8 files changed, 54 insertions, 22 deletions
diff --git a/ext/-test-/integer/my_integer.c b/ext/-test-/integer/my_integer.c
index d86474bd7d..94f14d2765 100644
--- a/ext/-test-/integer/my_integer.c
+++ b/ext/-test-/integer/my_integer.c
@@ -1,9 +1,13 @@
 #include "ruby.h"
 
+static const rb_data_type_t my_integer_type = {
+    "MyInteger", {0}, 0, 0, RUBY_TYPED_FREE_IMMEDIATELY
+};
+
 static VALUE
 my_integer_s_new(VALUE klass)
 {
-    return Data_Wrap_Struct(klass, 0, 0, 0);
+    return TypedData_Wrap_Struct(klass, &my_integer_type, 0);
 }
 
 void
diff --git a/ext/-test-/load/resolve_symbol_target/resolve_symbol_target.def b/ext/-test-/load/resolve_symbol_target/resolve_symbol_target.def
deleted file mode 100644
index c2ed3610fe..0000000000
--- a/ext/-test-/load/resolve_symbol_target/resolve_symbol_target.def
+++ /dev/null
@@ -1,4 +0,0 @@
-LIBRARY resolve_symbol_target
-EXPORTS
-  Init_resolve_symbol_target
-  rst_any_method
diff --git a/ext/-test-/load/stringify_target/stringify_target.def b/ext/-test-/load/stringify_target/stringify_target.def
deleted file mode 100644
index 89c2b762de..0000000000
--- a/ext/-test-/load/stringify_target/stringify_target.def
+++ /dev/null
@@ -1,4 +0,0 @@
-LIBRARY stringify_target
-EXPORTS
-  Init_stringify_target
-  stt_any_method
diff --git a/ext/-test-/public_header_warnings/extconf.rb b/ext/-test-/public_header_warnings/extconf.rb
new file mode 100644
index 0000000000..f6a8a51f63
--- /dev/null
+++ b/ext/-test-/public_header_warnings/extconf.rb
@@ -0,0 +1,23 @@
+#
+#  Under compilers with WERRORFLAG, MakeMakefile.try_compile treats warnings as errors, so we can
+#  use append_cflags to test whether the public header files emit warnings with certain flags turned
+#  on.
+#
+def check_append_cflags(flag, msg = nil)
+  msg ||= "flag #{flag} is not acceptable"
+  !$CFLAGS.include?(flag) or raise("flag #{flag} already present in $CFLAGS")
+  append_cflags(flag)
+  $CFLAGS.include?(flag) or raise(msg)
+end
+
+if %w[gcc clang].include?(RbConfig::CONFIG['CC'])
+  config_string("WERRORFLAG") or raise("expected WERRORFLAG to be defined")
+
+  # should be acceptable on all modern C compilers
+  check_append_cflags("-D_TEST_OK", "baseline compiler warning test failed")
+
+  # Feature #20507: Allow compilation of C extensions with -Wconversion
+  check_append_cflags("-Wconversion", "-Wconversion raising warnings in public headers")
+end
+
+create_makefile("-test-/public_header_warnings")
diff --git a/ext/-test-/string/chilled.c b/ext/-test-/string/chilled.c
deleted file mode 100644
index c98fc72c47..0000000000
--- a/ext/-test-/string/chilled.c
+++ /dev/null
@@ -1,13 +0,0 @@
-#include "ruby.h"
-
-static VALUE
-bug_s_rb_str_chilled_p(VALUE self, VALUE str)
-{
-    return rb_str_chilled_p(str) ? Qtrue : Qfalse;
-}
-
-void
-Init_string_chilled(VALUE klass)
-{
-    rb_define_singleton_method(klass, "rb_str_chilled_p", bug_s_rb_str_chilled_p, 1);
-}
diff --git a/ext/-test-/string/set_len.c b/ext/-test-/string/set_len.c
index 049da2cdb5..b55ef6f469 100644
--- a/ext/-test-/string/set_len.c
+++ b/ext/-test-/string/set_len.c
@@ -16,9 +16,17 @@ bug_str_append(VALUE str, VALUE addendum)
     return str;
 }
 
+static VALUE
+bug_str_resize(VALUE str, VALUE len)
+{
+    rb_str_resize(str, NUM2LONG(len));
+    return str;
+}
+
 void
 Init_string_set_len(VALUE klass)
 {
     rb_define_method(klass, "set_len", bug_str_set_len, 1);
     rb_define_method(klass, "append", bug_str_append, 1);
+    rb_define_method(klass, "resize", bug_str_resize, 1);
 }
diff --git a/ext/-test-/thread/id/extconf.rb b/ext/-test-/thread/id/extconf.rb
new file mode 100644
index 0000000000..a0ae0eff15
--- /dev/null
+++ b/ext/-test-/thread/id/extconf.rb
@@ -0,0 +1,3 @@
+if have_func("gettid")
+  create_makefile("-test-/thread/id")
+end
diff --git a/ext/-test-/thread/id/id.c b/ext/-test-/thread/id/id.c
new file mode 100644
index 0000000000..b46a5955e2
--- /dev/null
+++ b/ext/-test-/thread/id/id.c
@@ -0,0 +1,15 @@
+#include <ruby.h>
+
+static VALUE
+bug_gettid(VALUE self)
+{
+    pid_t tid = gettid();
+    return PIDT2NUM(tid);
+}
+
+void
+Init_id(void)
+{
+    VALUE klass = rb_define_module_under(rb_define_module("Bug"), "ThreadID");
+    rb_define_module_function(klass, "gettid", bug_gettid, 0);
+}