[PATCH 07/21] Add selftests to bitmap.c

[David Malcolm <dmalcolm at redhat dot com>]

Jeff pre-approved the plugin version of this (as a new
file unittests/test-bitmap.c):
  https://gcc.gnu.org/ml/gcc-patches/2015-10/msg03284.html
with:
> OK if/when prereqs are approved.  Minor twiddling if we end up moving it
> elsewhere or standardizing/reducing header files is pre-approved.

This version moves them to bitmap.c

One issue: how to express:
  TEST (bitmap_test, gc_alloc)
in a ChangeLog entry.

I've chosen to write it as (bitmap_test, gc_alloc) since that
has the greatest chance of being found via grep.

gcc/ChangeLog:
	* bitmap.c: Include "selftest.h".
	(bitmap_test, gc_alloc): New selftest.
	(bitmap_test, set_range): New selftest.
	(bitmap_test, clear_bit_in_middle): New selftest.
	(bitmap_test, copying): New selftest.
	(bitmap_test, bitmap_single_bit_set_p): New selftest.
---
 gcc/bitmap.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 92 insertions(+)

diff --git a/gcc/bitmap.c b/gcc/bitmap.c
index 0c05512..7db7c68 100644
--- a/gcc/bitmap.c
+++ b/gcc/bitmap.c
@@ -21,6 +21,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "system.h"
 #include "coretypes.h"
 #include "bitmap.h"
+#include "selftest.h"
 
 /* Memory allocation statistics purpose instance.  */
 mem_alloc_description<bitmap_usage> bitmap_mem_desc;
@@ -2162,5 +2163,96 @@ debug (const bitmap_head *ptr)
     fprintf (stderr, "<nil>\n");
 }
 
+#if CHECKING_P
+namespace {
+
+/* Freshly-created bitmaps ought to be empty.  */
+
+TEST (bitmap_test, gc_alloc)
+{
+  bitmap b = bitmap_gc_alloc ();
+  EXPECT_TRUE (bitmap_empty_p (b));
+}
+
+/* Verify bitmap_set_range.  */
+
+TEST (bitmap_test, set_range)
+{
+  bitmap b = bitmap_gc_alloc ();
+  EXPECT_TRUE (bitmap_empty_p (b));
+
+  bitmap_set_range (b, 7, 5);
+  EXPECT_FALSE (bitmap_empty_p (b));
+  EXPECT_EQ (5, bitmap_count_bits (b));
+
+  /* Verify bitmap_bit_p at the boundaries.  */
+  EXPECT_FALSE (bitmap_bit_p (b, 6));
+  EXPECT_TRUE (bitmap_bit_p (b, 7));
+  EXPECT_TRUE (bitmap_bit_p (b, 11));
+  EXPECT_FALSE (bitmap_bit_p (b, 12));
+}
+
+/* Verify splitting a range into two pieces using bitmap_clear_bit.  */
+
+TEST (bitmap_test, clear_bit_in_middle)
+{
+  bitmap b = bitmap_gc_alloc ();
+
+  /* Set b to [100..200].  */
+  bitmap_set_range (b, 100, 100);
+  EXPECT_EQ (100, bitmap_count_bits (b));
+
+  /* Clear a bit in the middle.  */
+  bool changed = bitmap_clear_bit (b, 150);
+  EXPECT_TRUE (changed);
+  EXPECT_EQ (99, bitmap_count_bits (b));
+  EXPECT_TRUE (bitmap_bit_p (b, 149));
+  EXPECT_FALSE (bitmap_bit_p (b, 150));
+  EXPECT_TRUE (bitmap_bit_p (b, 151));
+}
+
+/* Verify bitmap_copy.  */
+
+TEST (bitmap_test, copying)
+{
+  bitmap src = bitmap_gc_alloc ();
+  bitmap_set_range (src, 40, 10);
+
+  bitmap dst = bitmap_gc_alloc ();
+  EXPECT_FALSE (bitmap_equal_p (src, dst));
+  bitmap_copy (dst, src);
+  EXPECT_TRUE (bitmap_equal_p (src, dst));
+
+  /* Verify that we can make them unequal again...  */
+  bitmap_set_range (src, 70, 5);
+  EXPECT_FALSE (bitmap_equal_p (src, dst));
+
+  /* ...and that changing src after the copy didn't affect
+     the other: */
+  EXPECT_FALSE (bitmap_bit_p (dst, 70));
+}
+
+/* Verify bitmap_single_bit_set_p.  */
+TEST (bitmap_test, bitmap_single_bit_set_p)
+{
+  bitmap b = bitmap_gc_alloc ();
+
+  EXPECT_FALSE (bitmap_single_bit_set_p (b));
+
+  bitmap_set_range (b, 42, 1);
+  EXPECT_TRUE (bitmap_single_bit_set_p (b));
+  EXPECT_EQ (42, bitmap_first_set_bit (b));
+
+  bitmap_set_range (b, 1066, 1);
+  EXPECT_FALSE (bitmap_single_bit_set_p (b));
+  EXPECT_EQ (42, bitmap_first_set_bit (b));
+
+  bitmap_clear_range (b, 0, 100);
+  EXPECT_TRUE (bitmap_single_bit_set_p (b));
+  EXPECT_EQ (1066, bitmap_first_set_bit (b));
+}
+
+}  // anon namespace
+#endif /* CHECKING_P */
 
 #include "gt-bitmap.h"
-- 
1.8.5.3