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Re: [PATCH] Don't ICE with huge alignment (PR middle-end/60226)
- From: Marek Polacek <polacek at redhat dot com>
- To: Mike Stump <mikestump at comcast dot net>
- Cc: Jeff Law <law at redhat dot com>, GCC Patches <gcc-patches at gcc dot gnu dot org>
- Date: Thu, 3 Jul 2014 12:18:24 +0200
- Subject: Re: [PATCH] Don't ICE with huge alignment (PR middle-end/60226)
- Authentication-results: sourceware.org; auth=none
- References: <20140304164029 dot GN16545 at redhat dot com> <53B1BF74 dot 2060801 at redhat dot com> <53648E99-800C-455B-B975-CD9BB4BEF1CD at comcast dot net>
On Mon, Jun 30, 2014 at 03:40:18PM -0700, Mike Stump wrote:
> I glanced at it:
>
> (gdb) p/x TYPE_ALIGN (type)
> $1 = 2147483648
> (gdb) p/x TYPE_ALIGN (type)
> $2 = 0x80000000
>
> The callee is int, the caller uses unsigned int. The assert I see is because the routines are not type correct:
>
> => TYPE_SIZE (type) = round_up (TYPE_SIZE (type), TYPE_ALIGN (type));
>
> (gdb) ptype TYPE_ALIGN (type)
> type = unsigned int
>
>
> tree
> round_up_loc (location_t loc, tree value, int divisor)
> {
> tree div = NULL_TREE;
>
> =>gcc_assert (divisor > 0);
>
> Would be nice if the routine was type correct (wrt unsigned).
Yeah, I did that. One issue with that is that round_up now wraps
the value, so I had to add a check for huge size before rounding up,
otherwise we'd regress on e.g. PR42611.
How about the following?
Bootstrapped/regtested on x86_64-linux, ok for trunk?
2014-07-03 Marek Polacek <polacek@redhat.com>
PR c/60226
* fold-const.c (round_up_loc): Change the parameter type.
Remove assert.
* fold-const.h (round_up_loc): Adjust declaration.
* stor-layout.c (finalize_record_size): Check for too large types.
* c-c++-common/pr60226.c: New test.
diff --git gcc/fold-const.c gcc/fold-const.c
index d22eac1..c57ac7b 100644
--- gcc/fold-const.c
+++ gcc/fold-const.c
@@ -16647,11 +16647,10 @@ fold_ignored_result (tree t)
/* Return the value of VALUE, rounded up to a multiple of DIVISOR. */
tree
-round_up_loc (location_t loc, tree value, int divisor)
+round_up_loc (location_t loc, tree value, unsigned int divisor)
{
tree div = NULL_TREE;
- gcc_assert (divisor > 0);
if (divisor == 1)
return value;
diff --git gcc/fold-const.h gcc/fold-const.h
index dcb97a1..3b5fd84 100644
--- gcc/fold-const.h
+++ gcc/fold-const.h
@@ -144,7 +144,7 @@ extern tree combine_comparisons (location_t, enum tree_code, enum tree_code,
extern void debug_fold_checksum (const_tree);
extern bool may_negate_without_overflow_p (const_tree);
#define round_up(T,N) round_up_loc (UNKNOWN_LOCATION, T, N)
-extern tree round_up_loc (location_t, tree, int);
+extern tree round_up_loc (location_t, tree, unsigned int);
#define round_down(T,N) round_down_loc (UNKNOWN_LOCATION, T, N)
extern tree round_down_loc (location_t, tree, int);
extern tree size_int_kind (HOST_WIDE_INT, enum size_type_kind);
diff --git gcc/stor-layout.c gcc/stor-layout.c
index cfd436f..19e7adb 100644
--- gcc/stor-layout.c
+++ gcc/stor-layout.c
@@ -1587,6 +1587,11 @@ finalize_record_size (record_layout_info rli)
unpadded_size_unit
= size_binop (PLUS_EXPR, unpadded_size_unit, size_one_node);
+ if (TREE_CODE (unpadded_size_unit) == INTEGER_CST
+ && !TREE_OVERFLOW (unpadded_size_unit)
+ && !valid_constant_size_p (unpadded_size_unit))
+ error ("type %qT is too large", rli->t);
+
/* Round the size up to be a multiple of the required alignment. */
TYPE_SIZE (rli->t) = round_up (unpadded_size, TYPE_ALIGN (rli->t));
TYPE_SIZE_UNIT (rli->t)
diff --git gcc/testsuite/c-c++-common/pr60226.c gcc/testsuite/c-c++-common/pr60226.c
index e69de29..3a1c261 100644
--- gcc/testsuite/c-c++-common/pr60226.c
+++ gcc/testsuite/c-c++-common/pr60226.c
@@ -0,0 +1,14 @@
+/* PR c/60226 */
+/* { dg-do compile } */
+/* { dg-options "-Wno-c++-compat" { target c } } */
+
+typedef int __attribute__ ((aligned (1 << 28))) int28;
+int28 foo[4] = {}; /* { dg-error "alignment of array elements is greater than element size" } */
+typedef int __attribute__ ((aligned (1 << 29))) int29; /* { dg-error "requested alignment is too large" } */
+
+void
+f (void)
+{
+ struct { __attribute__((aligned (1 << 28))) double a; } x1;
+ struct { __attribute__((aligned (1 << 29))) double a; } x2; /* { dg-error "requested alignment is too large" } */
+}
Marek