qapi: Permit flat union members for any tag value

Flat union branch names match the tag enum's member names.  Omitted
branches default to "no members for this tag value".

Branch names starting with a digit get rejected like "'data' member
'0' has an invalid name".  However, omitting the branch works.

This is because flat union tag values get checked twice: as enum
member name, and as union branch name.  The former accepts leading
digits, the latter doesn't.

Branches whose names start with a digit therefore cannot have members.
Feels wrong.  Get rid of the restriction by skipping the latter check.

This can expose c_name() to input it can't handle: a name starting
with a digit.  Improve it to return a valid C identifier for any
input.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20210323094025.3569441-9-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[Commit message rewritten]
This commit is contained in:
Markus Armbruster 2021-03-23 10:40:05 +01:00
parent dbfe3c7c28
commit 5fbc78dd36
2 changed files with 7 additions and 5 deletions

View File

@ -18,7 +18,6 @@ from typing import Optional, Sequence
#: Magic string that gets removed along with all space to its right.
EATSPACE = '\033EATSPACE.'
POINTER_SUFFIX = ' *' + EATSPACE
_C_NAME_TRANS = str.maketrans('.-', '__')
def camel_to_upper(value: str) -> str:
@ -109,9 +108,10 @@ def c_name(name: str, protect: bool = True) -> str:
'not_eq', 'or', 'or_eq', 'xor', 'xor_eq'])
# namespace pollution:
polluted_words = set(['unix', 'errno', 'mips', 'sparc', 'i386'])
name = name.translate(_C_NAME_TRANS)
if protect and (name in c89_words | c99_words | c11_words | gcc_words
| cpp_words | polluted_words):
name = re.sub(r'[^A-Za-z0-9_]', '_', name)
if protect and (name in (c89_words | c99_words | c11_words | gcc_words
| cpp_words | polluted_words)
or name[0].isdigit()):
return 'q_' + name
return name

View File

@ -246,7 +246,9 @@ def check_union(expr, info):
for (key, value) in members.items():
source = "'data' member '%s'" % key
check_name_str(key, info, source)
if discriminator is None:
check_name_str(key, info, source)
# else: name is in discriminator enum, which gets checked
check_keys(value, info, source, ['type'], ['if'])
check_if(value, info, source)
check_type(value['type'], info, source, allow_array=not base)