Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu.
Successful run of analyzer integration tests on x86_64-pc-linux-gnu.
Pushed to trunk as r14-9090-g79d4c7ddc83e00.
gcc/analyzer/ChangeLog:
PR analyzer/113998
* ranges.cc (symbolic_byte_range::intersection): Handle empty ranges.
(selftest::test_intersects): Add test coverage for empty ranges.
gcc/testsuite/ChangeLog:
PR analyzer/113998
* c-c++-common/analyzer/overlapping-buffers-pr113998.c: New test.
Signed-off-by: David Malcolm <dmalc...@redhat.com>
---
gcc/analyzer/ranges.cc | 18 ++++++++++++++++
.../analyzer/overlapping-buffers-pr113998.c | 21 +++++++++++++++++++
2 files changed, 39 insertions(+)
create mode 100644
gcc/testsuite/c-c++-common/analyzer/overlapping-buffers-pr113998.c
diff --git a/gcc/analyzer/ranges.cc b/gcc/analyzer/ranges.cc
index f46b04121d3f..ffdd0d4c5722 100644
--- a/gcc/analyzer/ranges.cc
+++ b/gcc/analyzer/ranges.cc
@@ -193,6 +193,12 @@ tristate
symbolic_byte_range::intersection (const symbolic_byte_range &other,
const region_model &model) const
{
+ /* If either is empty, then there is no intersection. */
+ if (empty_p ())
+ return tristate::TS_FALSE;
+ if (other.empty_p ())
+ return tristate::TS_FALSE;
+
/* For brevity, consider THIS to be "range A", and OTHER to be "range B". */
region_model_manager *mgr = model.get_manager ();
@@ -262,12 +268,17 @@ static void test_intersects (void)
ASSERT_EQ (r0_9.get_next_byte_offset (mgr), ten);
ASSERT_EQ (r0_9.get_last_byte_offset (mgr), nine);
+ symbolic_byte_range concrete_empty (zero, zero);
+ ASSERT_TRUE (concrete_empty.empty_p ());
+
ASSERT_EQ (r0_9.intersection (r0, m), tristate::TS_TRUE);
ASSERT_EQ (r0.intersection (r0_9, m), tristate::TS_TRUE);
ASSERT_EQ (r0_9.intersection (r9, m), tristate::TS_TRUE);
ASSERT_EQ (r9.intersection (r0_9, m), tristate::TS_TRUE);
ASSERT_EQ (r0_9.intersection (r10, m), tristate::TS_FALSE);
ASSERT_EQ (r10.intersection (r0_9, m), tristate::TS_FALSE);
+ ASSERT_EQ (concrete_empty.intersection (r0_9, m), tristate::TS_FALSE);
+ ASSERT_EQ (r0_9.intersection (concrete_empty, m), tristate::TS_FALSE);
ASSERT_EQ (r5_9.intersection (r0, m), tristate::TS_FALSE);
ASSERT_EQ (r0.intersection (r5_9, m), tristate::TS_FALSE);
@@ -286,6 +297,9 @@ static void test_intersects (void)
symbolic_byte_range ry (y_init_sval, one);
symbolic_byte_range rx_x_plus_y_minus_1 (x_init_sval, y_init_sval);
+ symbolic_byte_range symbolic_empty (x_init_sval, zero);
+ ASSERT_TRUE (symbolic_empty.empty_p ());
+
ASSERT_EQ (rx_x_plus_y_minus_1.get_start_byte_offset (), x_init_sval);
ASSERT_EQ (rx_x_plus_y_minus_1.get_size_in_bytes (), y_init_sval);
ASSERT_EQ
@@ -296,6 +310,10 @@ static void test_intersects (void)
SK_BINOP);
ASSERT_EQ (rx.intersection (ry, m), tristate::TS_UNKNOWN);
+ ASSERT_EQ (rx.intersection (concrete_empty, m), tristate::TS_FALSE);
+ ASSERT_EQ (concrete_empty.intersection (rx, m), tristate::TS_FALSE);
+ ASSERT_EQ (rx.intersection (symbolic_empty, m), tristate::TS_FALSE);
+ ASSERT_EQ (symbolic_empty.intersection (rx, m), tristate::TS_FALSE);
ASSERT_EQ (r0_x_minus_1.intersection (r0, m), tristate::TS_TRUE);
#if 0
ASSERT_EQ (r0_x_minus_1.intersection (rx, m), tristate::TS_FALSE);
diff --git a/gcc/testsuite/c-c++-common/analyzer/overlapping-buffers-pr113998.c
b/gcc/testsuite/c-c++-common/analyzer/overlapping-buffers-pr113998.c
new file mode 100644
index 000000000000..5c6352eb42f4
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/analyzer/overlapping-buffers-pr113998.c
@@ -0,0 +1,21 @@
+/* Verify we don't ICE on -Wanalyzer-overlapping-buffers on
+ execution paths where the size is constant zero, but the
+ optimizer didn't see that. */
+
+typedef __SIZE_TYPE__ size_t;
+
+extern char a[];
+size_t n;
+
+size_t __attribute__((noinline))
+get_hidden_zero ()
+{
+ return 0;
+}
+
+void
+test_pr113998 ()
+{
+ size_t n = get_hidden_zero ();
+ __builtin_strncpy (a, a, n); /* { dg-warning "overlapping buffers passed as
arguments to" } */
+}
--
2.26.3
