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From: Jason Merrill <jason@redhat.com>
To: Paul Iannetta <piannetta@kalrayinc.com>
Cc: gcc-patches@gcc.gnu.org
Subject: Re: [PATCH v2] c++: parser - Support for target address spaces in C++
Date: Thu, 13 Oct 2022 11:47:42 -0400	[thread overview]
Message-ID: <d657b11c-17ef-da83-34cb-3f16076cd7b4@redhat.com> (raw)
In-Reply-To: <20221013152341.bztoqunwtmhdzi3f@ws2202.lin.mbt.kalray.eu>

On 10/13/22 11:23, Paul Iannetta wrote:
> On Thu, Oct 13, 2022 at 11:02:24AM -0400, Jason Merrill wrote:
>> On 10/12/22 20:52, Paul Iannetta wrote:
>>> On Tue, Oct 11, 2022 at 09:49:43PM -0400, Jason Merrill wrote:
>>>>
>>>> It surprises that this is the only place we complain about an object with an
>>>> address-space qualifier.  Shouldn't we also complain about e.g. automatic
>>>> variables/parameters or non-static data members with address-space qualified
>>>> type?
>>>>
>>>
>>> Indeed, I was missing quite a few things here.  Thanks.
>>> I used the draft as basis this time and imported from the C
>>> implementation the relevant parts.  This time, the errors get properly
>>> emitted when an address space is unduly specified; and comparisons,
>>> assignments and comparisons are taken care of.
>>>
>>> There are quite a few things I would like to clarify concerning some
>>> implementation details.
>>>     - A variable with automatic storage (which is neither a pointer nor
>>>       a reference) cannot be qualified with an address space.  I detect
>>>       this by the combination of `sc_none' and `! toplevel_bindings_p ()',
>>>       but I've also seen the use of `at_function_scope' at other places.
>>>       And I'm unsure which one is appropriate here.
>>>       This detection happens at the very end of grokdeclarator because I
>>>       need to know that the type is a pointer, which is not know until
>>>       very late in the function.
>>
>> At that point you have the decl, and you can ask directly what its storage
>> duration is, perhaps using decl_storage_duration.
>>
>> But why do you need to know whether the type is a pointer?  The attribute
>> applies to the target type of the pointer, not the pointer type.  I think
>> the problem is that you're looking at declspecs when you ought to be looking
>> at type_quals.
> 
> I need to know that the base type is a pointer to reject invalid
> declarations such as:
> 
>      int f (__seg_fs int a) { }     or     int f () { __seg_fs int a; }
> 
> because parameters and auto variables can have an address space
> qualifier only if they are pointer or reference type, which I can't
> tell only from type_quals.

But "int *__seg_fs a" is just as invalid as the above; the difference is 
not whether a is a pointer, but whether the address-space-qualified is 
the type of a itself or some sub-type.

You need to look at the qualifiers on type (which should also be the 
ones in type_quals), not the qualifiers in the declspecs.

>>>     - I'm having some trouble deciding whether I include those three
>>>       stub programs as tests, they all compile fine and clang accepts
>>>       them as well.
>>
>> Why not?
> 
> I thought they were pretty contrived, since it does not make much
> sense to strip address space qualifiers, even though it does prove
> that the implementation support those contrived but valid uses.

Testcases are full of contrived examples testing corner cases.  :)

>>
>>> Ex1:
>>> ```
>>> int __seg_fs * fs1;
>>> int __seg_gs * gs1;
>>>
>>> template<typename T> struct strip;
>>> template<typename T> struct strip<__seg_fs T *> { typedef T type; };
>>> template<typename T> struct strip<__seg_gs T *> { typedef T type; };
>>>
>>> int
>>> main ()
>>> {
>>>       *(strip<decltype(fs1)>::type *) fs1 == *(strip<decltype(gs1)>::type *) gs1;
>>>       return 0;
>>> }
>>> ```
>>>
>>> Ex2:
>>> ```
>>> int __seg_fs * fs1;
>>> int __seg_fs * fs2;
>>>
>>> template<typename T, typename U> auto f (T __seg_fs * a, U __seg_gs * b) { return a; }
>>> template<typename T, typename U> auto f (T __seg_gs * a, U __seg_fs * b) { return a; }
>>>
>>> int
>>> main ()
>>> {
>>>       f (fs1, gs1);
>>>       f (gs1, fs1);
>>>       return 0;
>>> }
>>> ```
>>>
>>> Ex3:
>>> ```
>>> int __seg_fs * fs1;
>>> int __seg_gs * gs1;
>>>
>>> template<typename T, typename U>
>>> auto f (T __seg_fs * a, U __seg_gs * b)
>>> {
>>>       return *(T *) a == *(U *) b;
>>> }
>>>
>>> int
>>> main ()
>>> {
>>>       return f (fs1, gs1);
>>> }
>>> ```
>>>
>>>
>>> Add support for custom address spaces in C++
>>>
>>> gcc/
>>>           * tree.h (ENCODE_QUAL_ADDR_SPACE): Missing parentheses.
>>>
>>> gcc/c/
>>>           * c-decl.cc: Remove c_register_addr_space.
>>>
>>> gcc/c-family/
>>>           * c-common.cc (c_register_addr_space): Imported from c-decl.cc
>>>           (addr_space_superset): Imported from gcc/c/c-typecheck.cc
>>>           * c-common.h: Remove the FIXME.
>>>           (addr_space_superset): New declaration.
>>>
>>> gcc/cp/
>>>           * cp-tree.h (enum cp_decl_spec): Add addr_space support.
>>>           (struct cp_decl_specifier_seq): Likewise.
>>>           * decl.cc (get_type_quals): Likewise.
>>>           (check_tag_decl): Likewise.
>>> 	(grokdeclarator): Likewise.
>>>           * parser.cc (cp_parser_type_specifier): Likewise.
>>>           (cp_parser_cv_qualifier_seq_opt): Likewise.
>>>           (cp_parser_postfix_expression): Likewise.
>>>           (cp_parser_type_specifier): Likewise.
>>>           (set_and_check_decl_spec_loc): Likewise.
>>>           * typeck.cc (composite_pointer_type): Likewise
>>>           (comp_ptr_ttypes_real): Likewise.
>>> 	(same_type_ignoring_top_level_qualifiers_p): Likewise.
>>>           * pt.cc (check_cv_quals_for_unify): Likewise.
>>>           (unify): Likewise.
>>>           * tree.cc: Remove c_register_addr_space stub.
>>>           * mangle.cc (write_CV_qualifiers_for_type): Mangle address spaces
>>>             using the extended qualifier notation.
>>>
>>> gcc/doc
>>>           * extend.texi (Named Address Spaces): add a mention about C++
>>>             support.
>>>
>>> gcc/testsuite/
>>>           * g++.dg/abi/mangle-addr-space1.C: New test.
>>>           * g++.dg/abi/mangle-addr-space2.C: New test.
>>>           * g++.dg/parse/addr-space.C: New test.
>>>           * g++.dg/parse/addr-space1.C: New test.
>>>           * g++.dg/parse/addr-space2.C: New test.
>>>           * g++.dg/parse/template/spec-addr-space.C: New test.
>>>           * g++.dg/ext/addr-space-decl.C: New test.
>>>           * g++.dg/ext/addr-space-ref.C: New test.
>>>           * g++.dg/ext/addr-space-ops.C: New test.
>>>
>>> # Please enter the commit message for your changes. Lines starting
>>> # with '#' will be ignored, and an empty message aborts the commit.
>>> #
>>> # Date:      Sun Oct 9 16:02:22 2022 +0200
>>> #
>>> # On branch releases/gcc-12
>>> # Your branch is ahead of 'origin/releases/gcc-12' by 2 commits.
>>> #   (use "git push" to publish your local commits)
>>> #
>>> # Changes to be committed:
>>> #	modified:   gcc/c-family/c-common.cc
>>> #	modified:   gcc/c-family/c-common.h
>>> #	modified:   gcc/c/c-decl.cc
>>> #	modified:   gcc/c/c-typeck.cc
>>> #	modified:   gcc/cp/cp-tree.h
>>> #	modified:   gcc/cp/decl.cc
>>> #	modified:   gcc/cp/mangle.cc
>>> #	modified:   gcc/cp/parser.cc
>>> #	modified:   gcc/cp/pt.cc
>>> #	modified:   gcc/cp/tree.cc
>>> #	modified:   gcc/cp/typeck.cc
>>> #	modified:   gcc/doc/extend.texi
>>> #	new file:   gcc/testsuite/g++.dg/abi/mangle-addr-space1.C
>>> #	new file:   gcc/testsuite/g++.dg/abi/mangle-addr-space2.C
>>> #	new file:   gcc/testsuite/g++.dg/ext/addr-space-decl.C
>>> #	new file:   gcc/testsuite/g++.dg/ext/addr-space-ops.C
>>> #	new file:   gcc/testsuite/g++.dg/ext/addr-space-ref.C
>>> #	new file:   gcc/testsuite/g++.dg/parse/addr-space.C
>>> #	new file:   gcc/testsuite/g++.dg/parse/addr-space1.C
>>> #	new file:   gcc/testsuite/g++.dg/parse/addr-space2.C
>>> #	new file:   gcc/testsuite/g++.dg/template/spec-addr-space.C
>>> #	modified:   gcc/tree.h
>>> #
>>> # Untracked files:
>>> #	Makefile
>>> #	addr-space-decl.C
>>> #	addr-space-decl.s
>>> #	addr-space-ops.C
>>> #	addr-space-ref.C
>>> #	addr-space-template.C
>>> #	addr-space-template.s
>>> #	addr-space-template2.C
>>> #	addr-space-template2.C.006t.gimple
>>> #	addr-space-template2.s
>>> #	addr-space-traits.C
>>> #	addr-space4.C
>>> #	addr-space4.C.006t.gimple
>>> #	addr-space4.s
>>> #	build-x86_64-pc-linux-gnu/
>>> #	compare
>>> #	host-x86_64-pc-linux-gnu/
>>> #	mangle-addr-space1.s
>>> #	prev-x86_64-pc-linux-gnu/
>>> #	rename
>>> #	stage1-x86_64-pc-linux-gnu/
>>> #	stage_current
>>> #	stage_final
>>> #	stage_last
>>> #	x86_64-pc-linux-gnu/
>>> #
>>> # ------------------------ >8 ------------------------
>>> # Do not modify or remove the line above.
>>> # Everything below it will be ignored.
>>> diff --git a/gcc/c-family/c-common.cc b/gcc/c-family/c-common.cc
>>> index bb0544eeaea..ff1146ecc25 100644
>>> --- a/gcc/c-family/c-common.cc
>>> +++ b/gcc/c-family/c-common.cc
>>> @@ -615,6 +615,33 @@ c_addr_space_name (addr_space_t as)
>>>      return IDENTIFIER_POINTER (ridpointers [rid]);
>>>    }
>>> +/* Return true if between two named address spaces, whether there is a superset
>>> +   named address space that encompasses both address spaces.  If there is a
>>> +   superset, return which address space is the superset.  */
>>> +
>>> +bool
>>> +addr_space_superset (addr_space_t as1, addr_space_t as2,
>>> +		     addr_space_t * common)
>>> +{
>>> +  if (as1 == as2)
>>> +    {
>>> +      *common = as1;
>>> +      return true;
>>> +    }
>>> +  else if (targetm.addr_space.subset_p (as1, as2))
>>> +    {
>>> +      *common = as2;
>>> +      return true;
>>> +    }
>>> +  else if (targetm.addr_space.subset_p (as2, as1))
>>> +    {
>>> +      *common = as1;
>>> +      return true;
>>> +    }
>>> +  else
>>> +    return false;
>>> +}
>>> +
>>>    /* Push current bindings for the function name VAR_DECLS.  */
>>>    void
>>> @@ -2809,6 +2836,25 @@ c_build_bitfield_integer_type (unsigned HOST_WIDE_INT width, int unsignedp)
>>>      return build_nonstandard_integer_type (width, unsignedp);
>>>    }
>>> +/* Register reserved keyword WORD as qualifier for address space AS.  */
>>> +
>>> +void
>>> +c_register_addr_space (const char *word, addr_space_t as)
>>> +{
>>> +  int rid = RID_FIRST_ADDR_SPACE + as;
>>> +  tree id;
>>> +
>>> +  /* Address space qualifiers are only supported
>>> +     in C with GNU extensions enabled.  */
>>> +  if (c_dialect_objc () || flag_no_asm)
>>> +    return;
>>> +
>>> +  id = get_identifier (word);
>>> +  C_SET_RID_CODE (id, rid);
>>> +  TREE_LANG_FLAG_0 (id) = 1;
>>> +  ridpointers[rid] = id;
>>> +}
>>> +
>>>    /* The C version of the register_builtin_type langhook.  */
>>>    void
>>> diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
>>> index 52a85bfb783..d36f9e4975b 100644
>>> --- a/gcc/c-family/c-common.h
>>> +++ b/gcc/c-family/c-common.h
>>> @@ -829,12 +829,11 @@ extern const struct attribute_spec c_common_format_attribute_table[];
>>>    extern tree (*make_fname_decl) (location_t, tree, int);
>>> -/* In c-decl.cc and cp/tree.cc.  FIXME.  */
>>> -extern void c_register_addr_space (const char *str, addr_space_t as);
>>> -
>>>    /* In c-common.cc.  */
>>>    extern bool in_late_binary_op;
>>>    extern const char *c_addr_space_name (addr_space_t as);
>>> +extern const char *c_addr_space_name (addr_space_t as);
>>> +extern bool addr_space_superset (addr_space_t, addr_space_t, addr_space_t *);
>>>    extern tree identifier_global_value (tree);
>>>    extern tree identifier_global_tag (tree);
>>>    extern bool names_builtin_p (const char *);
>>> @@ -952,6 +951,7 @@ extern void c_common_finish (void);
>>>    extern void c_common_parse_file (void);
>>>    extern FILE *get_dump_info (int, dump_flags_t *);
>>>    extern alias_set_type c_common_get_alias_set (tree);
>>> +extern void c_register_addr_space (const char *, addr_space_t);
>>>    extern void c_register_builtin_type (tree, const char*);
>>>    extern bool c_promoting_integer_type_p (const_tree);
>>>    extern bool self_promoting_args_p (const_tree);
>>> diff --git a/gcc/c/c-decl.cc b/gcc/c/c-decl.cc
>>> index c701f07befe..e1bb4f1cf37 100644
>>> --- a/gcc/c/c-decl.cc
>>> +++ b/gcc/c/c-decl.cc
>>> @@ -12337,25 +12337,6 @@ c_parse_final_cleanups (void)
>>>      ext_block = NULL;
>>>    }
>>> -/* Register reserved keyword WORD as qualifier for address space AS.  */
>>> -
>>> -void
>>> -c_register_addr_space (const char *word, addr_space_t as)
>>> -{
>>> -  int rid = RID_FIRST_ADDR_SPACE + as;
>>> -  tree id;
>>> -
>>> -  /* Address space qualifiers are only supported
>>> -     in C with GNU extensions enabled.  */
>>> -  if (c_dialect_objc () || flag_no_asm)
>>> -    return;
>>> -
>>> -  id = get_identifier (word);
>>> -  C_SET_RID_CODE (id, rid);
>>> -  C_IS_RESERVED_WORD (id) = 1;
>>> -  ridpointers [rid] = id;
>>> -}
>>> -
>>>    /* Return identifier to look up for omp declare reduction.  */
>>>    tree
>>> diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc
>>> index b271af9bedb..c4b01368534 100644
>>> --- a/gcc/c/c-typeck.cc
>>> +++ b/gcc/c/c-typeck.cc
>>> @@ -296,32 +296,6 @@ c_type_promotes_to (tree type)
>>>      return type;
>>>    }
>>> -/* Return true if between two named address spaces, whether there is a superset
>>> -   named address space that encompasses both address spaces.  If there is a
>>> -   superset, return which address space is the superset.  */
>>> -
>>> -static bool
>>> -addr_space_superset (addr_space_t as1, addr_space_t as2, addr_space_t *common)
>>> -{
>>> -  if (as1 == as2)
>>> -    {
>>> -      *common = as1;
>>> -      return true;
>>> -    }
>>> -  else if (targetm.addr_space.subset_p (as1, as2))
>>> -    {
>>> -      *common = as2;
>>> -      return true;
>>> -    }
>>> -  else if (targetm.addr_space.subset_p (as2, as1))
>>> -    {
>>> -      *common = as1;
>>> -      return true;
>>> -    }
>>> -  else
>>> -    return false;
>>> -}
>>> -
>>>    /* Return a variant of TYPE which has all the type qualifiers of LIKE
>>>       as well as those of TYPE.  */
>>> diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
>>> index 72f4398a8f9..82a6d72f5df 100644
>>> --- a/gcc/cp/cp-tree.h
>>> +++ b/gcc/cp/cp-tree.h
>>> @@ -6206,6 +6206,7 @@ enum cp_decl_spec {
>>>      ds_const,
>>>      ds_volatile,
>>>      ds_restrict,
>>> +  ds_addr_space,
>>>      ds_inline,
>>>      ds_virtual,
>>>      ds_explicit,
>>> @@ -6252,6 +6253,8 @@ struct cp_decl_specifier_seq {
>>>      cp_storage_class storage_class;
>>>      /* For the __intN declspec, this stores the index into the int_n_* arrays.  */
>>>      int int_n_idx;
>>> +  /* The address space that the declaration belongs to.  */
>>> +  addr_space_t address_space;
>>>      /* True iff TYPE_SPEC defines a class or enum.  */
>>>      BOOL_BITFIELD type_definition_p : 1;
>>>      /* True iff multiple types were (erroneously) specified for this
>>> diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
>>> index 9f78c500a15..fa5a1ddb21d 100644
>>> --- a/gcc/cp/decl.cc
>>> +++ b/gcc/cp/decl.cc
>>> @@ -5280,6 +5280,8 @@ get_type_quals (const cp_decl_specifier_seq *declspecs)
>>>        type_quals |= TYPE_QUAL_VOLATILE;
>>>      if (decl_spec_seq_has_spec_p (declspecs, ds_restrict))
>>>        type_quals |= TYPE_QUAL_RESTRICT;
>>> +  if (decl_spec_seq_has_spec_p (declspecs, ds_addr_space))
>>> +    type_quals |= ENCODE_QUAL_ADDR_SPACE (declspecs->address_space);
>>>      return type_quals;
>>>    }
>>> @@ -5402,6 +5404,10 @@ check_tag_decl (cp_decl_specifier_seq *declspecs,
>>>    	error_at (declspecs->locations[ds_restrict],
>>>    		  "%<__restrict%> can only be specified for objects and "
>>>    		  "functions");
>>> +      else if (decl_spec_seq_has_spec_p (declspecs, ds_addr_space))
>>> +	error_at (declspecs->locations[ds_addr_space],
>>> +		  "address space can only be specified for objects and "
>>> +		  "functions");
>>>          else if (decl_spec_seq_has_spec_p (declspecs, ds_thread))
>>>    	error_at (declspecs->locations[ds_thread],
>>>    		  "%<__thread%> can only be specified for objects "
>>> @@ -14572,6 +14578,57 @@ grokdeclarator (const cp_declarator *declarator,
>>>        if (!processing_template_decl)
>>>          cp_apply_type_quals_to_decl (type_quals, decl);
>>> +    addr_space_t address_space = declspecs->address_space;
>>> +    if (!ADDR_SPACE_GENERIC_P (address_space) && !INDIRECT_TYPE_P (type))
>>> +      {
>>> +	if (decl_context == NORMAL)
>>> +	  {
>>> +	    switch (storage_class)
>>> +	      {
>>> +	      case sc_auto:
>>> +		error ("%qs combined with C++98 %<auto%> qualifier for %qs",
>>> +		       c_addr_space_name (address_space), name);
>>> +		break;
>>> +	      case sc_register:
>>> +		error ("%qs combined with %<register%> qualifier for %qs",
>>> +		       c_addr_space_name (address_space), name);
>>> +		break;
>>> +	      case sc_none:
>>> +		if (! toplevel_bindings_p ())
>>> +		  error ("%qs specified for auto variable %qs",
>>> +			 c_addr_space_name (address_space), name);
>>> +		break;
>>> +	      case sc_mutable:
>>> +		error ("%qs combined with %<mutable%> qualifier for %qs",
>>> +		       c_addr_space_name (address_space), name);
>>> +		break;
>>> +	      case sc_static:
>>> +	      case sc_extern:
>>> +		break;
>>> +	      default:
>>> +		gcc_unreachable ();
>>> +	      }
>>> +	  }
>>> +	else if (decl_context == PARM && TREE_CODE (type) != ARRAY_TYPE)
>>> +	  {
>>> +	    if (name)
>>> +	      error ("%qs specified for parameter %qs",
>>> +		     c_addr_space_name (address_space), name);
>>> +	    else
>>> +	      error ("%qs specified for unnamed parameter",
>>> +		     c_addr_space_name (address_space));
>>> +	  }
>>> +	else if (decl_context == FIELD)
>>> +	  {
>>> +	    if (name)
>>> +	      error ("%qs specified for structure field %qs",
>>> +		     c_addr_space_name (address_space), name);
>>> +	    else
>>> +	      error ("%qs specified for structure field",
>>> +		     c_addr_space_name (address_space));
>>> +	  }
>>> +      }
>>> +
>>>        return decl;
>>>      }
>>>    }
>>> diff --git a/gcc/cp/mangle.cc b/gcc/cp/mangle.cc
>>> index eb53e0ebeb4..16cb2ff4332 100644
>>> --- a/gcc/cp/mangle.cc
>>> +++ b/gcc/cp/mangle.cc
>>> @@ -2509,6 +2509,14 @@ write_CV_qualifiers_for_type (const tree type)
>>>         array.  */
>>>      cp_cv_quals quals = TYPE_QUALS (type);
>>> +  if (addr_space_t as = DECODE_QUAL_ADDR_SPACE (quals))
>>> +    {
>>> +      const char *as_name = c_addr_space_name (as);
>>> +      write_char ('U');
>>> +      write_unsigned_number (strlen (as_name));
>>> +      write_string (as_name);
>>> +      ++num_qualifiers;
>>> +    }
>>>      if (quals & TYPE_QUAL_RESTRICT)
>>>        {
>>>          write_char ('r');
>>> diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
>>> index 763df6f479b..f0169d83ab0 100644
>>> --- a/gcc/cp/parser.cc
>>> +++ b/gcc/cp/parser.cc
>>> @@ -7640,6 +7640,14 @@ cp_parser_postfix_expression (cp_parser *parser, bool address_p, bool cast_p,
>>>    		    postfix_expression = error_mark_node;
>>>    		    break;
>>>    		  }
>>> +		if (type != error_mark_node
>>> +		    && !ADDR_SPACE_GENERIC_P (TYPE_ADDR_SPACE (type))
>>> +		    && current_function_decl)
>>> +		  {
>>> +		    error
>>> +		      ("compound literal qualified by address-space qualifier");
>>> +		    type = error_mark_node;
>>> +		  }
>>>    		/* Form the representation of the compound-literal.  */
>>>    		postfix_expression
>>>    		  = finish_compound_literal (type, initializer,
>>> @@ -19408,6 +19416,15 @@ cp_parser_type_specifier (cp_parser* parser,
>>>          break;
>>>        }
>>> +
>>> +  if (RID_FIRST_ADDR_SPACE <= keyword && keyword <= RID_LAST_ADDR_SPACE)
>>> +    {
>>> +      ds = ds_addr_space;
>>> +      if (is_cv_qualifier)
>>> +	*is_cv_qualifier = true;
>>> +    }
>>> +
>>> +
>>>      /* Handle simple keywords.  */
>>>      if (ds != ds_last)
>>>        {
>>> @@ -23776,6 +23793,7 @@ cp_parser_ptr_operator (cp_parser* parser,
>>>       GNU Extension:
>>>       cv-qualifier:
>>> +     address-space-qualifier
>>>         __restrict__
>>>       Returns a bitmask representing the cv-qualifiers.  */
>>> @@ -23812,6 +23830,11 @@ cp_parser_cv_qualifier_seq_opt (cp_parser* parser)
>>>    	  break;
>>>    	}
>>> +      if (RID_FIRST_ADDR_SPACE <= token->keyword &&
>>> +	  token->keyword <= RID_LAST_ADDR_SPACE)
>>> +	cv_qualifier =
>>> +	  ENCODE_QUAL_ADDR_SPACE (token->keyword - RID_FIRST_ADDR_SPACE);
>>> +
>>>          if (!cv_qualifier)
>>>    	break;
>>> @@ -32705,6 +32728,8 @@ set_and_check_decl_spec_loc (cp_decl_specifier_seq *decl_specs,
>>>          decl_specs->locations[ds] = location;
>>>          if (ds == ds_thread)
>>>    	decl_specs->gnu_thread_keyword_p = token_is__thread (token);
>>> +      else if (ds == ds_addr_space)
>>> +	decl_specs->address_space = token->keyword - RID_FIRST_ADDR_SPACE;
>>>        }
>>>      else
>>>        {
>>> @@ -32737,6 +32762,25 @@ set_and_check_decl_spec_loc (cp_decl_specifier_seq *decl_specs,
>>>    	      error_at (&richloc, "duplicate %qD", token->u.value);
>>>    	    }
>>>    	}
>>> +      else if (ds == ds_addr_space)
>>> +	{
>>> +	  addr_space_t as1 = decl_specs->address_space;
>>> +	  addr_space_t as2 = token->keyword - RID_FIRST_ADDR_SPACE;
>>> +
>>> +	  gcc_rich_location richloc (location);
>>> +	  richloc.add_fixit_remove ();
>>> +	  if (!ADDR_SPACE_GENERIC_P (as1) && !ADDR_SPACE_GENERIC_P (as2)
>>> +	      && as1 != as2)
>>> +	    error_at (&richloc,
>>> +		      "conflicting named address spaces (%s vs %s)",
>>> +		      c_addr_space_name (as1), c_addr_space_name (as2));
>>> +	  if (as1 == as2 && !ADDR_SPACE_GENERIC_P (as1))
>>> +	    error_at (&richloc,
>>> +		      "duplicate named address space %s",
>>> +		      c_addr_space_name (as1));
>>> +
>>> +	  decl_specs->address_space = as2;
>>> +	}
>>>          else
>>>    	{
>>>    	  static const char *const decl_spec_names[] = {
>>> diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
>>> index bef31416fb7..c9d1c01f4ce 100644
>>> --- a/gcc/cp/pt.cc
>>> +++ b/gcc/cp/pt.cc
>>> @@ -23655,8 +23655,19 @@ template_decl_level (tree decl)
>>>    static int
>>>    check_cv_quals_for_unify (int strict, tree arg, tree parm)
>>>    {
>>> -  int arg_quals = cp_type_quals (arg);
>>> -  int parm_quals = cp_type_quals (parm);
>>> +  int arg_quals = CLEAR_QUAL_ADDR_SPACE (cp_type_quals (arg));
>>> +  int parm_quals = CLEAR_QUAL_ADDR_SPACE (cp_type_quals (parm));
>>> +
>>> +  /*  Try to unify ARG's address space into PARM's address space.
>>> +      If PARM does not have any address space qualifiers (ie., as_parm is 0),
>>> +      there are no constraints on address spaces for this type.  */
>>> +  addr_space_t as_arg = DECODE_QUAL_ADDR_SPACE (cp_type_quals (arg));
>>> +  addr_space_t as_parm = DECODE_QUAL_ADDR_SPACE (cp_type_quals (parm));
>>> +  addr_space_t as_common;
>>> +  addr_space_superset (as_arg, as_parm, &as_common);
>>> +
>>> +  if (!(as_parm == as_common || as_parm == 0))
>>> +    return 0;
>>>      if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
>>>          && !(strict & UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
>>> @@ -24292,10 +24303,26 @@ unify (tree tparms, tree targs, tree parm, tree arg, int strict,
>>>    					 arg, parm))
>>>    	    return unify_cv_qual_mismatch (explain_p, parm, arg);
>>> +	  int arg_cv_quals = cp_type_quals (arg);
>>> +	  int parm_cv_quals = cp_type_quals (parm);
>>> +
>>> +	  /* If PARM does not contain any address space constraints it can
>>> +	     fully match the address space of ARG.  However, if PARM contains an
>>> +	     address space constraint, it becomes the upper bound.  That is,
>>> +	     AS_ARG may be promoted to AS_PARM but not the converse.  If we
>>> +	     ended up here, it means that `check_cv_quals_for_unify' succeeded
>>> +	     and that either AS_PARM is 0 (ie., no constraints) or AS_COMMON ==
>>> +	     AS_PARM.  */
>>> +	  addr_space_t as_arg = DECODE_QUAL_ADDR_SPACE (arg_cv_quals);
>>> +	  addr_space_t as_parm = DECODE_QUAL_ADDR_SPACE (parm_cv_quals);
>>> +	  addr_space_t as_common = as_parm ? 0 : as_arg;
>>> +
>>>    	  /* Consider the case where ARG is `const volatile int' and
>>>    	     PARM is `const T'.  Then, T should be `volatile int'.  */
>>> -	  arg = cp_build_qualified_type_real
>>> -	    (arg, cp_type_quals (arg) & ~cp_type_quals (parm), tf_none);
>>> +	  int unified_cv =
>>> +	    CLEAR_QUAL_ADDR_SPACE (arg_cv_quals & ~parm_cv_quals)
>>> +	    | ENCODE_QUAL_ADDR_SPACE (as_common);
>>> +	  arg = cp_build_qualified_type_real (arg, unified_cv, tf_none);
>>>    	  if (arg == error_mark_node)
>>>    	    return unify_invalid (explain_p);
>>> diff --git a/gcc/cp/tree.cc b/gcc/cp/tree.cc
>>> index 3b37567cbd7..5e14ac837fc 100644
>>> --- a/gcc/cp/tree.cc
>>> +++ b/gcc/cp/tree.cc
>>> @@ -6048,15 +6048,6 @@ cp_free_lang_data (tree t)
>>>        DECL_CHAIN (t) = NULL_TREE;
>>>    }
>>> -/* Stub for c-common.  Please keep in sync with c-decl.cc.
>>> -   FIXME: If address space support is target specific, then this
>>> -   should be a C target hook.  But currently this is not possible,
>>> -   because this function is called via REGISTER_TARGET_PRAGMAS.  */
>>> -void
>>> -c_register_addr_space (const char * /*word*/, addr_space_t /*as*/)
>>> -{
>>> -}
>>> -
>>>    /* Return the number of operands in T that we care about for things like
>>>       mangling.  */
>>> diff --git a/gcc/cp/typeck.cc b/gcc/cp/typeck.cc
>>> index ceb80d9744f..7d810c6a12c 100644
>>> --- a/gcc/cp/typeck.cc
>>> +++ b/gcc/cp/typeck.cc
>>> @@ -656,10 +656,26 @@ composite_pointer_type (const op_location_t &location,
>>>    	  else
>>>    	    return error_mark_node;
>>>            }
>>> +      /* If possible merge the address space into the superset of the address
>>> +	  spaces of t1 and t2, or raise an error. */
>>> +      addr_space_t as_t1 = TYPE_ADDR_SPACE (t1);
>>> +      addr_space_t as_t2 = TYPE_ADDR_SPACE (t2);
>>> +      addr_space_t as_common;
>>> +
>>> +      /* If the two named address spaces are different, determine the common
>>> +	 superset address space.  If there isn't one, raise an error.  */
>>> +      if (!addr_space_superset (as_t1, as_t2, &as_common))
>>> +	{
>>> +	  as_common = as_t1;
>>> +	  error_at (location,
>>> +		    "%qT and %qT are in disjoint named address spaces",
>>> +		    t1, t2);
>>> +	}
>>>          result_type
>>>    	= cp_build_qualified_type (void_type_node,
>>> -				   (cp_type_quals (TREE_TYPE (t1))
>>> -				    | cp_type_quals (TREE_TYPE (t2))));
>>> +				   (CLEAR_QUAL_ADDR_SPACE (cp_type_quals (TREE_TYPE (t1)))
>>> +				    | CLEAR_QUAL_ADDR_SPACE (cp_type_quals (TREE_TYPE (t2)))
>>> +				    | ENCODE_QUAL_ADDR_SPACE (as_common)));
>>>          result_type = build_pointer_type (result_type);
>>>          /* Merge the attributes.  */
>>>          attributes = (*targetm.merge_type_attributes) (t1, t2);
>>> @@ -1579,7 +1595,9 @@ comptypes (tree t1, tree t2, int strict)
>>>    }
>>>    /* Returns nonzero iff TYPE1 and TYPE2 are the same type, ignoring
>>> -   top-level qualifiers.  */
>>> +   top-level qualifiers, except for named address spaces.  If the pointers point
>>> +   to different named addresses spaces, then we must determine if one address
>>> +   space is a subset of the other.  */
>>>    bool
>>>    same_type_ignoring_top_level_qualifiers_p (tree type1, tree type2)
>>> @@ -1589,6 +1607,14 @@ same_type_ignoring_top_level_qualifiers_p (tree type1, tree type2)
>>>      if (type1 == type2)
>>>        return true;
>>> +  addr_space_t as_type1 = TYPE_ADDR_SPACE (type1);
>>> +  addr_space_t as_type2 = TYPE_ADDR_SPACE (type2);
>>> +  addr_space_t as_common;
>>> +
>>> +  /* Fail if pointers point to incompatible address spaces.  */
>>> +  if (!addr_space_superset (as_type1, as_type2, &as_common))
>>> +    return false;
>>> +
>>>      type1 = cp_build_qualified_type (type1, TYPE_UNQUALIFIED);
>>>      type2 = cp_build_qualified_type (type2, TYPE_UNQUALIFIED);
>>>      return same_type_p (type1, type2);
>>> @@ -6374,10 +6400,32 @@ static tree
>>>    pointer_diff (location_t loc, tree op0, tree op1, tree ptrtype,
>>>    	      tsubst_flags_t complain, tree *instrument_expr)
>>>    {
>>> -  tree result, inttype;
>>>      tree restype = ptrdiff_type_node;
>>> +  tree result, inttype;
>>> +
>>> +  addr_space_t as0 = TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (op0)));
>>> +  addr_space_t as1 = TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (op1)));
>>>      tree target_type = TREE_TYPE (ptrtype);
>>> +  /* If the operands point into different address spaces, we need to
>>> +     explicitly convert them to pointers into the common address space
>>> +     before we can subtract the numerical address values.  */
>>> +  if (as0 != as1)
>>> +    {
>>> +      addr_space_t as_common;
>>> +      tree common_type;
>>> +
>>> +      /* Determine the common superset address space.  This is guaranteed
>>> +	 to exist because the caller verified that comp_target_types
>>> +	 returned non-zero.  */
>>> +      if (!addr_space_superset (as0, as1, &as_common))
>>> +	gcc_unreachable ();
>>> +
>>> +      common_type = common_pointer_type (TREE_TYPE (op0), TREE_TYPE (op1));
>>> +      op0 = convert (common_type, op0);
>>> +      op1 = convert (common_type, op1);
>>> +    }
>>> +
>>>      if (!complete_type_or_maybe_complain (target_type, NULL_TREE, complain))
>>>        return error_mark_node;
>>> @@ -10805,6 +10853,19 @@ comp_ptr_ttypes_real (tree to, tree from, int constp)
>>>    	      to_more_cv_qualified = true;
>>>    	    }
>>> +      /* Warn about conversions between pointers to disjoint
>>> +	 address spaces.  */
>>> +      if (TREE_CODE (from) == POINTER_TYPE
>>> +	  && TREE_CODE (to) == POINTER_TYPE)
>>> +	{
>>> +	  addr_space_t as_from = TYPE_ADDR_SPACE (TREE_TYPE (from));
>>> +	  addr_space_t as_to = TYPE_ADDR_SPACE (TREE_TYPE (to));
>>> +	  addr_space_t as_common;
>>> +
>>> +	  if (!addr_space_superset (as_to, as_from, &as_common))
>>> +	    return false;
>>> +	}
>>> +
>>>    	  if (constp > 0)
>>>    	    constp &= TYPE_READONLY (to);
>>>    	}
>>> diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
>>> index ac3db88566d..1e0d436c02c 100644
>>> --- a/gcc/doc/extend.texi
>>> +++ b/gcc/doc/extend.texi
>>> @@ -1448,7 +1448,7 @@ Fixed-point types are supported by the DWARF debug information format.
>>>    @section Named Address Spaces
>>>    @cindex Named Address Spaces
>>> -As an extension, GNU C supports named address spaces as
>>> +As an extension, GNU C and GNU C++ support named address spaces as
>>>    defined in the N1275 draft of ISO/IEC DTR 18037.  Support for named
>>>    address spaces in GCC will evolve as the draft technical report
>>>    changes.  Calling conventions for any target might also change.  At
>>> diff --git a/gcc/testsuite/g++.dg/abi/mangle-addr-space1.C b/gcc/testsuite/g++.dg/abi/mangle-addr-space1.C
>>> new file mode 100644
>>> index 00000000000..c01f8d6054a
>>> --- /dev/null
>>> +++ b/gcc/testsuite/g++.dg/abi/mangle-addr-space1.C
>>> @@ -0,0 +1,10 @@
>>> +// { dg-do run { target { i?86-*-* x86_64-*-* } } }
>>> +// { dg-options "-fabi-version=8 -Wabi -save-temps" }
>>> +// { dg-final { scan-assembler "_Z1fPU8__seg_fsVi" } }
>>> +
>>> +int f (int volatile __seg_fs *a)
>>> +{
>>> +  return *a;
>>> +}
>>> +
>>> +int main () {}
>>> diff --git a/gcc/testsuite/g++.dg/abi/mangle-addr-space2.C b/gcc/testsuite/g++.dg/abi/mangle-addr-space2.C
>>> new file mode 100644
>>> index 00000000000..862bbbdcdf2
>>> --- /dev/null
>>> +++ b/gcc/testsuite/g++.dg/abi/mangle-addr-space2.C
>>> @@ -0,0 +1,9 @@
>>> +// { dg-do run { target { i?86-*-* x86_64-*-* } } }
>>> +// { dg-options "-fabi-version=8 -Wabi -save-temps" }
>>> +// { dg-final { scan-assembler "_Z1fIU8__seg_fsiEiPT_" } }
>>> +
>>> +template <class T>
>>> +int f (T *p) { return *p; }
>>> +int g (__seg_fs int *p) { return *p; }
>>> +__seg_fs int *a;
>>> +int main() { f(a); }
>>> diff --git a/gcc/testsuite/g++.dg/ext/addr-space-decl.C b/gcc/testsuite/g++.dg/ext/addr-space-decl.C
>>> new file mode 100644
>>> index 00000000000..c04d2f497da
>>> --- /dev/null
>>> +++ b/gcc/testsuite/g++.dg/ext/addr-space-decl.C
>>> @@ -0,0 +1,5 @@
>>> +// { dg-do compile { target { i?86-*-* x86_64-*-* } } }
>>> +__seg_fs char a, b, c;
>>> +__seg_fs const int *p;
>>> +static /* give internal linkage to the following anonymous struct */
>>> +__seg_fs struct { int a; char b; } * __seg_gs q;
>>> diff --git a/gcc/testsuite/g++.dg/ext/addr-space-ops.C b/gcc/testsuite/g++.dg/ext/addr-space-ops.C
>>> new file mode 100644
>>> index 00000000000..86c02d1e7f5
>>> --- /dev/null
>>> +++ b/gcc/testsuite/g++.dg/ext/addr-space-ops.C
>>> @@ -0,0 +1,20 @@
>>> +// { dg-do compile { target { i?86-*-* x86_64-*-* } } }
>>> +int __seg_fs * fs1;
>>> +int __seg_fs * fs2;
>>> +float __seg_gs * gs1;
>>> +float __seg_gs * gs2;
>>> +
>>> +int
>>> +main ()
>>> +{
>>> +  fs1 + fs2; // { dg-error "invalid operands of types .__seg_fs int.. and .__seg_fs int.. to binary .operator.." }
>>> +  fs1 - fs2;
>>> +  fs1 - gs2; // { dg-error "invalid operands of types .__seg_fs int.. and .__seg_gs float.. to binary .operator.." }
>>> +  fs1 == fs2;
>>> +  fs1 != gs2; // { dg-error "comparison between distinct pointer types .__seg_fs int.. and .__seg_gs float.. lacks a cast" }
>>> +  fs1 = fs2;
>>> +  fs1 = gs2; // { dg-error "cannot convert .__seg_gs float.. to .__seg_fs int.. in assignment" }
>>> +  fs1 > fs2;
>>> +  fs1 < gs2; // { dg-error "comparison between distinct pointer types .__seg_fs int.. and .__seg_gs float.. lacks a cast" }
>>> +  return 0;
>>> +}
>>> diff --git a/gcc/testsuite/g++.dg/ext/addr-space-ref.C b/gcc/testsuite/g++.dg/ext/addr-space-ref.C
>>> new file mode 100644
>>> index 00000000000..12d7975e560
>>> --- /dev/null
>>> +++ b/gcc/testsuite/g++.dg/ext/addr-space-ref.C
>>> @@ -0,0 +1,31 @@
>>> +// { dg-do compile { target { i?86-*-* x86_64-*-* } } }
>>> +// { dg-prune-output "does not allow .register. storage class specifier" }
>>> +int __seg_fs * outer_b;
>>> +
>>> +struct s {
>>> +  __seg_fs int * ok;
>>> +  __seg_gs int ko; // { dg-error ".__seg_gs. specified for structure field .ko." }
>>> +};
>>> +
>>> +int register __seg_fs reg_fs; // { dg-error ".__seg_fs. combined with .register. qualifier for .reg_fs." }
>>> +
>>> +namespace ns_a
>>> +{
>>> +  int __seg_fs * inner_b;
>>> +
>>> +  template<typename T>
>>> +  int f (T &a) { return a; }
>>> +  int g (__seg_fs int a) { return a; } // { dg-error ".__seg_fs. specified for parameter .a." }
>>> +  int h (__seg_fs int *a) { return *a; }
>>> +}
>>> +
>>> +int
>>> +main ()
>>> +{
>>> +  int register __seg_gs reg_gs; // { dg-error ".__seg_gs. combined with .register. qualifier for .reg_gs." }
>>> +  static __seg_gs int static_gs;
>>> +  __seg_fs int auto_fs; // { dg-error ".__seg_fs. specified for auto variable .auto_fs." }
>>> +  __seg_fs int *pa = outer_b;
>>> +  __seg_fs int& ra = *ns_a::inner_b;
>>> +  return ns_a::f(ra) + ns_a::f(*pa);
>>> +}
>>> diff --git a/gcc/testsuite/g++.dg/parse/addr-space.C b/gcc/testsuite/g++.dg/parse/addr-space.C
>>> new file mode 100644
>>> index 00000000000..ebb6316054a
>>> --- /dev/null
>>> +++ b/gcc/testsuite/g++.dg/parse/addr-space.C
>>> @@ -0,0 +1,9 @@
>>> +// { dg-do compile { target { i?86-*-* x86_64-*-* } } }
>>> +
>>> +__seg_fs struct foo; // { dg-error "address space can only be specified for objects and functions" }
>>> +
>>> +int
>>> +main ()
>>> +{
>>> +	return 0;
>>> +}
>>> diff --git a/gcc/testsuite/g++.dg/parse/addr-space1.C b/gcc/testsuite/g++.dg/parse/addr-space1.C
>>> new file mode 100644
>>> index 00000000000..2e8ee32a885
>>> --- /dev/null
>>> +++ b/gcc/testsuite/g++.dg/parse/addr-space1.C
>>> @@ -0,0 +1,10 @@
>>> +// { dg-do compile { target { i?86-*-* x86_64-*-* } } }
>>> +// { dg-options "-std=gnu++98" }
>>> +
>>> +int
>>> +main ()
>>> +{
>>> +	struct foo {int a; char b[2];} structure;
>>> +	structure = ((__seg_fs struct foo) {1 + 2, 'a', 0}); // { dg-error "compound literal qualified by address-space qualifier" }
>>> +	return 0;
>>> +}
>>> diff --git a/gcc/testsuite/g++.dg/parse/addr-space2.C b/gcc/testsuite/g++.dg/parse/addr-space2.C
>>> new file mode 100644
>>> index 00000000000..5b2c0f28078
>>> --- /dev/null
>>> +++ b/gcc/testsuite/g++.dg/parse/addr-space2.C
>>> @@ -0,0 +1,9 @@
>>> +// { dg-do compile { target { i?86-*-* x86_64-*-* } } }
>>> +
>>> +__seg_fs __seg_gs int *a; // { dg-error "conflicting named address spaces .__seg_fs vs __seg_gs." }
>>> +
>>> +int
>>> +main ()
>>> +{
>>> +	return 0;
>>> +}
>>> diff --git a/gcc/testsuite/g++.dg/template/spec-addr-space.C b/gcc/testsuite/g++.dg/template/spec-addr-space.C
>>> new file mode 100644
>>> index 00000000000..ae9f4de0e1f
>>> --- /dev/null
>>> +++ b/gcc/testsuite/g++.dg/template/spec-addr-space.C
>>> @@ -0,0 +1,8 @@
>>> +// { dg-do compile { target { i?86-*-* x86_64-*-* } } }
>>> +
>>> +template <class T>
>>> +int f (T __seg_gs *p) { return *p; } // { dg-note "candidate: 'template<class T> int f.__seg_gs T\*." }
>>> +				     // { dg-note "template argument deduction/substitution failed:" "" { target *-*-* } .-1 }
>>> +__seg_fs int *a;
>>> +int main() { f(a); } // { dg-error "no matching" }
>>> +// { dg-note "types .__seg_gs T. and .__seg_fs int. have incompatible cv-qualifiers" "" { target *-*-* } .-1 }
>>> diff --git a/gcc/tree.h b/gcc/tree.h
>>> index 8844471e9a5..b7da4c5141a 100644
>>> --- a/gcc/tree.h
>>> +++ b/gcc/tree.h
>>> @@ -2229,7 +2229,7 @@ extern tree vector_element_bits_tree (const_tree);
>>>    /* Encode/decode the named memory support as part of the qualifier.  If more
>>>       than 8 qualifiers are added, these macros need to be adjusted.  */
>>> -#define ENCODE_QUAL_ADDR_SPACE(NUM) ((NUM & 0xFF) << 8)
>>> +#define ENCODE_QUAL_ADDR_SPACE(NUM) (((NUM) & 0xFF) << 8)
>>>    #define DECODE_QUAL_ADDR_SPACE(X) (((X) >> 8) & 0xFF)
>>>    /* Return all qualifiers except for the address space qualifiers.  */
>>>
>>>
>>>
>>>
>>
>>
>>
>>
>>
>>
>>
> 
> 
> 
> 
> 


  reply	other threads:[~2022-10-13 15:47 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-06 14:34 [RFC] " Paul Iannetta
2022-10-06 17:34 ` Jason Merrill
2022-10-09 16:12   ` [PATCH] " Paul Iannetta
2022-10-10 19:20     ` Jason Merrill
2022-10-11 22:03       ` [PATCH v2] " Paul Iannetta
2022-10-12  1:49         ` Jason Merrill
2022-10-13  0:52           ` Paul Iannetta
2022-10-13  5:46             ` Jakub Jelinek
2022-10-13 15:14               ` Paul Iannetta
2022-10-13 15:02             ` Jason Merrill
2022-10-13 15:23               ` Paul Iannetta
2022-10-13 15:47                 ` Jason Merrill [this message]
2022-10-13 16:02                   ` Paul Iannetta
2022-10-13 19:41                     ` Jason Merrill
2022-10-13 21:57                       ` Paul Iannetta
2022-10-14 15:19                         ` Jason Merrill
2022-10-18  7:37                           ` [PATCH v3] " Paul Iannetta
2022-10-18 14:24                             ` Jason Merrill
2022-10-18 17:01                               ` Paul Iannetta
2022-10-19 18:55                                 ` Jason Merrill
2022-10-26  7:18                                   ` Paul Iannetta
2022-10-26 16:28                                     ` Jason Merrill
2022-11-10 15:42                                       ` [PATCH v4] " Paul Iannetta
2022-11-03 13:38                                     ` [PATCH v3] " Georg-Johann Lay
2022-11-10 14:08                                       ` Paul Iannetta
2022-11-10 16:40                                         ` Georg-Johann Lay
2022-11-14 17:55                                           ` Jason Merrill
2022-11-15 12:15                                             ` Georg-Johann Lay

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