[PRISM] Use correct warning encoding

error.c

@@ -386,18 +386,28 @@ warn_vsprintf(rb_encoding *enc, const char *file, int line, const char *fmt, va_
     return rb_str_cat2(str, "\n");
 }
 
-#define with_warn_vsprintf(file, line, fmt) \
+#define with_warn_vsprintf(enc, file, line, fmt) \
     VALUE str; \
     va_list args; \
     va_start(args, fmt); \
-    str = warn_vsprintf(NULL, file, line, fmt, args); \
+    str = warn_vsprintf(enc, file, line, fmt, args); \
     va_end(args);
 
 void
 rb_compile_warn(const char *file, int line, const char *fmt, ...)
 {
     if (!NIL_P(ruby_verbose)) {
-        with_warn_vsprintf(file, line, fmt) {
+        with_warn_vsprintf(NULL, file, line, fmt) {
+            rb_write_warning_str(str);
+        }
+    }
+}
+
+void
+rb_enc_compile_warn(rb_encoding *enc, const char *file, int line, const char *fmt, ...)
+{
+    if (!NIL_P(ruby_verbose)) {
+        with_warn_vsprintf(enc, file, line, fmt) {
             rb_write_warning_str(str);
         }
     }
@@ -408,7 +418,18 @@ void
 rb_compile_warning(const char *file, int line, const char *fmt, ...)
 {
     if (RTEST(ruby_verbose)) {
-        with_warn_vsprintf(file, line, fmt) {
+        with_warn_vsprintf(NULL, file, line, fmt) {
+            rb_write_warning_str(str);
+        }
+    }
+}
+
+/* rb_enc_compile_warning() reports only in verbose mode */
+void
+rb_enc_compile_warning(rb_encoding *enc, const char *file, int line, const char *fmt, ...)
+{
+    if (RTEST(ruby_verbose)) {
+        with_warn_vsprintf(enc, file, line, fmt) {
             rb_write_warning_str(str);
         }
     }
@@ -418,7 +439,7 @@ void
 rb_category_compile_warn(rb_warning_category_t category, const char *file, int line, const char *fmt, ...)
 {
     if (!NIL_P(ruby_verbose)) {
-        with_warn_vsprintf(file, line, fmt) {
+        with_warn_vsprintf(NULL, file, line, fmt) {
             rb_warn_category(str, rb_warning_category_to_name(category));
         }
     }

prism_compile.c

@@ -9280,6 +9280,9 @@ pm_parse_process_error(const pm_parse_result_t *result)
     return error;
 }
 
+void rb_enc_compile_warning(rb_encoding *enc, const char *file, int line, const char *fmt, ...);
+void rb_enc_compile_warn(rb_encoding *enc, const char *file, int line, const char *fmt, ...);
+
 /**
  * Parse the parse result and raise a Ruby error if there are any syntax errors.
  * It returns an error if one should be raised. It is assumed that the parse
@@ -9298,6 +9301,9 @@ pm_parse_process(pm_parse_result_t *result, pm_node_t *node)
     pm_scope_node_init(node, scope_node, NULL);
     scope_node->filepath_encoding = filepath_encoding;
 
+    scope_node->encoding = rb_enc_find(parser->encoding->name);
+    if (!scope_node->encoding) rb_bug("Encoding not found %s!", parser->encoding->name);
+
     // Emit all of the various warnings from the parse.
     const pm_diagnostic_t *warning;
     const char *warning_filepath = (const char *) pm_string_source(&parser->filepath);
@@ -9306,10 +9312,10 @@ pm_parse_process(pm_parse_result_t *result, pm_node_t *node)
         int line = pm_location_line_number(parser, &warning->location);
 
         if (warning->level == PM_WARNING_LEVEL_VERBOSE) {
-            rb_compile_warning(warning_filepath, line, "%s", warning->message);
+            rb_enc_compile_warning(scope_node->encoding, warning_filepath, line, "%s", warning->message);
         }
         else {
-            rb_compile_warn(warning_filepath, line, "%s", warning->message);
+            rb_enc_compile_warn(scope_node->encoding, warning_filepath, line, "%s", warning->message);
         }
     }
 
@@ -9324,9 +9330,6 @@ pm_parse_process(pm_parse_result_t *result, pm_node_t *node)
 
     // Now set up the constant pool and intern all of the various constants into
     // their corresponding IDs.
-    scope_node->encoding = rb_enc_find(parser->encoding->name);
-    if (!scope_node->encoding) rb_bug("Encoding not found %s!", parser->encoding->name);
-
     scope_node->parser = parser;
     scope_node->constants = calloc(parser->constant_pool.size, sizeof(ID));
 

test/.excludes-prism/TestParse.rb

@@ -8,5 +8,4 @@
 exclude(:test_truncated_source_line, "unknown")
 exclude(:test_unexpected_eof, "unknown")
 exclude(:test_unexpected_token_after_numeric, "unknown")
-exclude(:test_unused_variable, "missing warning")
 exclude(:test_void_value_in_rhs, "unknown")