[Qemu-devel] [PATCH v6 04/16] qapi: Drop useless 'data' member of unions

[Eric Blake <eblake@redhat.com>]

Now that we no longer have any clients of the 'void *data'
member injected into unions, we can drop it.  Update the
testsuite to drop the negative test union-clash-data, and
replace it with a positive test in qapi-schema-test that
proves that we no longer have a name collision.

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

---
v6: rebase to earlier changes
---
 scripts/qapi-types.py                   |  9 ---------
 tests/Makefile                          |  1 -
 tests/qapi-schema/qapi-schema-test.json |  2 +-
 tests/qapi-schema/qapi-schema-test.out  |  4 ++--
 tests/qapi-schema/union-clash-data.err  |  0
 tests/qapi-schema/union-clash-data.exit |  1 -
 tests/qapi-schema/union-clash-data.json |  7 -------
 tests/qapi-schema/union-clash-data.out  | 11 -----------
 8 files changed, 3 insertions(+), 32 deletions(-)
 delete mode 100644 tests/qapi-schema/union-clash-data.err
 delete mode 100644 tests/qapi-schema/union-clash-data.exit
 delete mode 100644 tests/qapi-schema/union-clash-data.json
 delete mode 100644 tests/qapi-schema/union-clash-data.out

diff --git a/scripts/qapi-types.py b/scripts/qapi-types.py
index 47a6523..8597942 100644
--- a/scripts/qapi-types.py
+++ b/scripts/qapi-types.py
@@ -99,17 +99,8 @@ static inline %(base)s *qapi_%(c_name)s_base(const %(c_name)s *obj)


 def gen_variants(variants):
-    # FIXME: What purpose does data serve, besides preventing a union that
-    # has a branch named 'data'? We use it in qapi-visit.py to decide
-    # whether to bypass the switch statement if visiting the discriminator
-    # failed; but since we 0-initialize structs, and cannot tell what
-    # branch of the union is in use if the discriminator is invalid, there
-    # should not be any data leaks even without a data pointer.  Or, if
-    # 'data' is merely added to guarantee we don't have an empty union,
-    # shouldn't we enforce that at .json parse time?
     ret = mcgen('''
     union { /* union tag is @%(c_name)s */
-        void *data;
 ''',
                 c_name=c_name(variants.tag_member.name))

diff --git a/tests/Makefile b/tests/Makefile
index b7352f1..84caf98 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -356,7 +356,6 @@ qapi-schema += unicode-str.json
 qapi-schema += union-base-no-discriminator.json
 qapi-schema += union-branch-case.json
 qapi-schema += union-clash-branches.json
-qapi-schema += union-clash-data.json
 qapi-schema += union-empty.json
 qapi-schema += union-invalid-base.json
 qapi-schema += union-optional-branch.json
diff --git a/tests/qapi-schema/qapi-schema-test.json b/tests/qapi-schema/qapi-schema-test.json
index a0fdb88..44c1965 100644
--- a/tests/qapi-schema/qapi-schema-test.json
+++ b/tests/qapi-schema/qapi-schema-test.json
@@ -112,7 +112,7 @@
             'number': ['number'],
             'boolean': ['bool'],
             'string': ['str'],
-            'sizes': ['size'],
+            'data': ['size'],
             'any': ['any'] } }

 # testing commands
diff --git a/tests/qapi-schema/qapi-schema-test.out b/tests/qapi-schema/qapi-schema-test.out
index a2a3c8b..e6088a5 100644
--- a/tests/qapi-schema/qapi-schema-test.out
+++ b/tests/qapi-schema/qapi-schema-test.out
@@ -171,9 +171,9 @@ object UserDefNativeListUnion
     case number: :obj-numberList-wrapper
     case boolean: :obj-boolList-wrapper
     case string: :obj-strList-wrapper
-    case sizes: :obj-sizeList-wrapper
+    case data: :obj-sizeList-wrapper
     case any: :obj-anyList-wrapper
-enum UserDefNativeListUnionKind ['integer', 's8', 's16', 's32', 's64', 'u8', 'u16', 'u32', 'u64', 'number', 'boolean', 'string', 'sizes', 'any']
+enum UserDefNativeListUnionKind ['integer', 's8', 's16', 's32', 's64', 'u8', 'u16', 'u32', 'u64', 'number', 'boolean', 'string', 'data', 'any']
 object UserDefOne
     base UserDefZero
     member string: str optional=False
diff --git a/tests/qapi-schema/union-clash-data.err b/tests/qapi-schema/union-clash-data.err
deleted file mode 100644
index e69de29..0000000
diff --git a/tests/qapi-schema/union-clash-data.exit b/tests/qapi-schema/union-clash-data.exit
deleted file mode 100644
index 573541a..0000000
--- a/tests/qapi-schema/union-clash-data.exit
+++ /dev/null
@@ -1 +0,0 @@
-0
diff --git a/tests/qapi-schema/union-clash-data.json b/tests/qapi-schema/union-clash-data.json
deleted file mode 100644
index 7308e69..0000000
--- a/tests/qapi-schema/union-clash-data.json
+++ /dev/null
@@ -1,7 +0,0 @@
-# Union branch 'data'
-# FIXME: this parses, but then fails to compile due to a duplicate 'data'
-# (one from the branch name, another as a filler to avoid an empty union).
-# we should either detect the collision at parse time, or change the
-# generated struct to allow this to compile.
-{ 'union': 'TestUnion',
-  'data': { 'data': 'int' } }
diff --git a/tests/qapi-schema/union-clash-data.out b/tests/qapi-schema/union-clash-data.out
deleted file mode 100644
index 19031a2..0000000
--- a/tests/qapi-schema/union-clash-data.out
+++ /dev/null
@@ -1,11 +0,0 @@
-object :empty
-object :obj-int-wrapper
-    base :empty
-    member data: int optional=False
-enum QType ['none', 'qnull', 'qint', 'qstring', 'qdict', 'qlist', 'qfloat', 'qbool']
-    prefix QTYPE
-object TestUnion
-    base :empty
-    member type: TestUnionKind optional=False
-    case data: :obj-int-wrapper
-enum TestUnionKind ['data']
-- 
2.4.3