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From c4c2e01b3fa861de40f809785a0643d56e2b311e Mon Sep 17 00:00:00 2001
From: Markus Armbruster <armbru@redhat.com>
Date: Wed, 27 Jul 2016 07:35:03 +0200
Subject: [PATCH 05/16] qjson: Spell out some silent assumptions

RH-Author: Markus Armbruster <armbru@redhat.com>
Message-id: <1469604913-12442-7-git-send-email-armbru@redhat.com>
Patchwork-id: 71473
O-Subject: [RHEL-7.3 qemu-kvm PATCH v2 05/15] qjson: Spell out some silent assumptions
Bugzilla: 1276036
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
RH-Acked-by: John Snow <jsnow@redhat.com>
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1448486613-17634-5-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
(cherry picked from commit b8d3b1da3cdbb02e180618d6be346c564723015d)
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 include/qapi/qmp/json-lexer.h | 3 ++-
 qobject/json-lexer.c          | 7 ++++++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/include/qapi/qmp/json-lexer.h b/include/qapi/qmp/json-lexer.h
index cdff046..61a143f 100644
--- a/include/qapi/qmp/json-lexer.h
+++ b/include/qapi/qmp/json-lexer.h
@@ -18,7 +18,8 @@
 #include "qapi/qmp/qlist.h"
 
 typedef enum json_token_type {
-    JSON_OPERATOR = 100,
+    JSON_MIN = 100,
+    JSON_OPERATOR = JSON_MIN,
     JSON_INTEGER,
     JSON_FLOAT,
     JSON_KEYWORD,
diff --git a/qobject/json-lexer.c b/qobject/json-lexer.c
index 440df60..f106ffb 100644
--- a/qobject/json-lexer.c
+++ b/qobject/json-lexer.c
@@ -30,7 +30,7 @@
  */
 
 enum json_lexer_state {
-    IN_ERROR = 0,
+    IN_ERROR = 0,               /* must really be 0, see json_lexer[] */
     IN_DQ_UCODE3,
     IN_DQ_UCODE2,
     IN_DQ_UCODE1,
@@ -62,6 +62,8 @@ enum json_lexer_state {
     IN_START,
 };
 
+QEMU_BUILD_BUG_ON((int)JSON_MIN <= (int)IN_START);
+
 #define TERMINAL(state) [0 ... 0x7F] = (state)
 
 /* Return whether TERMINAL is a terminal state and the transition to it
@@ -71,6 +73,8 @@ enum json_lexer_state {
             (json_lexer[(old_state)][0] == (terminal))
 
 static const uint8_t json_lexer[][256] =  {
+    /* Relies on default initialization to IN_ERROR! */
+
     /* double quote string */
     [IN_DQ_UCODE3] = {
         ['0' ... '9'] = IN_DQ_STRING,
@@ -287,6 +291,7 @@ static int json_lexer_feed_char(JSONLexer *lexer, char ch, bool flush)
     }
 
     do {
+        assert(lexer->state <= ARRAY_SIZE(json_lexer));
         new_state = json_lexer[lexer->state][(uint8_t)ch];
         char_consumed = !TERMINAL_NEEDED_LOOKAHEAD(lexer->state, new_state);
         if (char_consumed) {
-- 
1.8.3.1