--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/overflow-warn-4.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,131 @@
+/* Test for diagnostics for constant overflow.  Test with -pedantic-errors.  */
+/* Origin: Joseph Myers <joseph@codesourcery.com> */
+/* { dg-do compile } */
+/* { dg-options "-std=c99 -pedantic-errors" } */
+
+#include <limits.h>
+
+enum e {
+  E0 = INT_MAX,
+  /* Unsigned overflow wraps around.  */
+  E1 = UINT_MAX + 1,
+  /* Overflow in an unevaluated part of an expression is OK (example
+     in the standard).  */
+  E2 = 2 || 1 / 0,
+  E3 = 1 / 0, /* { dg-warning "division by zero" } */
+  /* { dg-error "enumerator value for 'E3' is not an integer constant" "enum error" { target *-*-* } .-1 } */
+  /* But as in DR#031, the 1/0 in an evaluated subexpression means the
+     whole expression violates the constraints.  */
+  E4 = 0 * (1 / 0), /* { dg-warning "division by zero" } */
+  /* { dg-error "enumerator value for 'E4' is not an integer constant" "enum error" { target *-*-* } .-1 } */
+  E5 = INT_MAX + 1, /* { dg-warning "integer overflow in expression" } */
+  /* { dg-error "overflow in constant expression" "constant" { target *-*-* } .-1 } */
+  /* Again, overflow in evaluated subexpression.  */
+  E6 = 0 * (INT_MAX + 1), /* { dg-warning "integer overflow in expression of type .int. results in .-\[0-9\]+." } */
+  /* { dg-error "overflow in constant expression" "constant" { target *-*-* } .-1 } */
+  /* A cast does not constitute overflow in conversion.  */
+  E7 = (char) INT_MAX
+};
+
+struct s {
+  int a;
+  int : 0 * (1 / 0); /* { dg-warning "division by zero" } */
+  /* { dg-error "not an integer constant" "integer constant" { target *-*-* } .-1 } */
+  int : 0 * (INT_MAX + 1); /* { dg-warning "integer overflow in expression" } */
+  /* { dg-error "overflow in constant expression" "constant" { target *-*-* } .-1 } */
+};
+
+void
+f (void)
+{
+  /* This expression is not required to be a constant expression, so
+     it should just involve undefined behavior at runtime.  */
+  int c = INT_MAX + 1; /* { dg-warning "integer overflow in expression" } */
+
+}
+
+/* But this expression does need to be constant.  */
+static int sc = INT_MAX + 1; /* { dg-warning "integer overflow in expression" } */
+/* { dg-error "overflow in constant expression" "constant" { target *-*-* } .-1 } */
+
+/* The first two of these involve overflow, so are not null pointer
+   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 "overflow in constant expression" "constant" { target *-*-* } .-1 } */
+/* { dg-error "initialization of 'void \\*' from 'int' makes pointer from integer without a cast" "null" { target *-*-* } .-2 } */
+void *q = 0 * (1 / 0); /* { dg-warning "division by zero" } */
+/* { dg-error "initializer element is not constant" "constant" { target *-*-* } .-1 } */
+/* { dg-error "initialization of 'void \\*' from 'int' makes pointer from integer without a cast" "null" { target *-*-* } .-2 } */
+void *r = (1 ? 0 : INT_MAX+1);
+
+void
+g (int i)
+{
+  switch (i)
+    {
+    case 0 * (1/0): /* { dg-warning "division by zero" } */
+      /* { dg-error "case label does not reduce to an integer constant" "constant" { target *-*-* } .-1 } */
+      ;
+    case 1 + 0 * (INT_MAX + 1): /* { dg-warning "integer overflow in expression" } */
+      /* { dg-error "overflow in constant expression" "constant" { target *-*-* } .-1 } */
+      ;
+    }
+}
+
+int
+h (void)
+{
+  return INT_MAX + 1; /* { dg-warning "integer overflow in expression" } */
+}
+
+int
+h1 (void)
+{
+  return INT_MAX + 1 - INT_MAX; /* { dg-warning "integer overflow in expression" } */
+}
+
+void fuc (unsigned char);
+void fsc (signed char);
+
+void
+h2 (void)
+{
+  fsc (SCHAR_MAX + 1); /* { dg-warning "overflow in conversion from .int. to .signed char. changes value" } */
+  fsc (SCHAR_MIN - 1); /* { dg-warning "overflow in conversion" } */
+  fsc (UCHAR_MAX); /* { dg-warning "overflow in conversion" } */
+  fsc (UCHAR_MAX + 1); /* { dg-warning "overflow in conversion" } */
+  fuc (-1);
+  fuc (UCHAR_MAX + 1); /* { dg-warning "unsigned conversion from .int. to .unsigned char. changes value" } */
+  fuc (SCHAR_MIN);
+  fuc (SCHAR_MIN - 1); /* { dg-warning "unsigned conversion" } */
+  fuc (-UCHAR_MAX); /* { dg-warning "unsigned conversion" } */
+}
+
+void fui (unsigned int);
+void fsi (signed int);
+
+int si;
+unsigned ui;
+
+void
+h2i (int x)
+{
+  /* For some reason, we only give certain warnings for implicit
+     conversions among values of the same precision with -Wconversion,
+     while we don't give others at all.  */
+  fsi ((unsigned)INT_MAX + 1);
+  si = (unsigned)INT_MAX + 1;
+  si = x ? (unsigned)INT_MAX + 1 : 1;
+  fsi ((unsigned)INT_MAX + 2);
+  si = (unsigned)INT_MAX + 2;
+  si = x ? (unsigned)INT_MAX + 2 : 1;
+  fsi (UINT_MAX);
+  si = UINT_MAX;
+  fui (-1);
+  ui = -1;
+  ui = x ? -1 : 1U;
+  fui (INT_MIN);
+  ui = INT_MIN;
+  ui = x ? INT_MIN : 1U;
+}