Issue #9011: Remove buggy and unnecessary ST->AST compilation code

dealing with unary minus applied to a constant.  The removed code was
mutating the ST, causing a second compilation to fail.  (The peephole
optimizer already takes care of optimizing this case, so there's no
lost optimization opportunity here.)

1 files changed, 0 insertions, 26 deletions

diff --git a/Python/ast.c b/Python/ast.c
index 0703abc..34dc30f 100644
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -1678,34 +1678,8 @@ ast_for_trailer(struct compiling *c, const node *n, expr_ty left_expr)
 static expr_ty
 ast_for_factor(struct compiling *c, const node *n)
 {
-    node *pfactor, *ppower, *patom, *pnum;
     expr_ty expression;
 
-    /* If the unary - operator is applied to a constant, don't generate
-       a UNARY_NEGATIVE opcode.  Just store the approriate value as a
-       constant.  The peephole optimizer already does something like
-       this but it doesn't handle the case where the constant is
-       (sys.maxint - 1).  In that case, we want a PyIntObject, not a
-       PyLongObject.
-    */
-    if (TYPE(CHILD(n, 0)) == MINUS
-        && NCH(n) == 2
-        && TYPE((pfactor = CHILD(n, 1))) == factor
-        && NCH(pfactor) == 1
-        && TYPE((ppower = CHILD(pfactor, 0))) == power
-        && NCH(ppower) == 1
-        && TYPE((patom = CHILD(ppower, 0))) == atom
-        && TYPE((pnum = CHILD(patom, 0))) == NUMBER) {
-        char *s = PyObject_MALLOC(strlen(STR(pnum)) + 2);
-        if (s == NULL)
-            return NULL;
-        s[0] = '-';
-        strcpy(s + 1, STR(pnum));
-        PyObject_FREE(STR(pnum));
-        STR(pnum) = s;
-        return ast_for_atom(c, patom);
-    }
-
     expression = ast_for_expr(c, CHILD(n, 1));
     if (!expression)
         return NULL;