1 files changed, 111 insertions, 0 deletions
diff --git a/src/etc/generate-deriving-span-tests.py b/src/etc/generate-deriving-span-tests.py
new file mode 100755
index 000000000..d38f5add7
--- /dev/null
+++ b/src/etc/generate-deriving-span-tests.py
@@ -0,0 +1,111 @@
+#!/usr/bin/env python
+
+"""
+This script creates a pile of UI tests check that all the
+derives have spans that point to the fields, rather than the
+#[derive(...)] line.
+
+sample usage: src/etc/generate-deriving-span-tests.py
+"""
+
+import os
+import stat
+
+TEST_DIR = os.path.abspath(
+    os.path.join(os.path.dirname(__file__), '../test/ui/derives/'))
+
+TEMPLATE = """\
+// This file was auto-generated using 'src/etc/generate-deriving-span-tests.py'
+
+{error_deriving}
+struct Error;
+{code}
+fn main() {{}}
+"""
+
+ENUM_STRING = """
+#[derive({traits})]
+enum Enum {{
+   A(
+     Error {errors}
+     )
+}}
+"""
+ENUM_STRUCT_VARIANT_STRING = """
+#[derive({traits})]
+enum Enum {{
+   A {{
+     x: Error {errors}
+   }}
+}}
+"""
+STRUCT_STRING = """
+#[derive({traits})]
+struct Struct {{
+    x: Error {errors}
+}}
+"""
+STRUCT_TUPLE_STRING = """
+#[derive({traits})]
+struct Struct(
+    Error {errors}
+);
+"""
+
+ENUM_TUPLE, ENUM_STRUCT, STRUCT_FIELDS, STRUCT_TUPLE = range(4)
+
+
+def create_test_case(type, trait, super_traits, error_count):
+    string = [ENUM_STRING, ENUM_STRUCT_VARIANT_STRING, STRUCT_STRING, STRUCT_TUPLE_STRING][type]
+    all_traits = ','.join([trait] + super_traits)
+    super_traits = ','.join(super_traits)
+    error_deriving = '#[derive(%s)]' % super_traits if super_traits else ''
+
+    errors = '\n'.join('//~%s ERROR' % ('^' * n) for n in range(error_count))
+    code = string.format(traits=all_traits, errors=errors)
+    return TEMPLATE.format(error_deriving=error_deriving, code=code)
+
+
+def write_file(name, string):
+    test_file = os.path.join(TEST_DIR, 'derives-span-%s.rs' % name)
+
+    # set write permission if file exists, so it can be changed
+    if os.path.exists(test_file):
+        os.chmod(test_file, stat.S_IWUSR)
+
+    with open(test_file, 'w') as f:
+        f.write(string)
+
+    # mark file read-only
+    os.chmod(test_file, stat.S_IRUSR|stat.S_IRGRP|stat.S_IROTH)
+
+
+ENUM = 1
+STRUCT = 2
+ALL = STRUCT | ENUM
+
+traits = {
+    'Default': (STRUCT, [], 1),
+    'FromPrimitive': (0, [], 0),  # only works for C-like enums
+
+    'Decodable': (0, [], 0),  # FIXME: quoting gives horrible spans
+    'Encodable': (0, [], 0),  # FIXME: quoting gives horrible spans
+}
+
+for (trait, supers, errs) in [('Clone', [], 1),
+                              ('PartialEq', [], 2),
+                              ('PartialOrd', ['PartialEq'], 1),
+                              ('Eq', ['PartialEq'], 1),
+                              ('Ord', ['Eq', 'PartialOrd', 'PartialEq'], 1),
+                              ('Debug', [], 1),
+                              ('Hash', [], 1)]:
+    traits[trait] = (ALL, supers, errs)
+
+for (trait, (types, super_traits, error_count)) in traits.items():
+    mk = lambda ty: create_test_case(ty, trait, super_traits, error_count)
+    if types & ENUM:
+        write_file(trait + '-enum', mk(ENUM_TUPLE))
+        write_file(trait + '-enum-struct-variant', mk(ENUM_STRUCT))
+    if types & STRUCT:
+        write_file(trait + '-struct', mk(STRUCT_FIELDS))
+        write_file(trait + '-tuple-struct', mk(STRUCT_TUPLE))