motiejus/zig
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implement string escapes

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This commit is contained in:
Andrew Kelley
2016-05-01 14:53:48 -07:00
parent 037283c3b3
commit 9ccd0ba961
4 changed files with 180 additions and 34 deletions
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76
src/parser.cpp
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@@ -219,7 +219,7 @@ static uint8_t parse_char_literal(ParseContext *pc, Token *token) {
return return_value;
}
static int get_hex_digit(uint8_t c) {
static uint32_t get_hex_digit(uint8_t c) {
switch (c) {
case '0': return 0;
case '1': return 1;
@@ -251,7 +251,7 @@ static int get_hex_digit(uint8_t c) {
case 'F':
return 15;
default:
return -1;
return UINT32_MAX;
}
}
@@ -279,13 +279,17 @@ static void parse_string_literal(ParseContext *pc, Token *token, Buf *buf, bool
StateEscape,
StateHex1,
StateHex2,
StateUnicode,
};
buf_resize(buf, 0);
int unicode_index;
int unicode_end;
State state = StatePre;
SrcPos pos = {token->start_line, token->start_column};
int hex_value = 0;
uint32_t hex_value = 0;
for (int i = token->start_pos; i < token->end_pos - 1; i += 1) {
uint8_t c = *((uint8_t*)buf_ptr(pc->buf) + i);
@@ -348,17 +352,34 @@ static void parse_string_literal(ParseContext *pc, Token *token, Buf *buf, bool
if (offset_map) offset_map->append(pos);
state = StateStart;
break;
case '\'':
buf_append_char(buf, '\'');
if (offset_map) offset_map->append(pos);
state = StateStart;
break;
case 'x':
state = StateHex1;
break;
case 'u':
state = StateUnicode;
unicode_index = 0;
unicode_end = 4;
hex_value = 0;
break;
case 'U':
state = StateUnicode;
unicode_index = 0;
unicode_end = 6;
hex_value = 0;
break;
default:
ast_error(pc, token, "invalid escape character");
}
break;
case StateHex1:
{
int hex_digit = get_hex_digit(c);
if (hex_digit == -1) {
uint32_t hex_digit = get_hex_digit(c);
if (hex_digit == UINT32_MAX) {
ast_error(pc, token, "invalid hex digit: '%c'", c);
}
hex_value = hex_digit * 16;
@@ -367,8 +388,8 @@ static void parse_string_literal(ParseContext *pc, Token *token, Buf *buf, bool
}
case StateHex2:
{
int hex_digit = get_hex_digit(c);
if (hex_digit == -1) {
uint32_t hex_digit = get_hex_digit(c);
if (hex_digit == UINT32_MAX) {
ast_error(pc, token, "invalid hex digit: '%c'", c);
}
hex_value += hex_digit;
@@ -377,6 +398,47 @@ static void parse_string_literal(ParseContext *pc, Token *token, Buf *buf, bool
state = StateStart;
break;
}
case StateUnicode:
{
uint32_t hex_digit = get_hex_digit(c);
if (hex_digit == UINT32_MAX) {
ast_error(pc, token, "invalid hex digit: '%c'", c);
}
hex_value *= 16;
hex_value += hex_digit;
unicode_index += 1;
if (unicode_index >= unicode_end) {
if (hex_value <= 0x7f) {
// 00000000 00000000 00000000 0xxxxxxx
buf_append_char(buf, hex_value);
} else if (hex_value <= 0x7ff) {
// 00000000 00000000 00000xxx xx000000
buf_append_char(buf, (unsigned char)(0xc0 | (hex_value >> 6)));
// 00000000 00000000 00000000 00xxxxxx
buf_append_char(buf, (unsigned char)(0x80 | (hex_value & 0x3f)));
} else if (hex_value <= 0xffff) {
// 00000000 00000000 xxxx0000 00000000
buf_append_char(buf, (unsigned char)(0xe0 | (hex_value >> 12)));
// 00000000 00000000 0000xxxx xx000000
buf_append_char(buf, (unsigned char)(0x80 | ((hex_value >> 6) & 0x3f)));
// 00000000 00000000 00000000 00xxxxxx
buf_append_char(buf, (unsigned char)(0x80 | (hex_value & 0x3f)));
} else if (hex_value <= 0x10ffff) {
// 00000000 000xxx00 00000000 00000000
buf_append_char(buf, (unsigned char)(0xf0 | (hex_value >> 18)));
// 00000000 000000xx xxxx0000 00000000
buf_append_char(buf, (unsigned char)(0x80 | ((hex_value >> 12) & 0x3f)));
// 00000000 00000000 0000xxxx xx000000
buf_append_char(buf, (unsigned char)(0x80 | ((hex_value >> 6) & 0x3f)));
// 00000000 00000000 00000000 00xxxxxx
buf_append_char(buf, (unsigned char)(0x80 | (hex_value & 0x3f)));
} else {
ast_error(pc, token, "unicode value out of range: %x", hex_value);
}
state = StateStart;
}
break;
}
}
if (c == '\n') {
pos.line += 1;