ast, read_verilog: ownership in AST, use C++ styles for parser and lexer

frontends/verilog/verilog_lexer.h

@@ -0,0 +1,48 @@
+#ifndef VERILOG_LEXER_H
+#define VERILOG_LEXER_H
+
+#include "kernel/yosys.h"
+#include "frontends/ast/ast.h"
+#include "frontends/verilog/verilog_parser.tab.hh"
+
+YOSYS_NAMESPACE_BEGIN
+
+namespace VERILOG_FRONTEND {
+    // lexer input stream
+	using parser = frontend_verilog_yy::parser;
+	class VerilogLexer : public frontend_verilog_yyFlexLexer {
+		ParseState* extra;
+		ParseMode* mode;
+	public:
+		VerilogLexer(ParseState* e, ParseMode* m) : frontend_verilog_yyFlexLexer(e->lexin), extra(e), mode(m) {}
+		~VerilogLexer() override {}
+		// autogenerated body due to YY_DECL
+		parser::symbol_type nextToken();
+		// get rid of override virtual function warning
+		using FlexLexer::yylex;
+		parser::symbol_type terminate() {
+			return parser::make_FRONTEND_VERILOG_YYEOF(out_loc);
+		}
+		parser::location_type out_loc;
+		[[noreturn]]
+		void err(char const *fmt, ...)
+		{
+			va_list args;
+			va_start(args, fmt);
+			verr_at(AST::current_filename, yylineno, fmt, args);
+		}
+	private:
+		std::vector<std::string> fn_stack;
+		std::vector<int> ln_stack;
+		parser::location_type real_loc;
+		parser::location_type old_loc;
+		int LexerInput(char* buf, int max_size) override {
+			return readsome(*extra->lexin, buf, max_size);
+		}
+	};
+
+};
+
+YOSYS_NAMESPACE_END
+
+#endif