ast.rb: RubyVM::AST.parse and .of accepts `save_script_lines: true`

This option makes the parser keep the original source as an array of
the original code lines. This feature exploits the mechanism of
`SCRIPT_LINES__` but records only the specified code that is passed to
RubyVM::AST.of or .parse, instead of recording all parsed program texts.

1 files changed, 17 insertions, 0 deletions

diff --git a/parse.y b/parse.y
index 6b42b6b31b..47b63e810d 100644
--- a/parse.y
+++ b/parse.y
@@ -337,6 +337,7 @@ struct parser_params {
     unsigned int do_loop: 1;
     unsigned int do_chomp: 1;
     unsigned int do_split: 1;
+    unsigned int save_script_lines: 1;
 
     NODE *eval_tree_begin;
     NODE *eval_tree;
@@ -6241,6 +6242,13 @@ yycompile0(VALUE arg)
 	    cov = Qtrue;
 	}
     }
+    if (p->save_script_lines) {
+        if (!p->debug_lines) {
+            p->debug_lines = rb_ary_new();
+        }
+
+        RB_OBJ_WRITE(p->ast, &p->ast->body.script_lines, p->debug_lines);
+    }
 
     parser_prepare(p);
 #define RUBY_DTRACE_PARSE_HOOK(name) \
@@ -13186,6 +13194,15 @@ rb_parser_set_context(VALUE vparser, const struct rb_iseq_struct *base, int main
     p->parent_iseq = base;
     return vparser;
 }
+
+void
+rb_parser_save_script_lines(VALUE vparser)
+{
+    struct parser_params *p;
+
+    TypedData_Get_Struct(vparser, struct parser_params, &parser_data_type, p);
+    p->save_script_lines = 1;
+}
 #endif
 
 #ifdef RIPPER