diff mbox series

[01/10] c++: implement __is_reference built-in trait

Message ID 20230326043032.11096-2-kmatsui@cs.washington.edu
State New
Headers show
Series c++, libstdc++: get std::is_object to dispatch to new built-in traits | expand

Commit Message

Ken Matsui March 26, 2023, 4:30 a.m. UTC 
This patch implements built-in trait for std::is_reference.

gcc/cp/ChangeLog:

	* cp-trait.def: Define __is_reference.
	* constraint.cc (diagnose_trait_expr): Handle CPTK_IS_REFERENCE.
	* semantics.cc (trait_expr_value): Likewise.
	(finish_trait_expr): Likewise.

gcc/testsuite/ChangeLog:

	* g++.dg/ext/has-builtin-1.C: Test existence of __is_reference.
	* g++.dg/ext/is_reference.C: New test.

Signed-off-by: Ken Matsui <kmatsui@cs.washington.edu>
---
 gcc/cp/constraint.cc                     |  3 +++
 gcc/cp/cp-trait.def                      |  1 +
 gcc/cp/semantics.cc                      |  4 +++
 gcc/testsuite/g++.dg/ext/has-builtin-1.C |  3 +++
 gcc/testsuite/g++.dg/ext/is_reference.C  | 34 ++++++++++++++++++++++++
 5 files changed, 45 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/ext/is_reference.C
diff mbox series

Patch

diff --git a/gcc/cp/constraint.cc b/gcc/cp/constraint.cc
index 273d15ab097..23e5bc24dbb 100644
--- a/gcc/cp/constraint.cc
+++ b/gcc/cp/constraint.cc
@@ -3701,6 +3701,9 @@  diagnose_trait_expr (tree expr, tree args)
     case CPTK_HAS_VIRTUAL_DESTRUCTOR:
       inform (loc, "  %qT does not have a virtual destructor", t1);
       break;
+    case CPTK_IS_REFERENCE:
+      inform (loc, "  %qT is not a reference", t1);
+      break;
     case CPTK_IS_ABSTRACT:
       inform (loc, "  %qT is not an abstract class", t1);
       break;
diff --git a/gcc/cp/cp-trait.def b/gcc/cp/cp-trait.def
index bac593c0094..63a64152ce6 100644
--- a/gcc/cp/cp-trait.def
+++ b/gcc/cp/cp-trait.def
@@ -67,6 +67,7 @@  DEFTRAIT_EXPR (IS_CONVERTIBLE, "__is_convertible", 2)
 DEFTRAIT_EXPR (IS_EMPTY, "__is_empty", 1)
 DEFTRAIT_EXPR (IS_ENUM, "__is_enum", 1)
 DEFTRAIT_EXPR (IS_FINAL, "__is_final", 1)
+DEFTRAIT_EXPR (IS_REFERENCE, "__is_reference", 1)
 DEFTRAIT_EXPR (IS_LAYOUT_COMPATIBLE, "__is_layout_compatible", 2)
 DEFTRAIT_EXPR (IS_LITERAL_TYPE, "__is_literal_type", 1)
 DEFTRAIT_EXPR (IS_NOTHROW_ASSIGNABLE, "__is_nothrow_assignable", 2)
diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
index 99a76e3ed65..b17fbf8005d 100644
--- a/gcc/cp/semantics.cc
+++ b/gcc/cp/semantics.cc
@@ -11996,6 +11996,9 @@  trait_expr_value (cp_trait_kind kind, tree type1, tree type2)
     case CPTK_IS_FINAL:
       return CLASS_TYPE_P (type1) && CLASSTYPE_FINAL (type1);
 
+    case CPTK_IS_REFERENCE:
+      return type_code1 == REFERENCE_TYPE;
+
     case CPTK_IS_LAYOUT_COMPATIBLE:
       return layout_compatible_type_p (type1, type2);
 
@@ -12201,6 +12204,7 @@  finish_trait_expr (location_t loc, cp_trait_kind kind, tree type1, tree type2)
     case CPTK_IS_ENUM:
     case CPTK_IS_UNION:
     case CPTK_IS_SAME:
+    case CPTK_IS_REFERENCE:
       break;
 
     case CPTK_IS_LAYOUT_COMPATIBLE:
diff --git a/gcc/testsuite/g++.dg/ext/has-builtin-1.C b/gcc/testsuite/g++.dg/ext/has-builtin-1.C
index f343e153e56..b697673790c 100644
--- a/gcc/testsuite/g++.dg/ext/has-builtin-1.C
+++ b/gcc/testsuite/g++.dg/ext/has-builtin-1.C
@@ -146,3 +146,6 @@ 
 #if !__has_builtin (__remove_cvref)
 # error "__has_builtin (__remove_cvref) failed"
 #endif
+#if !__has_builtin (__is_reference)
+# error "__has_builtin (__is_reference) failed"
+#endif
diff --git a/gcc/testsuite/g++.dg/ext/is_reference.C b/gcc/testsuite/g++.dg/ext/is_reference.C
new file mode 100644
index 00000000000..b5ce4db7afd
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/is_reference.C
@@ -0,0 +1,34 @@ 
+// { dg-do compile { target c++11 } }
+
+#include <testsuite_tr1.h>
+
+using namespace __gnu_test;
+
+#define SA(X) static_assert((X),#X)
+#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)
+
+// Positive tests.
+SA_TEST_CATEGORY(__is_reference, int&, true);
+SA_TEST_CATEGORY(__is_reference, ClassType&, true);
+SA(__is_reference(int(&)(int)));
+SA_TEST_CATEGORY(__is_reference, int&&, true);
+SA_TEST_CATEGORY(__is_reference, ClassType&&, true);
+SA(__is_reference(int(&&)(int)));
+SA_TEST_CATEGORY(__is_reference, IncompleteClass&, true);
+
+// Negative tests
+SA_TEST_CATEGORY(__is_reference, void, false);
+SA_TEST_CATEGORY(__is_reference, int*, false);
+SA_TEST_CATEGORY(__is_reference, int[3], false);
+SA(!__is_reference(int(int)));
+SA(!__is_reference(int(*const)(int)));
+SA(!__is_reference(int(*volatile)(int)));
+SA(!__is_reference(int(*const volatile)(int)));
+
+// Sanity check.
+SA_TEST_CATEGORY(__is_reference, ClassType, false);
+SA_TEST_CATEGORY(__is_reference, IncompleteClass, false);