[Qemu-devel] [PATCH v11 26/28] qapi: Move duplicate member checks to schema check()

[Eric Blake <eblake@redhat.com>]

With the previous commit, we have two different locations for
detecting member name clashes - one at parse time, and another
at QAPISchema*.check() time.  Consolidate some of the checks
into a single place, which is also in line with our TODO to
eventually move all of the parse time semantic checking into
the newer schema code.  The check_member_clash() function is
no longer needed.

The wording of several error messages has changed, but in many
cases feels like an improvement rather than a regression.  The
recent change (commit 7b2a5c2) to avoid an assertion failure
when a flat union branch name collides with its discriminator
name is also handled nicely by this code; but there is more work
needed before we can detect all collisions in the generated enum
associated with simple union branch names.

No change to generated code.

Signed-off-by: Eric Blake <eblake@redhat.com>

---
v11 (no v10): no change
v9: simplify on top of earlier check() improvements
v8: decide whether to inline members based on union vs. alternate,
not on flat vs. simple, and fix logic to avoid breaking
union-clash-data in the process; add comments; assumes
pull-qapi-2015-10-12 will go in without modifying commit ids
v7: comment improvements, retitle subject
v6: rebase to earlier testsuite improvements, fold in cleanup
of flat-union-clash-type
---
 scripts/qapi.py                               | 34 +--------------------------
 tests/qapi-schema/alternate-clash.err         |  2 +-
 tests/qapi-schema/flat-union-clash-member.err |  2 +-
 tests/qapi-schema/struct-base-clash-deep.err  |  2 +-
 tests/qapi-schema/struct-base-clash.err       |  2 +-
 5 files changed, 5 insertions(+), 37 deletions(-)

diff --git a/scripts/qapi.py b/scripts/qapi.py
index b17f843..1d59ce9 100644
--- a/scripts/qapi.py
+++ b/scripts/qapi.py
@@ -502,21 +502,6 @@ def check_type(expr_info, source, value, allow_array=False,
                                 'enum'])


-def check_member_clash(expr_info, base_name, data, source=""):
-    base = find_struct(base_name)
-    assert base
-    base_members = base['data']
-    for key in data.keys():
-        if key.startswith('*'):
-            key = key[1:]
-        if key in base_members or "*" + key in base_members:
-            raise QAPIExprError(expr_info,
-                                "Member name '%s'%s clashes with base '%s'"
-                                % (key, source, base_name))
-    if base.get('base'):
-        check_member_clash(expr_info, base['base'], data, source)
-
-
 def check_command(expr, expr_info):
     name = expr['command']

@@ -595,15 +580,9 @@ def check_union(expr, expr_info):
     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 with no overlapping member names
+        # Each value must name a known type
         check_type(expr_info, "Member '%s' of union '%s'" % (key, name),
                    value, allow_array=not base, allow_metas=allow_metas)
-        if base:
-            branch_struct = find_struct(value)
-            assert branch_struct
-            check_member_clash(expr_info, base, branch_struct['data'],
-                               " of branch '%s'" % key)

         # If the discriminator names an enum type, then all members
         # of 'data' must also be members of the enum type.
@@ -627,21 +606,12 @@ def check_union(expr, expr_info):
 def check_alternate(expr, expr_info):
     name = expr['alternate']
     members = expr['data']
-    values = {}
     types_seen = {}

     # Check every branch
     for (key, value) in members.items():
         check_name(expr_info, "Member of alternate '%s'" % name, key)

-        # Check for conflicts in the branch names
-        c_key = c_name(key)
-        if c_key in values:
-            raise QAPIExprError(expr_info,
-                                "Alternate '%s' member '%s' clashes with '%s'"
-                                % (name, key, values[c_key]))
-        values[c_key] = key
-
         # Ensure alternates have no type conflicts.
         check_type(expr_info, "Member '%s' of alternate '%s'" % (key, name),
                    value,
@@ -687,8 +657,6 @@ def check_struct(expr, expr_info):
                allow_dict=True, allow_optional=True)
     check_type(expr_info, "'base' for struct '%s'" % name, expr.get('base'),
                allow_metas=['struct'])
-    if expr.get('base'):
-        check_member_clash(expr_info, expr['base'], expr['data'])


 def check_keys(expr_elem, meta, required, optional=[]):
diff --git a/tests/qapi-schema/alternate-clash.err b/tests/qapi-schema/alternate-clash.err
index a475ab6..604d849 100644
--- a/tests/qapi-schema/alternate-clash.err
+++ b/tests/qapi-schema/alternate-clash.err
@@ -1 +1 @@
-tests/qapi-schema/alternate-clash.json:7: Alternate 'Alt1' member 'a_b' clashes with 'a-b'
+tests/qapi-schema/alternate-clash.json:7: 'a_b' (branch of Alt1) collides with 'a-b' (branch of Alt1)
diff --git a/tests/qapi-schema/flat-union-clash-member.err b/tests/qapi-schema/flat-union-clash-member.err
index 2f0397a..2adf697 100644
--- a/tests/qapi-schema/flat-union-clash-member.err
+++ b/tests/qapi-schema/flat-union-clash-member.err
@@ -1 +1 @@
-tests/qapi-schema/flat-union-clash-member.json:11: Member name 'name' of branch 'value1' clashes with base 'Base'
+tests/qapi-schema/flat-union-clash-member.json:11: 'name' (member of Branch1) collides with 'name' (member of Base)
diff --git a/tests/qapi-schema/struct-base-clash-deep.err b/tests/qapi-schema/struct-base-clash-deep.err
index f7a25a3..e2d7943 100644
--- a/tests/qapi-schema/struct-base-clash-deep.err
+++ b/tests/qapi-schema/struct-base-clash-deep.err
@@ -1 +1 @@
-tests/qapi-schema/struct-base-clash-deep.json:10: Member name 'name' clashes with base 'Base'
+tests/qapi-schema/struct-base-clash-deep.json:10: 'name' (member of Sub) collides with 'name' (member of Base)
diff --git a/tests/qapi-schema/struct-base-clash.err b/tests/qapi-schema/struct-base-clash.err
index 3a9f66b..c52f33d 100644
--- a/tests/qapi-schema/struct-base-clash.err
+++ b/tests/qapi-schema/struct-base-clash.err
@@ -1 +1 @@
-tests/qapi-schema/struct-base-clash.json:5: Member name 'name' clashes with base 'Base'
+tests/qapi-schema/struct-base-clash.json:5: 'name' (member of Sub) collides with 'name' (member of Base)
-- 
2.4.3