[ruby/prism] Add and test ibm863 encoding

(https://github.com/ruby/prism/pull/1853)

* Add and test ibm863

* Remove dup encoding and add alias

* Update test/prism/encoding_test.rb

Co-authored-by: Kevin Newton <kddnewton@gmail.com>

* Readd bitfield table lol

---------

https://github.com/ruby/prism/commit/4cd756d7ff

Co-authored-by: Kevin Newton <kddnewton@gmail.com>

4 files changed, 39 insertions, 0 deletions

diff --git a/prism/enc/pm_encoding.h b/prism/enc/pm_encoding.h
index 7279dfd7fb..0cccd5a58d 100644
--- a/prism/enc/pm_encoding.h
+++ b/prism/enc/pm_encoding.h
@@ -176,6 +176,7 @@ extern pm_encoding_t pm_encoding_ibm857;
 extern pm_encoding_t pm_encoding_ibm860;
 extern pm_encoding_t pm_encoding_ibm861;
 extern pm_encoding_t pm_encoding_ibm862;
+extern pm_encoding_t pm_encoding_ibm863;
 extern pm_encoding_t pm_encoding_ibm864;
 extern pm_encoding_t pm_encoding_ibm865;
 extern pm_encoding_t pm_encoding_ibm866;
diff --git a/prism/enc/pm_tables.c b/prism/enc/pm_tables.c
index d0414590cb..c726b99887 100644
--- a/prism/enc/pm_tables.c
+++ b/prism/enc/pm_tables.c
@@ -362,6 +362,30 @@ static uint8_t pm_encoding_ibm862_table[256] = {
 
 /**
  * Each element of the following table contains a bitfield that indicates a
+ * piece of information about the corresponding IBM863 character.
+ */
+static uint8_t pm_encoding_ibm863_table[256] = {
+//  0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 0x
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 1x
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 2x
+    2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 0, 0, 0, 0, 0, 0, // 3x
+    0, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, // 4x
+    7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 0, 0, 0, 0, 0, // 5x
+    0, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, // 6x
+    3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 0, 0, 0, 0, 0, // 7x
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 8x
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 9x
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // Ax
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // Bx
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // Cx
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // Dx
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // Ex
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // Fx
+};
+
+/**
+ * Each element of the following table contains a bitfield that indicates a
  * piece of information about the corresponding IBM864 character.
  */
 static uint8_t pm_encoding_ibm864_table[256] = {
@@ -1375,6 +1399,7 @@ PRISM_ENCODING_TABLE(ibm857)
 PRISM_ENCODING_TABLE(ibm860)
 PRISM_ENCODING_TABLE(ibm861)
 PRISM_ENCODING_TABLE(ibm862)
+PRISM_ENCODING_TABLE(ibm863)
 PRISM_ENCODING_TABLE(ibm864)
 PRISM_ENCODING_TABLE(ibm865)
 PRISM_ENCODING_TABLE(ibm866)
@@ -1577,6 +1602,16 @@ pm_encoding_t pm_encoding_ibm862 = {
     .multibyte = false
 };
 
+/** IBM863 */
+pm_encoding_t pm_encoding_ibm863 = {
+    .name = "IBM863",
+    .char_width = pm_encoding_single_char_width,
+    .alnum_char = pm_encoding_ibm863_alnum_char,
+    .alpha_char = pm_encoding_ibm863_alpha_char,
+    .isupper_char = pm_encoding_ibm863_isupper_char,
+    .multibyte = false
+};
+
 /** IBM864 */
 pm_encoding_t pm_encoding_ibm864 = {
     .name = "IBM864",
diff --git a/prism/prism.c b/prism/prism.c
index 2607a84cdc..4935bdc4bf 100644
--- a/prism/prism.c
+++ b/prism/prism.c
@@ -6091,6 +6091,7 @@ parser_lex_magic_comment_encoding_value(pm_parser_t *parser, const uint8_t *star
                 ENCODING1("CP866", pm_encoding_ibm866);
                 ENCODING1("CP874", pm_encoding_windows_874);
                 ENCODING1("CP878", pm_encoding_koi8_r);
+                ENCODING1("CP863", pm_encoding_ibm863);
                 ENCODING2("CP932", "csWindows31J", pm_encoding_windows_31j);
                 ENCODING1("CP936", pm_encoding_gbk);
                 ENCODING1("CP1250", pm_encoding_windows_1250);
@@ -6128,6 +6129,7 @@ parser_lex_magic_comment_encoding_value(pm_parser_t *parser, const uint8_t *star
                 ENCODING1("IBM860", pm_encoding_ibm860);
                 ENCODING1("IBM861", pm_encoding_ibm861);
                 ENCODING1("IBM862", pm_encoding_ibm862);
+                ENCODING1("IBM863", pm_encoding_ibm863);
                 ENCODING1("IBM864", pm_encoding_ibm864);
                 ENCODING1("IBM865", pm_encoding_ibm865);
                 ENCODING1("IBM866", pm_encoding_ibm866);
diff --git a/test/prism/encoding_test.rb b/test/prism/encoding_test.rb
index a059e22716..9a3efa7d8e 100644
--- a/test/prism/encoding_test.rb
+++ b/test/prism/encoding_test.rb
@@ -23,6 +23,7 @@ module Prism
       Encoding::IBM860 =>       0x00...0x100,
       Encoding::IBM861 =>       0x00...0x100,
       Encoding::IBM862 =>       0x00...0x100,
+      Encoding::IBM863 =>       0x00...0x100,
       Encoding::IBM864 =>       0x00...0x100,
       Encoding::IBM865 =>       0x00...0x100,
       Encoding::IBM866 =>       0x00...0x100,