[gcc r14-6371] c++: Implement __is_bounded_array built-in trait

[Jason Merrill]

https://gcc.gnu.org/g:ea0a0e6bf1470e48cc5f337bc1be40c40ac8e5ed

commit r14-6371-gea0a0e6bf1470e48cc5f337bc1be40c40ac8e5ed
Author: Ken Matsui <kmatsui@gcc.gnu.org>
Date:   Wed Dec 6 21:33:01 2023 -0800

    c++: Implement __is_bounded_array built-in trait
    
    This patch implements built-in trait for std::is_bounded_array.
    
    gcc/cp/ChangeLog:
    
            * cp-trait.def: Define __is_bounded_array.
            * constraint.cc (diagnose_trait_expr): Handle
            CPTK_IS_BOUNDED_ARRAY.
            * semantics.cc (trait_expr_value): Likewise.
            (finish_trait_expr): Likewise.
    
    gcc/testsuite/ChangeLog:
    
            * g++.dg/ext/has-builtin-1.C: Test existence of
            __is_bounded_array.
            * g++.dg/ext/is_bounded_array.C: New test.
    
    Signed-off-by: Ken Matsui <kmatsui@gcc.gnu.org>

Diff:
---
 gcc/cp/constraint.cc                        |  3 +++
 gcc/cp/semantics.cc                         |  4 +++
 gcc/testsuite/g++.dg/ext/has-builtin-1.C    |  3 +++
 gcc/testsuite/g++.dg/ext/is_bounded_array.C | 38 +++++++++++++++++++++++++++++
 gcc/cp/cp-trait.def                         |  1 +
 5 files changed, 49 insertions(+)

diff --git a/gcc/cp/constraint.cc b/gcc/cp/constraint.cc
index d75132e8e82..2311bab28c4 100644
--- a/gcc/cp/constraint.cc
+++ b/gcc/cp/constraint.cc
@@ -3728,6 +3728,9 @@ diagnose_trait_expr (tree expr, tree args)
     case CPTK_IS_BASE_OF:
       inform (loc, "  %qT is not a base of %qT", t1, t2);
       break;
+    case CPTK_IS_BOUNDED_ARRAY:
+      inform (loc, "  %qT is not a bounded array", t1);
+      break;
     case CPTK_IS_CLASS:
       inform (loc, "  %qT is not a class", t1);
       break;
diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
index 399a33a82a8..ecbd858b6dd 100644
--- a/gcc/cp/semantics.cc
+++ b/gcc/cp/semantics.cc
@@ -12398,6 +12398,9 @@ trait_expr_value (cp_trait_kind kind, tree type1, tree type2)
 	      && (same_type_ignoring_top_level_qualifiers_p (type1, type2)
 		  || DERIVED_FROM_P (type1, type2)));
 
+    case CPTK_IS_BOUNDED_ARRAY:
+      return type_code1 == ARRAY_TYPE && TYPE_DOMAIN (type1);
+
     case CPTK_IS_CLASS:
       return NON_UNION_CLASS_TYPE_P (type1);
 
@@ -12618,6 +12621,7 @@ finish_trait_expr (location_t loc, cp_trait_kind kind, tree type1, tree type2)
       break;
 
     case CPTK_IS_ARRAY:
+    case CPTK_IS_BOUNDED_ARRAY:
     case CPTK_IS_CLASS:
     case CPTK_IS_ENUM:
     case CPTK_IS_SAME:
diff --git a/gcc/testsuite/g++.dg/ext/has-builtin-1.C b/gcc/testsuite/g++.dg/ext/has-builtin-1.C
index 6b9437f7c47..4cfb817788c 100644
--- a/gcc/testsuite/g++.dg/ext/has-builtin-1.C
+++ b/gcc/testsuite/g++.dg/ext/has-builtin-1.C
@@ -65,6 +65,9 @@
 #if !__has_builtin (__is_base_of)
 # error "__has_builtin (__is_base_of) failed"
 #endif
+#if !__has_builtin (__is_bounded_array)
+# error "__has_builtin (__is_bounded_array) failed"
+#endif
 #if !__has_builtin (__is_class)
 # error "__has_builtin (__is_class) failed"
 #endif
diff --git a/gcc/testsuite/g++.dg/ext/is_bounded_array.C b/gcc/testsuite/g++.dg/ext/is_bounded_array.C
new file mode 100644
index 00000000000..346790eba12
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/is_bounded_array.C
@@ -0,0 +1,38 @@
+// { dg-do compile { target c++11 } }
+
+#include <testsuite_tr1.h>
+
+using namespace __gnu_test;
+
+#define SA(X) static_assert((X),#X)
+
+#define SA_TEST_CONST(TRAIT, TYPE, EXPECT)	\
+  SA(TRAIT(TYPE) == EXPECT);			\
+  SA(TRAIT(const TYPE) == EXPECT)
+
+#define SA_TEST_CATEGORY(TRAIT, TYPE, EXPECT)	\
+  SA(TRAIT(TYPE) == EXPECT);					\
+  SA(TRAIT(const TYPE) == EXPECT);				\
+  SA(TRAIT(volatile TYPE) == EXPECT);			\
+  SA(TRAIT(const volatile TYPE) == EXPECT)
+
+SA_TEST_CATEGORY(__is_bounded_array, int[2], true);
+SA_TEST_CATEGORY(__is_bounded_array, int[], false);
+SA_TEST_CATEGORY(__is_bounded_array, int[2][3], true);
+SA_TEST_CATEGORY(__is_bounded_array, int[][3], false);
+SA_TEST_CATEGORY(__is_bounded_array, float*[2], true);
+SA_TEST_CATEGORY(__is_bounded_array, float*[], false);
+SA_TEST_CATEGORY(__is_bounded_array, float*[2][3], true);
+SA_TEST_CATEGORY(__is_bounded_array, float*[][3], false);
+SA_TEST_CATEGORY(__is_bounded_array, ClassType[2], true);
+SA_TEST_CATEGORY(__is_bounded_array, ClassType[], false);
+SA_TEST_CATEGORY(__is_bounded_array, ClassType[2][3], true);
+SA_TEST_CATEGORY(__is_bounded_array, ClassType[][3], false);
+SA_TEST_CATEGORY(__is_bounded_array, int(*)[2], false);
+SA_TEST_CATEGORY(__is_bounded_array, int(*)[], false);
+SA_TEST_CATEGORY(__is_bounded_array, int(&)[2], false);
+SA_TEST_CONST(__is_bounded_array, int(&)[], false);
+
+// Sanity check.
+SA_TEST_CATEGORY(__is_bounded_array, ClassType, false);
+SA_TEST_CONST(__is_bounded_array, void(), false);
diff --git a/gcc/cp/cp-trait.def b/gcc/cp/cp-trait.def
index 759f10a3532..0e93e2b7114 100644
--- a/gcc/cp/cp-trait.def
+++ b/gcc/cp/cp-trait.def
@@ -62,6 +62,7 @@ DEFTRAIT_EXPR (IS_AGGREGATE, "__is_aggregate", 1)
 DEFTRAIT_EXPR (IS_ARRAY, "__is_array", 1)
 DEFTRAIT_EXPR (IS_ASSIGNABLE, "__is_assignable", 2)
 DEFTRAIT_EXPR (IS_BASE_OF, "__is_base_of", 2)
+DEFTRAIT_EXPR (IS_BOUNDED_ARRAY, "__is_bounded_array", 1)
 DEFTRAIT_EXPR (IS_CLASS, "__is_class", 1)
 DEFTRAIT_EXPR (IS_CONSTRUCTIBLE, "__is_constructible", -1)
 DEFTRAIT_EXPR (IS_CONVERTIBLE, "__is_convertible", 2)