From 00e596aad29b3ee8c64e72d6f0cf5480e6904673 Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Mon, 19 Feb 2018 20:33:16 -0500 Subject: [PATCH] qapi: Tighten the regex on valid names We already documented that qapi names should match specific patterns (such as starting with a letter unless it was an enum value or a downstream extension). Tighten that from a suggestion into a hard requirement, which frees up names beginning with a single underscore for qapi internal usage. The tighter regex doesn't forbid everything insane that a user could provide (for example, a user could name a type 'Foo-lookup' to collide with the generated 'Foo_lookup[]' for an enum 'Foo'), but does a good job at protecting the most obvious uses, and also happens to reserve single leading underscore for later use. The handling of enum values starting with a digit is tricky: commit 9fb081e introduced a subtle bug by using c_name() on a munged value, which would allow an enum to include the member 'q-int' in spite of our reservation. Furthermore, munging with a leading '_' would fail our tighter regex. So fix it by only munging for leading digits (which are never ticklish in c_name()) and by using a different prefix (I picked 'D', although any letter should do). Add new tests, reserved-member-underscore and reserved-enum-q, to demonstrate the tighter checking. Backports commit 59a92feedc6927e0e1ff87fdaccfb4dd42ad4c84 from qemu --- qemu/scripts/qapi.py | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/qemu/scripts/qapi.py b/qemu/scripts/qapi.py index 4a26ec04..41c4b4f4 100644 --- a/qemu/scripts/qapi.py +++ b/qemu/scripts/qapi.py @@ -356,9 +356,13 @@ def discriminator_find_enum_define(expr): return find_enum(discriminator_type) -# FIXME should enforce "other than downstream extensions [...], all -# names should begin with a letter". -valid_name = re.compile('^[a-zA-Z_][a-zA-Z0-9_.-]*$') +# Names must be letters, numbers, -, and _. They must start with letter, +# except for downstream extensions which must start with __RFQDN_. +# Dots are only valid in the downstream extension prefix. +valid_name = re.compile('^(__[a-zA-Z0-9.-]+_)?' + '[a-zA-Z][a-zA-Z0-9_-]*$') + + def check_name(expr_info, source, name, allow_optional=False, enum_member=False): global valid_name @@ -375,8 +379,8 @@ def check_name(expr_info, source, name, allow_optional=False, % (source, name)) # Enum members can start with a digit, because the generated C # code always prefixes it with the enum name - if enum_member: - membername = '_' + membername + if enum_member and membername[0].isdigit(): + membername = 'D' + membername # Reserve the entire 'q_' namespace for c_name() if not valid_name.match(membername) or \ c_name(membername, False).startswith('q_'):