[PRISM] Implement MatchLastLineNode

This PR implements `MatchLastLineNode` for Prism.

Related: ruby/prism#1335

2 files changed, 37 insertions, 0 deletions

diff --git a/prism/prism_compiler.c b/prism/prism_compiler.c
index 56f0907f6f..7247d701bd 100644
--- a/prism/prism_compiler.c
+++ b/prism/prism_compiler.c
@@ -1594,6 +1594,32 @@ pm_compile_node(rb_iseq_t *iseq, const pm_node_t *node, LINK_ANCHOR *const ret,
           ADD_SETLOCAL(ret, &dummy_line_node, (int)index, local_write_node->depth);
           return;
       }
+      case PM_MATCH_LAST_LINE_NODE: {
+          if (!popped) {
+              pm_match_last_line_node_t *regular_expression_node = (pm_match_last_line_node_t *) node;
+              VALUE regex_str = parse_string(&regular_expression_node->unescaped);
+              int flags = 0;
+
+              if (regular_expression_node->base.flags & PM_REGULAR_EXPRESSION_FLAGS_IGNORE_CASE) {
+                  flags |= ONIG_OPTION_IGNORECASE;
+              }
+
+              if (regular_expression_node->base.flags & PM_REGULAR_EXPRESSION_FLAGS_MULTI_LINE) {
+                  flags |= ONIG_OPTION_MULTILINE;
+              }
+
+              if (regular_expression_node->base.flags & PM_REGULAR_EXPRESSION_FLAGS_EXTENDED) {
+                  flags |= ONIG_OPTION_EXTEND;
+              }
+
+              VALUE regex = rb_reg_new(RSTRING_PTR(regex_str), RSTRING_LEN(regex_str), flags);
+              ADD_INSN1(ret, &dummy_line_node, putobject, regex);
+              ADD_INSN2(ret, &dummy_line_node, getspecial, INT2FIX(0), INT2FIX(0));
+              ADD_SEND(ret, &dummy_line_node, idEqTilde, INT2NUM(1));
+          }
+
+          return;
+      }
       case PM_MISSING_NODE: {
           rb_bug("A pm_missing_node_t should not exist in prism's AST.");
           return;
diff --git a/test/prism/iseq_test.rb b/test/prism/iseq_test.rb
index d719923413..8fe5c99505 100644
--- a/test/prism/iseq_test.rb
+++ b/test/prism/iseq_test.rb
@@ -37,6 +37,17 @@ module Prism
       test_prism_eval("010")
     end
 
+    def test_MatchLastLineNode
+      test_prism_eval("if /foo/; end")
+      test_prism_eval("if /foo/i; end")
+      test_prism_eval("if /foo/x; end")
+      test_prism_eval("if /foo/m; end")
+      test_prism_eval("if /foo/im; end")
+      test_prism_eval("if /foo/mx; end")
+      test_prism_eval("if /foo/xi; end")
+      test_prism_eval("if /foo/ixm; end")
+    end
+
     def test_NilNode
       test_prism_eval("nil")
     end