Add function to get the number of DFSan labels allocated.

Expose the number of DFSan labels allocated by adding function dfsan_get_label_count().

Patch by Sam Kerner!

Differential Revision: http://llvm-reviews.chandlerc.com/D3109

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@204854 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 75 insertions, 0 deletions

diff --git a/test/dfsan/label_count.c b/test/dfsan/label_count.c
new file mode 100644
index 000000000..5e368ca1b
--- /dev/null
+++ b/test/dfsan/label_count.c
@@ -0,0 +1,75 @@
+// RUN: %clang_dfsan -DLIB -m64 -c %s -o %t.lib.o && \
+// RUN: %clang_dfsan       -m64 -c %s -o %t.o && \
+// RUN: %clang_dfsan -m64 %t.lib.o %t.o -o %t.bin && \
+// RUN: %t.bin
+
+// RUN: %clang_dfsan -mllvm -dfsan-args-abi -m64 -DLIB -c %s -o %t.lib.o && \
+// RUN: %clang_dfsan -mllvm -dfsan-args-abi -m64 -c %s -o %t.o && \
+// RUN: %clang_dfsan -mllvm -dfsan-args-abi -m64 %t.o %t.lib.o -o %t.bin && \
+// RUN: %t.bin
+
+#include <sanitizer/dfsan_interface.h>
+#include <assert.h>
+
+#ifdef LIB
+// Compiling this file with and without LIB defined allows this file to be
+// built as two separate translation units.  This ensures that the code
+// can not be optimized in a way that removes behavior we wish to test.  For
+// example, computing a value should cause labels to be allocated only if
+// the computation is actually done.  Putting the computation here prevents
+// the compiler from optimizing away the computation (and labeling) that
+// tests wish to verify.
+
+int add_in_separate_translation_unit(int a, int b) {
+  return a + b;
+}
+
+int multiply_in_separate_translation_unit(int a, int b) {
+  return a * b;
+}
+
+#else
+
+int add_in_separate_translation_unit(int i, int j);
+int multiply_in_separate_translation_unit(int i, int j);
+
+int main(void) {
+  size_t label_count;
+
+  // No labels allocated yet.
+  label_count = dfsan_get_label_count();
+  assert(0 == label_count);
+
+  int i = 1;
+  dfsan_label i_label = dfsan_create_label("i", 0);
+  dfsan_set_label(i_label, &i, sizeof(i));
+
+  // One label allocated for i.
+  label_count = dfsan_get_label_count();
+  assert(1u == label_count);
+
+  int j = 2;
+  dfsan_label j_label = dfsan_create_label("j", 0);
+  dfsan_set_label(j_label, &j, sizeof(j));
+
+  // Check that a new label was allocated for j.
+  label_count = dfsan_get_label_count();
+  assert(2u == label_count);
+
+  // Create a value that combines i and j.
+  int i_plus_j = add_in_separate_translation_unit(i, j);
+
+  // Check that a label was created for the union of i and j.
+  label_count = dfsan_get_label_count();
+  assert(3u == label_count);
+
+  // Combine i and j in a different way.  Check that the existing label is
+  // reused, and a new label is not created.
+  int j_times_i = multiply_in_separate_translation_unit(j, i);
+  label_count = dfsan_get_label_count();
+  assert(3u == label_count);
+  assert(dfsan_get_label(i_plus_j) == dfsan_get_label(j_times_i));
+
+  return 0;
+}
+#endif  // #ifdef LIB