Make RubyVM::AbstractSyntaxTree.of raise for method/proc created in eval

This changes Thread::Location::Backtrace#absolute_path to return
nil for methods/procs defined in eval.  If the realpath of an iseq
is nil, that indicates it was defined in eval, in which case you
cannot use RubyVM::AbstractSyntaxTree.of.

Fixes [Bug #16983]

Co-authored-by: Koichi Sasada <ko1@atdot.net>

1 files changed, 21 insertions, 4 deletions

diff --git a/vm_eval.c b/vm_eval.c
index bc40c15b6c..19ba6dd96b 100644
--- a/vm_eval.c
+++ b/vm_eval.c
@@ -1661,13 +1661,15 @@ rb_each(VALUE obj)
 }
 
 void rb_parser_warn_location(VALUE, int);
+
+static VALUE eval_default_path;
+
 static const rb_iseq_t *
 eval_make_iseq(VALUE src, VALUE fname, int line, const rb_binding_t *bind,
 	       const struct rb_block *base_block)
 {
     const VALUE parser = rb_parser_new();
     const rb_iseq_t *const parent = vm_block_iseq(base_block);
-    VALUE realpath = Qnil;
     rb_iseq_t *iseq = NULL;
     rb_ast_t *ast;
     int isolated_depth = 0;
@@ -1694,10 +1696,14 @@ eval_make_iseq(VALUE src, VALUE fname, int line, const rb_binding_t *bind,
 
     if (fname != Qundef) {
         if (!NIL_P(fname)) fname = rb_fstring(fname);
-	realpath = fname;
     }
     else {
         fname = rb_fstring_lit("(eval)");
+        if (!eval_default_path) {
+            eval_default_path = rb_fstring_lit("(eval)");
+            rb_gc_register_mark_object(eval_default_path);
+        }
+        fname = eval_default_path;
     }
 
     rb_parser_set_context(parser, parent, FALSE);
@@ -1705,7 +1711,7 @@ eval_make_iseq(VALUE src, VALUE fname, int line, const rb_binding_t *bind,
     if (ast->body.root) {
         iseq = rb_iseq_new_eval(&ast->body,
                                 parent->body->location.label,
-                                fname, realpath, INT2FIX(line),
+                                fname, Qnil, INT2FIX(line),
                                 parent, isolated_depth);
     }
     rb_ast_dispose(ast);
@@ -2590,7 +2596,18 @@ rb_current_realfilepath(void)
     const rb_execution_context_t *ec = GET_EC();
     rb_control_frame_t *cfp = ec->cfp;
     cfp = vm_get_ruby_level_caller_cfp(ec, RUBY_VM_PREVIOUS_CONTROL_FRAME(cfp));
-    if (cfp != 0) return rb_iseq_realpath(cfp->iseq);
+    if (cfp != NULL) {
+        VALUE path = rb_iseq_realpath(cfp->iseq);
+        if (RTEST(path)) return path;
+        // eval context
+        path = rb_iseq_path(cfp->iseq);
+        if (path == eval_default_path) {
+            return Qnil;
+        }
+        else {
+            return path;
+        }
+    }
     return Qnil;
 }