[Qemu-devel] [PATCH v7 25/39] qapi: Require valid names

[Eric Blake <eblake@redhat.com>]

Previous commits demonstrated that the generator overlooked various
bad naming situations:
- types, commands, and events need a valid name
- enum members must be valid names, when combined with prefix
- union and alternate branches cannot be marked optional

Valid upstream names match [a-zA-Z][a-zA-Z0-9_-]*; valid downstream
names match __[a-zA-Z][a-zA-Z0-9._-]*.  Enumerations match the
weaker [a-zA-Z0-9._-]+ (in part thanks to QKeyCode picking an enum
that starts with a digit, which we can't change now due to
backwards compatibility).  Rather than call out three separate
regex, this patch just uses a broader combination that allows both
upstream and downstream names, as well as a small hack that
realizes that any enum name is merely a suffix to an already valid
name prefix (that is, any enum name is valid if prepending _ fits
the normal rules).

We could reject new enumeration names beginning with a digit by
whitelisting existing exceptions.  We could also be stricter
about the distinction between upstream names (no leading
underscore, no use of dot) and downstream (mandatory leading
double underscore), but it is probably not worth the bother.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>

---

v7: improve commit message
---
 scripts/qapi.py                                    | 63 ++++++++++++++++------
 tests/qapi-schema/bad-ident.err                    |  1 +
 tests/qapi-schema/bad-ident.exit                   |  2 +-
 tests/qapi-schema/bad-ident.json                   |  2 +-
 tests/qapi-schema/bad-ident.out                    |  3 --
 tests/qapi-schema/enum-bad-name.err                |  1 +
 tests/qapi-schema/enum-bad-name.exit               |  2 +-
 tests/qapi-schema/enum-bad-name.json               |  2 +-
 tests/qapi-schema/enum-bad-name.out                |  3 --
 tests/qapi-schema/enum-dict-member.err             |  2 +-
 tests/qapi-schema/flat-union-bad-discriminator.err |  2 +-
 .../flat-union-optional-discriminator.err          |  1 +
 .../flat-union-optional-discriminator.exit         |  2 +-
 .../flat-union-optional-discriminator.json         |  2 +-
 .../flat-union-optional-discriminator.out          |  7 ---
 tests/qapi-schema/union-optional-branch.err        |  1 +
 tests/qapi-schema/union-optional-branch.exit       |  2 +-
 tests/qapi-schema/union-optional-branch.json       |  2 +-
 tests/qapi-schema/union-optional-branch.out        |  3 --
 19 files changed, 60 insertions(+), 43 deletions(-)

diff --git a/scripts/qapi.py b/scripts/qapi.py
index 61e1c43..c6ab8f3 100644
--- a/scripts/qapi.py
+++ b/scripts/qapi.py
@@ -276,8 +276,31 @@ def discriminator_find_enum_define(expr):

     return find_enum(discriminator_type)

+valid_name = re.compile('^[a-zA-Z_][a-zA-Z0-9_.-]*$')
+def check_name(expr_info, source, name, allow_optional = False,
+               enum_member = False):
+    global valid_name
+    membername = name
+
+    if not isinstance(name, str):
+        raise QAPIExprError(expr_info,
+                            "%s requires a string name" % source)
+    if name.startswith('*'):
+        membername = name[1:]
+        if not allow_optional:
+            raise QAPIExprError(expr_info,
+                                "%s does not allow optional name '%s'"
+                                % (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 = "_%s" %membername
+    if not valid_name.match(membername):
+        raise QAPIExprError(expr_info,
+                            "%s uses invalid name '%s'" % (source, name))
+
 def check_type(expr_info, source, value, allow_array = False,
-               allow_dict = False, allow_metas = []):
+               allow_dict = False, allow_optional = False, allow_metas = []):
     global all_names
     orig_value = value

@@ -319,18 +342,21 @@ def check_type(expr_info, source, value, allow_array = False,
         raise QAPIExprError(expr_info,
                             "%s should be a type name" % source)
     for (key, arg) in value.items():
+        check_name(expr_info, "Member of %s" % source, key,
+                   allow_optional=allow_optional)
         check_type(expr_info, "Member '%s' of %s" % (key, source), arg,
-                   allow_array=True, allow_dict=True,
+                   allow_array=True, allow_dict=True, allow_optional=True,
                    allow_metas=['built-in', 'union', 'alternate', 'struct',
                                 'enum'])

 def check_command(expr, expr_info):
     name = expr['command']
     check_type(expr_info, "'data' for command '%s'" % name,
-               expr.get('data'), allow_dict=True,
+               expr.get('data'), allow_dict=True, allow_optional=True,
                allow_metas=['union', 'struct'])
     check_type(expr_info, "'returns' for command '%s'" % name,
                expr.get('returns'), allow_array=True, allow_dict=True,
+               allow_optional=True,
                allow_metas=['built-in', 'union', 'alternate', 'struct',
                             'enum'])

@@ -343,7 +369,7 @@ def check_event(expr, expr_info):
         raise QAPIExprError(expr_info, "Event name 'MAX' cannot be created")
     events.append(name)
     check_type(expr_info, "'data' for event '%s'" % name,
-               expr.get('data'), allow_dict=True,
+               expr.get('data'), allow_dict=True, allow_optional=True,
                allow_metas=['union', 'struct'])
     if params:
         for argname, argentry, optional, structured in parse_args(params):
@@ -392,12 +418,10 @@ def check_union(expr, expr_info):
                                 "Base '%s' is not a valid type"
                                 % base)

-        # The value of member 'discriminator' must name a member of the
-        # base type.
-        if not isinstance(discriminator, str):
-            raise QAPIExprError(expr_info,
-                                "Flat union '%s' discriminator must be a string"
-                                % name)
+        # The value of member 'discriminator' must name a non-optional
+        # member of the base type.
+        check_name(expr_info, "Discriminator of flat union '%s'" % name,
+                   discriminator)
         discriminator_type = base_fields.get(discriminator)
         if not discriminator_type:
             raise QAPIExprError(expr_info,
@@ -414,6 +438,8 @@ def check_union(expr, expr_info):

     # Check every branch
     for (key, value) in members.items():
+        check_name(expr_info, "Member of union '%s'" % name, key)
+
         # Each value must name a known type; furthermore, in flat unions,
         # branches must be a struct
         check_type(expr_info, "Member '%s' of union '%s'" % (key, name),
@@ -445,6 +471,8 @@ def check_alternate(expr, expr_info):

     # Check every branch
     for (key, value) in members.items():
+        check_name(expr_info, "Member of alternate '%s'" % name, key)
+
         # Check for conflicts in the generated enum
         c_key = _generate_enum_string(key)
         if c_key in values:
@@ -475,10 +503,8 @@ def check_enum(expr, expr_info):
         raise QAPIExprError(expr_info,
                             "Enum '%s' requires an array for 'data'" % name)
     for member in members:
-        if not isinstance(member, str):
-            raise QAPIExprError(expr_info,
-                                "Enum '%s' member '%s' is not a string"
-                                % (name, member))
+        check_name(expr_info, "Member of enum '%s'" %name, member,
+                   enum_member=True)
         key = _generate_enum_string(member)
         if key in values:
             raise QAPIExprError(expr_info,
@@ -491,7 +517,7 @@ def check_struct(expr, expr_info):
     members = expr['data']

     check_type(expr_info, "'data' for type '%s'" % name, members,
-               allow_dict=True)
+               allow_dict=True, allow_optional=True)
     check_type(expr_info, "'base' for type '%s'" % name, expr.get('base'),
                allow_metas=['struct'])

@@ -682,8 +708,11 @@ def type_name(name):
         return c_list_type(name[0])
     return name

-def add_name(name, info, meta, implicit = False):
+def add_name(name, info, meta, implicit = False, source = None):
     global all_names
+    if not source:
+        source = "'%s'" % meta
+    check_name(info, source, name)
     if name in all_names:
         raise QAPIExprError(info,
                             "%s '%s' is already defined"
@@ -697,7 +726,7 @@ def add_name(name, info, meta, implicit = False):
 def add_struct(definition, info):
     global struct_types
     name = definition['type']
-    add_name(name, info, 'struct')
+    add_name(name, info, 'struct', source="'type'")
     struct_types.append(definition)

 def find_struct(name):
diff --git a/tests/qapi-schema/bad-ident.err b/tests/qapi-schema/bad-ident.err
index e69de29..42b490c 100644
--- a/tests/qapi-schema/bad-ident.err
+++ b/tests/qapi-schema/bad-ident.err
@@ -0,0 +1 @@
+tests/qapi-schema/bad-ident.json:2: 'type' does not allow optional name '*oops'
diff --git a/tests/qapi-schema/bad-ident.exit b/tests/qapi-schema/bad-ident.exit
index 573541a..d00491f 100644
--- a/tests/qapi-schema/bad-ident.exit
+++ b/tests/qapi-schema/bad-ident.exit
@@ -1 +1 @@
-0
+1
diff --git a/tests/qapi-schema/bad-ident.json b/tests/qapi-schema/bad-ident.json
index f139110..da949e8 100644
--- a/tests/qapi-schema/bad-ident.json
+++ b/tests/qapi-schema/bad-ident.json
@@ -1,2 +1,2 @@
-# FIXME: we should reject creating a type name with bad name
+# we reject creating a type name with bad name
 { 'type': '*oops', 'data': { 'i': 'int' } }
diff --git a/tests/qapi-schema/bad-ident.out b/tests/qapi-schema/bad-ident.out
index 165e346..e69de29 100644
--- a/tests/qapi-schema/bad-ident.out
+++ b/tests/qapi-schema/bad-ident.out
@@ -1,3 +0,0 @@
-[OrderedDict([('type', '*oops'), ('data', OrderedDict([('i', 'int')]))])]
-[]
-[OrderedDict([('type', '*oops'), ('data', OrderedDict([('i', 'int')]))])]
diff --git a/tests/qapi-schema/enum-bad-name.err b/tests/qapi-schema/enum-bad-name.err
index e69de29..9c3c100 100644
--- a/tests/qapi-schema/enum-bad-name.err
+++ b/tests/qapi-schema/enum-bad-name.err
@@ -0,0 +1 @@
+tests/qapi-schema/enum-bad-name.json:2: Member of enum 'MyEnum' uses invalid name 'not^possible'
diff --git a/tests/qapi-schema/enum-bad-name.exit b/tests/qapi-schema/enum-bad-name.exit
index 573541a..d00491f 100644
--- a/tests/qapi-schema/enum-bad-name.exit
+++ b/tests/qapi-schema/enum-bad-name.exit
@@ -1 +1 @@
-0
+1
diff --git a/tests/qapi-schema/enum-bad-name.json b/tests/qapi-schema/enum-bad-name.json
index 0c32448..8506562 100644
--- a/tests/qapi-schema/enum-bad-name.json
+++ b/tests/qapi-schema/enum-bad-name.json
@@ -1,2 +1,2 @@
-# FIXME: we should ensure all enum names can map to C
+# we ensure all enum names can map to C
 { 'enum': 'MyEnum', 'data': [ 'not^possible' ] }
diff --git a/tests/qapi-schema/enum-bad-name.out b/tests/qapi-schema/enum-bad-name.out
index d24ea49..e69de29 100644
--- a/tests/qapi-schema/enum-bad-name.out
+++ b/tests/qapi-schema/enum-bad-name.out
@@ -1,3 +0,0 @@
-[OrderedDict([('enum', 'MyEnum'), ('data', ['not^possible'])])]
-[{'enum_name': 'MyEnum', 'enum_values': ['not^possible']}]
-[]
diff --git a/tests/qapi-schema/enum-dict-member.err b/tests/qapi-schema/enum-dict-member.err
index 7e966a8..8ca146e 100644
--- a/tests/qapi-schema/enum-dict-member.err
+++ b/tests/qapi-schema/enum-dict-member.err
@@ -1 +1 @@
-tests/qapi-schema/enum-dict-member.json:2: Enum 'MyEnum' member 'OrderedDict([('value', 'str')])' is not a string
+tests/qapi-schema/enum-dict-member.json:2: Member of enum 'MyEnum' requires a string name
diff --git a/tests/qapi-schema/flat-union-bad-discriminator.err b/tests/qapi-schema/flat-union-bad-discriminator.err
index 507e2ba..c38cc8e 100644
--- a/tests/qapi-schema/flat-union-bad-discriminator.err
+++ b/tests/qapi-schema/flat-union-bad-discriminator.err
@@ -1 +1 @@
-tests/qapi-schema/flat-union-bad-discriminator.json:11: Flat union 'TestUnion' discriminator must be a string
+tests/qapi-schema/flat-union-bad-discriminator.json:11: Discriminator of flat union 'TestUnion' requires a string name
diff --git a/tests/qapi-schema/flat-union-optional-discriminator.err b/tests/qapi-schema/flat-union-optional-discriminator.err
index e69de29..aaabedb 100644
--- a/tests/qapi-schema/flat-union-optional-discriminator.err
+++ b/tests/qapi-schema/flat-union-optional-discriminator.err
@@ -0,0 +1 @@
+tests/qapi-schema/flat-union-optional-discriminator.json:6: Discriminator of flat union 'MyUnion' does not allow optional name '*switch'
diff --git a/tests/qapi-schema/flat-union-optional-discriminator.exit b/tests/qapi-schema/flat-union-optional-discriminator.exit
index 573541a..d00491f 100644
--- a/tests/qapi-schema/flat-union-optional-discriminator.exit
+++ b/tests/qapi-schema/flat-union-optional-discriminator.exit
@@ -1 +1 @@
-0
+1
diff --git a/tests/qapi-schema/flat-union-optional-discriminator.json b/tests/qapi-schema/flat-union-optional-discriminator.json
index ece0d31..25ce0e6 100644
--- a/tests/qapi-schema/flat-union-optional-discriminator.json
+++ b/tests/qapi-schema/flat-union-optional-discriminator.json
@@ -1,4 +1,4 @@
-# FIXME: we should require the discriminator to be non-optional
+# we require the discriminator to be non-optional
 { 'enum': 'Enum', 'data': [ 'one', 'two' ] }
 { 'type': 'Base',
   'data': { '*switch': 'Enum' } }
diff --git a/tests/qapi-schema/flat-union-optional-discriminator.out b/tests/qapi-schema/flat-union-optional-discriminator.out
index bb7db00..e69de29 100644
--- a/tests/qapi-schema/flat-union-optional-discriminator.out
+++ b/tests/qapi-schema/flat-union-optional-discriminator.out
@@ -1,7 +0,0 @@
-[OrderedDict([('enum', 'Enum'), ('data', ['one', 'two'])]),
- OrderedDict([('type', 'Base'), ('data', OrderedDict([('*switch', 'Enum')]))]),
- OrderedDict([('type', 'Branch'), ('data', OrderedDict([('name', 'str')]))]),
- OrderedDict([('union', 'MyUnion'), ('base', 'Base'), ('discriminator', '*switch'), ('data', OrderedDict([('one', 'Branch'), ('two', 'Branch')]))])]
-[{'enum_name': 'Enum', 'enum_values': ['one', 'two']}]
-[OrderedDict([('type', 'Base'), ('data', OrderedDict([('*switch', 'Enum')]))]),
- OrderedDict([('type', 'Branch'), ('data', OrderedDict([('name', 'str')]))])]
diff --git a/tests/qapi-schema/union-optional-branch.err b/tests/qapi-schema/union-optional-branch.err
index e69de29..3ada133 100644
--- a/tests/qapi-schema/union-optional-branch.err
+++ b/tests/qapi-schema/union-optional-branch.err
@@ -0,0 +1 @@
+tests/qapi-schema/union-optional-branch.json:2: Member of union 'Union' does not allow optional name '*a'
diff --git a/tests/qapi-schema/union-optional-branch.exit b/tests/qapi-schema/union-optional-branch.exit
index 573541a..d00491f 100644
--- a/tests/qapi-schema/union-optional-branch.exit
+++ b/tests/qapi-schema/union-optional-branch.exit
@@ -1 +1 @@
-0
+1
diff --git a/tests/qapi-schema/union-optional-branch.json b/tests/qapi-schema/union-optional-branch.json
index c513db7..591615f 100644
--- a/tests/qapi-schema/union-optional-branch.json
+++ b/tests/qapi-schema/union-optional-branch.json
@@ -1,2 +1,2 @@
-# FIXME: union branches cannot be optional
+# union branches cannot be optional
 { 'union': 'Union', 'data': { '*a': 'int', 'b': 'str' } }
diff --git a/tests/qapi-schema/union-optional-branch.out b/tests/qapi-schema/union-optional-branch.out
index b03b5d2..e69de29 100644
--- a/tests/qapi-schema/union-optional-branch.out
+++ b/tests/qapi-schema/union-optional-branch.out
@@ -1,3 +0,0 @@
-[OrderedDict([('union', 'Union'), ('data', OrderedDict([('*a', 'int'), ('b', 'str')]))])]
-[{'enum_name': 'UnionKind', 'enum_values': None}]
-[]
-- 
2.1.0