This patch implements built-in trait for std::is_void.
gcc/cp/ChangeLog:
* cp-trait.def: Define __is_void.
* constraint.cc (diagnose_trait_expr): Handle CPTK_IS_VOID.
* semantics.cc (trait_expr_value): Likewise.
(finish_trait_expr): Likewise.
gcc/testsuite/ChangeLog:
* g++.dg/ext/has-builtin-1.C: Test existence of __is_void.
* g++.dg/ext/is_void.C: New test.
Signed-off-by: Ken Matsui <kmat...@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_void.C | 35 ++++++++++++++++++++++++
5 files changed, 46 insertions(+)
create mode 100644 gcc/testsuite/g++.dg/ext/is_void.C
diff --git a/gcc/cp/constraint.cc b/gcc/cp/constraint.cc
index 500ac9177c7..e67c0ffeaac 100644
--- a/gcc/cp/constraint.cc
+++ b/gcc/cp/constraint.cc
@@ -3753,6 +3753,9 @@ diagnose_trait_expr (tree expr, tree args)
case CPTK_IS_FUNCTION:
inform (loc, " %qT is not a function", t1);
break;
+ case CPTK_IS_VOID:
+ inform (loc, " %qT is not a void type", t1);
+ break;
case CPTK_IS_AGGREGATE:
inform (loc, " %qT is not an aggregate", t1);
break;
diff --git a/gcc/cp/cp-trait.def b/gcc/cp/cp-trait.def
index 99195201676..6284924630a 100644
--- a/gcc/cp/cp-trait.def
+++ b/gcc/cp/cp-trait.def
@@ -84,6 +84,7 @@ DEFTRAIT_EXPR (IS_TRIVIALLY_CONSTRUCTIBLE,
"__is_trivially_constructible", -1)
DEFTRAIT_EXPR (IS_TRIVIALLY_COPYABLE, "__is_trivially_copyable", 1)
DEFTRAIT_EXPR (IS_UNION, "__is_union", 1)
DEFTRAIT_EXPR (IS_FUNCTION, "__is_function", 1)
+DEFTRAIT_EXPR (IS_VOID, "__is_void", 1)
DEFTRAIT_EXPR (REF_CONSTRUCTS_FROM_TEMPORARY,
"__reference_constructs_from_temporary", 2)
DEFTRAIT_EXPR (REF_CONVERTS_FROM_TEMPORARY,
"__reference_converts_from_temporary", 2)
/* FIXME Added space to avoid direct usage in GCC 13. */
diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
index 36fe370da2d..a6598fedfbc 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_FUNCTION:
return type_code1 == FUNCTION_TYPE;
+ case CPTK_IS_VOID:
+ return VOID_TYPE_P (type1);
+
case CPTK_IS_FINAL:
return CLASS_TYPE_P (type1) && CLASSTYPE_FINAL (type1);
@@ -12209,6 +12212,7 @@ finish_trait_expr (location_t loc, cp_trait_kind kind,
tree type1, tree type2)
case CPTK_IS_SAME:
case CPTK_IS_REFERENCE:
case CPTK_IS_FUNCTION:
+ case CPTK_IS_VOID:
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 90eb00ebf2d..b96cc9e6f50 100644
--- a/gcc/testsuite/g++.dg/ext/has-builtin-1.C
+++ b/gcc/testsuite/g++.dg/ext/has-builtin-1.C
@@ -152,3 +152,6 @@
#if !__has_builtin (__is_function)
# error "__has_builtin (__is_function) failed"
#endif
+#if !__has_builtin (__is_void)
+# error "__has_builtin (__is_void) failed"
+#endif
diff --git a/gcc/testsuite/g++.dg/ext/is_void.C
b/gcc/testsuite/g++.dg/ext/is_void.C
new file mode 100644
index 00000000000..707f0d6875b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/is_void.C
@@ -0,0 +1,35 @@
+// { 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)
+
+SA_TEST_CATEGORY(__is_void, void, true);
+
+SA_TEST_CATEGORY(__is_void, char, false);
+SA_TEST_CATEGORY(__is_void, signed char, false);
+SA_TEST_CATEGORY(__is_void, unsigned char, false);
+SA_TEST_CATEGORY(__is_void, wchar_t, false);
+SA_TEST_CATEGORY(__is_void, short, false);
+SA_TEST_CATEGORY(__is_void, unsigned short, false);
+SA_TEST_CATEGORY(__is_void, int, false);
+SA_TEST_CATEGORY(__is_void, unsigned int, false);
+SA_TEST_CATEGORY(__is_void, long, false);
+SA_TEST_CATEGORY(__is_void, unsigned long, false);
+SA_TEST_CATEGORY(__is_void, long long, false);
+SA_TEST_CATEGORY(__is_void, unsigned long long, false);
+SA_TEST_CATEGORY(__is_void, float, false);
+SA_TEST_CATEGORY(__is_void, double, false);
+SA_TEST_CATEGORY(__is_void, long double, false);
+
+// Sanity check.
+SA_TEST_CATEGORY(__is_void, ClassType, false);
+SA_TEST_CATEGORY(__is_void, IncompleteClass, false);
+SA_TEST_CATEGORY(__is_void, IncompleteUnion, false);
--
2.40.0
