sv_parser: return lexer character tokens as unsigned char - #9
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The sieve catch-all rule and the addr special-character rules used "return yytext[0]". That expression is not portable: its value depends on whether plain char is signed. Bison treats any yylex() result <= 0 as end-of-input. After a successful scan, flex can present a 0xff byte to the catch-all rule. On signed-char hosts (e.g. x86) that becomes -1 and is accepted as EOF; on unsigned-char hosts (RISC-V Linux, many ARM ABIs) it becomes token 255, the parse fails with a syntax error, and every non-trivial script is rejected. Cast the octet through unsigned char so the token is always in 0..255, and map 0xff to EOF so both kinds of ABI finish the token stream the same way. Apply the same cast to addr-lex special-character returns.
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The sieve catch-all rule and the addr special-character rules used "return yytext[0]". That expression is not portable: its value depends on whether plain char is signed.
Bison treats any yylex() result <= 0 as end-of-input. After a successful scan, flex can present a 0xff byte to the catch-all rule. On signed-char hosts (e.g. x86) that becomes -1 and is accepted as EOF; on unsigned-char hosts (RISC-V Linux, many ARM ABIs) it becomes token 255, the parse fails with a syntax error, and every non-trivial script is rejected.
Cast the octet through unsigned char so the token is always in 0..255, and map 0xff to EOF so both kinds of ABI finish the token stream the same way. Apply the same cast to addr-lex special-character returns.
Fixes #6