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]

diff --git a/scripts/qapi/common.py b/scripts/qapi/common.py
index 11b86beeabe6337ef2e35e78d1a1ac7363175651..cbd3fd81d36408d9786ff729f50b7966654f9580 100644 (file)
--- a/scripts/qapi/common.py
+++ b/scripts/qapi/common.py
@@ -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
 

diff --git a/scripts/qapi/expr.py b/scripts/qapi/expr.py
index cf09fa9fd3b8e8965e0d46495852d9758415b570..507550c3405ae2f9334bc3b496d4d7fa49f4dc66 100644 (file)
--- a/scripts/qapi/expr.py
+++ b/scripts/qapi/expr.py
@@ -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)