[DFSan] Add flag to dump the labels when the program terminates.

Differential Revision: http://reviews.llvm.org/D6306



git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@222425 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 69 insertions, 0 deletions

diff --git a/test/dfsan/dump_labels.c b/test/dfsan/dump_labels.c
new file mode 100644
index 000000000..67801af18
--- /dev/null
+++ b/test/dfsan/dump_labels.c
@@ -0,0 +1,69 @@
+// RUN: %clang_dfsan -m64 %s -o %t
+// RUN: DFSAN_OPTIONS=dump_labels_at_exit=/dev/stdout %run %t 2>&1 | FileCheck %s
+// RUN: DFSAN_OPTIONS=dump_labels_at_exit=/dev/stdout not %run %t c 2>&1 | FileCheck %s --check-prefix=CHECK-OOL
+// RUN: DFSAN_OPTIONS=dump_labels_at_exit=/dev/stdout not %run %t u 2>&1 | FileCheck %s --check-prefix=CHECK-OOL
+
+// Tests that labels are properly dumped at program termination.
+
+#include <sanitizer/dfsan_interface.h>
+#include <assert.h>
+#include <stdio.h>
+
+int main(int argc, char** argv) {
+  int i = 1;
+  dfsan_label i_label = dfsan_create_label("i", 0);
+  dfsan_set_label(i_label, &i, sizeof(i));
+
+  int j = 2;
+  dfsan_label j_label = dfsan_create_label("j", 0);
+  dfsan_set_label(j_label, &j, sizeof(j));
+
+  int k = 3;
+  dfsan_label k_label = dfsan_create_label("k", 0);
+  dfsan_set_label(k_label, &k, sizeof(k));
+
+  dfsan_label ij_label = dfsan_get_label(i + j);
+  dfsan_label ijk_label = dfsan_get_label(i + j + k);
+
+  fprintf(stderr, "i %d j %d k %d ij %d ijk %d\n", i_label, j_label, k_label,
+          ij_label, ijk_label);
+
+  // CHECK: 1 0 0 i
+  // CHECK: 2 0 0 j
+  // CHECK: 3 0 0 k
+  // CHECK: 4 1 2
+  // CHECK: 5 3 4
+
+  if (argc > 1) {
+    // Exhaust the labels.
+    unsigned long num_labels = 1 << (sizeof(dfsan_label) * 8);
+    for (unsigned long i =  ijk_label + 1; i < num_labels - 2; ++i) {
+      dfsan_label l = dfsan_create_label("l", 0);
+      assert(l == i);
+    }
+
+    // Consume the last available label.
+    dfsan_label l = dfsan_union(5, 6);
+    assert(l == num_labels - 2);
+
+    // Try to allocate another label (either explicitly or by unioning two
+    // existing labels), but expect a crash.
+    if (argv[1][0] == 'c') {
+      l = dfsan_create_label("l", 0);
+    } else {
+      l = dfsan_union(6, 7);
+    }
+
+    // CHECK-OOL: FATAL: DataFlowSanitizer: out of labels
+    // CHECK-OOL: 1 0 0 i
+    // CHECK-OOL: 2 0 0 j
+    // CHECK-OOL: 3 0 0 k
+    // CHECK-OOL: 4 1 2
+    // CHECK-OOL: 5 3 4
+    // CHECK-OOL: 6 0 0
+    // CHECK-OOL: 65534 5 6
+    // CHECK-OOL: 65535 0 0 <init label>
+  }
+
+  return 0;
+}