Implement P0482R5, char8_t: A type for UTF-8 characters and strings

gcc/cp/
	* cvt.c (type_promotes_to): Handle char8_t promotion.
	* decl.c (grokdeclarator): Handle invalid type specifier
	combinations involving char8_t.
	* lex.c (init_reswords): Add char8_t as a reserved word.
	* mangle.c (write_builtin_type): Add name mangling for char8_t (Du).
	* parser.c (cp_keyword_starts_decl_specifier_p)
	(cp_parser_simple_type_specifier): Recognize char8_t as a simple
	type specifier.
	(cp_parser_string_literal): Use char8_array_type_node for the type
	of CPP_UTF8STRING.
	(cp_parser_set_decl_spec_type): Tolerate char8_t typedefs in system
	headers.
	* rtti.c (emit_support_tinfos): type_info support for char8_t.
	* tree.c (char_type_p): Recognize char8_t as a character type.
	* typeck.c (string_conv_p): Handle conversions of u8 string
	literals of char8_t type.
	(check_literal_operator_args): Handle UDLs with u8 string literals
	of char8_t type.
	* typeck2.c (ordinary_char_type_p): New.
	(digest_init_r): Disallow initializing a char array with a u8 string
	literal.
gcc/c-family/
	* c-common.c (c_common_reswords): Add char8_t.
	(fix_string_type): Use char8_t for the type of u8 string literals.
	(c_common_get_alias_set): char8_t doesn't alias.
	(c_common_nodes_and_builtins): Define char8_t as a builtin type in
	C++.
	(c_stddef_cpp_builtins): Add __CHAR8_TYPE__.
	(keyword_begins_type_specifier): Add RID_CHAR8.
	* c-common.h (rid): Add RID_CHAR8.
	(c_tree_index): Add CTI_CHAR8_TYPE and CTI_CHAR8_ARRAY_TYPE.
	Define D_CXX_CHAR8_T and D_CXX_CHAR8_T_FLAGS.
	Define char8_type_node and char8_array_type_node.
	* c-cppbuiltin.c (cpp_atomic_builtins): Predefine
	__GCC_ATOMIC_CHAR8_T_LOCK_FREE.
	(c_cpp_builtins): Predefine __cpp_char8_t.
	* c-lex.c (lex_string): Use char8_array_type_node as the type of
	CPP_UTF8STRING.
	(lex_charconst): Use char8_type_node as the type of CPP_UTF8CHAR.
	* c-opts.c: If not otherwise specified, enable -fchar8_t when
	targeting C++2a.
	* c.opt: Add the -fchar8_t command line option.
libiberty/
	* cp-demangle.c (cplus_demangle_builtin_types)
	(cplus_demangle_type): Add name demangling for char8_t (Du).
	* cp-demangle.h: Increase D_BUILTIN_TYPE_COUNT to accommodate the
	new char8_t type.

From-SVN: r267923

1 files changed, 21 insertions, 12 deletions

diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
index 9f790bc..9fe90f3 100644
--- a/gcc/c-family/c-common.h
+++ b/gcc/c-family/c-common.h
@@ -180,6 +180,9 @@ enum rid
   /* C++11 */
   RID_CONSTEXPR, RID_DECLTYPE, RID_NOEXCEPT, RID_NULLPTR, RID_STATIC_ASSERT,
 
+  /* char8_t */
+  RID_CHAR8,
+
   /* C++ concepts */
   RID_CONCEPT, RID_REQUIRES,
 
@@ -287,6 +290,7 @@ extern GTY ((length ("(int) RID_MAX"))) tree *ridpointers;
 
 enum c_tree_index
 {
+    CTI_CHAR8_TYPE,
     CTI_CHAR16_TYPE,
     CTI_CHAR32_TYPE,
     CTI_WCHAR_TYPE,
@@ -330,6 +334,7 @@ enum c_tree_index
     CTI_UINTPTR_TYPE,
 
     CTI_CHAR_ARRAY_TYPE,
+    CTI_CHAR8_ARRAY_TYPE,
     CTI_CHAR16_ARRAY_TYPE,
     CTI_CHAR32_ARRAY_TYPE,
     CTI_WCHAR_ARRAY_TYPE,
@@ -409,20 +414,22 @@ extern machine_mode c_default_pointer_mode;
    mask) is _true_.  Thus for keywords which are present in all
    languages the disable field is zero.  */
 
-#define D_CONLY		0x001	/* C only (not in C++).  */
-#define D_CXXONLY	0x002	/* C++ only (not in C).  */
-#define D_C99		0x004	/* In C, C99 only.  */
-#define D_CXX11         0x008	/* In C++, C++11 only.  */
-#define D_EXT		0x010	/* GCC extension.  */
-#define D_EXT89		0x020	/* GCC extension incorporated in C99.  */
-#define D_ASM		0x040	/* Disabled by -fno-asm.  */
-#define D_OBJC		0x080	/* In Objective C and neither C nor C++.  */
-#define D_CXX_OBJC	0x100	/* In Objective C, and C++, but not C.  */
-#define D_CXXWARN	0x200	/* In C warn with -Wcxx-compat.  */
-#define D_CXX_CONCEPTS  0x400   /* In C++, only with concepts. */
-#define D_TRANSMEM	0X800   /* C++ transactional memory TS.  */
+#define D_CONLY		0x0001	/* C only (not in C++).  */
+#define D_CXXONLY	0x0002	/* C++ only (not in C).  */
+#define D_C99		0x0004	/* In C, C99 only.  */
+#define D_CXX11         0x0008	/* In C++, C++11 only.  */
+#define D_EXT		0x0010	/* GCC extension.  */
+#define D_EXT89		0x0020	/* GCC extension incorporated in C99.  */
+#define D_ASM		0x0040	/* Disabled by -fno-asm.  */
+#define D_OBJC		0x0080	/* In Objective C and neither C nor C++.  */
+#define D_CXX_OBJC	0x0100	/* In Objective C, and C++, but not C.  */
+#define D_CXXWARN	0x0200	/* In C warn with -Wcxx-compat.  */
+#define D_CXX_CONCEPTS  0x0400	/* In C++, only with concepts.  */
+#define D_TRANSMEM	0X0800	/* C++ transactional memory TS.  */
+#define D_CXX_CHAR8_T	0X1000	/* In C++, only with -fchar8_t.  */
 
 #define D_CXX_CONCEPTS_FLAGS D_CXXONLY | D_CXX_CONCEPTS
+#define D_CXX_CHAR8_T_FLAGS D_CXXONLY | D_CXX_CHAR8_T
 
 /* The reserved keyword table.  */
 extern const struct c_common_resword c_common_reswords[];
@@ -430,6 +437,7 @@ extern const struct c_common_resword c_common_reswords[];
 /* The number of items in the reserved keyword table.  */
 extern const unsigned int num_c_common_reswords;
 
+#define char8_type_node			c_global_trees[CTI_CHAR8_TYPE]
 #define char16_type_node		c_global_trees[CTI_CHAR16_TYPE]
 #define char32_type_node		c_global_trees[CTI_CHAR32_TYPE]
 #define wchar_type_node			c_global_trees[CTI_WCHAR_TYPE]
@@ -475,6 +483,7 @@ extern const unsigned int num_c_common_reswords;
 #define truthvalue_false_node		c_global_trees[CTI_TRUTHVALUE_FALSE]
 
 #define char_array_type_node		c_global_trees[CTI_CHAR_ARRAY_TYPE]
+#define char8_array_type_node		c_global_trees[CTI_CHAR8_ARRAY_TYPE]
 #define char16_array_type_node		c_global_trees[CTI_CHAR16_ARRAY_TYPE]
 #define char32_array_type_node		c_global_trees[CTI_CHAR32_ARRAY_TYPE]
 #define wchar_array_type_node		c_global_trees[CTI_WCHAR_ARRAY_TYPE]