Encapuslate UTF-8 decoder state in a struct

src/link/output.cpp

@@ -275,23 +275,24 @@ static void writeSymName(std::string const &name, FILE *file) {
 
 		// Output illegal characters using Unicode escapes ('\u' or '\U')
 		// Decode the UTF-8 codepoint; or at least attempt to
-		uint32_t state = UTF8_ACCEPT, codepoint;
+		Utf8Decoder decoder;
 		do {
-			decode(&state, &codepoint, *ptr);
-			if (state != UTF8_REJECT) {
+			if (decoder.update(*ptr) != UTF8_REJECT) {
 				++ptr;
 				continue;
 			}
 			// This sequence was invalid; emit a U+FFFD, and recover
-			codepoint = 0xFFFD;
+			decoder.codepoint = 0xFFFD;
 			// Skip continuation bytes
 			// A NUL byte does not qualify, so we're good
 			while ((*ptr & 0xC0) == 0x80) {
 				++ptr;
 			}
 			break;
-		} while (state != UTF8_ACCEPT);
-		fprintf(file, codepoint <= 0xFFFF ? "\\u%04" PRIx32 : "\\U%08" PRIx32, codepoint);
+		} while (decoder.state != UTF8_ACCEPT);
+		fprintf(
+		    file, decoder.codepoint <= 0xFFFF ? "\\u%04" PRIx32 : "\\U%08" PRIx32, decoder.codepoint
+		);
 	}
 }