discover/grub2: improve handling of word & delimiter tokens

Currently, the delimiter token handling is a little fragile: we try to
ignore non-inter-word delimiters in the lexer with a selective set of
regexes on the possible delimiter characters.

This means we don't need to handle potential delimiters in every grammar
rule, but there are other situations (not regex-able) where we may see
delimters, and this will cause a parse error.

Instead of relying on the regex behaviour, we have an 'inter_word' flag,
which is set when we see the first word token, and cleared when we see
an end-of-line token. We only emit TOKEN_DELIM when this flag is set.

This means that we only get the delim tokens when they're required -
when we're looking for word separators (becuase WORD DELIM WORD is
distinct from WORD WORD - eg "linux /vmlinux" and "x$var").

We add a few new tests for the "menuentry" and "if" syntax, with
different delimiter configurations.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/discover/grub2/grub2.h b/discover/grub2/grub2.h
index e79bf41..0a89324 100644
--- a/discover/grub2/grub2.h
+++ b/discover/grub2/grub2.h
@@ -103,6 +103,7 @@ struct grub2_script {
 struct grub2_parser {
 	void			*scanner;
 	struct grub2_script	*script;
+	bool			inter_word;
 };
 
 /* type for builtin functions */