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

3 files changed, 20 insertions, 7 deletions

diff --git a/libiberty/ChangeLog b/libiberty/ChangeLog
index 2206b91..bcc0227 100644
--- a/libiberty/ChangeLog
+++ b/libiberty/ChangeLog
@@ -1,3 +1,10 @@
+2019-01-14  Tom Honermann  <tom@honermann.net>
+
+	* 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.
+
 2019-01-09  Sandra Loosemore  <sandra@codesourcery.com>
 
 	PR other/16615
diff --git a/libiberty/cp-demangle.c b/libiberty/cp-demangle.c
index ddcd3be..b34b485 100644
--- a/libiberty/cp-demangle.c
+++ b/libiberty/cp-demangle.c
@@ -2364,9 +2364,10 @@ cplus_demangle_builtin_types[D_BUILTIN_TYPE_COUNT] =
   /* 27 */ { NL ("decimal64"),	NL ("decimal64"),	D_PRINT_DEFAULT },
   /* 28 */ { NL ("decimal128"),	NL ("decimal128"),	D_PRINT_DEFAULT },
   /* 29 */ { NL ("half"),	NL ("half"),		D_PRINT_FLOAT },
-  /* 30 */ { NL ("char16_t"),	NL ("char16_t"),	D_PRINT_DEFAULT },
-  /* 31 */ { NL ("char32_t"),	NL ("char32_t"),	D_PRINT_DEFAULT },
-  /* 32 */ { NL ("decltype(nullptr)"),	NL ("decltype(nullptr)"),
+  /* 30 */ { NL ("char8_t"),	NL ("char8_t"),		D_PRINT_DEFAULT },
+  /* 31 */ { NL ("char16_t"),	NL ("char16_t"),	D_PRINT_DEFAULT },
+  /* 32 */ { NL ("char32_t"),	NL ("char32_t"),	D_PRINT_DEFAULT },
+  /* 33 */ { NL ("decltype(nullptr)"),	NL ("decltype(nullptr)"),
 	     D_PRINT_DEFAULT },
 };
 
@@ -2654,14 +2655,19 @@ cplus_demangle_type (struct d_info *di)
 	  ret = d_make_builtin_type (di, &cplus_demangle_builtin_types[29]);
 	  di->expansion += ret->u.s_builtin.type->len;
 	  break;
+	case 'u':
+	  /* char8_t */
+	  ret = d_make_builtin_type (di, &cplus_demangle_builtin_types[30]);
+	  di->expansion += ret->u.s_builtin.type->len;
+	  break;
 	case 's':
 	  /* char16_t */
-	  ret = d_make_builtin_type (di, &cplus_demangle_builtin_types[30]);
+	  ret = d_make_builtin_type (di, &cplus_demangle_builtin_types[31]);
 	  di->expansion += ret->u.s_builtin.type->len;
 	  break;
 	case 'i':
 	  /* char32_t */
-	  ret = d_make_builtin_type (di, &cplus_demangle_builtin_types[31]);
+	  ret = d_make_builtin_type (di, &cplus_demangle_builtin_types[32]);
 	  di->expansion += ret->u.s_builtin.type->len;
 	  break;
 
@@ -2687,7 +2693,7 @@ cplus_demangle_type (struct d_info *di)
 
         case 'n':
           /* decltype(nullptr) */
-	  ret = d_make_builtin_type (di, &cplus_demangle_builtin_types[32]);
+	  ret = d_make_builtin_type (di, &cplus_demangle_builtin_types[33]);
 	  di->expansion += ret->u.s_builtin.type->len;
 	  break;
 
diff --git a/libiberty/cp-demangle.h b/libiberty/cp-demangle.h
index b739bdf..92191cf 100644
--- a/libiberty/cp-demangle.h
+++ b/libiberty/cp-demangle.h
@@ -176,7 +176,7 @@ d_advance (struct d_info *di, int i)
 extern const struct demangle_operator_info cplus_demangle_operators[];
 #endif
 
-#define D_BUILTIN_TYPE_COUNT (33)
+#define D_BUILTIN_TYPE_COUNT (34)
 
 CP_STATIC_IF_GLIBCPP_V3
 const struct demangle_builtin_type_info