Lexer prints token to stdout when multi-line string is attempted to be used

[widlarizer]

Version

0.48

On which OS did this happen?

Linux

Reproduction Steps

read_verilog on this

(* attr="longlonglonglong\
longlonglongString" *)
module alu();
endmodule

Expected Behavior

Legible error about unsupported multi-line strings

Actual Behavior

1. Executing Verilog-2005 frontend: tests/sat/alu.v
Parsing Verilog input from `tests/sat/alu.v' to AST representation.
longlonglonglong\
Generating RTLIL representation for module `\alu'.
Successfully finished Verilog frontend.

and the attribute is silently dropped

[widlarizer]

Generated verilog_lexer.cc contains

case 188:
YY_RULE_SETUP
#line 600 "frontends/verilog/verilog_lexer.l"
ECHO;
	YY_BREAK

ECHO is a macro to /* Copy whatever the last rule matched to the standard output. */