj, &PyId_value, &tmp) < 0) {
-            return 1;
-        }
-        if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"value\" missing from NameConstant");
-            return 1;
-        }
-        else {
-            int res;
-            res = obj2ast_singleton(tmp, &value, arena);
-            if (res != 0) goto failed;
-            Py_CLEAR(tmp);
-        }
-        *out = NameConstant(value, lineno, col_offset, arena);
-        if (*out == NULL) goto failed;
-        return 0;
-    }
-    isinstance = PyObject_IsInstance(obj, (PyObject*)Ellipsis_type);
-    if (isinstance == -1) {
-        return 1;
-    }
-    if (isinstance) {
-
-        *out = Ellipsis(lineno, col_offset, arena);
-        if (*out == NULL) goto failed;
-        return 0;
-    }
     isinstance = PyObject_IsInstance(obj, (PyObject*)Constant_type);
     if (isinstance == -1) {
         return 1;
@@ -8244,18 +7948,10 @@ PyInit__ast(void)
     if (PyDict_SetItemString(d, "Compare", (PyObject*)Compare_type) < 0) return
         NULL;
     if (PyDict_SetItemString(d, "Call", (PyObject*)Call_type) < 0) return NULL;
-    if (PyDict_SetItemString(d, "Num", (PyObject*)Num_type) < 0) return NULL;
-    if (PyDict_SetItemString(d, "Str", (PyObject*)Str_type) < 0) return NULL;
     if (PyDict_SetItemString(d, "FormattedValue",
         (PyObject*)FormattedValue_type) < 0) return NULL;
     if (PyDict_SetItemString(d, "JoinedStr", (PyObject*)JoinedStr_type) < 0)
         return NULL;
-    if (PyDict_SetItemString(d, "Bytes", (PyObject*)Bytes_type) < 0) return
-        NULL;
-    if (PyDict_SetItemString(d, "NameConstant", (PyObject*)NameConstant_type) <
-        0) return NULL;
-    if (PyDict_SetItemString(d, "Ellipsis", (PyObject*)Ellipsis_type) < 0)
-        return NULL;
     if (PyDict_SetItemString(d, "Constant", (PyObject*)Constant_type) < 0)
         return NULL;
     if (PyDict_SetItemString(d, "Attribute", (PyObject*)Attribute_type) < 0)
diff --git a/Python/ast.c b/Python/ast.c
index b2fcb21..587f838 100644
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -295,23 +295,6 @@ validate_expr(expr_ty exp, expr_context_ty ctx)
             return 0;
         }
         return 1;
-    case Num_kind: {
-        PyObject *n = exp->v.Num.n;
-        if (!PyLong_CheckExact(n) && !PyFloat_CheckExact(n) &&
-            !PyComplex_CheckExact(n)) {
-            PyErr_SetString(PyExc_TypeError, "non-numeric type in Num");
-            return 0;
-        }
-        return 1;
-    }
-    case Str_kind: {
-        PyObject *s = exp->v.Str.s;
-        if (!PyUnicode_CheckExact(s)) {
-            PyErr_SetString(PyExc_TypeError, "non-string type in Str");
-            return 0;
-        }
-        return 1;
-    }
     case JoinedStr_kind:
         return validate_exprs(exp->v.JoinedStr.values, Load, 0);
     case FormattedValue_kind:
@@ -320,14 +303,6 @@ validate_expr(expr_ty exp, expr_context_ty ctx)
         if (exp->v.FormattedValue.format_spec)
             return validate_expr(exp->v.FormattedValue.format_spec, Load);
         return 1;
-    case Bytes_kind: {
-        PyObject *b = exp->v.Bytes.s;
-        if (!PyBytes_CheckExact(b)) {
-            PyErr_SetString(PyExc_TypeError, "non-bytes type in Bytes");
-            return 0;
-        }
-        return 1;
-    }
     case Attribute_kind:
         return validate_expr(exp->v.Attribute.value, Load);
     case Subscript_kind:
@@ -339,10 +314,8 @@ validate_expr(expr_ty exp, expr_context_ty ctx)
         return validate_exprs(exp->v.List.elts, ctx, 0);
     case Tuple_kind:
         return validate_exprs(exp->v.Tuple.elts, ctx, 0);
-    /* These last cases don't have any checking. */
+    /* This last case doesn't have any checking. */
     case Name_kind:
-    case NameConstant_kind:
-    case Ellipsis_kind:
         return 1;
     default:
         PyErr_SetString(PyExc_SystemError, "unexpected expression");
@@ -1040,19 +1013,23 @@ set_context(struct compiling *c, expr_ty e, expr_context_ty ctx, const node *n)
             break;
         case Dict_kind:
         case Set_kind:
-        case Num_kind:
-        case Str_kind:
-        case Bytes_kind:
         case JoinedStr_kind:
         case FormattedValue_kind:
             expr_name = "literal";
             break;
-        case NameConstant_kind:
-            expr_name = "keyword";
-            break;
-        case Ellipsis_kind:
-            expr_name = "Ellipsis";
+        case Constant_kind: {
+            PyObject *value = e->v.Constant.value;
+            if (value == Py_None || value == Py_False || value == Py_True) {
+                expr_name = "keyword";
+            }
+            else if (value == Py_Ellipsis) {
+                expr_name = "Ellipsis";
+            }
+            else {
+                expr_name = "literal";
+            }
             break;
+        }
         case Compare_kind:
             expr_name = "comparison";
             break;
@@ -2091,11 +2068,11 @@ ast_for_atom(struct compiling *c, const node *n)
         size_t len = strlen(s);
         if (len >= 4 && len <= 5) {
             if (!strcmp(s, "None"))
-                return NameConstant(Py_None, LINENO(n), n->n_col_offset, c->c_arena);
+                return Constant(Py_None, LINENO(n), n->n_col_offset, c->c_arena);
             if (!strcmp(s, "True"))
-                return NameConstant(Py_True, LINENO(n), n->n_col_offset, c->c_arena);
+                return Constant(Py_True, LINENO(n), n->n_col_offset, c->c_arena);
             if (!strcmp(s, "False"))
-                return NameConstant(Py_False, LINENO(n), n->n_col_offset, c->c_arena);
+                return Constant(Py_False, LINENO(n), n->n_col_offset, c->c_arena);
         }
         name = new_identifier(s, c);
         if (!name)
@@ -2144,10 +2121,10 @@ ast_for_atom(struct compiling *c, const node *n)
             Py_DECREF(pynum);
             return NULL;
         }
-        return Num(pynum, LINENO(n), n->n_col_offset, c->c_arena);
+        return Constant(pynum, LINENO(n), n->n_col_offset, c->c_arena);
     }
     case ELLIPSIS: /* Ellipsis */
-        return Ellipsis(LINENO(n), n->n_col_offset, c->c_arena);
+        return Constant(Py_Ellipsis, LINENO(n), n->n_col_offset, c->c_arena);
     case LPAR: /* some parenthesized expressions */
         ch = CHILD(n, 1);
 
@@ -4751,7 +4728,7 @@ typedef struct {
        expr_ty's, and then after that start dynamically allocating,
        doubling the number allocated each time. Note that the f-string
        f'{0}a{1}' contains 3 expr_ty's: 2 FormattedValue's, and one
-       Str for the literal 'a'. So you add expr_ty's about twice as
+       Constant for the literal 'a'. So you add expr_ty's about twice as
        fast as you add exressions in an f-string. */
 
     Py_ssize_t allocated;  /* Number we've allocated. */
@@ -4903,7 +4880,7 @@ FstringParser_Dealloc(FstringParser *state)
     ExprList_Dealloc(&state->expr_list);
 }
 
-/* Make a Str node, but decref the PyUnicode object being added. */
+/* Make a Constant node, but decref the PyUnicode object being added. */
 static expr_ty
 make_str_node_and_del(PyObject **str, struct compiling *c, const node* n)
 {
@@ -4914,7 +4891,7 @@ make_str_node_and_del(PyObject **str, struct compiling *c, const node* n)
         Py_DECREF(s);
         return NULL;
     }
-    return Str(s, LINENO(n), n->n_col_offset, c->c_arena);
+    return Constant(s, LINENO(n), n->n_col_offset, c->c_arena);
 }
 
 /* Add a non-f-string (that is, a regular literal string). str is
@@ -5002,11 +4979,11 @@ FstringParser_ConcatFstring(FstringParser *state, const char **str,
             break;
 
         /* We know we have an expression. Convert any existing string
-           to a Str node. */
+           to a Constant node. */
         if (!state->last_str) {
             /* Do nothing. No previous literal. */
         } else {
-            /* Convert the existing last_str literal to a Str node. */
+            /* Convert the existing last_str literal to a Constant node. */
             expr_ty str = make_str_node_and_del(&state->last_str, c, n);
             if (!str || ExprList_Append(&state->expr_list, str) < 0)
                 return -1;
@@ -5033,7 +5010,7 @@ FstringParser_ConcatFstring(FstringParser *state, const char **str,
 }
 
 /* Convert the partial state reflected in last_str and expr_list to an
-   expr_ty. The expr_ty can be a Str, or a JoinedStr. */
+   expr_ty. The expr_ty can be a Constant, or a JoinedStr. */
 static expr_ty
 FstringParser_Finish(FstringParser *state, struct compiling *c,
                      const node *n)
@@ -5055,7 +5032,7 @@ FstringParser_Finish(FstringParser *state, struct compiling *c,
         return make_str_node_and_del(&state->last_str, c, n);
     }
 
-    /* Create a Str node out of last_str, if needed. It will be the
+    /* Create a Constant node out of last_str, if needed. It will be the
        last node in our expression list. */
     if (state->last_str) {
         expr_ty str = make_str_node_and_del(&state->last_str, c, n);
@@ -5206,9 +5183,9 @@ parsestr(struct compiling *c, const node *n, int *bytesmode, int *rawmode,
 
 /* Accepts a STRING+ atom, and produces an expr_ty node. Run through
    each STRING atom, and process it as needed. For bytes, just
-   concatenate them together, and the result will be a Bytes node. For
+   concatenate them together, and the result will be a Constant node. For
    normal strings and f-strings, concatenate them together. The result
-   will be a Str node if there were no f-strings; a FormattedValue
+   will be a Constant node if there were no f-strings; a FormattedValue
    node if there's just an f-string (with no leading or trailing
    literals), or a JoinedStr node if there are multiple f-strings or
    any literals involved. */
@@ -5279,7 +5256,7 @@ parsestrplus(struct compiling *c, const node *n)
         /* Just return the bytes object and we're done. */
         if (PyArena_AddPyObject(c->c_arena, bytes_str) < 0)
             goto error;
-        return Bytes(bytes_str, LINENO(n), n->n_col_offset, c->c_arena);
+        return Constant(bytes_str, LINENO(n), n->n_col_offset, c->c_arena);
     }
 
     /* We're not a bytes string, bytes_str should never have been set. */
@@ -5304,9 +5281,6 @@ _PyAST_GetDocString(asdl_seq *body)
         return NULL;
     }
     expr_ty e = st->v.Expr.value;
-    if (e->kind == Str_kind) {
-        return e->v.Str.s;
-    }
     if (e->kind == Constant_kind && PyUnicode_CheckExact(e->v.Constant.value)) {
         return e->v.Constant.value;
     }
diff --git a/Python/ast_opt.c b/Python/ast_opt.c
index 5e57638..1f9cb77 100644
--- a/Python/ast_opt.c
+++ b/Python/ast_opt.c
@@ -5,47 +5,6 @@
 #include "ast.h"
 
 
-/* TODO: is_const and get_const_value are copied from Python/compile.c.
-   It should be deduped in the future.  Maybe, we can include this file
-   from compile.c?
-*/
-static int
-is_const(expr_ty e)
-{
-    switch (e->kind) {
-    case Constant_kind:
-    case Num_kind:
-    case Str_kind:
-    case Bytes_kind:
-    case Ellipsis_kind:
-    case NameConstant_kind:
-        return 1;
-    default:
-        return 0;
-    }
-}
-
-static PyObject *
-get_const_value(expr_ty e)
-{
-    switch (e->kind) {
-    case Constant_kind:
-        return e->v.Constant.value;
-    case Num_kind:
-        return e->v.Num.n;
-    case Str_kind:
-        return e->v.Str.s;
-    case Bytes_kind:
-        return e->v.Bytes.s;
-    case Ellipsis_kind:
-        return Py_Ellipsis;
-    case NameConstant_kind:
-        return e->v.NameConstant.value;
-    default:
-        Py_UNREACHABLE();
-    }
-}
-
 static int
 make_const(expr_ty node, PyObject *val, PyArena *arena)
 {
@@ -81,7 +40,7 @@ fold_unaryop(expr_ty node, PyArena *arena, int optimize)
 {
     expr_ty arg = node->v.UnaryOp.operand;
 
-    if (!is_const(arg)) {
+    if (arg->kind != Constant_kind) {
         /* Fold not into comparison */
         if (node->v.UnaryOp.op == Not && arg->kind == Compare_kind &&
                 asdl_seq_LEN(arg->v.Compare.ops) == 1) {
@@ -123,7 +82,7 @@ fold_unaryop(expr_ty node, PyArena *arena, int optimize)
         [UAdd] = PyNumber_Positive,
         [USub] = PyNumber_Negative,
     };
-    PyObject *newval = ops[node->v.UnaryOp.op](get_const_value(arg));
+    PyObject *newval = ops[node->v.UnaryOp.op](arg->v.Constant.value);
     return make_const(node, newval, arena);
 }
 
@@ -259,12 +218,12 @@ fold_binop(expr_ty node, PyArena *arena, int optimize)
     expr_ty lhs, rhs;
     lhs = node->v.BinOp.left;
     rhs = node->v.BinOp.right;
-    if (!is_const(lhs) || !is_const(rhs)) {
+    if (lhs->kind != Constant_kind || rhs->kind != Constant_kind) {
         return 1;
     }
 
-    PyObject *lv = get_const_value(lhs);
-    PyObject *rv = get_const_value(rhs);
+    PyObject *lv = lhs->v.Constant.value;
+    PyObject *rv = rhs->v.Constant.value;
     PyObject *newval;
 
     switch (node->v.BinOp.op) {
@@ -316,7 +275,7 @@ make_const_tuple(asdl_seq *elts)
 {
     for (int i = 0; i < asdl_seq_LEN(elts); i++) {
         expr_ty e = (expr_ty)asdl_seq_GET(elts, i);
-        if (!is_const(e)) {
+        if (e->kind != Constant_kind) {
             return NULL;
         }
     }
@@ -328,7 +287,7 @@ make_const_tuple(asdl_seq *elts)
 
     for (int i = 0; i < asdl_seq_LEN(elts); i++) {
         expr_ty e = (expr_ty)asdl_seq_GET(elts, i);
-        PyObject *v = get_const_value(e);
+        PyObject *v = e->v.Constant.value;
         Py_INCREF(v);
         PyTuple_SET_ITEM(newval, i, v);
     }
@@ -357,16 +316,16 @@ fold_subscr(expr_ty node, PyArena *arena, int optimize)
     arg = node->v.Subscript.value;
     slice = node->v.Subscript.slice;
     if (node->v.Subscript.ctx != Load ||
-            !is_const(arg) ||
+            arg->kind != Constant_kind ||
             /* TODO: handle other types of slices */
             slice->kind != Index_kind ||
-            !is_const(slice->v.Index.value))
+            slice->v.Index.value->kind != Constant_kind)
     {
         return 1;
     }
 
     idx = slice->v.Index.value;
-    newval = PyObject_GetItem(get_const_value(arg), get_const_value(idx));
+    newval = PyObject_GetItem(arg->v.Constant.value, idx->v.Constant.value);
     return make_const(node, newval, arena);
 }
 
diff --git a/Python/ast_unparse.c b/Python/ast_unparse.c
index 725ce31..56ea3c4 100644
--- a/Python/ast_unparse.c
+++ b/Python/ast_unparse.c
@@ -567,8 +567,6 @@ append_fstring_element(_PyUnicodeWriter *writer, expr_ty e, bool is_format_spec)
     switch (e->kind) {
     case Constant_kind:
         return append_fstring_unicode(writer, e->v.Constant.value);
-    case Str_kind:
-        return append_fstring_unicode(writer, e->v.Str.s);
     case JoinedStr_kind:
         return append_joinedstr(writer, e, is_format_spec);
     case FormattedValue_kind:
@@ -690,13 +688,12 @@ static int
 append_ast_attribute(_PyUnicodeWriter *writer, expr_ty e)
 {
     const char *period;
-    APPEND_EXPR(e->v.Attribute.value, PR_ATOM);
+    expr_ty v = e->v.Attribute.value;
+    APPEND_EXPR(v, PR_ATOM);
 
     /* Special case: integers require a space for attribute access to be
-       unambiguous.  Floats and complex numbers don't but work with it, too. */
-    if (e->v.Attribute.value->kind == Num_kind ||
-        e->v.Attribute.value->kind == Constant_kind)
-    {
+       unambiguous. */
+    if (v->kind == Constant_kind && PyLong_CheckExact(v->v.Constant.value)) {
         period = " .";
     }
     else {
@@ -841,21 +838,14 @@ append_ast_expr(_PyUnicodeWriter *writer, expr_ty e, int level)
     case Call_kind:
         return append_ast_call(writer, e);
     case Constant_kind:
+        if (e->v.Constant.value == Py_Ellipsis) {
+            APPEND_STR_FINISH("...");
+        }
         return append_repr(writer, e->v.Constant.value);
-    case Num_kind:
-        return append_repr(writer, e->v.Num.n);
-    case Str_kind:
-        return append_repr(writer, e->v.Str.s);
     case JoinedStr_kind:
         return append_joinedstr(writer, e, false);
     case FormattedValue_kind:
         return append_formattedvalue(writer, e, false);
-    case Bytes_kind:
-        return append_repr(writer, e->v.Bytes.s);
-    case Ellipsis_kind:
-        APPEND_STR_FINISH("...");
-    case NameConstant_kind:
-        return append_repr(writer, e->v.NameConstant.value);
     /* The following exprs can be assignment targets. */
     case Attribute_kind:
         return append_ast_attribute(writer, e);
diff --git a/Python/compile.c b/Python/compile.c
index 3a45804..096b762 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -1398,43 +1398,6 @@ compiler_addop_j(struct compiler *c, int opcode, basicblock *b, int absolute)
     } \
 }
 
-static int
-is_const(expr_ty e)
-{
-    switch (e->kind) {
-    case Constant_kind:
-    case Num_kind:
-    case Str_kind:
-    case Bytes_kind:
-    case Ellipsis_kind:
-    case NameConstant_kind:
-        return 1;
-    default:
-        return 0;
-    }
-}
-
-static PyObject *
-get_const_value(expr_ty e)
-{
-    switch (e->kind) {
-    case Constant_kind:
-        return e->v.Constant.value;
-    case Num_kind:
-        return e->v.Num.n;
-    case Str_kind:
-        return e->v.Str.s;
-    case Bytes_kind:
-        return e->v.Bytes.s;
-    case Ellipsis_kind:
-        return Py_Ellipsis;
-    case NameConstant_kind:
-        return e->v.NameConstant.value;
-    default:
-        Py_UNREACHABLE();
-    }
-}
-
 /* Search if variable annotations are present statically in a block. */
 
 static int
@@ -2568,7 +2531,7 @@ static int
 compiler_return(struct compiler *c, stmt_ty s)
 {
     int preserve_tos = ((s->v.Return.value != NULL) &&
-                        !is_const(s->v.Return.value));
+                        (s->v.Return.value->kind != Constant_kind));
     if (c->u->u_ste->ste_type != FunctionBlock)
         return compiler_error(c, "'return' outside function");
     if (s->v.Return.value != NULL &&
@@ -3054,7 +3017,7 @@ compiler_visit_stmt_expr(struct compiler *c, expr_ty value)
         return 1;
     }
 
-    if (is_const(value)) {
+    if (value->kind == Constant_kind) {
         /* ignore constant statement */
         return 1;
     }
@@ -3502,7 +3465,7 @@ are_all_items_const(asdl_seq *seq, Py_ssize_t begin, Py_ssize_t end)
     Py_ssize_t i;
     for (i = begin; i < end; i++) {
         expr_ty key = (expr_ty)asdl_seq_GET(seq, i);
-        if (key == NULL || !is_const(key))
+        if (key == NULL || key->kind != Constant_kind)
             return 0;
     }
     return 1;
@@ -3522,7 +3485,7 @@ compiler_subdict(struct compiler *c, expr_ty e, Py_ssize_t begin, Py_ssize_t end
             return 0;
         }
         for (i = begin; i < end; i++) {
-            key = get_const_value((expr_ty)asdl_seq_GET(e->v.Dict.keys, i));
+            key = ((expr_ty)asdl_seq_GET(e->v.Dict.keys, i))->v.Constant.value;
             Py_INCREF(key);
             PyTuple_SET_ITEM(keys, i - begin, key);
         }
@@ -4244,8 +4207,8 @@ compiler_visit_keyword(struct compiler *c, keyword_ty k)
 static int
 expr_constant(expr_ty e)
 {
-    if (is_const(e)) {
-        return PyObject_IsTrue(get_const_value(e));
+    if (e->kind == Constant_kind) {
+        return PyObject_IsTrue(e->v.Constant.value);
     }
     return -1;
 }
@@ -4505,25 +4468,10 @@ compiler_visit_expr1(struct compiler *c, expr_ty e)
     case Constant_kind:
         ADDOP_LOAD_CONST(c, e->v.Constant.value);
         break;
-    case Num_kind:
-        ADDOP_LOAD_CONST(c, e->v.Num.n);
-        break;
-    case Str_kind:
-        ADDOP_LOAD_CONST(c, e->v.Str.s);
-        break;
     case JoinedStr_kind:
         return compiler_joined_str(c, e);
     case FormattedValue_kind:
         return compiler_formatted_value(c, e);
-    case Bytes_kind:
-        ADDOP_LOAD_CONST(c, e->v.Bytes.s);
-        break;
-    case Ellipsis_kind:
-        ADDOP_LOAD_CONST(c, Py_Ellipsis);
-        break;
-    case NameConstant_kind:
-        ADDOP_LOAD_CONST(c, e->v.NameConstant.value);
-        break;
     /* The following exprs can be assignment targets. */
     case Attribute_kind:
         if (e->v.Attribute.ctx != AugStore)
diff --git a/Python/symtable.c b/Python/symtable.c
index e721614..16b706b 100644
--- a/Python/symtable.c
+++ b/Python/symtable.c
@@ -1461,11 +1461,6 @@ symtable_visit_expr(struct symtable *st, expr_ty e)
         VISIT_SEQ(st, expr, e->v.JoinedStr.values);
         break;
     case Constant_kind:
-    case Num_kind:
-    case Str_kind:
-    case Bytes_kind:
-    case Ellipsis_kind:
-    case NameConstant_kind:
         /* Nothing to do here. */
         break;
     /* The following exprs can be assignment targets. */