2014-01-16  Nick Clifton  <nickc@redhat.com>

	PR middle-end/28865

	* varasm.c (output_constant): Return the number of bytes actually

	emitted.

	(output_constructor_array_range): Update the field size with the

	number of bytes emitted by output_constant.

	(output_constructor_regular_field): Likewise.  Also do not

	complain if the total number of bytes emitted is now greater

	than the expected fieldpos.

	* output.h (output_constant): Update prototype and descriptive

	comment.

	* gcc.c-torture/compile/pr28865.c: New.

	* gcc.c-torture/execute/pr28865.c: New.

--- gcc/varasm.c	(revision 206660)

+++ gcc/varasm.c	(revision 206661)

@@ -4474,8 +4474,10 @@ static unsigned HOST_WIDE_INT

    This includes the pseudo-op such as ".int" or ".byte", and a newline.

    Assumes output_addressed_constants has been done on EXP already.

-   Generate exactly SIZE bytes of assembler data, padding at the end

-   with zeros if necessary.  SIZE must always be specified.

+   Generate at least SIZE bytes of assembler data, padding at the end

+   with zeros if necessary.  SIZE must always be specified.  The returned

+   value is the actual number of bytes of assembler data generated, which

+   may be bigger than SIZE if the object contains a variable length field.

    SIZE is important for structure constructors,

    since trailing members may have been omitted from the constructor.

@@ -4490,14 +4492,14 @@ static unsigned HOST_WIDE_INT

    ALIGN is the alignment of the data in bits.  */

-void

+unsigned HOST_WIDE_INT

 output_constant (tree exp, unsigned HOST_WIDE_INT size, unsigned int align)

 {

   enum tree_code code;

   unsigned HOST_WIDE_INT thissize;

   if (size == 0 || flag_syntax_only)

-    return;

+    return size;

   /* See if we're trying to initialize a pointer in a non-default mode

      to the address of some declaration somewhere.  If the target says

@@ -4562,7 +4564,7 @@ output_constant (tree exp, unsigned HOST

       && vec_safe_is_empty (CONSTRUCTOR_ELTS (exp)))

     {

       assemble_zeros (size);

-      return;

+      return size;

     }

   if (TREE_CODE (exp) == FDESC_EXPR)

@@ -4574,7 +4576,7 @@ output_constant (tree exp, unsigned HOST

 #else

       gcc_unreachable ();

 #endif

-      return;

+      return size;

     }

   /* Now output the underlying data.  If we've handling the padding, return.

@@ -4612,8 +4614,7 @@ output_constant (tree exp, unsigned HOST

       switch (TREE_CODE (exp))

 	{

 	case CONSTRUCTOR:

-	    output_constructor (exp, size, align, NULL);

-	  return;

+	  return output_constructor (exp, size, align, NULL);

 	case STRING_CST:

 	  thissize = MIN ((unsigned HOST_WIDE_INT)TREE_STRING_LENGTH (exp),

 			  size);

@@ -4648,11 +4649,10 @@ output_constant (tree exp, unsigned HOST

     case RECORD_TYPE:

     case UNION_TYPE:

       gcc_assert (TREE_CODE (exp) == CONSTRUCTOR);

-      output_constructor (exp, size, align, NULL);

-      return;

+      return output_constructor (exp, size, align, NULL);

     case ERROR_MARK:

-      return;

+      return 0;

     default:

       gcc_unreachable ();

@@ -4660,6 +4660,8 @@ output_constant (tree exp, unsigned HOST

   if (size > thissize)

     assemble_zeros (size - thissize);

+

+  return size;

 }

@@ -4759,7 +4761,7 @@ output_constructor_array_range (oc_local

       if (local->val == NULL_TREE)

 	assemble_zeros (fieldsize);

       else

-	output_constant (local->val, fieldsize, align2);

+	fieldsize = output_constant (local->val, fieldsize, align2);

       /* Count its size.  */

       local->total_bytes += fieldsize;

@@ -4808,9 +4810,8 @@ output_constructor_regular_field (oc_loc

      Note no alignment needed in an array, since that is guaranteed

      if each element has the proper size.  */

   if ((local->field != NULL_TREE || local->index != NULL_TREE)

-      && fieldpos != local->total_bytes)

+      && fieldpos > local->total_bytes)

     {

-      gcc_assert (fieldpos >= local->total_bytes);

       assemble_zeros (fieldpos - local->total_bytes);

       local->total_bytes = fieldpos;

     }

@@ -4847,7 +4848,7 @@ output_constructor_regular_field (oc_loc

   if (local->val == NULL_TREE)

     assemble_zeros (fieldsize);

   else

-    output_constant (local->val, fieldsize, align2);

+    fieldsize = output_constant (local->val, fieldsize, align2);

   /* Count its size.  */

   local->total_bytes += fieldsize;

--- gcc/output.h	(revision 206660)

+++ gcc/output.h	(revision 206661)

@@ -294,11 +294,13 @@ extern void output_quoted_string (FILE *

    This includes the pseudo-op such as ".int" or ".byte", and a newline.

    Assumes output_addressed_constants has been done on EXP already.

-   Generate exactly SIZE bytes of assembler data, padding at the end

-   with zeros if necessary.  SIZE must always be specified.

+   Generate at least SIZE bytes of assembler data, padding at the end

+   with zeros if necessary.  SIZE must always be specified.  The returned

+   value is the actual number of bytes of assembler data generated, which

+   may be bigger than SIZE if the object contains a variable length field.

    ALIGN is the alignment in bits that may be assumed for the data.  */

-extern void output_constant (tree, unsigned HOST_WIDE_INT, unsigned int);

+extern unsigned HOST_WIDE_INT output_constant (tree, unsigned HOST_WIDE_INT, unsigned int);

 /* When outputting delayed branch sequences, this rtx holds the

    sequence being output.  It is null when no delayed branch

--- gcc/testsuite/gcc.c-torture/execute/pr28865.c	(revision 0)

+++ gcc/testsuite/gcc.c-torture/execute/pr28865.c	(revision 206661)

@@ -0,0 +1,21 @@

+struct A { int a; char b[]; };

+union B { struct A a; char b[sizeof (struct A) + 31]; };

+union B b = { { 1, "123456789012345678901234567890" } };

+union B c = { { 2, "123456789012345678901234567890" } };

+

+__attribute__((noinline, noclone)) void

+foo (int *x[2])

+{

+  x[0] = &b.a.a;

+  x[1] = &c.a.a;

+}

+

+int

+main ()

+{

+  int *x[2];

+  foo (x);

+  if (*x[0] != 1 || *x[1] != 2)

+    __builtin_abort ();

+  return 0;

+}

--- gcc/testsuite/gcc.c-torture/compile/pr28865.c	(revision 0)

+++ gcc/testsuite/gcc.c-torture/compile/pr28865.c	(revision 206661)

@@ -0,0 +1,16 @@

+struct var_len

+{

+  int field1;

+  const char field2[];

+};

+

+/* Note - strictly speaking this array declaration is illegal

+   since each element has a variable length.  GCC allows it

+   (for the moment) because it is used in existing code, such

+   as glibc.  */

+static const struct var_len var_array[] = 

+{

+  { 1, "Long exposure noise reduction" },

+  { 2, "Shutter/AE lock buttons" },

+  { 3, "Mirror lockup" }

+};