On 2019-02-04 11:39 a.m., Richard Biener wrote: > On February 4, 2019 5:07:00 PM GMT+01:00, Jeff Law <l...@redhat.com> wrote: >> On 2/4/19 6:15 AM, Richard Biener wrote: >>> >>> When I introduced tree-form bitmaps I forgot to think about GC. >>> The following drops the chain_prev annotation to make the marker >>> work for trees. I've also maked the obstack member GTY skip >>> (and prevent bitmap_obstack from gengtype processing) because >>> the obstack isn't used for GC allocated bitmaps. >>> >>> Bootstrap & regtest running on x86_64-unknown-linux-gnu. >>> >>> Richard. >>> >>> 2019-02-04 Richard Biener <rguent...@suse.de> >>> >>> PR middle-end/89150 >>> * bitmap.h (struct bitmap_obstack): Do not mark GTY. >>> (struct bitmap_element): Drop chain_prev so we properly recurse on >>> the prev member, supporting tree views. >>> (struct bitmap_head): GTY skip the obstack member. >> Was there a particular failure mode you observed or was this discovered >> by inspection. > > It was discovered via an out of tree patch, the issue is only latent on trunk > (together with another unfixed pch issue of bitmaps).
My apologies for not noticing this thread/PR earlier. I originally discovered this issue while working on an experimental patch, but since then I've also come up with a test case for this specific issue. Is it worth adding it to trunk? - Michael
From 9f1049a1e24cd1aa9852c5dddd1342dce0226416 Mon Sep 17 00:00:00 2001
From: Michael Ploujnikov <michael.ploujni...@oracle.com>
Date: Thu, 7 Feb 2019 14:43:40 -0500
Subject: [PATCH] Add a test for GC marking bitmaps in tree view mode
gcc/ChangeLog:
2019-02-07 Michael Ploujnikov <michael.ploujni...@oracle.com>
PR middle-end/89150
* bitmap.c (test_bitmap_tree_marking): New test.
(NOT_NULL_OR_GARBAGE): For shortening
test_bitmap_tree_marking.
(bitmap_c_tests): Add test_bitmap_tree_marking.
---
gcc/bitmap.c | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 82 insertions(+)
diff --git gcc/bitmap.c gcc/bitmap.c
index 5a8236de75..7e802a1600 100644
--- gcc/bitmap.c
+++ gcc/bitmap.c
@@ -2626,6 +2626,11 @@ bitmap_head::dump ()
#if CHECKING_P
+static GTY(()) bitmap selftest_test_bitmap;
+
+/* From ggc-internal.h */
+extern bool ggc_force_collect;
+
namespace selftest {
/* Selftests for bitmaps. */
@@ -2722,6 +2727,82 @@ test_bitmap_single_bit_set_p ()
ASSERT_EQ (1066, bitmap_first_set_bit (b));
}
+#define NOT_NULL_OR_GARBAGE(NODE) \
+ (NODE != NULL && (unsigned long)(NODE) != 0xa5a5a5a5UL)
+
+static void
+test_bitmap_tree_marking ()
+{
+ selftest_test_bitmap = BITMAP_GGC_ALLOC ();
+ bitmap_tree_view (selftest_test_bitmap);
+
+ ASSERT_TRUE (bitmap_set_bit (selftest_test_bitmap, 1*BITMAP_ELEMENT_ALL_BITS));
+ ASSERT_TRUE (bitmap_set_bit (selftest_test_bitmap, 5*BITMAP_ELEMENT_ALL_BITS));
+ ASSERT_TRUE (bitmap_set_bit (selftest_test_bitmap, 10*BITMAP_ELEMENT_ALL_BITS));
+ ASSERT_TRUE (bitmap_set_bit (selftest_test_bitmap, 15*BITMAP_ELEMENT_ALL_BITS));
+ ASSERT_TRUE (bitmap_set_bit (selftest_test_bitmap, 30*BITMAP_ELEMENT_ALL_BITS));
+ ASSERT_TRUE (bitmap_set_bit (selftest_test_bitmap, 25*BITMAP_ELEMENT_ALL_BITS));
+ ASSERT_TRUE (bitmap_set_bit (selftest_test_bitmap, 3*BITMAP_ELEMENT_ALL_BITS));
+ ASSERT_TRUE (bitmap_set_bit (selftest_test_bitmap, 4*BITMAP_ELEMENT_ALL_BITS));
+ ASSERT_TRUE (bitmap_set_bit (selftest_test_bitmap, 26*BITMAP_ELEMENT_ALL_BITS));
+ /* At this point it should look like:
+ 26
+ / \
+ 25 30
+ /
+ 5
+ / \
+ 4 15
+ / /
+ 3 10
+ /
+ 1
+
+ */
+ ggc_force_collect = true;
+ ggc_collect ();
+ ggc_force_collect = false;
+
+ ASSERT_TRUE (NOT_NULL_OR_GARBAGE (selftest_test_bitmap->first));
+ ASSERT_TRUE (selftest_test_bitmap->first->indx == 26);
+
+ ASSERT_TRUE (NOT_NULL_OR_GARBAGE (selftest_test_bitmap->first->next));
+ ASSERT_TRUE (selftest_test_bitmap->first->next->indx == 30);
+ ASSERT_TRUE (selftest_test_bitmap->first->next->next == NULL);
+ ASSERT_TRUE (selftest_test_bitmap->first->next->prev == NULL);
+
+ ASSERT_TRUE (NOT_NULL_OR_GARBAGE (selftest_test_bitmap->first->prev));
+ ASSERT_TRUE (selftest_test_bitmap->first->prev->indx == 25);
+ ASSERT_TRUE (selftest_test_bitmap->first->prev->next == NULL);
+
+ ASSERT_TRUE (NOT_NULL_OR_GARBAGE (selftest_test_bitmap->first->prev->prev));
+ ASSERT_TRUE (selftest_test_bitmap->first->prev->prev->indx == 5);
+
+ ASSERT_TRUE (NOT_NULL_OR_GARBAGE (selftest_test_bitmap->first->prev->prev->next));
+ ASSERT_TRUE (selftest_test_bitmap->first->prev->prev->next->indx == 15);
+ ASSERT_TRUE (selftest_test_bitmap->first->prev->prev->next->next == NULL);
+
+ ASSERT_TRUE (NOT_NULL_OR_GARBAGE (selftest_test_bitmap->first->prev->prev->next->prev));
+ ASSERT_TRUE (selftest_test_bitmap->first->prev->prev->next->prev->indx == 10);
+ ASSERT_TRUE (selftest_test_bitmap->first->prev->prev->next->prev->prev == NULL);
+ ASSERT_TRUE (selftest_test_bitmap->first->prev->prev->next->prev->next == NULL);
+
+ ASSERT_TRUE (NOT_NULL_OR_GARBAGE (selftest_test_bitmap->first->prev->prev->prev));
+ ASSERT_TRUE (selftest_test_bitmap->first->prev->prev->prev->indx == 4);
+ ASSERT_TRUE (selftest_test_bitmap->first->prev->prev->prev->next == NULL);
+
+ ASSERT_TRUE (NOT_NULL_OR_GARBAGE (selftest_test_bitmap->first->prev->prev->prev->prev));
+ ASSERT_TRUE (selftest_test_bitmap->first->prev->prev->prev->prev->indx == 3);
+ ASSERT_TRUE (selftest_test_bitmap->first->prev->prev->prev->prev->next == NULL);
+
+ ASSERT_TRUE (NOT_NULL_OR_GARBAGE (selftest_test_bitmap->first->prev->prev->prev->prev->prev));
+ ASSERT_TRUE (selftest_test_bitmap->first->prev->prev->prev->prev->prev->indx == 1);
+ ASSERT_TRUE (selftest_test_bitmap->first->prev->prev->prev->prev->prev->prev == NULL);
+ ASSERT_TRUE (selftest_test_bitmap->first->prev->prev->prev->prev->prev->next == NULL);
+
+ ASSERT_TRUE (bitmap_bit_p (selftest_test_bitmap, 15*BITMAP_ELEMENT_ALL_BITS));
+}
+
/* Run all of the selftests within this file. */
void
@@ -2732,6 +2813,7 @@ bitmap_c_tests ()
test_clear_bit_in_middle ();
test_copying ();
test_bitmap_single_bit_set_p ();
+ test_bitmap_tree_marking ();
}
} // namespace selftest
--
2.19.1
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