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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" }
+};
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