From 72e4f4d7bc516b6d7692a07b1a6c812871c4fd4a Mon Sep 17 00:00:00 2001
From: Guido van Rossum <guido@python.org>
Date: Sat, 19 Jan 2019 12:04:08 -0800
Subject: [PATCH] Define flags to turn on parsing type comments

Demo: `compile(sample, "<sample>", "exec", PyCF_ONLY_AST|0x1000)`
This will crash if type comments are present.

It doesn't *work* yet -- type comments cause crashes in ast.c and type
ignore comments aren't passed on to Module yet.
---
 Include/compile.h    | 1 +
 Include/parsetok.h   | 1 +
 Parser/parsetok.c    | 6 ++++++
 Python/bltinmodule.c | 2 +-
 Python/pythonrun.c   | 2 ++
 5 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/Include/compile.h b/Include/compile.h
index 2dacfff37f8c..36477c01e2ba 100644
--- a/Include/compile.h
+++ b/Include/compile.h
@@ -22,6 +22,7 @@ PyAPI_FUNC(PyCodeObject *) PyNode_Compile(struct _node *, const char *);
 #define PyCF_DONT_IMPLY_DEDENT 0x0200
 #define PyCF_ONLY_AST 0x0400
 #define PyCF_IGNORE_COOKIE 0x0800
+#define PyCF_TYPE_COMMENTS 0x1000
 
 #ifndef Py_LIMITED_API
 typedef struct {
diff --git a/Include/parsetok.h b/Include/parsetok.h
index 1217c46d0ed7..e95dd31fb79a 100644
--- a/Include/parsetok.h
+++ b/Include/parsetok.h
@@ -37,6 +37,7 @@ typedef struct {
 
 #define PyPARSE_IGNORE_COOKIE 0x0010
 #define PyPARSE_BARRY_AS_BDFL 0x0020
+#define PyPARSE_TYPE_COMMENTS 0x0040
 
 PyAPI_FUNC(node *) PyParser_ParseString(const char *, grammar *, int,
                                               perrdetail *);
diff --git a/Parser/parsetok.c b/Parser/parsetok.c
index 40db8a2b8290..042fff71a02f 100644
--- a/Parser/parsetok.c
+++ b/Parser/parsetok.c
@@ -91,6 +91,9 @@ PyParser_ParseStringObject(const char *s, PyObject *filename,
         err_ret->error = PyErr_Occurred() ? E_DECODE : E_NOMEM;
         return NULL;
     }
+    if (*flags & PyPARSE_TYPE_COMMENTS) {
+        tok->type_comments = 1;
+    }
 
 #ifndef PGEN
     Py_INCREF(err_ret->filename);
@@ -159,6 +162,9 @@ PyParser_ParseFileObject(FILE *fp, PyObject *filename,
         err_ret->error = E_NOMEM;
         return NULL;
     }
+    if (*flags & PyPARSE_TYPE_COMMENTS) {
+        tok->type_comments = 1;
+    }
 #ifndef PGEN
     Py_INCREF(err_ret->filename);
     tok->filename = err_ret->filename;
diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index 332142fc6ffc..930adb496e14 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -771,7 +771,7 @@ builtin_compile_impl(PyObject *module, PyObject *source, PyObject *filename,
     cf.cf_flags = flags | PyCF_SOURCE_IS_UTF8;
 
     if (flags &
-        ~(PyCF_MASK | PyCF_MASK_OBSOLETE | PyCF_DONT_IMPLY_DEDENT | PyCF_ONLY_AST))
+        ~(PyCF_MASK | PyCF_MASK_OBSOLETE | PyCF_DONT_IMPLY_DEDENT | PyCF_ONLY_AST | PyCF_TYPE_COMMENTS))
     {
         PyErr_SetString(PyExc_ValueError,
                         "compile(): unrecognised flags");
diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index 9b6371d9c0da..c7a622c83d37 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -158,6 +158,8 @@ static int PARSER_FLAGS(PyCompilerFlags *flags)
         parser_flags |= PyPARSE_IGNORE_COOKIE;
     if (flags->cf_flags & CO_FUTURE_BARRY_AS_BDFL)
         parser_flags |= PyPARSE_BARRY_AS_BDFL;
+    if (flags->cf_flags & PyCF_TYPE_COMMENTS)
+        parser_flags |= PyPARSE_TYPE_COMMENTS;
     return parser_flags;
 }
 
-- 
2.47.3