[esan] Add circular buffer data structure

Summary:
Adds a new class, CircularBuffer, for holding a wrap-around fixed-size
sequence of a primitive data type.  This will be used initially by the
working set tool.

Adds a unit test for CircularBuffer, including infrastructure support to
include esan headers and to link with the esan library by pretending to
want the working set tool.

Reviewers: aizatsky, filcab

Subscribers: vitalybuka, zhaoqin, kcc, eugenis, llvm-commits, kubabrecka

Differential Revision: http://reviews.llvm.org/D20579

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@271286 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 67 insertions, 0 deletions

diff --git a/test/esan/Unit/circular_buffer.cpp b/test/esan/Unit/circular_buffer.cpp
new file mode 100644
index 000000000..a788418b7
--- /dev/null
+++ b/test/esan/Unit/circular_buffer.cpp
@@ -0,0 +1,61 @@
+// RUN: %clangxx_unit -O0 %s -o %t 2>&1
+// RUN: %run %t 2>&1 | FileCheck %s
+
+#include "esan/esan_circular_buffer.h"
+#include "sanitizer_common/sanitizer_placement_new.h"
+#include <assert.h>
+#include <stdio.h>
+
+static const int TestBufCapacity = 4;
+
+// The buffer should have a capacity of TestBufCapacity.
+void testBuffer(__esan::CircularBuffer<int> *Buf) {
+  assert(Buf->size() == 0);
+  assert(Buf->empty());
+
+  Buf->push_back(1);
+  assert(Buf->back() == 1);
+  assert((*Buf)[0] == 1);
+  assert(Buf->size() == 1);
+  assert(!Buf->empty());
+
+  Buf->push_back(2);
+  Buf->push_back(3);
+  Buf->push_back(4);
+  Buf->push_back(5);
+  assert((*Buf)[0] == 2);
+  assert(Buf->size() == 4);
+
+  Buf->pop_back();
+  assert((*Buf)[0] == 2);
+  assert(Buf->size() == 3);
+
+  Buf->pop_back();
+  Buf->pop_back();
+  assert((*Buf)[0] == 2);
+  assert(Buf->size() == 1);
+  assert(!Buf->empty());
+
+  Buf->pop_back();
+  assert(Buf->empty());
+}
+
+int main()
+{
+  // Test initialize/free.
+  __esan::CircularBuffer<int> GlobalBuf;
+  GlobalBuf.initialize(TestBufCapacity);
+  testBuffer(&GlobalBuf);
+  GlobalBuf.free();
+
+  // Test constructor/free.
+  __esan::CircularBuffer<int> *LocalBuf;
+  static char placeholder[sizeof(*LocalBuf)];
+  LocalBuf = new(placeholder) __esan::CircularBuffer<int>(TestBufCapacity);
+  testBuffer(LocalBuf);
+  LocalBuf->free();
+
+  fprintf(stderr, "All checks passed.\n");
+  // CHECK: All checks passed.
+  return 0;
+}
diff --git a/test/esan/lit.cfg b/test/esan/lit.cfg
index cc7492c88..9eb296d90 100644
--- a/test/esan/lit.cfg
+++ b/test/esan/lit.cfg
@@ -14,6 +14,10 @@ base_cxxflags = config.cxx_mode_flags + base_cflags
 
 frag_cflags = (["-fsanitize=efficiency-cache-frag"] + base_cflags)
 wset_cflags = (["-fsanitize=efficiency-working-set"] + base_cflags)
+esan_incdir = config.test_source_root + "/../../lib"
+unit_cxxflags = (["-I%s" % esan_incdir, "-std=c++11",
+                  # We need to link with the esan runtime.
+                  "-fsanitize=efficiency-working-set"] + base_cxxflags)
 
 def build_invocation(compile_flags):
   return " " + " ".join([config.clang] + compile_flags) + " "
@@ -22,6 +26,8 @@ config.substitutions.append( ("%clang_esan_frag ",
                               build_invocation(frag_cflags)) )
 config.substitutions.append( ("%clang_esan_wset ",
                               build_invocation(wset_cflags)) )
+config.substitutions.append( ("%clangxx_unit",
+                              build_invocation(unit_cxxflags)) )
 
 default_esan_opts = ''
 config.substitutions.append(('%env_esan_opts=',