[2.7] bpo-10544: Deprecate "yield" in comprehensions and generator expressions in Py3k mode. (GH-4579) (#4676)
diff --git a/Python/symtable.c b/Python/symtable.c
index 3b4247b..21790b1 100644
--- a/Python/symtable.c
+++ b/Python/symtable.c
@@ -162,12 +162,14 @@
};
static int symtable_analyze(struct symtable *st);
-static int symtable_warn(struct symtable *st, char *msg, int lineno);
+static int symtable_warn(struct symtable *st,
+ PyObject *warn, const char *msg, int lineno);
static int symtable_enter_block(struct symtable *st, identifier name,
_Py_block_ty block, void *ast, int lineno);
static int symtable_exit_block(struct symtable *st, void *ast);
static int symtable_visit_stmt(struct symtable *st, stmt_ty s);
static int symtable_visit_expr(struct symtable *st, expr_ty s);
+static int symtable_visit_listcomp(struct symtable *st, expr_ty e);
static int symtable_visit_genexp(struct symtable *st, expr_ty s);
static int symtable_visit_setcomp(struct symtable *st, expr_ty e);
static int symtable_visit_dictcomp(struct symtable *st, expr_ty e);
@@ -796,14 +798,18 @@
static int
-symtable_warn(struct symtable *st, char *msg, int lineno)
+symtable_warn(struct symtable *st, PyObject *warn, const char *msg, int lineno)
{
- if (PyErr_WarnExplicit(PyExc_SyntaxWarning, msg, st->st_filename,
- lineno, NULL, NULL) < 0) {
- if (PyErr_ExceptionMatches(PyExc_SyntaxWarning)) {
+ if (lineno < 0) {
+ lineno = st->st_cur->ste_lineno;
+ }
+ if (PyErr_WarnExplicit(warn, msg, st->st_filename, lineno, NULL, NULL) < 0) {
+ if (PyErr_ExceptionMatches(warn)) {
+ /* Replace the warning exception with a SyntaxError
+ to get a more accurate error report */
+ PyErr_Clear();
PyErr_SetString(PyExc_SyntaxError, msg);
- PyErr_SyntaxLocation(st->st_filename,
- st->st_cur->ste_lineno);
+ PyErr_SyntaxLocation(st->st_filename, lineno);
}
return 0;
}
@@ -1153,7 +1159,7 @@
PyOS_snprintf(buf, sizeof(buf),
GLOBAL_AFTER_USE,
c_name);
- if (!symtable_warn(st, buf, s->lineno))
+ if (!symtable_warn(st, PyExc_SyntaxWarning, buf, s->lineno))
return 0;
}
if (!symtable_add_def(st, name, DEF_GLOBAL))
@@ -1221,8 +1227,8 @@
VISIT_SEQ(st, expr, e->v.Set.elts);
break;
case ListComp_kind:
- VISIT(st, expr, e->v.ListComp.elt);
- VISIT_SEQ(st, comprehension, e->v.ListComp.generators);
+ if (!symtable_visit_listcomp(st, e))
+ return 0;
break;
case GeneratorExp_kind:
if (!symtable_visit_genexp(st, e))
@@ -1420,12 +1426,11 @@
return r;
}
else {
- if (st->st_cur->ste_type != ModuleBlock) {
- int lineno = st->st_cur->ste_lineno;
- if (!symtable_warn(st, IMPORT_STAR_WARNING, lineno)) {
- Py_DECREF(store_name);
- return 0;
- }
+ if (st->st_cur->ste_type != ModuleBlock &&
+ !symtable_warn(st, PyExc_SyntaxWarning, IMPORT_STAR_WARNING, -1))
+ {
+ Py_DECREF(store_name);
+ return 0;
}
st->st_cur->ste_unoptimized |= OPT_IMPORT_STAR;
Py_DECREF(store_name);
@@ -1509,7 +1514,10 @@
!symtable_enter_block(st, scope_name, FunctionBlock, (void *)e, 0)) {
return 0;
}
- st->st_cur->ste_generator = is_generator;
+ /* In order to check for yield expressions under '-3', we clear
+ the generator flag, and restore it at the end */
+ is_generator |= st->st_cur->ste_generator;
+ st->st_cur->ste_generator = 0;
/* Outermost iter is received as an argument */
if (!symtable_implicit_arg(st, 0)) {
symtable_exit_block(st, (void *)e);
@@ -1527,10 +1535,56 @@
if (value)
VISIT_IN_BLOCK(st, expr, value, (void*)e);
VISIT_IN_BLOCK(st, expr, elt, (void*)e);
+ if (Py_Py3kWarningFlag && st->st_cur->ste_generator) {
+ const char *msg = (
+ (e->kind == SetComp_kind) ? "'yield' inside set comprehension" :
+ (e->kind == DictComp_kind) ? "'yield' inside dict comprehension" :
+ "'yield' inside generator expression");
+ if (!symtable_warn(st, PyExc_DeprecationWarning, msg, -1)) {
+ symtable_exit_block(st, (void *)e);
+ return 0;
+ }
+ }
+ st->st_cur->ste_generator |= is_generator;
return symtable_exit_block(st, (void *)e);
}
static int
+symtable_visit_listcomp(struct symtable *st, expr_ty e)
+{
+ asdl_seq *generators = e->v.ListComp.generators;
+ int i, is_generator;
+ /* In order to check for yield expressions under '-3', we clear
+ the generator flag, and restore it at the end */
+ is_generator = st->st_cur->ste_generator;
+ st->st_cur->ste_generator = 0;
+ VISIT(st, expr, e->v.ListComp.elt);
+ for (i = 0; i < asdl_seq_LEN(generators); i++) {
+ comprehension_ty lc = (comprehension_ty)asdl_seq_GET(generators, i);
+ VISIT(st, expr, lc->target);
+ if (i == 0 && !st->st_cur->ste_generator) {
+ /* 'yield' in the outermost iterator doesn't cause a warning */
+ VISIT(st, expr, lc->iter);
+ is_generator |= st->st_cur->ste_generator;
+ st->st_cur->ste_generator = 0;
+ }
+ else {
+ VISIT(st, expr, lc->iter);
+ }
+ VISIT_SEQ(st, expr, lc->ifs);
+ }
+
+ if (Py_Py3kWarningFlag && st->st_cur->ste_generator) {
+ const char *msg = "'yield' inside list comprehension";
+ if (!symtable_warn(st, PyExc_DeprecationWarning, msg, -1)) {
+ return 0;
+ }
+ }
+ st->st_cur->ste_generator |= is_generator;
+ return 1;
+}
+
+static int
symtable_visit_genexp(struct symtable *st, expr_ty e)
{
return symtable_handle_comprehension(st, e, GET_IDENTIFIER(genexpr),