From f85efc9748b193bceaefd2e94293927404ac951f Mon Sep 17 00:00:00 2001
From: Kevin Newton <kddnewton@gmail.com>
Date: Fri, 13 Sep 2024 15:00:03 -0400
Subject: [PATCH] [ruby/prism] Expose main_script in serialization API

https://github.com/ruby/prism/commit/0b527ca93f
---
 lib/prism/ffi.rb  | 3 +++
 prism/extension.c | 5 +++++
 prism/options.c   | 1 +
 3 files changed, 9 insertions(+)

diff --git a/lib/prism/ffi.rb b/lib/prism/ffi.rb
index b972520be1..40a4b32621 100644
--- a/lib/prism/ffi.rb
+++ b/lib/prism/ffi.rb
@@ -448,6 +448,9 @@ module Prism
       template << "C"
       values << (options[:encoding] == false ? 1 : 0)
 
+      template << "C"
+      values << (options.fetch(:main_script, false) ? 1 : 0)
+
       template << "L"
       if (scopes = options[:scopes])
         values << scopes.length
diff --git a/prism/extension.c b/prism/extension.c
index 94fc5a104b..f08682e0f3 100644
--- a/prism/extension.c
+++ b/prism/extension.c
@@ -756,6 +756,11 @@ parse_input(pm_string_t *input, const pm_options_t *options) {
  *       has been set. This should be a boolean or nil.
  * * `line` - the line number that the parse starts on. This should be an
  *       integer or nil. Note that this is 1-indexed.
+ * * `main_script` - a boolean indicating whether or not the source being parsed
+ *       is the main script being run by the interpreter. This controls whether
+ *       or not shebangs are parsed for additional flags and whether or not the
+ *       parser will attempt to find a matching shebang if the first one does
+ *       not contain the word "ruby".
  * * `scopes` - the locals that are in scope surrounding the code that is being
  *       parsed. This should be an array of arrays of symbols or nil. Scopes are
  *       ordered from the outermost scope to the innermost one.
diff --git a/prism/options.c b/prism/options.c
index e0b4735e4a..67b257138c 100644
--- a/prism/options.c
+++ b/prism/options.c
@@ -241,6 +241,7 @@ pm_options_read(pm_options_t *options, const char *data) {
     options->command_line = (uint8_t) *data++;
     options->version = (pm_options_version_t) *data++;
     options->encoding_locked = ((uint8_t) *data++) > 0;
+    options->main_script = ((uint8_t) *data++) > 0;
 
     uint32_t scopes_count = pm_options_read_u32(data);
     data += 4;