qapi: Tighten the regex on valid names

We already documented that qapi names should match specific
patterns (such as starting with a letter unless it was an enum
value or a downstream extension).  Tighten that from a suggestion
into a hard requirement, which frees up names beginning with a
single underscore for qapi internal usage.

The tighter regex doesn't forbid everything insane that a user
could provide (for example, a user could name a type 'Foo-lookup'
to collide with the generated 'Foo_lookup[]' for an enum 'Foo'),
but does a good job at protecting the most obvious uses, and
also happens to reserve single leading underscore for later use.

The handling of enum values starting with a digit is tricky:
commit 9fb081e introduced a subtle bug by using c_name() on
a munged value, which would allow an enum to include the
member 'q-int' in spite of our reservation.  Furthermore,
munging with a leading '_' would fail our tighter regex.  So
fix it by only munging for leading digits (which are never
ticklish in c_name()) and by using a different prefix (I
picked 'D', although any letter should do).

Add new tests, reserved-member-underscore and reserved-enum-q,
to demonstrate the tighter checking.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447836791-369-22-git-send-email-eblake@redhat.com>
Message-Id: <1447883135-18020-1-git-send-email-eblake@redhat.com>
[Eric's fixup squashed in]
Signed-off-by: Markus Armbruster <armbru@redhat.com>

8 files changed, 12 insertions, 0 deletions

diff --git a/tests/qapi-schema/reserved-enum-q.err b/tests/qapi-schema/reserved-enum-q.err
new file mode 100644
index 0000000000..e1c3480ee2
--- /dev/null
+++ b/tests/qapi-schema/reserved-enum-q.err
@@ -0,0 +1 @@
+tests/qapi-schema/reserved-enum-q.json:4: Member of enum 'Foo' uses invalid name 'q-Unix'
diff --git a/tests/qapi-schema/reserved-enum-q.exit b/tests/qapi-schema/reserved-enum-q.exit
new file mode 100644
index 0000000000..d00491fd7e
--- /dev/null
+++ b/tests/qapi-schema/reserved-enum-q.exit
@@ -0,0 +1 @@
+1
diff --git a/tests/qapi-schema/reserved-enum-q.json b/tests/qapi-schema/reserved-enum-q.json
new file mode 100644
index 0000000000..3593a765ea
--- /dev/null
+++ b/tests/qapi-schema/reserved-enum-q.json
@@ -0,0 +1,4 @@
+# C entity name collision
+# We reject names like 'q-unix', because they can collide with the mangled
+# name for 'unix' in generated C.
+{ 'enum': 'Foo', 'data': [ 'unix', 'q-Unix' ] }
diff --git a/tests/qapi-schema/reserved-enum-q.out b/tests/qapi-schema/reserved-enum-q.out
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/tests/qapi-schema/reserved-enum-q.out
diff --git a/tests/qapi-schema/reserved-member-underscore.err b/tests/qapi-schema/reserved-member-underscore.err
new file mode 100644
index 0000000000..65ff0da8ce
--- /dev/null
+++ b/tests/qapi-schema/reserved-member-underscore.err
@@ -0,0 +1 @@
+tests/qapi-schema/reserved-member-underscore.json:4: Member of 'data' for struct 'Oops' uses invalid name '_oops'
diff --git a/tests/qapi-schema/reserved-member-underscore.exit b/tests/qapi-schema/reserved-member-underscore.exit
new file mode 100644
index 0000000000..d00491fd7e
--- /dev/null
+++ b/tests/qapi-schema/reserved-member-underscore.exit
@@ -0,0 +1 @@
+1
diff --git a/tests/qapi-schema/reserved-member-underscore.json b/tests/qapi-schema/reserved-member-underscore.json
new file mode 100644
index 0000000000..4a3a017638
--- /dev/null
+++ b/tests/qapi-schema/reserved-member-underscore.json
@@ -0,0 +1,4 @@
+# C member name collision
+# We reject use of a single leading underscore in all names (names must
+# begin with a letter or a downstream extension double-underscore prefix).
+{ 'struct': 'Oops', 'data': { '_oops': 'str' } }
diff --git a/tests/qapi-schema/reserved-member-underscore.out b/tests/qapi-schema/reserved-member-underscore.out
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/tests/qapi-schema/reserved-member-underscore.out