From: Mukesh Kapoor <mukesh.kapoor@oracle.com>
Date: Tue, 24 Oct 2017 13:49:13 +0000 (+0000)
Subject: re PR c++/82307 (unscoped enum-base incorrect cast)
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=eab01c18fdf287aaac60224ddbecae6574631b7b;p=gcc.git

re PR c++/82307 (unscoped enum-base incorrect cast)

/cp
2017-10-24  Mukesh Kapoor  <mukesh.kapoor@oracle.com>
	    Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/82307
	* cvt.c (type_promotes_to): Implement C++17, 7.6/4, about unscoped
	enumeration type whose underlying type is fixed.

/testsuite
2017-10-24  Mukesh Kapoor  <mukesh.kapoor@oracle.com>
	    Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/82307
	* g++.dg/cpp0x/enum35.C: New.
	* g++.dg/cpp0x/enum36.C: Likewise.

Co-Authored-By: Paolo Carlini <paolo.carlini@oracle.com>

From-SVN: r254046
---

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 2d9c0b133c0..8228c8f0a9d 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,10 @@
+2017-10-24  Mukesh Kapoor  <mukesh.kapoor@oracle.com>
+	    Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/82307
+	* cvt.c (type_promotes_to): Implement C++17, 7.6/4, about unscoped
+	enumeration type whose underlying type is fixed.
+
 2017-10-23  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/80449
diff --git a/gcc/cp/cvt.c b/gcc/cp/cvt.c
index c0d0a600562..9ce094eb2a5 100644
--- a/gcc/cp/cvt.c
+++ b/gcc/cp/cvt.c
@@ -1834,12 +1834,27 @@ type_promotes_to (tree type)
 	   || type == char32_type_node
 	   || type == wchar_type_node)
     {
+      tree prom = type;
+
+      if (TREE_CODE (type) == ENUMERAL_TYPE)
+	{
+	  prom = ENUM_UNDERLYING_TYPE (prom);
+	  if (!ENUM_IS_SCOPED (type)
+	      && ENUM_FIXED_UNDERLYING_TYPE_P (type))
+	    {
+	      /* ISO C++17, 7.6/4.  A prvalue of an unscoped enumeration type
+		 whose underlying type is fixed (10.2) can be converted to a
+		 prvalue of its underlying type. Moreover, if integral promotion
+		 can be applied to its underlying type, a prvalue of an unscoped
+		 enumeration type whose underlying type is fixed can also be 
+		 converted to a prvalue of the promoted underlying type.  */
+	      return type_promotes_to (prom);
+	    }
+	}
+
       int precision = MAX (TYPE_PRECISION (type),
 			   TYPE_PRECISION (integer_type_node));
       tree totype = c_common_type_for_size (precision, 0);
-      tree prom = type;
-      if (TREE_CODE (prom) == ENUMERAL_TYPE)
-	prom = ENUM_UNDERLYING_TYPE (prom);
       if (TYPE_UNSIGNED (prom)
 	  && ! int_fits_type_p (TYPE_MAX_VALUE (prom), totype))
 	prom = c_common_type_for_size (precision, 1);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 35c31e70b61..a8a4a119886 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,10 @@
+2017-10-24  Mukesh Kapoor  <mukesh.kapoor@oracle.com>
+	    Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/82307
+	* g++.dg/cpp0x/enum35.C: New.
+	* g++.dg/cpp0x/enum36.C: Likewise.
+
 2017-10-24  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR target/82659
diff --git a/gcc/testsuite/g++.dg/cpp0x/enum35.C b/gcc/testsuite/g++.dg/cpp0x/enum35.C
new file mode 100644
index 00000000000..bcc1b26b390
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/enum35.C
@@ -0,0 +1,14 @@
+// PR c++/82307
+// { dg-do run { target c++11 } }
+
+#include <cassert>
+
+enum : unsigned long long { VAL };
+
+bool foo (unsigned long long) { return true; }
+bool foo (int) { return false; }
+
+int main()
+{
+  assert (foo(VAL));
+}
diff --git a/gcc/testsuite/g++.dg/cpp0x/enum36.C b/gcc/testsuite/g++.dg/cpp0x/enum36.C
new file mode 100644
index 00000000000..4859670309f
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/enum36.C
@@ -0,0 +1,14 @@
+// PR c++/82307
+// { dg-do run { target c++11 } }
+
+#include <cassert>
+
+enum : short { VAL };
+
+bool foo (int) { return true; }
+bool foo (unsigned long long) { return false; }
+
+int main()
+{
+  assert (foo (VAL));
+}