| Message ID | 20220924011611.433106-1-polacek@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | c++: P2513R4, char8_t Compatibility and Portability Fix [PR106656] | expand |
On 9/23/22 21:16, Marek Polacek wrote: > P0482R6, which added char8_t, didn't allow > > const char arr[] = u8"howdy"; > > because it said "Declarations of arrays of char may currently be initialized > with UTF-8 string literals. Under this proposal, such initializations would > become ill-formed." This caused too many issues, so P2513R4 alleviates some > of those compatibility problems. In particular, "Arrays of char or unsigned > char may now be initialized with a UTF-8 string literal." This restriction > has been lifted for initialization only, not implicit conversions. Also, > my reading is that 'signed char' was excluded from the allowable conversions. > > This is supposed to be treated as a DR in C++20. > > Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk? OK. > PR c++/106656 > > gcc/c-family/ChangeLog: > > * c-cppbuiltin.cc (c_cpp_builtins): Update value of __cpp_char8_t > for C++20. > > gcc/cp/ChangeLog: > > * typeck2.cc (array_string_literal_compatible_p): Allow > initializing arrays of char or unsigned char by a UTF-8 string literal. > > gcc/testsuite/ChangeLog: > > * g++.dg/cpp23/feat-cxx2b.C: Adjust. > * g++.dg/cpp2a/feat-cxx2a.C: Likewise. > * g++.dg/ext/char8_t-feature-test-macro-2.C: Likewise. > * g++.dg/ext/char8_t-init-2.C: Likewise. > * g++.dg/cpp2a/char8_t3.C: New test. > * g++.dg/cpp2a/char8_t4.C: New test. > --- > gcc/c-family/c-cppbuiltin.cc | 2 +- > gcc/cp/typeck2.cc | 9 +++++ > gcc/testsuite/g++.dg/cpp23/feat-cxx2b.C | 4 +- > gcc/testsuite/g++.dg/cpp2a/char8_t3.C | 37 +++++++++++++++++++ > gcc/testsuite/g++.dg/cpp2a/char8_t4.C | 17 +++++++++ > gcc/testsuite/g++.dg/cpp2a/feat-cxx2a.C | 4 +- > .../g++.dg/ext/char8_t-feature-test-macro-2.C | 4 +- > gcc/testsuite/g++.dg/ext/char8_t-init-2.C | 4 +- > 8 files changed, 72 insertions(+), 9 deletions(-) > create mode 100644 gcc/testsuite/g++.dg/cpp2a/char8_t3.C > create mode 100644 gcc/testsuite/g++.dg/cpp2a/char8_t4.C > > diff --git a/gcc/c-family/c-cppbuiltin.cc b/gcc/c-family/c-cppbuiltin.cc > index a1557eb23d5..b709f845c81 100644 > --- a/gcc/c-family/c-cppbuiltin.cc > +++ b/gcc/c-family/c-cppbuiltin.cc > @@ -1112,7 +1112,7 @@ c_cpp_builtins (cpp_reader *pfile) > if (flag_threadsafe_statics) > cpp_define (pfile, "__cpp_threadsafe_static_init=200806L"); > if (flag_char8_t) > - cpp_define (pfile, "__cpp_char8_t=201811L"); > + cpp_define (pfile, "__cpp_char8_t=202207L"); > #ifndef THREAD_MODEL_SPEC > /* Targets that define THREAD_MODEL_SPEC need to define > __STDCPP_THREADS__ in their config/XXX/XXX-c.c themselves. */ > diff --git a/gcc/cp/typeck2.cc b/gcc/cp/typeck2.cc > index 75fd0e2a9bf..739097a9734 100644 > --- a/gcc/cp/typeck2.cc > +++ b/gcc/cp/typeck2.cc > @@ -1118,6 +1118,15 @@ array_string_literal_compatible_p (tree type, tree init) > if (ordinary_char_type_p (to_char_type) > && ordinary_char_type_p (from_char_type)) > return true; > + > + /* P2513 (C++20/C++23): "an array of char or unsigned char may > + be initialized by a UTF-8 string literal, or by such a string > + literal enclosed in braces." */ > + if (from_char_type == char8_type_node > + && (to_char_type == char_type_node > + || to_char_type == unsigned_char_type_node)) > + return true; > + > return false; > } > > diff --git a/gcc/testsuite/g++.dg/cpp23/feat-cxx2b.C b/gcc/testsuite/g++.dg/cpp23/feat-cxx2b.C > index d3e40724085..0537e1d24b5 100644 > --- a/gcc/testsuite/g++.dg/cpp23/feat-cxx2b.C > +++ b/gcc/testsuite/g++.dg/cpp23/feat-cxx2b.C > @@ -504,8 +504,8 @@ > > #ifndef __cpp_char8_t > # error "__cpp_char8_t" > -#elif __cpp_char8_t != 201811 > -# error "__cpp_char8_t != 201811" > +#elif __cpp_char8_t != 202207 > +# error "__cpp_char8_t != 202207" > #endif > > #ifndef __cpp_designated_initializers > diff --git a/gcc/testsuite/g++.dg/cpp2a/char8_t3.C b/gcc/testsuite/g++.dg/cpp2a/char8_t3.C > new file mode 100644 > index 00000000000..071a718c4d0 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp2a/char8_t3.C > @@ -0,0 +1,37 @@ > +// PR c++/106656 - P2513 - char8_t Compatibility and Portability Fixes > +// { dg-do compile { target c++20 } } > + > +const char *p1 = u8""; // { dg-error "invalid conversion" } > +const unsigned char *p2 = u8""; // { dg-error "invalid conversion" } > +const signed char *p3 = u8""; // { dg-error "invalid conversion" } > +const char *p4 = { u8"" }; // { dg-error "invalid conversion" } > +const unsigned char *p5 = { u8"" }; // { dg-error "invalid conversion" } > +const signed char *p6 = { u8"" }; // { dg-error "invalid conversion" } > +const char *p7 = static_cast<const char *>(u8""); // { dg-error "invalid" } > +const char a1[] = u8"text"; > +const unsigned char a2[] = u8""; > +const signed char a3[] = u8""; // { dg-error "cannot initialize array" } > +const char a4[] = { u8"text" }; > +const unsigned char a5[] = { u8"" }; > +const signed char a6[] = { u8"" }; // { dg-error "cannot initialize array" } > + > +const char * > +resource_id () > +{ > + static const char res_id[] = u8""; > + return res_id; > +} > + > +const char8_t x[] = "fail"; // { dg-error "cannot initialize array" } > + > +void fn (const char a[]); > +void > +g () > +{ > + fn (u8"z"); // { dg-error "invalid conversion" } > +} > + > +char c = u8'c'; > +unsigned char uc = u8'c'; > +signed char sc = u8'c'; > +char8_t c8 = 'c'; > diff --git a/gcc/testsuite/g++.dg/cpp2a/char8_t4.C b/gcc/testsuite/g++.dg/cpp2a/char8_t4.C > new file mode 100644 > index 00000000000..c18081b66fb > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp2a/char8_t4.C > @@ -0,0 +1,17 @@ > +// PR c++/106656 - P2513 - char8_t Compatibility and Portability Fixes > +// { dg-do compile { target c++20 } } > +// [diff.cpp20.dcl] > + > +struct A { > + char8_t s[10]; > +}; > +struct B { > + char s[10]; > +}; > + > +void f(A); > +void f(B); > + > +int main() { > + f({u8""}); // { dg-error "ambiguous" } > +} > diff --git a/gcc/testsuite/g++.dg/cpp2a/feat-cxx2a.C b/gcc/testsuite/g++.dg/cpp2a/feat-cxx2a.C > index c65ea6bf48a..02f3a377fd0 100644 > --- a/gcc/testsuite/g++.dg/cpp2a/feat-cxx2a.C > +++ b/gcc/testsuite/g++.dg/cpp2a/feat-cxx2a.C > @@ -504,8 +504,8 @@ > > #ifndef __cpp_char8_t > # error "__cpp_char8_t" > -#elif __cpp_char8_t != 201811 > -# error "__cpp_char8_t != 201811" > +#elif __cpp_char8_t != 202207 > +# error "__cpp_char8_t != 202207" > #endif > > #ifndef __cpp_designated_initializers > diff --git a/gcc/testsuite/g++.dg/ext/char8_t-feature-test-macro-2.C b/gcc/testsuite/g++.dg/ext/char8_t-feature-test-macro-2.C > index df1063f6aa1..2d0f9045acf 100644 > --- a/gcc/testsuite/g++.dg/ext/char8_t-feature-test-macro-2.C > +++ b/gcc/testsuite/g++.dg/ext/char8_t-feature-test-macro-2.C > @@ -5,6 +5,6 @@ > > #if !defined(__cpp_char8_t) > # error __cpp_char8_t is not defined! > -#elif __cpp_char8_t != 201811 > -# error __cpp_char8_t != 201811 > +#elif __cpp_char8_t != 202207 > +# error __cpp_char8_t != 202207 > #endif > diff --git a/gcc/testsuite/g++.dg/ext/char8_t-init-2.C b/gcc/testsuite/g++.dg/ext/char8_t-init-2.C > index c713bc12266..02a96ffe5a4 100644 > --- a/gcc/testsuite/g++.dg/ext/char8_t-init-2.C > +++ b/gcc/testsuite/g++.dg/ext/char8_t-init-2.C > @@ -21,7 +21,7 @@ const char8_t (&rca4)[2] = u8"x"; > const char8_t (&rca5)[2] = u"x"; // { dg-error "invalid initialization of reference of type .const char8_t ....... from expression of type .const char16_t ...." "char8_t" } > > char ca1[] = "x"; > -char ca2[] = u8"x"; // { dg-error "from a string literal with type array of .char8_t." "char8_t" } > +char ca2[] = u8"x"; > char8_t ca3[] = "x"; // { dg-error "from a string literal with type array of .char." "char8_t" } > char8_t ca4[] = u8"x"; > char8_t ca5[] = u"x"; // { dg-error "from a string literal with type array of .char16_t." "char8_t" } > @@ -30,4 +30,4 @@ signed char sca1[] = "x"; > signed char sca2[] = u8"x"; // { dg-error "from a string literal with type array of .char8_t." "char8_t" } > > unsigned char uca1[] = "x"; > -unsigned char uca2[] = u8"x"; // { dg-error "from a string literal with type array of .char8_t." "char8_t" } > +unsigned char uca2[] = u8"x"; > > base-commit: f5072839c46acd185f40a5692aca06fac4ed6a48
diff --git a/gcc/c-family/c-cppbuiltin.cc b/gcc/c-family/c-cppbuiltin.cc index a1557eb23d5..b709f845c81 100644 --- a/gcc/c-family/c-cppbuiltin.cc +++ b/gcc/c-family/c-cppbuiltin.cc @@ -1112,7 +1112,7 @@ c_cpp_builtins (cpp_reader *pfile) if (flag_threadsafe_statics) cpp_define (pfile, "__cpp_threadsafe_static_init=200806L"); if (flag_char8_t) - cpp_define (pfile, "__cpp_char8_t=201811L"); + cpp_define (pfile, "__cpp_char8_t=202207L"); #ifndef THREAD_MODEL_SPEC /* Targets that define THREAD_MODEL_SPEC need to define __STDCPP_THREADS__ in their config/XXX/XXX-c.c themselves. */ diff --git a/gcc/cp/typeck2.cc b/gcc/cp/typeck2.cc index 75fd0e2a9bf..739097a9734 100644 --- a/gcc/cp/typeck2.cc +++ b/gcc/cp/typeck2.cc @@ -1118,6 +1118,15 @@ array_string_literal_compatible_p (tree type, tree init) if (ordinary_char_type_p (to_char_type) && ordinary_char_type_p (from_char_type)) return true; + + /* P2513 (C++20/C++23): "an array of char or unsigned char may + be initialized by a UTF-8 string literal, or by such a string + literal enclosed in braces." */ + if (from_char_type == char8_type_node + && (to_char_type == char_type_node + || to_char_type == unsigned_char_type_node)) + return true; + return false; } diff --git a/gcc/testsuite/g++.dg/cpp23/feat-cxx2b.C b/gcc/testsuite/g++.dg/cpp23/feat-cxx2b.C index d3e40724085..0537e1d24b5 100644 --- a/gcc/testsuite/g++.dg/cpp23/feat-cxx2b.C +++ b/gcc/testsuite/g++.dg/cpp23/feat-cxx2b.C @@ -504,8 +504,8 @@ #ifndef __cpp_char8_t # error "__cpp_char8_t" -#elif __cpp_char8_t != 201811 -# error "__cpp_char8_t != 201811" +#elif __cpp_char8_t != 202207 +# error "__cpp_char8_t != 202207" #endif #ifndef __cpp_designated_initializers diff --git a/gcc/testsuite/g++.dg/cpp2a/char8_t3.C b/gcc/testsuite/g++.dg/cpp2a/char8_t3.C new file mode 100644 index 00000000000..071a718c4d0 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/char8_t3.C @@ -0,0 +1,37 @@ +// PR c++/106656 - P2513 - char8_t Compatibility and Portability Fixes +// { dg-do compile { target c++20 } } + +const char *p1 = u8""; // { dg-error "invalid conversion" } +const unsigned char *p2 = u8""; // { dg-error "invalid conversion" } +const signed char *p3 = u8""; // { dg-error "invalid conversion" } +const char *p4 = { u8"" }; // { dg-error "invalid conversion" } +const unsigned char *p5 = { u8"" }; // { dg-error "invalid conversion" } +const signed char *p6 = { u8"" }; // { dg-error "invalid conversion" } +const char *p7 = static_cast<const char *>(u8""); // { dg-error "invalid" } +const char a1[] = u8"text"; +const unsigned char a2[] = u8""; +const signed char a3[] = u8""; // { dg-error "cannot initialize array" } +const char a4[] = { u8"text" }; +const unsigned char a5[] = { u8"" }; +const signed char a6[] = { u8"" }; // { dg-error "cannot initialize array" } + +const char * +resource_id () +{ + static const char res_id[] = u8""; + return res_id; +} + +const char8_t x[] = "fail"; // { dg-error "cannot initialize array" } + +void fn (const char a[]); +void +g () +{ + fn (u8"z"); // { dg-error "invalid conversion" } +} + +char c = u8'c'; +unsigned char uc = u8'c'; +signed char sc = u8'c'; +char8_t c8 = 'c'; diff --git a/gcc/testsuite/g++.dg/cpp2a/char8_t4.C b/gcc/testsuite/g++.dg/cpp2a/char8_t4.C new file mode 100644 index 00000000000..c18081b66fb --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/char8_t4.C @@ -0,0 +1,17 @@ +// PR c++/106656 - P2513 - char8_t Compatibility and Portability Fixes +// { dg-do compile { target c++20 } } +// [diff.cpp20.dcl] + +struct A { + char8_t s[10]; +}; +struct B { + char s[10]; +}; + +void f(A); +void f(B); + +int main() { + f({u8""}); // { dg-error "ambiguous" } +} diff --git a/gcc/testsuite/g++.dg/cpp2a/feat-cxx2a.C b/gcc/testsuite/g++.dg/cpp2a/feat-cxx2a.C index c65ea6bf48a..02f3a377fd0 100644 --- a/gcc/testsuite/g++.dg/cpp2a/feat-cxx2a.C +++ b/gcc/testsuite/g++.dg/cpp2a/feat-cxx2a.C @@ -504,8 +504,8 @@ #ifndef __cpp_char8_t # error "__cpp_char8_t" -#elif __cpp_char8_t != 201811 -# error "__cpp_char8_t != 201811" +#elif __cpp_char8_t != 202207 +# error "__cpp_char8_t != 202207" #endif #ifndef __cpp_designated_initializers diff --git a/gcc/testsuite/g++.dg/ext/char8_t-feature-test-macro-2.C b/gcc/testsuite/g++.dg/ext/char8_t-feature-test-macro-2.C index df1063f6aa1..2d0f9045acf 100644 --- a/gcc/testsuite/g++.dg/ext/char8_t-feature-test-macro-2.C +++ b/gcc/testsuite/g++.dg/ext/char8_t-feature-test-macro-2.C @@ -5,6 +5,6 @@ #if !defined(__cpp_char8_t) # error __cpp_char8_t is not defined! -#elif __cpp_char8_t != 201811 -# error __cpp_char8_t != 201811 +#elif __cpp_char8_t != 202207 +# error __cpp_char8_t != 202207 #endif diff --git a/gcc/testsuite/g++.dg/ext/char8_t-init-2.C b/gcc/testsuite/g++.dg/ext/char8_t-init-2.C index c713bc12266..02a96ffe5a4 100644 --- a/gcc/testsuite/g++.dg/ext/char8_t-init-2.C +++ b/gcc/testsuite/g++.dg/ext/char8_t-init-2.C @@ -21,7 +21,7 @@ const char8_t (&rca4)[2] = u8"x"; const char8_t (&rca5)[2] = u"x"; // { dg-error "invalid initialization of reference of type .const char8_t ....... from expression of type .const char16_t ...." "char8_t" } char ca1[] = "x"; -char ca2[] = u8"x"; // { dg-error "from a string literal with type array of .char8_t." "char8_t" } +char ca2[] = u8"x"; char8_t ca3[] = "x"; // { dg-error "from a string literal with type array of .char." "char8_t" } char8_t ca4[] = u8"x"; char8_t ca5[] = u"x"; // { dg-error "from a string literal with type array of .char16_t." "char8_t" } @@ -30,4 +30,4 @@ signed char sca1[] = "x"; signed char sca2[] = u8"x"; // { dg-error "from a string literal with type array of .char8_t." "char8_t" } unsigned char uca1[] = "x"; -unsigned char uca2[] = u8"x"; // { dg-error "from a string literal with type array of .char8_t." "char8_t" } +unsigned char uca2[] = u8"x";