[ruby/prism] GB18030 encoding

https://github.com/ruby/prism/commit/ca3ab7ec89

3 files changed, 47 insertions, 0 deletions

diff --git a/prism/enc/pm_big5.c b/prism/enc/pm_big5.c
index 948cfc4b11..e39ae63629 100644
--- a/prism/enc/pm_big5.c
+++ b/prism/enc/pm_big5.c
@@ -167,3 +167,48 @@ pm_encoding_t pm_encoding_stateless_iso_2022_jp_kddi = {
     .isupper_char = pm_encoding_emacs_mule_isupper_char,
     .multibyte = true
 };
+
+static size_t
+pm_encoding_gb18030_char_width(const uint8_t *b, ptrdiff_t n) {
+    // These are the 1 byte characters.
+    if (*b < 0x80) {
+        return 1;
+    }
+
+    // These are the 2 byte characters.
+    if ((n > 1) && (b[0] >= 0x81 && b[0] <= 0xFE) && (b[1] >= 0x40 && b[1] <= 0xFE && b[1] != 0x7F)) {
+        return 2;
+    }
+
+    // These are the 4 byte characters.
+    if ((n > 3) && ((b[0] >= 0x81 && b[0] <= 0xFE) && (b[1] >= 0x30 && b[1] <= 0x39) && (b[2] >= 0x81 && b[2] <= 0xFE) && (b[3] >= 0x30 && b[3] <= 0x39))) {
+        return 4;
+    }
+
+    return 0;
+}
+
+static size_t
+pm_encoding_gb18030_alpha_char(const uint8_t *b, ptrdiff_t n) {
+    return (pm_encoding_gb18030_char_width(b, n) == 1) ? pm_encoding_ascii_alpha_char(b, n) : 0;
+}
+
+static size_t
+pm_encoding_gb18030_alnum_char(const uint8_t *b, ptrdiff_t n) {
+    return (pm_encoding_gb18030_char_width(b, n) == 1) ? pm_encoding_ascii_alnum_char(b, n) : 0;
+}
+
+static bool
+pm_encoding_gb18030_isupper_char(const uint8_t *b, ptrdiff_t n) {
+    return (pm_encoding_gb18030_char_width(b, n) == 1) && pm_encoding_ascii_isupper_char(b, n);
+}
+
+/** GB18030 encoding */
+pm_encoding_t pm_encoding_gb18030 = {
+    .name = "GB18030",
+    .char_width = pm_encoding_gb18030_char_width,
+    .alnum_char = pm_encoding_gb18030_alnum_char,
+    .alpha_char = pm_encoding_gb18030_alpha_char,
+    .isupper_char = pm_encoding_gb18030_isupper_char,
+    .multibyte = true
+};
diff --git a/prism/enc/pm_encoding.h b/prism/enc/pm_encoding.h
index e14d4f6f2c..49dace45c7 100644
--- a/prism/enc/pm_encoding.h
+++ b/prism/enc/pm_encoding.h
@@ -173,6 +173,7 @@ extern pm_encoding_t pm_encoding_euc_jp_ms;
 extern pm_encoding_t pm_encoding_euc_jis_2004;
 extern pm_encoding_t pm_encoding_euc_kr;
 extern pm_encoding_t pm_encoding_gb12345;
+extern pm_encoding_t pm_encoding_gb18030;
 extern pm_encoding_t pm_encoding_gb1988;
 extern pm_encoding_t pm_encoding_gb2312;
 extern pm_encoding_t pm_encoding_gbk;
diff --git a/prism/prism.c b/prism/prism.c
index e32b444619..7ede34bea0 100644
--- a/prism/prism.c
+++ b/prism/prism.c
@@ -6262,6 +6262,7 @@ parser_lex_magic_comment_encoding_value(pm_parser_t *parser, const uint8_t *star
             case 'G': case 'g':
                 ENCODING1("GBK", pm_encoding_gbk);
                 ENCODING1("GB12345", pm_encoding_gb12345);
+                ENCODING1("GB18030", pm_encoding_gb18030);
                 ENCODING1("GB1988", pm_encoding_gb1988);
                 ENCODING1("GB2312", pm_encoding_gb2312);
                 break;