qapi: Don't let implicit enum MAX member collide

Now that we guarantee the user doesn't have any enum values
beginning with a single underscore, we can use that for our
own purposes.  Renaming ENUM_MAX to ENUM__MAX makes it obvious
that the sentinel is generated.

This patch was mostly generated by applying a temporary patch:

|diff --git a/scripts/qapi.py b/scripts/qapi.py
|index e6d014b..b862ec9 100644
|--- a/scripts/qapi.py
|+++ b/scripts/qapi.py
|@@ -1570,6 +1570,7 @@ const char *const %(c_name)s_lookup[] = {
|     max_index = c_enum_const(name, 'MAX', prefix)
|     ret += mcgen('''
|     [%(max_index)s] = NULL,
|+// %(max_index)s
| };
| ''',
|                max_index=max_index)

then running:

$ cat qapi-{types,event}.c tests/test-qapi-types.c |
    sed -n 's,^// \(.*\)MAX,s|\1MAX|\1_MAX|g,p' > list
$ git grep -l _MAX | xargs sed -i -f list

The only things not generated are the changes in scripts/qapi.py.

Rejecting enum members named 'MAX' is now useless, and will be dropped
in the next patch.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447836791-369-23-git-send-email-eblake@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
[Rebased to current master, commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/ui/input-keymap.c b/ui/input-keymap.c
index d36be4b60d..63d71d2632 100644
--- a/ui/input-keymap.c
+++ b/ui/input-keymap.c
@@ -132,7 +132,7 @@ static const int qcode_to_number[] = {
     [Q_KEY_CODE_RO] = 0x73,
     [Q_KEY_CODE_KP_COMMA] = 0x7e,
 
-    [Q_KEY_CODE_MAX] = 0,
+    [Q_KEY_CODE__MAX] = 0,
 };
 
 static int number_to_qcode[0x100];
@@ -154,7 +154,7 @@ int qemu_input_key_number_to_qcode(uint8_t nr)
     if (first) {
         int qcode, number;
         first = false;
-        for (qcode = 0; qcode < Q_KEY_CODE_MAX; qcode++) {
+        for (qcode = 0; qcode < Q_KEY_CODE__MAX; qcode++) {
             number = qcode_to_number[qcode];
             assert(number < ARRAY_SIZE(number_to_qcode));
             number_to_qcode[number] = qcode;