mirror of https://github.com/mrkite/regs.git
118 lines
2.3 KiB
C++
118 lines
2.3 KiB
C++
/** @copyright 2020 Sean Kasun */
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#include "file.h"
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void File::skipWhitespace() {
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while (p < end && isspace(*p)) {
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if (*p == '\n') {
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curLine++;
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}
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p++;
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}
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}
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Token File::token() {
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skipWhitespace();
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prev = p;
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Token t;
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t.filename = name;
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t.curLine = curLine;
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if (p == end) {
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t.type = END;
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return t;
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}
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char ch = *p++;
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if (isalpha(ch) || ch == '_') {
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t.asStr += ch;
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while (p < end && (isalnum(*p) || *p == '_')) {
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t.asStr += *p++;
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}
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t.type = checkKeywords(t.asStr);
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return t;
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}
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if (isdigit(ch) || ch == '-') {
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bool isNeg = ch == '-';
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if (isdigit(ch)) {
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t.asNum = ch - '0';
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}
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while (p < end && isdigit(*p)) {
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t.asNum *= 10;
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t.asNum += *p++ - '0';
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}
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if (isNeg) {
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t.asNum = -t.asNum;
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}
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t.type = NUMBER;
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return t;
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}
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if (ch == '$') {
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while (p < end && isxdigit(*p)) {
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t.asNum <<= 4;
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if (isdigit(*p)) {
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t.asNum |= *p++ - '0';
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} else if (*p >= 'a' && *p <= 'f') {
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t.asNum |= *p++ - 'a' + 10;
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} else {
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t.asNum |= *p++ - 'A' + 10;
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}
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}
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t.type = NUMBER;
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return t;
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}
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t.type = SYMBOL;
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t.asSym = ch;
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return t;
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}
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void File::reset() {
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p = prev;
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}
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TokenType File::checkKeywords(std::string keyword) {
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if (keyword == "enum") {
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return ENUM;
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} else if (keyword == "struct") {
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return STRUCT;
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} else if (keyword == "union") {
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return UNION;
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}
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return VAR;
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}
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bool Token::expect(char ch) {
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if (type != SYMBOL) {
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fprintf(stderr, "Error: %s:%d: ", filename.c_str(), curLine);
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fprintf(stderr, "'%c' expected\n", ch);
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return false;
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}
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if (asSym != ch) {
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fprintf(stderr, "Error: %s:%d: ", filename.c_str(), curLine);
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fprintf(stderr, "'%c' expected, found '%c' instead.\n", ch, asSym);
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return false;
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}
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return true;
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}
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bool Token::expect(const char *str) {
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if (type == SYMBOL) {
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for (const char *s = str; *s; s++) {
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if (*s == asSym) {
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return true;
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}
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}
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}
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fprintf(stderr, "Error: %s:%d: ", filename.c_str(), curLine);
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bool comma = false;
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for (const char *s = str; *s; s++) {
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fprintf(stderr, "%s'%c'", comma ? " or " : "", *s);
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comma = true;
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}
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if (type == SYMBOL) {
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fprintf(stderr, " expected, found '%c' instead\n", asSym);
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} else {
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fprintf(stderr, " expected\n");
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}
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return false;
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}
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