OK.
On Thu, Sep 29, 2016 at 4:21 PM, Jakub Jelinek <ja...@redhat.com> wrote:
> Hi!
>
> This patch pedwarns in C++17 on register storage class specifier, unless
> it is diagnosed errorneous for other reasons and unless it is used in the
> GNU global or local register variable extension. Even in C++17, users can
> use -Wno-register to suppress the pedwarn, and for C++98-C++14 users can on
> the other side use -Wregister to get warning about it. Clang seems to
> warn/error out similarly on variables with register storage class under
> -Wregister too, is quiet about the uses in register int var __asm ("...")
> (global and local), though strangely doesn't complain about register
> keywords on function arguments, which this patch diagnoses.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
>
> 2016-09-29 Jakub Jelinek <ja...@redhat.com>
>
> Implement P0001R1 - C++17 removal of register storage class specifier
> c-family/
> * c.opt (Wregister): New warning.
> * c-opts.c (c_common_post_options): Enable -Wregister by
> default for C++17.
> cp/
> * decl.c (cp_finish_decl): Diagnose register storage class
> on vars except when used in GNU global or local register variable
> extension.
> (grokdeclarator): Diagnose register storage class on parameters.
> * except.c (expand_start_catch_block): Set DECL_REGISTER only
> after cp_finish_decl call.
> testsuite/
> * c-c++-common/Wvarargs-2.c (foo1): Except new warning for C++17.
> * c-c++-common/vector-subscript-2.c (vf): Expect new error for
> C++17.
> * c-c++-common/vector-subscript-5.c (foo): Don't use register
> keyword if not __SSE2__.
> * c-c++-common/Wvarargs.c (foo1, foo3): Expect new warnings for
> C++17.
> * g++.dg/compat/struct-layout-1_generate.c (iterative_hash): Remove
> register keywords.
> * g++.dg/eh/pr29166.C: Add -Wno-register option.
> * g++.dg/warn/register-parm-1.C (erroneous_warning,
> no_erroneous_warning): Expect new warnings for C++17.
> * g++.dg/warn/register-var-2.C (f): Likewise.
> * g++.dg/parse/register1.C (f): Expect new error for C++17.
> * g++.dg/parse/linkage2.C (foo): Likewise.
> * g++.dg/torture/pr36826.C (CoinMin, CoinMax): Avoid register
> keyword on parameters for C++17.
> * g++.dg/cpp1z/register1.C: New test.
> * g++.dg/cpp1z/register2.C: New test.
> * g++.dg/cpp1z/register3.C: New test.
>
> --- gcc/c-family/c.opt.jj 2016-09-26 12:06:37.000000000 +0200
> +++ gcc/c-family/c.opt 2016-09-29 14:54:17.712047430 +0200
> @@ -842,6 +842,10 @@ Wredundant-decls
> C ObjC C++ ObjC++ Var(warn_redundant_decls) Warning
> Warn about multiple declarations of the same object.
>
> +Wregister
> +C++ ObjC++ Var(warn_register) Warning
> +Warn about uses of register storage specifier.
> +
> Wreorder
> C++ ObjC++ Var(warn_reorder) Warning LangEnabledBy(C++ ObjC++,Wall)
> Warn when the compiler reorders code.
> --- gcc/c-family/c-opts.c.jj 2016-08-19 11:04:38.000000000 +0200
> +++ gcc/c-family/c-opts.c 2016-09-29 15:06:06.213254295 +0200
> @@ -871,6 +871,10 @@ c_common_post_options (const char **pfil
> warn_shift_negative_value = (extra_warnings
> && (cxx_dialect >= cxx11 || flag_isoc99));
>
> + /* -Wregister is enabled by default in C++17. */
> + if (!global_options_set.x_warn_register)
> + warn_register = cxx_dialect >= cxx1z;
> +
> /* Declone C++ 'structors if -Os. */
> if (flag_declone_ctor_dtor == -1)
> flag_declone_ctor_dtor = optimize_size;
> --- gcc/cp/decl.c.jj 2016-09-23 19:37:41.000000000 +0200
> +++ gcc/cp/decl.c 2016-09-29 16:05:03.724470275 +0200
> @@ -6711,6 +6711,19 @@ cp_finish_decl (tree decl, tree init, bo
> if (type == error_mark_node)
> return;
>
> + /* Warn about register storage specifiers except when in GNU global
> + or local register variable extension. */
> + if (VAR_P (decl) && DECL_REGISTER (decl) && asmspec_tree == NULL_TREE)
> + {
> + if (cxx_dialect >= cxx1z)
> + pedwarn (DECL_SOURCE_LOCATION (decl), OPT_Wregister,
> + "ISO C++1z does not allow %<register%> storage "
> + "class specifier");
> + else
> + warning_at (DECL_SOURCE_LOCATION (decl), OPT_Wregister,
> + "%<register%> storage class specifier used");
> + }
> +
> /* If a name was specified, get the string. */
> if (at_namespace_scope_p ())
> asmspec_tree = maybe_apply_renaming_pragma (decl, asmspec_tree);
> @@ -11634,7 +11647,20 @@ grokdeclarator (const cp_declarator *dec
> and in case doing stupid register allocation. */
>
> if (storage_class == sc_register)
> - DECL_REGISTER (decl) = 1;
> + {
> + DECL_REGISTER (decl) = 1;
> + /* Warn about register storage specifiers on PARM_DECLs. */
> + if (TREE_CODE (decl) == PARM_DECL)
> + {
> + if (cxx_dialect >= cxx1z)
> + pedwarn (DECL_SOURCE_LOCATION (decl), OPT_Wregister,
> + "ISO C++1z does not allow %<register%> storage "
> + "class specifier");
> + else
> + warning_at (DECL_SOURCE_LOCATION (decl), OPT_Wregister,
> + "%<register%> storage class specifier used");
> + }
> + }
> else if (storage_class == sc_extern)
> DECL_THIS_EXTERN (decl) = 1;
> else if (storage_class == sc_static)
> --- gcc/cp/except.c.jj 2016-04-28 21:03:09.000000000 +0200
> +++ gcc/cp/except.c 2016-09-29 15:08:49.891226456 +0200
> @@ -540,9 +540,9 @@ expand_start_catch_block (tree decl)
> if (init_type != TREE_TYPE (init))
> init = build1 (NOP_EXPR, init_type, init);
> exp = create_temporary_var (init_type);
> - DECL_REGISTER (exp) = 1;
> cp_finish_decl (exp, init, /*init_const_expr=*/false,
> NULL_TREE, LOOKUP_ONLYCONVERTING);
> + DECL_REGISTER (exp) = 1;
> initialize_handler_parm (decl, exp);
> }
>
> --- gcc/testsuite/c-c++-common/Wvarargs-2.c.jj 2012-05-02 09:38:12.000000000
> +0200
> +++ gcc/testsuite/c-c++-common/Wvarargs-2.c 2016-09-29 16:27:44.273604641
> +0200
> @@ -23,7 +23,7 @@ foo0 (int a, int b, ...)
> }
>
> void
> -foo1 (int a, register int b, ...)
> +foo1 (int a, register int b, ...) // { dg-warning "ISO C\\+\\+1z does
> not allow 'register' storage class specifier" "" { target c++1z } }
> {
> va_list vp;
> /* 'b' is declared with register storage, but don't warn
> --- gcc/testsuite/c-c++-common/vector-subscript-2.c.jj 2012-05-02
> 09:38:12.000000000 +0200
> +++ gcc/testsuite/c-c++-common/vector-subscript-2.c 2016-09-29
> 16:00:38.539756931 +0200
> @@ -7,6 +7,6 @@
>
> float vf(int i)
> {
> - register vector float a;
> + register vector float a; // { dg-error "ISO C++1z does not allow
> 'register' storage class specifier" "" { target c++1z } }
> return a[0];
> }
> --- gcc/testsuite/c-c++-common/vector-subscript-5.c.jj 2016-05-24
> 18:14:11.000000000 +0200
> +++ gcc/testsuite/c-c++-common/vector-subscript-5.c 2016-09-29
> 16:01:31.002106721 +0200
> @@ -5,7 +5,10 @@ typedef int U __attribute__ ((vector_siz
> int
> foo (int i)
> {
> - register U u
> +#if __SSE2__
> + register
> +#endif
> + U u
> #if __SSE2__
> asm ("xmm0")
> #endif
> --- gcc/testsuite/c-c++-common/Wvarargs.c.jj 2016-02-12 00:50:55.000000000
> +0100
> +++ gcc/testsuite/c-c++-common/Wvarargs.c 2016-09-29 16:29:07.213576262
> +0200
> @@ -23,7 +23,7 @@ foo0 (int a, int b, ...)
> }
>
> void
> -foo1 (int a, register int b, ...)
> +foo1 (int a, register int b, ...) // { dg-warning "ISO C\\+\\+1z does
> not allow 'register' storage class specifier" "" { target c++1z } }
> {
> va_list vp;
> /* 'b' is declared with register storage, but don't warn
> @@ -45,7 +45,7 @@ foo2 (int a, int b, ...)
> }
>
> void
> -foo3 (int a, register int b, ...)
> +foo3 (int a, register int b, ...) // { dg-warning "ISO C\\+\\+1z does
> not allow 'register' storage class specifier" "" { target c++1z } }
> {
> va_list vp;
> /* 'b' is declared with register storage, so warn. */
> --- gcc/testsuite/g++.dg/compat/struct-layout-1_generate.c.jj 2015-12-16
> 09:02:09.000000000 +0100
> +++ gcc/testsuite/g++.dg/compat/struct-layout-1_generate.c 2016-09-29
> 15:42:13.290440870 +0200
> @@ -1028,12 +1028,12 @@ acceptable. Do NOT use for cryptographi
>
> static hashval_t
> iterative_hash (const void *k_in /* the key */,
> - register size_t length /* the length of the key */,
> - register hashval_t initval /* the previous hash, or
> - an arbitrary value */)
> + size_t length /* the length of the key */,
> + hashval_t initval /* the previous hash, or
> + an arbitrary value */)
> {
> - register const unsigned char *k = (const unsigned char *)k_in;
> - register hashval_t a,b,c,len;
> + const unsigned char *k = (const unsigned char *)k_in;
> + hashval_t a,b,c,len;
>
> /* Set up the internal state */
> len = length;
> --- gcc/testsuite/g++.dg/eh/pr29166.C.jj 2008-09-05 12:55:05.000000000
> +0200
> +++ gcc/testsuite/g++.dg/eh/pr29166.C 2016-09-29 15:42:51.224971251 +0200
> @@ -1,5 +1,6 @@
> // PR 29166: r4-r7 corrupted when unwinding.
> // { dg-do run }
> +// { dg-additional-options "-Wno-register" }
>
> class Ex
> {
> --- gcc/testsuite/g++.dg/warn/register-parm-1.C.jj 2014-12-19
> 13:18:35.000000000 +0100
> +++ gcc/testsuite/g++.dg/warn/register-parm-1.C 2016-09-29 16:20:31.061976063
> +0200
> @@ -1,9 +1,9 @@
> // PR c++/60955
> // { dg-options "-Wextra" }
>
> -unsigned int erroneous_warning(register int a) {
> +unsigned int erroneous_warning(register int a) { // { dg-warning "ISO
> C\\+\\+1z does not allow 'register' storage class specifier" "" { target
> c++1z } }
> if ((a) & 0xff) return 1; else return 0;
> }
> -unsigned int no_erroneous_warning(register int a) {
> +unsigned int no_erroneous_warning(register int a) { // { dg-warning "ISO
> C\\+\\+1z does not allow 'register' storage class specifier" "" { target
> c++1z } }
> if (a & 0xff) return 1; else return 0;
> }
> --- gcc/testsuite/g++.dg/warn/register-var-2.C.jj 2008-09-05
> 12:55:03.000000000 +0200
> +++ gcc/testsuite/g++.dg/warn/register-var-2.C 2016-09-29 16:16:29.313973189
> +0200
> @@ -9,6 +9,6 @@ void g(int *);
>
> void f(void)
> {
> - register int x;
> + register int x; /* { dg-warning "ISO C\\+\\+1z does not allow
> 'register' storage class specifier" "" { target c++1z } } */
> g(&x); /* { dg-warning "address requested for 'x', which is declared
> 'register'" } */
> }
> --- gcc/testsuite/g++.dg/parse/register1.C.jj 2008-09-05 12:55:04.000000000
> +0200
> +++ gcc/testsuite/g++.dg/parse/register1.C 2016-09-29 16:16:25.642018699
> +0200
> @@ -8,7 +8,7 @@ public:
> operator int() { return i; }
> };
>
> -C f (register C x)
> +C f (register C x) // { dg-error "ISO C\\+\\+1z does not allow
> 'register' storage class specifier" "" { target c++1z } }
> {
> return x + 31;
> }
> --- gcc/testsuite/g++.dg/parse/linkage2.C.jj 2008-09-05 12:55:04.000000000
> +0200
> +++ gcc/testsuite/g++.dg/parse/linkage2.C 2016-09-29 16:16:23.164049410
> +0200
> @@ -1,3 +1,3 @@
> // PR c++/27884
>
> -extern "C" void foo(register int *my_perl);
> +extern "C" void foo(register int *my_perl); // { dg-error "ISO C\\+\\+1z
> does not allow 'register' storage class specifier" "" { target c++1z } }
> --- gcc/testsuite/g++.dg/torture/pr36826.C.jj 2008-10-23 13:21:06.000000000
> +0200
> +++ gcc/testsuite/g++.dg/torture/pr36826.C 2016-09-29 15:54:18.920457225
> +0200
> @@ -1,5 +1,10 @@
> +#if __cplusplus > 201402L
> +template <class T> T CoinMax(const T x1, const T x2);
> +template <class T> T CoinMin(const T x1, const T x2);
> +#else
> template <class T> T CoinMax(register const T x1, register const T x2);
> template <class T> T CoinMin(register const T x1, register const T x2);
> +#endif
> class CoinIndexedVector;
> class ClpModel {
> protected:
> --- gcc/testsuite/g++.dg/cpp1z/register1.C.jj 2016-09-29 15:38:59.976834015
> +0200
> +++ gcc/testsuite/g++.dg/cpp1z/register1.C 2016-09-29 16:15:12.972919348
> +0200
> @@ -0,0 +1,29 @@
> +// P0001R1 - C++17 removal of register keyword
> +// { dg-do compile }
> +
> +#if defined(__i386__) || defined(__x86_64__)
> +#define REG1 "ebx"
> +#define REG2 "edi"
> +#endif
> +
> +#ifdef REG1
> +register int a __asm (REG1); // { dg-bogus "ISO C\\+\\+1z does not allow
> 'register' storage class specifier" "" { target c++1z } }
> +#endif
> +register int b; // { dg-error "ISO C\\+\\+1z does not
> allow 'register' storage class specifier" "" { target c++1z } }
> +register int c (); // { dg-error "storage class 'register'
> invalid for function" }
> +int foo (register int d) // { dg-error "ISO C\\+\\+1z does not allow
> 'register' storage class specifier" "" { target c++1z } }
> +{
> + return d;
> +}
> +int bar ()
> +{
> +#ifdef REG2
> + register int e __asm (REG2); // { dg-bogus "ISO C\\+\\+1z does not allow
> 'register' storage class specifier" "" { target c++1z } }
> +#else
> + int e;
> +#endif
> + register int f; // { dg-error "ISO C\\+\\+1z does not allow
> 'register' storage class specifier" "" { target c++1z } }
> + e = 6;
> + f = 7;
> + return e + f;
> +}
> --- gcc/testsuite/g++.dg/cpp1z/register2.C.jj 2016-09-29 15:39:44.739279874
> +0200
> +++ gcc/testsuite/g++.dg/cpp1z/register2.C 2016-09-29 16:15:35.781636660
> +0200
> @@ -0,0 +1,30 @@
> +// P0001R1 - C++17 removal of register keyword
> +// { dg-do compile }
> +// { dg-options "-Wno-register" }
> +
> +#if defined(__i386__) || defined(__x86_64__)
> +#define REG1 "ebx"
> +#define REG2 "edi"
> +#endif
> +
> +#ifdef REG1
> +register int a __asm (REG1); // { dg-bogus "ISO C\\+\\+1z does not allow
> 'register' storage class specifier" "" { target c++1z } }
> +#endif
> +register int b; // { dg-bogus "ISO C\\+\\+1z does not
> allow 'register' storage class specifier" "" { target c++1z } }
> +register int c (); // { dg-error "storage class 'register'
> invalid for function" }
> +int foo (register int d) // { dg-bogus "ISO C\\+\\+1z does not allow
> 'register' storage class specifier" "" { target c++1z } }
> +{
> + return d;
> +}
> +int bar ()
> +{
> +#ifdef REG2
> + register int e __asm (REG2); // { dg-bogus "ISO C\\+\\+1z does not allow
> 'register' storage class specifier" "" { target c++1z } }
> +#else
> + int e;
> +#endif
> + register int f; // { dg-bogus "ISO C\\+\\+1z does not allow
> 'register' storage class specifier" "" { target c++1z } }
> + e = 6;
> + f = 7;
> + return e + f;
> +}
> --- gcc/testsuite/g++.dg/cpp1z/register3.C.jj 2016-09-29 15:40:32.064694004
> +0200
> +++ gcc/testsuite/g++.dg/cpp1z/register3.C 2016-09-29 16:24:04.311331969
> +0200
> @@ -0,0 +1,30 @@
> +// P0001R1 - C++17 removal of register keyword
> +// { dg-do compile { target c++14_down } }
> +// { dg-options "-Wregister" }
> +
> +#if defined(__i386__) || defined(__x86_64__)
> +#define REG1 "ebx"
> +#define REG2 "edi"
> +#endif
> +
> +#ifdef REG1
> +register int a __asm (REG1); // { dg-bogus "'register' storage class
> specifier used" }
> +#endif
> +register int b; // { dg-warning "'register' storage
> class specifier used" }
> +register int c (); // { dg-error "storage class 'register'
> invalid for function" }
> +int foo (register int d) // { dg-warning "'register' storage class
> specifier used" }
> +{
> + return d;
> +}
> +int bar ()
> +{
> +#ifdef REG2
> + register int e __asm (REG2); // { dg-bogus "'register' storage class
> specifier used" }
> +#else
> + int e;
> +#endif
> + register int f; // { dg-warning "'register' storage class
> specifier used" }
> + e = 6;
> + f = 7;
> + return e + f;
> +}
>
> Jakub
