fixup! ast, read_verilog: unify location types, reduce filename copying

frontends/verilog/verilog_location.h

@@ -0,0 +1,96 @@
+#ifndef VERILOG_LOCATION_H
+#define VERILOG_LOCATION_H
+
+#include <memory>
+#include <string>
+#include <stack>
+#include <string>
+
+/**
+ * Provide frontend-wide location tracking like what bison generates
+ * but using shared_ptr for filename
+ */
+
+struct position {
+	std::shared_ptr<std::string> filename;
+	int line;
+	int column;
+
+	position(std::shared_ptr<std::string> filename, int line = 1, int column = 1)
+		: filename(filename), line(line), column(column) {}
+	position() = default;
+	position(const position& other) = default;
+	position& operator=(const position& other) = default;
+
+	void advance() { ++column; }
+	void columns(int count = 1) {
+		column += count;
+	}
+
+	void lines(int count = 1) {
+		line += count;
+		column = 1;
+	}
+	std::string to_string() const  {
+		std::ostringstream oss;
+		if (filename && !filename->empty()) {
+			oss << *filename << ":";
+		}
+		oss << line << ":" << column;
+		return oss.str();
+	}
+};
+
+struct location {
+	position begin;
+	position end;
+
+	location() = default;
+	location(const position& b, const position& e)
+		: begin(b), end(e) {}
+	location(const location& other) = default;
+	location& operator=(const location& other) = default;
+
+	void step() { begin = end; }
+
+	void columns(int count = 1) {
+		end.columns(count);
+	}
+
+	void lines(int count = 1) {
+		end.lines(count);
+	}
+	std::string to_string() const {
+		std::ostringstream oss;
+		bool same_file = (!begin.filename && !end.filename) ||
+						(begin.filename && end.filename &&
+						*begin.filename == *end.filename);
+
+		if (same_file) {
+			if (begin.filename && !begin.filename->empty())
+				oss << *begin.filename << ":";
+
+			if (begin.line == end.line) {
+				if (begin.column == end.column) {
+					oss << begin.line << ":" << begin.column;
+				} else {
+					oss << begin.line << ":" << begin.column
+						<< "-" << end.column;
+				}
+			} else {
+				oss << begin.line << ":" << begin.column
+					<< "-" << end.line << ":" << end.column;
+			}
+		} else {
+			oss << begin.to_string() << "-" << end.to_string();
+		}
+
+		return oss.str();
+	}
+};
+
+static inline std::ostream& operator<<(std::ostream& os, const location& loc) {
+	return os << loc.to_string();
+}
+
+#endif