On Wed, Aug 09, 2023 at 09:17:57PM +0000, Joseph Myers wrote:
> > - _Complex _BitInt(N) isn't supported; again mainly because none of the psABIs
> > mention how those should be passed/returned; in a limited way they are
> > supported internally because the internal functions into which
> > __builtin_{add,sub,mul}_overflow{,_p} is lowered return COMPLEX_TYPE as a
> > hack to return 2 values without using references/pointers
>
> What happens when the usual arithmetic conversions are applied to
> operands, one of which is a complex integer type and the other of which is
> a wider _BitInt type? I don't see anything in the code to disallow this
> case (which would produce an expression with a _Complex _BitInt type), or
> any testcases for it.
I've added a sorry for that case (+ return the narrower COMPLEX_TYPE).
Also added testcase to verify we don't create VECTOR_TYPEs of BITINT_TYPE
even if they have mode precision and suitable size (others were rejected
already before).
> Other testcases I think should be present (along with any corresponding
> changes needed to the code itself):
>
> * Verifying that the new integer constant suffix is rejected for C++.
Done.
> * Verifying appropriate pedwarn-if-pedantic for the new constant suffix
> for versions of C before C2x (and probably for use of _BitInt type
> specifiers before C2x as well) - along with the expected -Wc11-c2x-compat
> handling (in C2x mode) / -pedantic -Wno-c11-c2x-compat in older modes.
Done.
Here is an incremental patch which does that:
2023-08-10 Jakub Jelinek <jakub@redhat.com>
PR c/102989
gcc/c/
* c-decl.cc (finish_declspecs): Emit pedwarn_c11 on _BitInt.
* c-typeck.cc (c_common_type): Emit sorry for common type between
_Complex integer and larger _BitInt and return the _Complex integer.
gcc/c-family/
* c-attribs.cc (type_valid_for_vector_size): Reject vector types
with BITINT_TYPE elements even if they have mode precision and
suitable size.
gcc/testsuite/
* gcc.dg/bitint-19.c: New test.
* gcc.dg/bitint-20.c: New test.
* gcc.dg/bitint-21.c: New test.
* gcc.dg/bitint-22.c: New test.
* gcc.dg/bitint-23.c: New test.
* gcc.dg/bitint-24.c: New test.
* gcc.dg/bitint-25.c: New test.
* gcc.dg/bitint-26.c: New test.
* gcc.dg/bitint-27.c: New test.
* g++.dg/ext/bitint1.C: New test.
* g++.dg/ext/bitint2.C: New test.
* g++.dg/ext/bitint3.C: New test.
* g++.dg/ext/bitint4.C: New test.
libcpp/
* expr.cc (cpp_classify_number): Diagnose wb literal suffixes
for -pedantic* before C2X or -Wc11-c2x-compat.
Jakub
@@ -12933,8 +12933,15 @@ finish_declspecs (struct c_declspecs *sp
if (specs->u.bitint_prec == -1)
specs->type = integer_type_node;
else
- specs->type = build_bitint_type (specs->u.bitint_prec,
- specs->unsigned_p);
+ {
+ pedwarn_c11 (specs->locations[cdw_typespec], OPT_Wpedantic,
+ "ISO C does not support %<%s_BitInt(%d)%> before C2X",
+ specs->unsigned_p ? "unsigned "
+ : specs->signed_p ? "signed " : "",
+ specs->u.bitint_prec);
+ specs->type = build_bitint_type (specs->u.bitint_prec,
+ specs->unsigned_p);
+ }
break;
default:
gcc_unreachable ();
@@ -819,6 +819,12 @@ c_common_type (tree t1, tree t2)
return t1;
else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
return t2;
+ else if (TREE_CODE (subtype) == BITINT_TYPE)
+ {
+ sorry ("%<_Complex _BitInt(%d)%> unsupported",
+ TYPE_PRECISION (subtype));
+ return code1 == COMPLEX_TYPE ? t1 : t2;
+ }
else
return build_complex_type (subtype);
}
@@ -4366,7 +4366,8 @@ type_valid_for_vector_size (tree type, t
&& GET_MODE_CLASS (orig_mode) != MODE_INT
&& !ALL_SCALAR_FIXED_POINT_MODE_P (orig_mode))
|| !tree_fits_uhwi_p (TYPE_SIZE_UNIT (type))
- || TREE_CODE (type) == BOOLEAN_TYPE)
+ || TREE_CODE (type) == BOOLEAN_TYPE
+ || TREE_CODE (type) == BITINT_TYPE)
{
if (error_p)
error ("invalid vector type for attribute %qE", atname);
@@ -0,0 +1,16 @@
+/* PR c/102989 */
+/* { dg-do compile { target bitint } } */
+/* { dg-options "-std=gnu2x" } */
+
+#define expr_has_type(e, t) _Generic (e, default : 0, t : 1)
+
+void
+foo (_Complex int ci, _Complex long long cl)
+{
+ _BitInt(__SIZEOF_INT__ * __CHAR_BIT__ - 1) bi = 0wb;
+ _BitInt(__SIZEOF_LONG_LONG__ * __CHAR_BIT__ - 1) bl = 0wb;
+ static_assert (expr_has_type (ci + bi, _Complex int));
+ static_assert (expr_has_type (cl + bl, _Complex long long));
+ static_assert (expr_has_type (bi + ci, _Complex int));
+ static_assert (expr_has_type (bl + cl, _Complex long long));
+}
@@ -0,0 +1,16 @@
+/* PR c/102989 */
+/* { dg-do compile { target bitint } } */
+/* { dg-options "-std=gnu2x" } */
+
+void
+foo (_Complex int ci, _Complex long long cl)
+{
+ _BitInt(__SIZEOF_INT__ * __CHAR_BIT__ + 1) bi = 0wb;
+ ci + bi; /* { dg-message "unsupported" } */
+ bi + ci; /* { dg-message "unsupported" } */
+#if __BITINT_MAXWIDTH__ >= 575
+ _BitInt(575) bw = 0wb;
+ cl + bw; /* { dg-message "unsupported" "" { target bitint575 } } */
+ bw + cl; /* { dg-message "unsupported" "" { target bitint575 } } */
+#endif
+}
@@ -0,0 +1,11 @@
+/* PR c/102989 */
+/* { dg-do compile { target bitint } } */
+/* { dg-options "-std=gnu2x" } */
+
+#define IB __SIZEOF_INT__ * __CHAR_BIT__
+typedef _BitInt(IB) V1 __attribute__((vector_size (sizeof (_BitInt(IB))))); /* { dg-error "invalid vector type for attribute 'vector_size'" } */
+typedef _BitInt(IB) V2 __attribute__((vector_size (8 * sizeof (_BitInt(IB))))); /* { dg-error "invalid vector type for attribute 'vector_size'" } */
+#if __BITINT_MAXWIDTH__ >= 575
+typedef _BitInt(575) V3 __attribute__((vector_size (sizeof (_BitInt(575))))); /* { dg-error "invalid vector type for attribute 'vector_size'" "" { target bitint575 } } */
+typedef _BitInt(575) V3 __attribute__((vector_size (16 * sizeof (_BitInt(575))))); /* { dg-error "invalid vector type for attribute 'vector_size'" "" { target bitint575 } } */
+#endif
@@ -0,0 +1,18 @@
+// PR c/102989
+// { dg-do compile }
+// { dg-options "-std=c2x -pedantic-errors" }
+
+_BitInt(63) a;
+signed _BitInt(15) b;
+unsigned _BitInt(31) c;
+int d = 21wb;
+long long e = 60594869054uwb;
+__extension__ _BitInt(63) f;
+__extension__ _BitInt(15) g;
+__extension__ unsigned _BitInt(31) h;
+int i = __extension__ 21wb;
+long long j = __extension__ 60594869054uwb;
+#if 0wb == 0
+#endif
+#if 0uwb == 0
+#endif
@@ -0,0 +1,18 @@
+// PR c/102989
+// { dg-do compile }
+// { dg-options "-std=c2x -pedantic-errors -Wc11-c2x-compat" }
+
+_BitInt(63) a; /* { dg-warning "ISO C does not support '_BitInt\\\(63\\\)' before C2X" } */
+signed _BitInt(15) b; /* { dg-warning "ISO C does not support 'signed _BitInt\\\(15\\\)' before C2X" } */
+unsigned _BitInt(31) c; /* { dg-warning "ISO C does not support 'unsigned _BitInt\\\(31\\\)' before C2X" } */
+int d = 21wb; /* { dg-warning "ISO C does not support literal 'wb' suffixes before C2X" } */
+long long e = 60594869054uwb; /* { dg-warning "ISO C does not support literal 'wb' suffixes before C2X" } */
+__extension__ _BitInt(63) f;
+__extension__ _BitInt(15) g;
+__extension__ unsigned _BitInt(31) h;
+int i = __extension__ 21wb;
+long long j = __extension__ 60594869054uwb;
+#if 0wb == 0 /* { dg-warning "ISO C does not support literal 'wb' suffixes before C2X" } */
+#endif
+#if 0uwb == 0 /* { dg-warning "ISO C does not support literal 'wb' suffixes before C2X" } */
+#endif
@@ -0,0 +1,18 @@
+// PR c/102989
+// { dg-do compile }
+// { dg-options "-std=c11" }
+
+_BitInt(63) a;
+signed _BitInt(15) b;
+unsigned _BitInt(31) c;
+int d = 21wb;
+long long e = 60594869054uwb;
+__extension__ _BitInt(63) f;
+__extension__ _BitInt(15) g;
+__extension__ unsigned _BitInt(31) h;
+int i = __extension__ 21wb;
+long long j = __extension__ 60594869054uwb;
+#if 0wb == 0
+#endif
+#if 0uwb == 0
+#endif
@@ -0,0 +1,18 @@
+// PR c/102989
+// { dg-do compile }
+// { dg-options "-std=c11 -Wno-c11-c2x-compat -pedantic-errors" }
+
+_BitInt(63) a;
+signed _BitInt(15) b;
+unsigned _BitInt(31) c;
+int d = 21wb;
+long long e = 60594869054uwb;
+__extension__ _BitInt(63) f;
+__extension__ _BitInt(15) g;
+__extension__ unsigned _BitInt(31) h;
+int i = __extension__ 21wb;
+long long j = __extension__ 60594869054uwb;
+#if 0wb == 0
+#endif
+#if 0uwb == 0
+#endif
@@ -0,0 +1,18 @@
+// PR c/102989
+// { dg-do compile }
+// { dg-options "-std=c11 -pedantic" }
+
+_BitInt(63) a; /* { dg-warning "ISO C does not support '_BitInt\\\(63\\\)' before C2X" } */
+signed _BitInt(15) b; /* { dg-warning "ISO C does not support 'signed _BitInt\\\(15\\\)' before C2X" } */
+unsigned _BitInt(31) c; /* { dg-warning "ISO C does not support 'unsigned _BitInt\\\(31\\\)' before C2X" } */
+int d = 21wb; /* { dg-warning "ISO C does not support literal 'wb' suffixes before C2X" } */
+long long e = 60594869054uwb; /* { dg-warning "ISO C does not support literal 'wb' suffixes before C2X" } */
+__extension__ _BitInt(63) f;
+__extension__ _BitInt(15) g;
+__extension__ unsigned _BitInt(31) h;
+int i = __extension__ 21wb;
+long long j = __extension__ 60594869054uwb;
+#if 0wb == 0 /* { dg-warning "ISO C does not support literal 'wb' suffixes before C2X" } */
+#endif
+#if 0uwb == 0 /* { dg-warning "ISO C does not support literal 'wb' suffixes before C2X" } */
+#endif
@@ -0,0 +1,18 @@
+// PR c/102989
+// { dg-do compile }
+// { dg-options "-std=c11 -pedantic-errors" }
+
+_BitInt(63) a; /* { dg-error "ISO C does not support '_BitInt\\\(63\\\)' before C2X" } */
+signed _BitInt(15) b; /* { dg-error "ISO C does not support 'signed _BitInt\\\(15\\\)' before C2X" } */
+unsigned _BitInt(31) c; /* { dg-error "ISO C does not support 'unsigned _BitInt\\\(31\\\)' before C2X" } */
+int d = 21wb; /* { dg-error "ISO C does not support literal 'wb' suffixes before C2X" } */
+long long e = 60594869054uwb; /* { dg-error "ISO C does not support literal 'wb' suffixes before C2X" } */
+__extension__ _BitInt(63) f;
+__extension__ _BitInt(15) g;
+__extension__ unsigned _BitInt(31) h;
+int i = __extension__ 21wb;
+long long j = __extension__ 60594869054uwb;
+#if 0wb == 0 /* { dg-error "ISO C does not support literal 'wb' suffixes before C2X" } */
+#endif
+#if 0uwb == 0 /* { dg-error "ISO C does not support literal 'wb' suffixes before C2X" } */
+#endif
@@ -0,0 +1,9 @@
+// PR c/102989
+// { dg-do compile }
+
+_BitInt(63) a; // { dg-error "expected" }
+unsigned _BitInt(31) b; // { dg-error "expected" }
+int c = 21wb; // { dg-error "invalid suffix \"wb\" on integer constant" "" { target c++98_only } }
+ // { dg-error "unable to find numeric literal operator 'operator\"\"wb'" "" { target c++11 } .-1 }
+long long d = 60594869054uwb; // { dg-error "invalid suffix \"uwb\" on integer constant" "" { target c++98_only } }
+ // { dg-error "unable to find numeric literal operator 'operator\"\"uwb'" "" { target c++11 } .-1 }
@@ -0,0 +1,10 @@
+// PR c/102989
+// { dg-do compile }
+// { dg-options "" }
+
+_BitInt(63) a; // { dg-error "expected" }
+unsigned _BitInt(31) b; // { dg-error "expected" }
+int c = 21wb; // { dg-error "invalid suffix \"wb\" on integer constant" "" { target c++98_only } }
+ // { dg-error "unable to find numeric literal operator 'operator\"\"wb'" "" { target c++11 } .-1 }
+long long d = 60594869054uwb; // { dg-error "invalid suffix \"uwb\" on integer constant" "" { target c++98_only } }
+ // { dg-error "unable to find numeric literal operator 'operator\"\"uwb'" "" { target c++11 } .-1 }
@@ -0,0 +1,8 @@
+// PR c/102989
+// { dg-do compile { target c++11 } }
+
+constexpr int operator""wb (unsigned long long) { return 0; } // { dg-warning "reserved for future standardization" }
+constexpr int operator""uwb (unsigned long long) { return 1; } // { dg-warning "reserved for future standardization" }
+
+static_assert (-42wb == 0, "");
+static_assert (81uwb == 1, "");
@@ -0,0 +1,9 @@
+// PR c/102989
+// { dg-do compile { target c++11 } }
+// { dg-options "" }
+
+constexpr int operator""wb (unsigned long long) { return 0; } // { dg-warning "reserved for future standardization" }
+constexpr int operator""uwb (unsigned long long) { return 1; } // { dg-warning "reserved for future standardization" }
+
+static_assert (-42wb == 0, "");
+static_assert (81uwb == 1, "");
@@ -856,6 +856,29 @@ cpp_classify_number (cpp_reader *pfile,
virtual_location, 0, message);
}
+ if ((result & CPP_N_BITINT) != 0
+ && CPP_OPTION (pfile, cpp_warn_c11_c2x_compat) != 0)
+ {
+ if (CPP_OPTION (pfile, cpp_warn_c11_c2x_compat) > 0)
+ {
+ const char *message = N_("ISO C does not support literal "
+ "%<wb%> suffixes before C2X");
+ if (CPP_PEDANTIC (pfile) && !CPP_OPTION (pfile, true_false))
+ cpp_pedwarning_with_line (pfile, CPP_W_C11_C2X_COMPAT,
+ virtual_location, 0, message);
+ else
+ cpp_warning_with_line (pfile, CPP_W_C11_C2X_COMPAT,
+ virtual_location, 0, message);
+ }
+ else if (CPP_PEDANTIC (pfile) && !CPP_OPTION (pfile, true_false))
+ {
+ const char *message = N_("ISO C does not support literal "
+ "%<wb%> suffixes before C2X");
+ cpp_error_with_line (pfile, CPP_DL_PEDWARN, virtual_location, 0,
+ message);
+ }
+ }
+
result |= CPP_N_INTEGER;
}