From b011f61931f0113b29b7cd7e921dd022e0b04834 Mon Sep 17 00:00:00 2001 From: Michael Roth Date: Wed, 1 Jun 2011 12:14:58 -0500 Subject: json-lexer: make lexer error-recovery more deterministic Currently when we reach an error state we effectively flush everything fed to the lexer, which can put us in a state where we keep feeding tokens into the parser at arbitrary offsets in the stream. This makes it difficult for the lexer/tokenizer/parser to get back in sync when bad input is made by the client. With these changes we emit an error state/token up to the tokenizer as soon as we reach an error state, and continue processing any data passed in rather than bailing out. The reset token will be used to reset the tokenizer and parser, such that they'll recover state as soon as the lexer begins generating valid token sequences again. We also map chr(192,193,245-255) to an error state here, since they are invalid UTF-8 characters. QMP guest proxy/agent will use chr(255) to force a flush/reset of previous input for reliable delivery of certain events, so also we document that thoroughly here. Signed-off-by: Michael Roth Signed-off-by: Anthony Liguori --- json-lexer.h | 1 + 1 file changed, 1 insertion(+) (limited to 'json-lexer.h') diff --git a/json-lexer.h b/json-lexer.h index 3b50c46..10bc0a7 100644 --- a/json-lexer.h +++ b/json-lexer.h @@ -25,6 +25,7 @@ typedef enum json_token_type { JSON_STRING, JSON_ESCAPE, JSON_SKIP, + JSON_ERROR, } JSONTokenType; typedef struct JSONLexer JSONLexer; -- cgit v1.1