diff --git a/gcc/c-family/c-lex.cc b/gcc/c-family/c-lex.cc
index 8bfa4f4024fff267de283876cf7bcd4b354b0349..0b6f94e18a82d10b0cd2a5aff3cb8c1741e18838 100644
--- a/gcc/c-family/c-lex.cc
+++ b/gcc/c-family/c-lex.cc
@@ -1352,7 +1352,14 @@ lex_string (const cpp_token *tok, tree *valp, bool objc_string, bool translate)
default:
case CPP_STRING:
case CPP_UTF8STRING:
- value = build_string (1, "");
+ if (type == CPP_UTF8STRING && flag_char8_t)
+ {
+ value = build_string (TYPE_PRECISION (char8_type_node)
+ / TYPE_PRECISION (char_type_node),
+ ""); /* char8_t is 8 bits */
+ }
+ else
+ value = build_string (1, "");
break;
case CPP_STRING16:
value = build_string (TYPE_PRECISION (char16_type_node)
@@ -1425,9 +1432,7 @@ lex_charconst (const cpp_token *token)
type = char16_type_node;
else if (token->type == CPP_UTF8CHAR)
{
- if (!c_dialect_cxx ())
- type = unsigned_char_type_node;
- else if (flag_char8_t)
+ if (flag_char8_t)
type = char8_type_node;
else
type = char_type_node;
diff --git a/gcc/c-family/c-opts.cc b/gcc/c-family/c-opts.cc
index 4e1463689de33f7b5ddc4e9e11f2fc5b1bfa3fae..1cf119a9becf8453ffafa1498384d3ff658d9459 100644
--- a/gcc/c-family/c-opts.cc
+++ b/gcc/c-family/c-opts.cc
@@ -1059,9 +1059,9 @@ c_common_post_options (const char **pfilename)
if (flag_sized_deallocation == -1)
flag_sized_deallocation = (cxx_dialect >= cxx14);
- /* char8_t support is new in C++20. */
+ /* char8_t support is implicitly enabled in C++20 and C2X. */
if (flag_char8_t == -1)
- flag_char8_t = (cxx_dialect >= cxx20);
+ flag_char8_t = (cxx_dialect >= cxx20) || flag_isoc2x;
if (flag_extern_tls_init)
{
diff --git a/gcc/c/c-parser.cc b/gcc/c/c-parser.cc
index 92049d1a101da86db8b000ac676b30c63e5947b3..fa9395986deee5ff8edde8fd79e87952a041e644 100644
--- a/gcc/c/c-parser.cc
+++ b/gcc/c/c-parser.cc
@@ -7447,7 +7447,14 @@ c_parser_string_literal (c_parser *parser, bool translate, bool wide_ok)
default:
case CPP_STRING:
case CPP_UTF8STRING:
- value = build_string (1, "");
+ if (type == CPP_UTF8STRING && flag_char8_t)
+ {
+ value = build_string (TYPE_PRECISION (char8_type_node)
+ / TYPE_PRECISION (char_type_node),
+ ""); /* char8_t is 8 bits */
+ }
+ else
+ value = build_string (1, "");
break;
case CPP_STRING16:
value = build_string (TYPE_PRECISION (char16_type_node)
@@ -7472,9 +7479,14 @@ c_parser_string_literal (c_parser *parser, bool translate, bool wide_ok)
{
default:
case CPP_STRING:
- case CPP_UTF8STRING:
TREE_TYPE (value) = char_array_type_node;
break;
+ case CPP_UTF8STRING:
+ if (flag_char8_t)
+ TREE_TYPE (value) = char8_array_type_node;
+ else
+ TREE_TYPE (value) = char_array_type_node;
+ break;
case CPP_STRING16:
TREE_TYPE (value) = char16_array_type_node;
break;
diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc
index 8514488b7a55e0b666732ce1cddf44b500117748..d37de2a313ba434f56600b935bec922bf397a083 100644
--- a/gcc/c/c-typeck.cc
+++ b/gcc/c/c-typeck.cc
@@ -8056,7 +8056,7 @@ digest_init (location_t init_loc, tree type, tree init, tree origtype,
if (char_array)
{
- if (typ2 != char_type_node)
+ if (typ2 != char_type_node && typ2 != char8_type_node)
incompat_string_cst = true;
}
else if (!comptypes (typ1, typ2))
diff --git a/gcc/ginclude/stdatomic.h b/gcc/ginclude/stdatomic.h
index bfcfdf664c7f819873ffa9615ffc5597c3be38b6..9f2475b739d1061c8bc27419bb9f611979992430 100644
--- a/gcc/ginclude/stdatomic.h
+++ b/gcc/ginclude/stdatomic.h
@@ -49,6 +49,9 @@ typedef _Atomic long atomic_long;
typedef _Atomic unsigned long atomic_ulong;
typedef _Atomic long long atomic_llong;
typedef _Atomic unsigned long long atomic_ullong;
+#ifdef __CHAR8_TYPE__
+typedef _Atomic __CHAR8_TYPE__ atomic_char8_t;
+#endif
typedef _Atomic __CHAR16_TYPE__ atomic_char16_t;
typedef _Atomic __CHAR32_TYPE__ atomic_char32_t;
typedef _Atomic __WCHAR_TYPE__ atomic_wchar_t;
@@ -97,6 +100,9 @@ extern void atomic_signal_fence (memory_order);
#define ATOMIC_BOOL_LOCK_FREE __GCC_ATOMIC_BOOL_LOCK_FREE
#define ATOMIC_CHAR_LOCK_FREE __GCC_ATOMIC_CHAR_LOCK_FREE
+#ifdef __GCC_ATOMIC_CHAR8_T_LOCK_FREE
+#define ATOMIC_CHAR8_T_LOCK_FREE __GCC_ATOMIC_CHAR8_T_LOCK_FREE
+#endif
#define ATOMIC_CHAR16_T_LOCK_FREE __GCC_ATOMIC_CHAR16_T_LOCK_FREE
#define ATOMIC_CHAR32_T_LOCK_FREE __GCC_ATOMIC_CHAR32_T_LOCK_FREE
#define ATOMIC_WCHAR_T_LOCK_FREE __GCC_ATOMIC_WCHAR_T_LOCK_FREE
diff --git a/gcc/testsuite/gcc.dg/atomic/c2x-stdatomic-lockfree-char8_t.c b/gcc/testsuite/gcc.dg/atomic/c2x-stdatomic-lockfree-char8_t.c
new file mode 100644
index 0000000000000000000000000000000000000000..1b692f55ed0fa47651ab833891245fe359ab94c0
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/atomic/c2x-stdatomic-lockfree-char8_t.c
@@ -0,0 +1,42 @@
+/* Test atomic_is_lock_free for char8_t. */
+/* { dg-do run } */
+/* { dg-options "-std=c2x -pedantic-errors" } */
+
+#include <stdatomic.h>
+#include <stdint.h>
+
+extern void abort (void);
+
+_Atomic __CHAR8_TYPE__ ac8a;
+atomic_char8_t ac8t;
+
+#define CHECK_TYPE(MACRO, V1, V2) \
+ do \
+ { \
+ int r1 = MACRO; \
+ int r2 = atomic_is_lock_free (&V1); \
+ int r3 = atomic_is_lock_free (&V2); \
+ if (r1 != 0 && r1 != 1 && r1 != 2) \
+ abort (); \
+ if (r2 != 0 && r2 != 1) \
+ abort (); \
+ if (r3 != 0 && r3 != 1) \
+ abort (); \
+ if (r1 == 2 && r2 != 1) \
+ abort (); \
+ if (r1 == 2 && r3 != 1) \
+ abort (); \
+ if (r1 == 0 && r2 != 0) \
+ abort (); \
+ if (r1 == 0 && r3 != 0) \
+ abort (); \
+ } \
+ while (0)
+
+int
+main ()
+{
+ CHECK_TYPE (ATOMIC_CHAR8_T_LOCK_FREE, ac8a, ac8t);
+
+ return 0;
+}
diff --git a/gcc/testsuite/gcc.dg/atomic/gnu2x-stdatomic-lockfree-char8_t.c b/gcc/testsuite/gcc.dg/atomic/gnu2x-stdatomic-lockfree-char8_t.c
new file mode 100644
index 0000000000000000000000000000000000000000..27a3cfe355281309a6c056f6196e6a8d5150085f
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/atomic/gnu2x-stdatomic-lockfree-char8_t.c
@@ -0,0 +1,5 @@
+/* Test atomic_is_lock_free for char8_t with -std=gnu2x. */
+/* { dg-do run } */
+/* { dg-options "-std=gnu2x -pedantic-errors" } */
+
+#include "c2x-stdatomic-lockfree-char8_t.c"
diff --git a/gcc/testsuite/gcc.dg/c11-utf8str-type.c b/gcc/testsuite/gcc.dg/c11-utf8str-type.c
new file mode 100644
index 0000000000000000000000000000000000000000..8be9abb9686d496d0e5d0a2f27789175820abc79
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/c11-utf8str-type.c
@@ -0,0 +1,6 @@
+/* Test C11 UTF-8 string literal type. */
+/* { dg-do compile } */
+/* { dg-options "-std=c11" } */
+
+_Static_assert (_Generic (u8"text", char*: 1, default: 2) == 1, "UTF-8 string literals have an unexpected type");
+_Static_assert (_Generic (u8"x"[0], char: 1, default: 2) == 1, "UTF-8 string literal elements have an unexpected type");
diff --git a/gcc/testsuite/gcc.dg/c17-utf8str-type.c b/gcc/testsuite/gcc.dg/c17-utf8str-type.c
new file mode 100644
index 0000000000000000000000000000000000000000..515c6db3970ea89dbc2b9848a2b9a0328d01e989
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/c17-utf8str-type.c
@@ -0,0 +1,6 @@
+/* Test C17 UTF-8 string literal type. */
+/* { dg-do compile } */
+/* { dg-options "-std=c17" } */
+
+_Static_assert (_Generic (u8"text", char*: 1, default: 2) == 1, "UTF-8 string literals have an unexpected type");
+_Static_assert (_Generic (u8"x"[0], char: 1, default: 2) == 1, "UTF-8 string literal elements have an unexpected type");
diff --git a/gcc/testsuite/gcc.dg/c2x-utf8str-type.c b/gcc/testsuite/gcc.dg/c2x-utf8str-type.c
new file mode 100644
index 0000000000000000000000000000000000000000..ebdde97b57a3c92e03e26e39eef90b172acd4b2b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/c2x-utf8str-type.c
@@ -0,0 +1,6 @@
+/* Test C2X UTF-8 string literal type. */
+/* { dg-do compile } */
+/* { dg-options "-std=c2x" } */
+
+_Static_assert (_Generic (u8"text", unsigned char*: 1, default: 2) == 1, "UTF-8 string literals have an unexpected type");
+_Static_assert (_Generic (u8"x"[0], unsigned char: 1, default: 2) == 1, "UTF-8 string literal elements have an unexpected type");
diff --git a/gcc/testsuite/gcc.dg/c2x-utf8str.c b/gcc/testsuite/gcc.dg/c2x-utf8str.c
new file mode 100644
index 0000000000000000000000000000000000000000..2e4c392da9f7650c1261a4c7af0a5a930cab587b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/c2x-utf8str.c
@@ -0,0 +1,34 @@
+/* Test initialization by UTF-8 string literal in C2X. */
+/* { dg-do compile } */
+/* { dg-require-effective-target wchar } */
+/* { dg-options "-std=c2x" } */
+
+typedef __CHAR8_TYPE__ char8_t;
+typedef __CHAR16_TYPE__ char16_t;
+typedef __CHAR32_TYPE__ char32_t;
+typedef __WCHAR_TYPE__ wchar_t;
+
+/* Test that char, signed char, unsigned char, and char8_t arrays can be
+ initialized by a UTF-8 string literal. */
+const char cbuf1[] = u8"text";
+const char cbuf2[] = { u8"text" };
+const signed char scbuf1[] = u8"text";
+const signed char scbuf2[] = { u8"text" };
+const unsigned char ucbuf1[] = u8"text";
+const unsigned char ucbuf2[] = { u8"text" };
+const char8_t c8buf1[] = u8"text";
+const char8_t c8buf2[] = { u8"text" };
+
+/* Test that a diagnostic is issued for attempted initialization of
+ other character types by a UTF-8 string literal. */
+const char16_t c16buf1[] = u8"text"; /* { dg-error "from a string literal with type array of .unsigned char." } */
+const char16_t c16buf2[] = { u8"text" }; /* { dg-error "from a string literal with type array of .unsigned char." } */
+const char32_t c32buf1[] = u8"text"; /* { dg-error "from a string literal with type array of .unsigned char." } */
+const char32_t c32buf2[] = { u8"text" }; /* { dg-error "from a string literal with type array of .unsigned char." } */
+const wchar_t wbuf1[] = u8"text"; /* { dg-error "from a string literal with type array of .unsigned char." } */
+const wchar_t wbuf2[] = { u8"text" }; /* { dg-error "from a string literal with type array of .unsigned char." } */
+
+/* Test that char8_t arrays can be initialized by an ordinary string
+ literal. */
+const char8_t c8buf3[] = "text";
+const char8_t c8buf4[] = { "text" };
diff --git a/gcc/testsuite/gcc.dg/gnu2x-utf8str-type.c b/gcc/testsuite/gcc.dg/gnu2x-utf8str-type.c
new file mode 100644
index 0000000000000000000000000000000000000000..efe16ffc28d50c1bd4f2158f61b24d7e4b68e5e2
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/gnu2x-utf8str-type.c
@@ -0,0 +1,5 @@
+/* Test C2X UTF-8 string literal type with -std=gnu2x. */
+/* { dg-do compile } */
+/* { dg-options "-std=gnu2x" } */
+
+#include "c2x-utf8str-type.c"
diff --git a/gcc/testsuite/gcc.dg/gnu2x-utf8str.c b/gcc/testsuite/gcc.dg/gnu2x-utf8str.c
new file mode 100644
index 0000000000000000000000000000000000000000..f3719ea8c774c62806dba425187c928fddf3256b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/gnu2x-utf8str.c
@@ -0,0 +1,34 @@
+/* Test initialization by UTF-8 string literal in C2X with -std=gnu2x. */
+/* { dg-do compile } */
+/* { dg-require-effective-target wchar } */
+/* { dg-options "-std=gnu2x" } */
+
+typedef __CHAR8_TYPE__ char8_t;
+typedef __CHAR16_TYPE__ char16_t;
+typedef __CHAR32_TYPE__ char32_t;
+typedef __WCHAR_TYPE__ wchar_t;
+
+/* Test that char, signed char, unsigned char, and char8_t arrays can be
+ initialized by a UTF-8 string literal. */
+const char cbuf1[] = u8"text";
+const char cbuf2[] = { u8"text" };
+const signed char scbuf1[] = u8"text";
+const signed char scbuf2[] = { u8"text" };
+const unsigned char ucbuf1[] = u8"text";
+const unsigned char ucbuf2[] = { u8"text" };
+const char8_t c8buf1[] = u8"text";
+const char8_t c8buf2[] = { u8"text" };
+
+/* Test that a diagnostic is issued for attempted initialization of
+ other character types by a UTF-8 string literal. */
+const char16_t c16buf1[] = u8"text"; /* { dg-error "from a string literal with type array of .unsigned char." } */
+const char16_t c16buf2[] = { u8"text" }; /* { dg-error "from a string literal with type array of .unsigned char." } */
+const char32_t c32buf1[] = u8"text"; /* { dg-error "from a string literal with type array of .unsigned char." } */
+const char32_t c32buf2[] = { u8"text" }; /* { dg-error "from a string literal with type array of .unsigned char." } */
+const wchar_t wbuf1[] = u8"text"; /* { dg-error "from a string literal with type array of .unsigned char." } */
+const wchar_t wbuf2[] = { u8"text" }; /* { dg-error "from a string literal with type array of .unsigned char." } */
+
+/* Test that char8_t arrays can be initialized by an ordinary string
+ literal. */
+const char8_t c8buf3[] = "text";
+const char8_t c8buf4[] = { "text" };