Error while using Unicode characters adjacent to braces.

[SouravKB]

When I write an unicode character directly adjacent to opening brace in lex file, it fails, saying '{' mismatched.

Minimal reproducible example:

%o main unicode
x .
%%
§{x} echo();
%%

Compilation output:

test.ll:4: error: malformed regular expression or unsupported syntax
error at position 4
§{x}
   \___mismatched { }

But the regex pattern itself isn't malformed. §+{x}, §""{x}, [§]{x} compiles perfectly fine. I have tried putting various non-ascii unicode characters. All gives same error.

[genivia-inc]

This works for me with freespace, which permits spacing in regex patterns (but actions must be placed in curly braces):

%o main unicode freespace
x x
%%
§ {x} { echo(); }
%%

I think the problem may have something to do with the macro expansion logic with unicode. Will check it further.