From c63d6bee7b1bba0308e72cb8d54538ff84af612a Mon Sep 17 00:00:00 2001
From: Earlopain <14981592+Earlopain@users.noreply.github.com>
Date: Fri, 12 Sep 2025 22:49:35 +0200
Subject: [PATCH] Explicitly use a ruby version for prism to parse the code as

Prism can parse multiple versions of ruby. Because of that branch release managers are ok with simply
bumping prism to its latest version.

However, if no version is specified, it will parse as the latest known version, which can be ahead of the maintenance branch.
So we need to explicitly pass a version to not accidentally introduce new syntax to maintenance branches.
---
 common.mk       |  2 ++
 prism_compile.c | 12 ++++++++++++
 prism_compile.h |  1 +
 3 files changed, 15 insertions(+)

diff --git a/common.mk b/common.mk
index 193ed127d9..f5b0ea9ee9 100644
--- a/common.mk
+++ b/common.mk
@@ -3425,6 +3425,7 @@ compile.$(OBJEXT): $(top_srcdir)/prism/util/pm_string.h
 compile.$(OBJEXT): $(top_srcdir)/prism/util/pm_strncasecmp.h
 compile.$(OBJEXT): $(top_srcdir)/prism/util/pm_strpbrk.h
 compile.$(OBJEXT): $(top_srcdir)/prism_compile.c
+compile.$(OBJEXT): $(top_srcdir)/version.h
 compile.$(OBJEXT): {$(VPATH)}assert.h
 compile.$(OBJEXT): {$(VPATH)}atomic.h
 compile.$(OBJEXT): {$(VPATH)}backward/2/assume.h
@@ -3618,6 +3619,7 @@ compile.$(OBJEXT): {$(VPATH)}prism_compile.h
 compile.$(OBJEXT): {$(VPATH)}ractor.h
 compile.$(OBJEXT): {$(VPATH)}re.h
 compile.$(OBJEXT): {$(VPATH)}regex.h
+compile.$(OBJEXT): {$(VPATH)}revision.h
 compile.$(OBJEXT): {$(VPATH)}ruby_assert.h
 compile.$(OBJEXT): {$(VPATH)}ruby_atomic.h
 compile.$(OBJEXT): {$(VPATH)}rubyparser.h
diff --git a/prism_compile.c b/prism_compile.c
index e892c80c5e..c31700e024 100644
--- a/prism_compile.c
+++ b/prism_compile.c
@@ -1,4 +1,5 @@
 #include "prism.h"
+#include "version.h"
 
 /**
  * This compiler defines its own concept of the location of a node. We do this
@@ -11351,6 +11352,8 @@ pm_parse_file(pm_parse_result_t *result, VALUE filepath, VALUE *script_lines)
     pm_options_filepath_set(&result->options, RSTRING_PTR(filepath));
     RB_GC_GUARD(filepath);
 
+    pm_options_version_for_current_ruby_set(&result->options);
+
     pm_parser_init(&result->parser, pm_string_source(&result->input), pm_string_length(&result->input), &result->options);
     pm_node_t *node = pm_parse(&result->parser);
 
@@ -11409,6 +11412,8 @@ pm_parse_string(pm_parse_result_t *result, VALUE source, VALUE filepath, VALUE *
     pm_options_filepath_set(&result->options, RSTRING_PTR(filepath));
     RB_GC_GUARD(filepath);
 
+    pm_options_version_for_current_ruby_set(&result->options);
+
     pm_parser_init(&result->parser, pm_string_source(&result->input), pm_string_length(&result->input), &result->options);
     pm_node_t *node = pm_parse(&result->parser);
 
@@ -11491,6 +11496,13 @@ pm_parse_stdin(pm_parse_result_t *result)
     return pm_parse_process(result, node, NULL);
 }
 
+#define PM_VERSION_FOR_RELEASE(major, minor) PM_VERSION_FOR_RELEASE_IMPL(major, minor)
+#define PM_VERSION_FOR_RELEASE_IMPL(major, minor) PM_OPTIONS_VERSION_CRUBY_##major##_##minor
+
+void pm_options_version_for_current_ruby_set(pm_options_t *options) {
+    options->version = PM_VERSION_FOR_RELEASE(RUBY_VERSION_MAJOR, RUBY_VERSION_MINOR);
+}
+
 #undef NEW_ISEQ
 #define NEW_ISEQ OLD_ISEQ
 
diff --git a/prism_compile.h b/prism_compile.h
index c032449bd6..e588122205 100644
--- a/prism_compile.h
+++ b/prism_compile.h
@@ -94,6 +94,7 @@ VALUE pm_parse_file(pm_parse_result_t *result, VALUE filepath, VALUE *script_lin
 VALUE pm_load_parse_file(pm_parse_result_t *result, VALUE filepath, VALUE *script_lines);
 VALUE pm_parse_string(pm_parse_result_t *result, VALUE source, VALUE filepath, VALUE *script_lines);
 VALUE pm_parse_stdin(pm_parse_result_t *result);
+void pm_options_version_for_current_ruby_set(pm_options_t *options);
 void pm_parse_result_free(pm_parse_result_t *result);
 
 rb_iseq_t *pm_iseq_new(pm_scope_node_t *node, VALUE name, VALUE path, VALUE realpath, const rb_iseq_t *parent, enum rb_iseq_type, int *error_state);