From 9ef51b0b89a10c8c401cb9f2337e47a25be72cbe Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=E5=8D=9C=E9=83=A8=E6=98=8C=E5=B9=B3?= Date: Wed, 28 Aug 2019 17:11:23 +0900 Subject: drop-in type check for rb_define_method The rb_define_method function takes a pointer to ANYARGS-ed functions, which in fact varies 18 different prototypes. We still need to preserve ANYARGS for storages but why not check the consistencies if possible. Q&As: Q: Where did the magic number "18" came from in the description above? A: Count the case branch of vm_method.c:call_cfunc_invoker_func(). Note also that the 18 branches has lasted for at least 25 years. See also 200e0ee2fd3c1c006c528874a88f684447215524. Q: What is this __weakref__ thing? A: That is a kind of function overloading mechanism that GCC provides. In this case for instance rb_define_method0 is an alias of rb_define_method, with a strong type. Q: What is this __transparent_union__ thing? A: That is another kind of function overloading mechanism that GCC provides. In this case the attributed function pointer is either VALUE(*)(int,VALUE*,VALUE) or VALUE(*)(int,const VALUE*,VALUE). This is better than void* or ANYARGS because we can reject all other possibilities than the two. Q: What does this rb_define_method macro mean? A: It selects appropriate alias of the rb_define_method function, depending on the arity. Q: Why the prototype change of rb_f_notimplement? A: Function pointer to rb_f_notimplement is special cased in vm_method.c:rb_add_method_cfunc(). That should be handled by the __builtin_choose_expr chain inside of rb_define_method macro expansion. In order to do so, comparison like (func == rb_f_notimplement) is inappropriate for __builtin_choose_expr's expression (which must be a compile-time integer constant but the address of rb_f_notimplement is not fixed until the linker). So instead we are using __builtin_types_compatible_p, and in doing so we need to distinguish rb_f_notimplement from others, by type. --- include/ruby/ruby.h | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) (limited to 'include/ruby/ruby.h') diff --git a/include/ruby/ruby.h b/include/ruby/ruby.h index e15e3e60ef..59793e6547 100644 --- a/include/ruby/ruby.h +++ b/include/ruby/ruby.h @@ -2688,4 +2688,52 @@ RUBY_SYMBOL_EXPORT_END #endif } /* extern "C" { */ #endif + +#if defined(__has_attribute) && defined(HAVE_BUILTIN___BUILTIN_CHOOSE_EXPR_CONSTANT_P) +#if __has_attribute(transparent_union) && __has_attribute(unused) && __has_attribute(weakref) && __has_attribute(nonnull) +__attribute__((__unused__,__weakref__("rb_define_method"),__nonnull__(2,3)))static void rb_define_methodm3(VALUE,const char*,VALUE(*)(ANYARGS),int); +__attribute__((__unused__,__weakref__("rb_define_method"),__nonnull__(2,3)))static void rb_define_methodm2(VALUE,const char*,VALUE(*)(VALUE,VALUE),int); +__attribute__((__unused__,__weakref__("rb_define_method"),__nonnull__(2,3)))static void rb_define_methodm1(VALUE,const char*,VALUE(*)(int,union __attribute__((__transparent_union__)){VALUE*x;const VALUE*y;},VALUE),int); +__attribute__((__unused__,__weakref__("rb_define_method"),__nonnull__(2,3)))static void rb_define_method0 (VALUE,const char*,VALUE(*)(VALUE),int); +__attribute__((__unused__,__weakref__("rb_define_method"),__nonnull__(2,3)))static void rb_define_method1 (VALUE,const char*,VALUE(*)(VALUE,VALUE),int); +__attribute__((__unused__,__weakref__("rb_define_method"),__nonnull__(2,3)))static void rb_define_method2 (VALUE,const char*,VALUE(*)(VALUE,VALUE,VALUE),int); +__attribute__((__unused__,__weakref__("rb_define_method"),__nonnull__(2,3)))static void rb_define_method3 (VALUE,const char*,VALUE(*)(VALUE,VALUE,VALUE,VALUE),int); +__attribute__((__unused__,__weakref__("rb_define_method"),__nonnull__(2,3)))static void rb_define_method4 (VALUE,const char*,VALUE(*)(VALUE,VALUE,VALUE,VALUE,VALUE),int); +__attribute__((__unused__,__weakref__("rb_define_method"),__nonnull__(2,3)))static void rb_define_method5 (VALUE,const char*,VALUE(*)(VALUE,VALUE,VALUE,VALUE,VALUE,VALUE),int); +__attribute__((__unused__,__weakref__("rb_define_method"),__nonnull__(2,3)))static void rb_define_method6 (VALUE,const char*,VALUE(*)(VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE),int); +__attribute__((__unused__,__weakref__("rb_define_method"),__nonnull__(2,3)))static void rb_define_method7 (VALUE,const char*,VALUE(*)(VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE),int); +__attribute__((__unused__,__weakref__("rb_define_method"),__nonnull__(2,3)))static void rb_define_method8 (VALUE,const char*,VALUE(*)(VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE),int); +__attribute__((__unused__,__weakref__("rb_define_method"),__nonnull__(2,3)))static void rb_define_method9 (VALUE,const char*,VALUE(*)(VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE),int); +__attribute__((__unused__,__weakref__("rb_define_method"),__nonnull__(2,3)))static void rb_define_method10(VALUE,const char*,VALUE(*)(VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE),int); +__attribute__((__unused__,__weakref__("rb_define_method"),__nonnull__(2,3)))static void rb_define_method11(VALUE,const char*,VALUE(*)(VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE),int); +__attribute__((__unused__,__weakref__("rb_define_method"),__nonnull__(2,3)))static void rb_define_method12(VALUE,const char*,VALUE(*)(VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE),int); +__attribute__((__unused__,__weakref__("rb_define_method"),__nonnull__(2,3)))static void rb_define_method13(VALUE,const char*,VALUE(*)(VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE),int); +__attribute__((__unused__,__weakref__("rb_define_method"),__nonnull__(2,3)))static void rb_define_method14(VALUE,const char*,VALUE(*)(VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE),int); +__attribute__((__unused__,__weakref__("rb_define_method"),__nonnull__(2,3)))static void rb_define_method15(VALUE,const char*,VALUE(*)(VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE,VALUE),int); + +#define rb_f_notimplement_p(f) __builtin_types_compatible_p(__typeof__(f),__typeof__(rb_f_notimplement)) +#define rb_define_method_if_constexpr(x, t, f) __builtin_choose_expr(__builtin_choose_expr(__builtin_constant_p(x),(x),0),(t),(f)) +#define rb_define_method_choose_prototype15(n) rb_define_method_if_constexpr((n)==15,rb_define_method15,rb_define_methodm3) +#define rb_define_method_choose_prototype14(n) rb_define_method_if_constexpr((n)==14,rb_define_method14,rb_define_method_choose_prototype15(n)) +#define rb_define_method_choose_prototype13(n) rb_define_method_if_constexpr((n)==13,rb_define_method13,rb_define_method_choose_prototype14(n)) +#define rb_define_method_choose_prototype12(n) rb_define_method_if_constexpr((n)==12,rb_define_method12,rb_define_method_choose_prototype13(n)) +#define rb_define_method_choose_prototype11(n) rb_define_method_if_constexpr((n)==11,rb_define_method11,rb_define_method_choose_prototype12(n)) +#define rb_define_method_choose_prototype10(n) rb_define_method_if_constexpr((n)==10,rb_define_method10,rb_define_method_choose_prototype11(n)) +#define rb_define_method_choose_prototype9(n) rb_define_method_if_constexpr((n)== 9,rb_define_method9, rb_define_method_choose_prototype10(n)) +#define rb_define_method_choose_prototype8(n) rb_define_method_if_constexpr((n)== 8,rb_define_method8, rb_define_method_choose_prototype9(n)) +#define rb_define_method_choose_prototype7(n) rb_define_method_if_constexpr((n)== 7,rb_define_method7, rb_define_method_choose_prototype8(n)) +#define rb_define_method_choose_prototype6(n) rb_define_method_if_constexpr((n)== 6,rb_define_method6, rb_define_method_choose_prototype7(n)) +#define rb_define_method_choose_prototype5(n) rb_define_method_if_constexpr((n)== 5,rb_define_method5, rb_define_method_choose_prototype6(n)) +#define rb_define_method_choose_prototype4(n) rb_define_method_if_constexpr((n)== 4,rb_define_method4, rb_define_method_choose_prototype5(n)) +#define rb_define_method_choose_prototype3(n) rb_define_method_if_constexpr((n)== 3,rb_define_method3, rb_define_method_choose_prototype4(n)) +#define rb_define_method_choose_prototype2(n) rb_define_method_if_constexpr((n)== 2,rb_define_method2, rb_define_method_choose_prototype3(n)) +#define rb_define_method_choose_prototype1(n) rb_define_method_if_constexpr((n)== 1,rb_define_method1, rb_define_method_choose_prototype2(n)) +#define rb_define_method_choose_prototype0(n) rb_define_method_if_constexpr((n)== 0,rb_define_method0, rb_define_method_choose_prototype1(n)) +#define rb_define_method_choose_prototypem1(n) rb_define_method_if_constexpr((n)==-1,rb_define_methodm1,rb_define_method_choose_prototype0(n)) +#define rb_define_method_choose_prototypem2(n) rb_define_method_if_constexpr((n)==-2,rb_define_methodm2,rb_define_method_choose_prototypem1(n)) +#define rb_define_method_choose_prototypem3(n, f) rb_define_method_if_constexpr(rb_f_notimplement_p(f),rb_define_methodm3,rb_define_method_choose_prototypem2(n)) +#define rb_define_method(klass, mid, func, arity) rb_define_method_choose_prototypem3((arity),(func))((klass),(mid),(func),(arity)); +#endif +#endif + #endif /* RUBY_RUBY_H */ -- cgit v1.2.3