bpo-1875: Raise SyntaxError in invalid blocks that will be optimised away (GH-13332)
Move the check for dead conditionals (if 0) to the peephole optimizer
and make sure that the code block is still compiled to report any
existing syntax errors within.
(cherry picked from commit af8646c8054d0f4180a2013383039b6a472f9698)
Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>
diff --git a/Lib/test/test_syntax.py b/Lib/test/test_syntax.py
index 2b96a94..4918e5c 100644
--- a/Lib/test/test_syntax.py
+++ b/Lib/test/test_syntax.py
@@ -650,6 +650,20 @@
def test_break_outside_loop(self):
self._check_error("break", "outside loop")
+ def test_yield_outside_function(self):
+ self._check_error("if 0: yield", "outside function")
+ self._check_error("class C:\n if 0: yield", "outside function")
+
+ def test_return_outside_function(self):
+ self._check_error("if 0: return", "outside function")
+ self._check_error("class C:\n if 0: return", "outside function")
+
+ def test_break_outside_loop(self):
+ self._check_error("if 0: break", "outside loop")
+
+ def test_continue_outside_loop(self):
+ self._check_error("if 0: continue", "not properly in loop")
+
def test_unexpected_indent(self):
self._check_error("foo()\n bar()\n", "unexpected indent",
subclass=IndentationError)
diff --git a/Misc/NEWS.d/next/Core and Builtins/2019-05-15-01-29-29.bpo-1875.9oxXFX.rst b/Misc/NEWS.d/next/Core and Builtins/2019-05-15-01-29-29.bpo-1875.9oxXFX.rst
new file mode 100644
index 0000000..8f095ed
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2019-05-15-01-29-29.bpo-1875.9oxXFX.rst
@@ -0,0 +1,3 @@
+A :exc:`SyntaxError` is now raised if a code blocks that will be optimized
+away (e.g. if conditions that are always false) contains syntax errors.
+Patch by Pablo Galindo.
diff --git a/Python/compile.c b/Python/compile.c
index 5688ef8..d2729d4 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -2301,13 +2301,12 @@
return 0;
constant = expr_constant(s->v.If.test);
- /* constant = 0: "if 0"
+ /* constant = 0: "if 0" Leave the optimizations to
+ * the pephole optimizer to check for syntax errors
+ * in the block.
* constant = 1: "if 1", "if 2", ...
* constant = -1: rest */
- if (constant == 0) {
- if (s->v.If.orelse)
- VISIT_SEQ(c, stmt, s->v.If.orelse);
- } else if (constant == 1) {
+ if (constant == 1) {
VISIT_SEQ(c, stmt, s->v.If.body);
} else {
if (asdl_seq_LEN(s->v.If.orelse)) {
diff --git a/Python/peephole.c b/Python/peephole.c
index 95b3dbb..1ae62fa 100644
--- a/Python/peephole.c
+++ b/Python/peephole.c
@@ -304,11 +304,19 @@
case LOAD_CONST:
cumlc = lastlc + 1;
if (nextop != POP_JUMP_IF_FALSE ||
- !ISBASICBLOCK(blocks, op_start, i + 1) ||
- !PyObject_IsTrue(PyList_GET_ITEM(consts, get_arg(codestr, i))))
+ !ISBASICBLOCK(blocks, op_start, i + 1)) {
break;
- fill_nops(codestr, op_start, nexti + 1);
- cumlc = 0;
+ }
+ PyObject* cnt = PyList_GET_ITEM(consts, get_arg(codestr, i));
+ int is_true = PyObject_IsTrue(cnt);
+ if (is_true == 1) {
+ fill_nops(codestr, op_start, nexti + 1);
+ cumlc = 0;
+ } else if (is_true == 0) {
+ h = get_arg(codestr, nexti) / sizeof(_Py_CODEUNIT);
+ tgt = find_op(codestr, codelen, h);
+ fill_nops(codestr, op_start, tgt);
+ }
break;
/* Try to fold tuples of constants.