diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index a99197af5a1..b01a75ae917 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,13 @@
+2007-09-25  Joseph Myers  <joseph@codesourcery.com>
+
+	PR c/32295
+	* c-typeck.c (default_conversion): Call require_complete_type
+	before perform_integral_promotions.
+	(build_unary_op): Call require_complete_type except for ADDR_EXPR.
+	(build_c_cast): Call require_complete_type except for casts to
+	void types.
+	(convert_for_assignment): Call require_complete_type.
+
 2007-09-25  Revital Eres  <eres@il.ibm.com>
 
 	* config/spu/spu.md: Fix doloop pattern.
diff --git a/gcc/c-typeck.c b/gcc/c-typeck.c
index a9220810c2f..0bad8e5a45c 100644
--- a/gcc/c-typeck.c
+++ b/gcc/c-typeck.c
@@ -1770,14 +1770,19 @@ default_conversion (tree exp)
   if (TREE_NO_WARNING (orig_exp))
     TREE_NO_WARNING (exp) = 1;
 
-  if (INTEGRAL_TYPE_P (type))
-    return perform_integral_promotions (exp);
-
   if (code == VOID_TYPE)
     {
       error ("void value not ignored as it ought to be");
       return error_mark_node;
     }
+
+  exp = require_complete_type (exp);
+  if (exp == error_mark_node)
+    return error_mark_node;
+
+  if (INTEGRAL_TYPE_P (type))
+    return perform_integral_promotions (exp);
+
   return exp;
 }
 
@@ -2871,11 +2876,15 @@ build_unary_op (enum tree_code code, tree xarg, int flag)
   /* No default_conversion here.  It causes trouble for ADDR_EXPR.  */
   tree arg = xarg;
   tree argtype = 0;
-  enum tree_code typecode = TREE_CODE (TREE_TYPE (arg));
+  enum tree_code typecode;
   tree val;
   int noconvert = flag;
   const char *invalid_op_diag;
 
+  if (code != ADDR_EXPR)
+    arg = require_complete_type (arg);
+
+  typecode = TREE_CODE (TREE_TYPE (arg));
   if (typecode == ERROR_MARK)
     return error_mark_node;
   if (typecode == ENUMERAL_TYPE || typecode == BOOLEAN_TYPE)
@@ -3589,6 +3598,13 @@ build_c_cast (tree type, tree expr)
       return error_mark_node;
     }
 
+  if (!VOID_TYPE_P (type))
+    {
+      value = require_complete_type (value);
+      if (value == error_mark_node)
+	return error_mark_node;
+    }
+
   if (type == TYPE_MAIN_VARIANT (TREE_TYPE (value)))
     {
       if (pedantic)
@@ -3998,6 +4014,9 @@ convert_for_assignment (tree type, tree rhs, enum impl_conv errtype,
       error ("void value not ignored as it ought to be");
       return error_mark_node;
     }
+  rhs = require_complete_type (rhs);
+  if (rhs == error_mark_node)
+    return error_mark_node;
   /* A type converts to a reference to it.
      This code doesn't fully support references, it's just for the
      special case of va_start and va_copy.  */
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 5d7a0f86b9c..4f8d576c4d1 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2007-09-25  Joseph Myers  <joseph@codesourcery.com>
+
+	PR c/32295
+	* gcc.dg/enum-incomplete-1.c: New test.
+
 2007-09-25  Bernd Schmidt  <bernd.schmidt@analog.com>
 
 	* gcc.c-torture/compile/20070919-1.c: New test.
diff --git a/gcc/testsuite/gcc.dg/enum-incomplete-1.c b/gcc/testsuite/gcc.dg/enum-incomplete-1.c
new file mode 100644
index 00000000000..06c247c2e51
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/enum-incomplete-1.c
@@ -0,0 +1,86 @@
+/* Test for uses of incomplete enum variables: should be allowed just
+   when incomplete structs are allowed.  PR 32295.  */
+/* Origin: Joseph Myers <joseph@codesourcery.com> */
+/* { dg-do compile } */
+/* { dg-options "" } */
+
+extern enum e ve;
+extern struct s vs;
+void *p;
+
+int
+f0 (int i)
+{
+  ve; /* { dg-error "incomplete" } */
+  vs; /* { dg-error "incomplete" } */
+  (void) ve;
+  (void) vs;
+  (void) (i ? ve : ve); /* { dg-error "incomplete" } */
+  (void) (i ? vs : vs); /* { dg-error "incomplete" } */
+  (void) (ve = ve); /* { dg-error "incomplete" } */
+  (void) (vs = vs); /* { dg-error "incomplete" } */
+  (void) ve, (void) ve;
+  (void) vs, (void) vs;
+  p = &ve;
+  p = &vs;
+  (void) sizeof (ve); /* { dg-error "incomplete" } */
+  (void) sizeof (vs); /* { dg-error "incomplete" } */
+  typeof (ve) *pe;
+  typeof (vs) *ps;
+  /* ??? alignof should probably not be accepted here.  */
+  (void) __alignof (ve);
+  (void) __alignof (vs);
+  (void) (ve + i); /* { dg-error "incomplete" } */
+  (void) (i * ve); /* { dg-error "incomplete" } */
+  (void) (i / ve); /* { dg-error "incomplete" } */
+  (void) (ve - i); /* { dg-error "incomplete" } */
+  (void) (ve << i); /* { dg-error "incomplete" } */
+  (void) (i >> ve); /* { dg-error "incomplete" } */
+  (void) (ve < i); /* { dg-error "incomplete" } */
+  (void) (ve <= i); /* { dg-error "incomplete" } */
+  (void) (i > ve); /* { dg-error "incomplete" } */
+  (void) (i >= ve); /* { dg-error "incomplete" } */
+  (void) (ve == i); /* { dg-error "incomplete" } */
+  (void) (i != ve); /* { dg-error "incomplete" } */
+  (void) (ve & i); /* { dg-error "incomplete" } */
+  (void) (ve ^ i); /* { dg-error "incomplete" } */
+  (void) (i | ve); /* { dg-error "incomplete" } */
+  (void) (i && ve); /* { dg-error "incomplete" } */
+  (void) (ve || i); /* { dg-error "incomplete" } */
+  (void) -ve; /* { dg-error "incomplete" } */
+  (void) +ve; /* { dg-error "incomplete" } */
+  (void) ~ve; /* { dg-error "incomplete" } */
+  (void) !ve; /* { dg-error "incomplete" } */
+  (void) --ve; /* { dg-error "incomplete" } */
+  (void) ++ve; /* { dg-error "incomplete" } */
+  (void) ve--; /* { dg-error "incomplete" } */
+  (void) ve++; /* { dg-error "incomplete" } */
+  i = ve; /* { dg-error "incomplete" } */
+  i *= ve; /* { dg-error "incomplete" } */
+  i /= ve; /* { dg-error "incomplete" } */
+  i %= ve; /* { dg-error "incomplete" } */
+  i += ve; /* { dg-error "incomplete" } */
+  i -= ve; /* { dg-error "incomplete" } */
+  i <<= ve; /* { dg-error "incomplete" } */
+  i >>= ve; /* { dg-error "incomplete" } */
+  i &= ve; /* { dg-error "incomplete" } */
+  i ^= ve; /* { dg-error "incomplete" } */
+  i |= ve; /* { dg-error "incomplete" } */
+  (void) (ve ? 1 : 1); /* { dg-error "incomplete" } */
+  (void) (int) ve; /* { dg-error "incomplete" } */
+  f0 (ve); /* { dg-error "incomplete" } */
+  if (ve) /* { dg-error "incomplete" } */
+    ;
+  do
+    ;
+  while (ve); /* { dg-error "incomplete" } */
+  while (ve) /* { dg-error "incomplete" } */
+    ;
+  _Bool b = ve; /* { dg-error "incomplete" } */
+  float f = ve; /* { dg-error "incomplete" } */
+  switch (ve) /* { dg-error "incomplete" } */
+    ;
+  for (; ve;) /* { dg-error "incomplete" } */
+    ;
+  return ve; /* { dg-error "incomplete" } */
+}