[XRay][compiler-rt] Profiling Mode: Include file header in buffers

Summary:
This change provides access to the file header even in the in-memory
buffer processing. This allows in-memory processing of the buffers to
also check the version, and the format, of the profile data.

Reviewers: eizan, kpw

Reviewed By: eizan

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D50037

llvm-svn: 338347

1 files changed, 34 insertions, 2 deletions

diff --git a/compiler-rt/lib/xray/tests/unit/profile_collector_test.cc b/compiler-rt/lib/xray/tests/unit/profile_collector_test.cc
index b7dbe567312..00a7d53dc99 100644
--- a/compiler-rt/lib/xray/tests/unit/profile_collector_test.cc
+++ b/compiler-rt/lib/xray/tests/unit/profile_collector_test.cc
@@ -15,6 +15,8 @@
 #include "xray_profile_collector.h"
 #include "xray_profiling_flags.h"
 #include <cstdint>
+#include <cstring>
+#include <memory>
 #include <thread>
 #include <utility>
 #include <vector>
@@ -24,6 +26,29 @@ namespace {
 
 static constexpr auto kHeaderSize = 16u;
 
+constexpr uptr ExpectedProfilingVersion = 0x20180424;
+
+struct ExpectedProfilingFileHeader {
+  const u64 MagicBytes = 0x7872617970726f66; // Identifier for XRay profiling
+                                             // files 'xrayprof' in hex.
+  const uptr Version = ExpectedProfilingVersion;
+  uptr Timestamp = 0;
+  uptr PID = 0;
+};
+
+void ValidateFileHeaderBlock(XRayBuffer B) {
+  ASSERT_NE(static_cast<const void *>(B.Data), nullptr);
+  ASSERT_EQ(B.Size, sizeof(ExpectedProfilingFileHeader));
+  typename std::aligned_storage<sizeof(ExpectedProfilingFileHeader)>::type
+      FileHeaderStorage;
+  ExpectedProfilingFileHeader ExpectedHeader;
+  std::memcpy(&FileHeaderStorage, B.Data, B.Size);
+  auto &FileHeader =
+      *reinterpret_cast<ExpectedProfilingFileHeader *>(&FileHeaderStorage);
+  ASSERT_EQ(ExpectedHeader.MagicBytes, FileHeader.MagicBytes);
+  ASSERT_EQ(ExpectedHeader.Version, FileHeader.Version);
+}
+
 void ValidateBlock(XRayBuffer B) {
   profilingFlags()->setDefaults();
   ASSERT_NE(static_cast<const void *>(B.Data), nullptr);
@@ -107,9 +132,13 @@ TEST(profileCollectorServiceTest, PostSerializeCollect) {
   // Then we serialize the data.
   profileCollectorService::serialize();
 
-  // Then we go through a single buffer to see whether we're getting the data we
-  // expect.
+  // Then we go through two buffers to see whether we're getting the data we
+  // expect. The first block must always be as large as a file header, which
+  // will have a fixed size.
   auto B = profileCollectorService::nextBuffer({nullptr, 0});
+  ValidateFileHeaderBlock(B);
+
+  B = profileCollectorService::nextBuffer(B);
   ValidateBlock(B);
   u32 BlockSize;
   u32 BlockNum;
@@ -169,6 +198,9 @@ TEST(profileCollectorServiceTest, PostSerializeCollectMultipleThread) {
 
   // Ensure that we see two buffers.
   auto B = profileCollectorService::nextBuffer({nullptr, 0});
+  ValidateFileHeaderBlock(B);
+
+  B = profileCollectorService::nextBuffer(B);
   ValidateBlock(B);
 
   B = profileCollectorService::nextBuffer(B);