[Qemu-devel] [PATCH 1/4] qobject: Correct JSON lexer grammar comments

[Eric Blake]

Fix the regex comments describing what we parse as JSON.  No change
to the lexer itself, just to the comments:
- The "" and '' string construction was missing alternation between
different escape sequences
- The construction for numbers forgot to handle optional leading '-'
- The construction for numbers was grouped incorrectly so that it
didn't permit '0.1'
- The construction for numbers forgot to mark the exponent as optional
- No mention that our '' string and "\'" are JSON extensions
- No mention of our %d and related extensions when constructing JSON

Signed-off-by: Eric Blake <address@hidden>
---
 qobject/json-lexer.c | 21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/qobject/json-lexer.c b/qobject/json-lexer.c
index 496374d..ebd15d8 100644
--- a/qobject/json-lexer.c
+++ b/qobject/json-lexer.c
@@ -18,11 +18,22 @@
 #define MAX_TOKEN_SIZE (64ULL << 20)

 /*
- * 
\"([^\\\"]|(\\\"\\'\\\\\\/\\b\\f\\n\\r\\t\\u[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]))*\"
- * 
'([^\\']|(\\\"\\'\\\\\\/\\b\\f\\n\\r\\t\\u[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]))*'
- * 0|([1-9][0-9]*(.[0-9]+)?([eE]([-+])?[0-9]+))
+ * Required by JSON (RFC 7159), plus \' extension in "":
+ *
+ * \"([^\\\"]|(\\\"|\\'|\\\\|\\/|\\b|\\f|\\n|\\r|\\t|
+ *    \\u[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]))*\"
+ * -?(0|[1-9][0-9]*)(.[0-9]+)?([eE][-+]?[0-9]+)?
  * [{}\[\],:]
- * [a-z]+
+ * [a-z]+   # covers null, true, false
+ *
+ * Extension of '' strings:
+ *
+ * '([^\\']|(\\\"|\\'|\\\\|\\/|\\b|\\f|\\n|\\r|\\t|
+ *    \\u[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]))*'
+ *
+ * Extension for vararg handling in JSON construction:
+ *
+ * %((l|ll|I64)?d|[ipsf])
  *
  */

@@ -213,7 +224,7 @@ static const uint8_t json_lexer[][256] =  {
         ['\t'] = IN_WHITESPACE,
         ['\r'] = IN_WHITESPACE,
         ['\n'] = IN_WHITESPACE,
-    },        
+    },

     /* escape */
     [IN_ESCAPE_LL] = {
-- 
2.5.5