type_traits (__make_unsigned_selector<>): Consider enums of size smaller than short.

	* include/std/type_traits (__make_unsigned_selector<>): Consider
	enums of size smaller than short.
	(__make_signed_selector<>): Likewise.
	* testsuite/20_util/make_signed/requirements/typedefs_neg.cc:
	Adjust line numbers.
	* testsuite/20_util/make_usigned/requirements/typedefs_neg.cc:
	Adjust line numbers.
	* testsuite/20_util/make_signed/requirements/typedefs-2.cc:
	Ensure test_enum is the same size as short.
	* testsuite/20_util/make_unsigned/requirements/typedefs-2.cc:
	Ensure test_enum is the same size as short.

From-SVN: r139875

libstdc++-v3/ChangeLog

+2008-09-01  Mark Mitchell  <mark@codesourcery.com>
+
+	* include/std/type_traits (__make_unsigned_selector<>): Consider
+	enums of size smaller than short.
+	(__make_signed_selector<>): Likewise.
+	* testsuite/20_util/make_signed/requirements/typedefs_neg.cc:
+	Adjust line numbers.
+	* testsuite/20_util/make_usigned/requirements/typedefs_neg.cc:
+	Adjust line numbers.
+	* testsuite/20_util/make_signed/requirements/typedefs-2.cc:
+	Ensure test_enum is the same size as short.
+	* testsuite/20_util/make_unsigned/requirements/typedefs-2.cc:
+	Ensure test_enum is the same size as short.
+
 2008-08-31  Aaron W. LaFramboise  <aaronavay62@aaronwl.com>
 
 	* acinclude.m4 <enable_symvers>: Don't use symvers on Windows.

libstdc++-v3/include/std/type_traits

@@ -455,15 +455,18 @@ namespace std
     struct __make_unsigned_selector<_Tp, false, true>
     {
     private:
-      // GNU enums start with sizeof short.
-      typedef unsigned short __smallest;
-      static const bool __b1 = sizeof(_Tp) <= sizeof(__smallest);
+      // With -fshort-enums, an enum may be as small as a char.
+      typedef unsigned char __smallest;
+      static const bool __b0 = sizeof(_Tp) <= sizeof(__smallest);
+      static const bool __b1 = sizeof(_Tp) <= sizeof(unsigned short);
       static const bool __b2 = sizeof(_Tp) <= sizeof(unsigned int);
-      typedef conditional<__b2, unsigned int, unsigned long> __cond;
-      typedef typename __cond::type __cond_type;
+      typedef conditional<__b2, unsigned int, unsigned long> __cond2;
+      typedef typename __cond2::type __cond2_type;
+      typedef conditional<__b1, unsigned short, __cond2_type> __cond1;
+      typedef typename __cond1::type __cond1_type;
 
     public:
-      typedef typename conditional<__b1, __smallest, __cond_type>::type __type;
+      typedef typename conditional<__b0, __smallest, __cond1_type>::type __type;
     };
 
   // Given an integral/enum type, return the corresponding unsigned
@@ -530,15 +533,18 @@ namespace std
     struct __make_signed_selector<_Tp, false, true>
     {
     private:
-      // GNU enums start with sizeof short.
-      typedef signed short __smallest;
-      static const bool __b1 = sizeof(_Tp) <= sizeof(__smallest);
+      // With -fshort-enums, an enum may be as small as a char.
+      typedef signed char __smallest;
+      static const bool __b0 = sizeof(_Tp) <= sizeof(__smallest);
+      static const bool __b1 = sizeof(_Tp) <= sizeof(signed short);
       static const bool __b2 = sizeof(_Tp) <= sizeof(signed int);
-      typedef conditional<__b2, signed int, signed long> __cond;
-      typedef typename __cond::type __cond_type;
+      typedef conditional<__b2, signed int, signed long> __cond2;
+      typedef typename __cond2::type __cond2_type;
+      typedef conditional<__b1, signed short, __cond2_type> __cond1;
+      typedef typename __cond1::type __cond1_type;
 
     public:
-      typedef typename conditional<__b1, __smallest, __cond_type>::type __type;
+      typedef typename conditional<__b0, __smallest, __cond1_type>::type __type;
     };
 
   // Given an integral/enum type, return the corresponding signed

libstdc++-v3/testsuite/20_util/make_signed/requirements/typedefs-2.cc

@@ -24,7 +24,8 @@
 #include <type_traits>
 #include <testsuite_hooks.h>
 
-enum test_enum { first_selection };
+// Ensure that this enum has "short" as its underlying type.
+enum test_enum { first_selection = ((unsigned char)-1) + 1 };
 
 void test01()
 {

libstdc++-v3/testsuite/20_util/make_signed/requirements/typedefs_neg.cc

@@ -49,8 +49,8 @@ void test01()
 // { dg-error "instantiated from here" "" { target *-*-* } 41 }
 // { dg-error "instantiated from here" "" { target *-*-* } 43 }
 
-// { dg-error "invalid use of incomplete type" "" { target *-*-* } 549 }
-// { dg-error "declaration of" "" { target *-*-* } 515 }
+// { dg-error "invalid use of incomplete type" "" { target *-*-* } 555 }
+// { dg-error "declaration of" "" { target *-*-* } 518 }
 
 // { dg-excess-errors "At global scope" }
 // { dg-excess-errors "In instantiation of" }

libstdc++-v3/testsuite/20_util/make_unsigned/requirements/typedefs-2.cc

@@ -24,7 +24,8 @@
 #include <type_traits>
 #include <testsuite_hooks.h>
 
-enum test_enum { first_selection };
+// Ensure that this enum has "short" as its underlying type.
+enum test_enum { first_selection = ((unsigned char)-1) + 1 };
 
 void test01()
 {

libstdc++-v3/testsuite/20_util/make_unsigned/requirements/typedefs_neg.cc

@@ -49,7 +49,7 @@ void test01()
 // { dg-error "instantiated from here" "" { target *-*-* } 41 }
 // { dg-error "instantiated from here" "" { target *-*-* } 43 }
 
-// { dg-error "invalid use of incomplete type" "" { target *-*-* } 474 }
+// { dg-error "invalid use of incomplete type" "" { target *-*-* } 477 }
 // { dg-error "declaration of" "" { target *-*-* } 440 }
 
 // { dg-excess-errors "At global scope" }