Correct conversion/overflow behavior.

	* cvt.c (ignore_overflows): Move here from typeck.c.
	(ocp_convert): Use it.
	(cp_fold_convert): Use it.  Don't call rvalue.
	* typeck.c (build_static_cast_1): Don't use it.  Do call rvalue.
	* error.c (location_of): Handle expressions, too.
	* class.c (check_bitfield_decl): Set input_location around call to
	cxx_constant_value.
	* semantics.c (cxx_eval_outermost_constant_expr): Don't
	print the expression if it already had TREE_OVERFLOW set.
	(reduced_constant_expression_p): Check TREE_OVERFLOW_P for C++98, too.
	(verify_constant): Allow overflow with a permerror if we're
	enforcing.
	(cxx_eval_outermost_constant_expr): Use verify_constant.
	(adjust_temp_type): Use cp_fold_convert.
	* decl.c (build_enumerator): Don't call constant_expression_warning.
	* decl2.c (grokbitfield): Likewise.

From-SVN: r166453

6 files changed, 41 insertions, 14 deletions

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 74d974b..7d2688e 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,11 @@
+2010-11-08  Jason Merrill  <jason@redhat.com>
+
+	* g++.dg/expr/overflow1.C: New.
+	* g++.dg/warn/overflow-warn-1.C: Add expected diagnostics.
+	* g++.dg/warn/overflow-warn-3.C: Remove unnecessary line number.
+	* g++.dg/warn/overflow-warn-4.C: Add expected diagnostics.
+	* g++.dg/warn/overflow-warn-5.C: Don't expect wrong warning.
+
 2010-11-08  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
 
 	* gcc.dg/pr35442.c: Adapt warning.
diff --git a/gcc/testsuite/g++.dg/expr/overflow1.C b/gcc/testsuite/g++.dg/expr/overflow1.C
new file mode 100644
index 0000000..b67b4e42
--- /dev/null
+++ b/gcc/testsuite/g++.dg/expr/overflow1.C
@@ -0,0 +1,8 @@
+#include <limits.h>
+
+enum E {
+  A = (unsigned char)-1,	/* OK */
+  B = (signed char)UCHAR_MAX,	/* implementation-defined */
+  C = INT_MAX+1,     /* undefined (C)/ill-formed (C++) { dg-message "" } */
+  D = UINT_MAX+1     /* OK */
+};
diff --git a/gcc/testsuite/g++.dg/warn/overflow-warn-1.C b/gcc/testsuite/g++.dg/warn/overflow-warn-1.C
index 17bd067..22c512a 100644
--- a/gcc/testsuite/g++.dg/warn/overflow-warn-1.C
+++ b/gcc/testsuite/g++.dg/warn/overflow-warn-1.C
@@ -1,7 +1,7 @@
 /* Test for diagnostics for constant overflow.  */
 /* Origin: Joseph Myers <joseph@codesourcery.com> */
 /* { dg-do compile } */
-/* { dg-options "" } */
+/* { dg-options "-fpermissive" } */
 
 #include <limits.h>
 
@@ -19,8 +19,10 @@ enum e {
   E4 = 0 * (1 / 0), /* { dg-warning "division by zero" } */
   /* { dg-error "enumerator value for 'E4' is not an integer constant" "enum error" { xfail *-*-* } 19 } */
   E5 = INT_MAX + 1, /* { dg-warning "integer overflow in expression" } */
+  /* { dg-warning "overflow in constant expression" "constant" { target *-*-* } 21 } */
   /* Again, overflow in evaluated subexpression.  */
   E6 = 0 * (INT_MAX + 1), /* { dg-warning "integer overflow in expression" } */
+  /* { dg-warning "overflow in constant expression" "constant" { target *-*-* } 24 } */
   /* A cast does not constitute overflow in conversion.  */
   E7 = (char) INT_MAX
 };
@@ -29,6 +31,7 @@ struct s {
   int a;
   int : 0 * (1 / 0); /* { dg-warning "division by zero" } */
   int : 0 * (INT_MAX + 1); /* { dg-warning "integer overflow in expression" } */
+  /* { dg-warning "overflow in constant expression" "constant" { target *-*-* } 33 } */
 };
 
 void
@@ -49,10 +52,10 @@ void *n = 0;
    constants.  The third has the overflow in an unevaluated
    subexpression, so is a null pointer constant.  */
 void *p = 0 * (INT_MAX + 1); /* { dg-warning "integer overflow in expression" } */
-/* { dg-error "invalid conversion from 'int' to 'void" "null" { target *-*-* } 51 } */
+/* { dg-warning "invalid conversion from 'int' to 'void" "null" { target *-*-* } 54 } */
 void *q = 0 * (1 / 0); /* { dg-warning "division by zero" } */
-/* { dg-error "invalid conversion from 'int' to 'void*'" "null" { xfail *-*-* } 53 } */
-void *r = (1 ? 0 : INT_MAX+1); /* { dg-bogus "integer overflow in expression" "" { xfail *-*-* } 55 } */
+/* { dg-error "invalid conversion from 'int' to 'void*'" "null" { xfail *-*-* } 56 } */
+void *r = (1 ? 0 : INT_MAX+1); /* { dg-bogus "integer overflow in expression" "" { xfail *-*-* } } */
 
 void
 g (int i)
@@ -62,6 +65,7 @@ g (int i)
     case 0 * (1/0): /* { dg-warning "division by zero" } */
       ;
     case 1 + 0 * (INT_MAX + 1): /* { dg-warning "integer overflow in expression" } */
+      /* { dg-warning "overflow in constant expression" "constant" { target *-*-* } 67 } */
       ;
     }
 }
diff --git a/gcc/testsuite/g++.dg/warn/overflow-warn-3.C b/gcc/testsuite/g++.dg/warn/overflow-warn-3.C
index ce03a97..d88c87a 100644
--- a/gcc/testsuite/g++.dg/warn/overflow-warn-3.C
+++ b/gcc/testsuite/g++.dg/warn/overflow-warn-3.C
@@ -57,7 +57,7 @@ void *p = 0 * (INT_MAX + 1); /* { dg-warning "integer overflow in expression" }
 
 void *q = 0 * (1 / 0); /* { dg-warning "division by zero" } */
 /* { dg-warning "invalid conversion from 'int' to 'void*'" "null" { xfail *-*-* } 58 } */
-void *r = (1 ? 0 : INT_MAX+1); /* { dg-bogus "integer overflow in expression" "" { xfail *-*-* } 60 } */
+void *r = (1 ? 0 : INT_MAX+1); /* { dg-bogus "integer overflow in expression" "" { xfail *-*-* } } */
 
 void
 g (int i)
diff --git a/gcc/testsuite/g++.dg/warn/overflow-warn-4.C b/gcc/testsuite/g++.dg/warn/overflow-warn-4.C
index 0c916d0..374d2942 100644
--- a/gcc/testsuite/g++.dg/warn/overflow-warn-4.C
+++ b/gcc/testsuite/g++.dg/warn/overflow-warn-4.C
@@ -11,7 +11,7 @@ enum e {
   E1 = UINT_MAX + 1,
   /* Overflow in an unevaluated part of an expression is OK (example
      in the standard).  */
-  E2 = 2 || 1 / 0, /* { dg-bogus "warning: division by zero" "" { xfail *-*-* } 14 } */
+  E2 = 2 || 1 / 0, /* { dg-bogus "warning: division by zero" "" { xfail *-*-* } } */
   E3 = 1 / 0, /* { dg-warning "division by zero" } */
   /* { dg-error "enumerator value for 'E3' is not an integer constant|not a constant expression" "enum error" { target *-*-* } 15 } */
   /* But as in DR#031, the 1/0 in an evaluated subexpression means the
@@ -20,9 +20,11 @@ enum e {
   /* { dg-error "enumerator value for 'E4' is not an integer constant" "enum error" { xfail *-*-* } 19 } */
   E5 = INT_MAX + 1, /* { dg-warning "integer overflow in expression" } */
   /* { dg-error "overflow in constant expression" "constant" { target *-*-* } 21 } */
+  /* { dg-error "enumerator value for 'E5' is not an integer constant" "enum error" { target *-*-* } 21 } */
   /* Again, overflow in evaluated subexpression.  */
   E6 = 0 * (INT_MAX + 1), /* { dg-warning "integer overflow in expression" } */
-  /* { dg-error "overflow in constant expression" "constant" { target *-*-* } 24 } */
+  /* { dg-error "overflow in constant expression" "constant" { target *-*-* } 25 } */
+  /* { dg-error "enumerator value for 'E6' is not an integer constant" "enum error" { target *-*-* } 25 } */
   /* A cast does not constitute overflow in conversion.  */
   E7 = (char) INT_MAX
 };
@@ -31,7 +33,8 @@ struct s {
   int a;
   int : 0 * (1 / 0); /* { dg-warning "division by zero" } */
   int : 0 * (INT_MAX + 1); /* { dg-warning "integer overflow in expression" } */
-  /* { dg-error "overflow in constant expression" "constant" { target *-*-* } 33 } */
+  /* { dg-error "overflow in constant expression" "constant" { target *-*-* } 35 } */
+  /* { dg-error "bit-field .* width not an integer constant" "" { target *-*-* } 35 } */
 };
 
 void
@@ -53,11 +56,11 @@ void *n = 0;
    constants.  The third has the overflow in an unevaluated
    subexpression, so is a null pointer constant.  */
 void *p = 0 * (INT_MAX + 1); /* { dg-warning "integer overflow in expression" } */
-/* { dg-error "invalid conversion from 'int' to 'void" "null" { target *-*-* } 55 } */
+/* { dg-error "invalid conversion from 'int' to 'void" "null" { target *-*-* } 58 } */
 
 void *q = 0 * (1 / 0); /* { dg-warning "division by zero" } */
-/* { dg-error "invalid conversion from 'int' to 'void*'" "null" { xfail *-*-* } 58 } */
-void *r = (1 ? 0 : INT_MAX+1); /* { dg-bogus "integer overflow in expression" "" { xfail *-*-* } 60 } */
+/* { dg-error "invalid conversion from 'int' to 'void*'" "null" { xfail *-*-* } 61 } */
+void *r = (1 ? 0 : INT_MAX+1); /* { dg-bogus "integer overflow in expression" "" { xfail *-*-* } } */
 
 void
 g (int i)
@@ -67,7 +70,7 @@ g (int i)
     case 0 * (1/0): /* { dg-warning "division by zero" } */
       ;
     case 1 + 0 * (INT_MAX + 1): /* { dg-warning "integer overflow in expression" } */
-      /* { dg-error "overflow in constant expression" "constant" { target *-*-* } 69 } */
+      /* { dg-error "overflow in constant expression" "constant" { target *-*-* } 72 } */
       ;
     }
 }
diff --git a/gcc/testsuite/g++.dg/warn/overflow-warn-5.C b/gcc/testsuite/g++.dg/warn/overflow-warn-5.C
index 472d4a7..bdfec4a 100644
--- a/gcc/testsuite/g++.dg/warn/overflow-warn-5.C
+++ b/gcc/testsuite/g++.dg/warn/overflow-warn-5.C
@@ -1,7 +1,11 @@
 /* PR c/27273 */
 /* { dg-do compile } */
-/* { dg-options "-Woverflow" } */
+
+// This used to warn about "overflow in implicit constant conversion",
+// which was wrong; 512 is never converted to unsigned char.  Rather, an
+// appropriate warning would be that the & expression always evaluates to 0
+// because of the limited range of unsigned char.
 
 unsigned char rx_async(unsigned char p) {
-    return p & 512; /* { dg-warning "overflow in implicit constant conversion" } */
+    return p & 512; /* { dg-warning "" "" { xfail *-*-* } } */
 }