From 9c3824aad7f727591798441a65af5e92eaef8f67 Mon Sep 17 00:00:00 2001
From: Michal Gorny <mgorny@gentoo.org>
Date: Fri, 26 Apr 2019 13:21:46 +0000
Subject: [PATCH] [lldb] [lit] Add feature flags for native CPU features

Add a new lit-cpuid tool that detects CPU features used by some of
the tests, and use it to populate available_features in lit.  For now,
this means that the test for MM/XMM register read will be run only
when the host CPU support SSE instruction set.  However, this is going
to make it possible to introduce additional tests relying on AVX.

Differential Revision: https://reviews.llvm.org/D61073

llvm-svn: 359303
---
 lldb/CMakeLists.txt                    |  1 +
 lldb/lit/CMakeLists.txt                |  1 +
 lldb/lit/Register/x86-mm-xmm-read.test |  2 +-
 lldb/lit/lit.cfg.py                    | 14 ++++++++++++++
 lldb/utils/lit-cpuid/CMakeLists.txt    |  5 +++++
 lldb/utils/lit-cpuid/lit-cpuid.cpp     | 33 +++++++++++++++++++++++++++++++++
 6 files changed, 55 insertions(+), 1 deletion(-)
 create mode 100644 lldb/utils/lit-cpuid/CMakeLists.txt
 create mode 100644 lldb/utils/lit-cpuid/lit-cpuid.cpp

diff --git a/lldb/CMakeLists.txt b/lldb/CMakeLists.txt
index a826c25..71a3de4 100644
--- a/lldb/CMakeLists.txt
+++ b/lldb/CMakeLists.txt
@@ -138,6 +138,7 @@ if(LLDB_INCLUDE_TESTS)
   add_subdirectory(test)
   add_subdirectory(unittests)
   add_subdirectory(lit)
+  add_subdirectory(utils/lit-cpuid)
   add_subdirectory(utils/lldb-dotest)
 endif()
 
diff --git a/lldb/lit/CMakeLists.txt b/lldb/lit/CMakeLists.txt
index ea7f897..e5b6249 100644
--- a/lldb/lit/CMakeLists.txt
+++ b/lldb/lit/CMakeLists.txt
@@ -20,6 +20,7 @@ string(REPLACE ${CMAKE_CFG_INTDIR} ${LLVM_BUILD_MODE} LLDB_DOTEST_ARGS "${LLDB_D
 list(APPEND LLDB_TEST_DEPS
   LLDBUnitTests
   dsymutil
+  lit-cpuid
   llc
   lldb
   lldb-test
diff --git a/lldb/lit/Register/x86-mm-xmm-read.test b/lldb/lit/Register/x86-mm-xmm-read.test
index 510d131..5902c34 100644
--- a/lldb/lit/Register/x86-mm-xmm-read.test
+++ b/lldb/lit/Register/x86-mm-xmm-read.test
@@ -1,6 +1,6 @@
 # XFAIL: system-darwin
 # XFAIL: system-windows
-# REQUIRES: native && (target-x86 || target-x86_64)
+# REQUIRES: native && (target-x86 || target-x86_64) && native-cpu-sse
 # RUN: %clangxx %p/Inputs/x86-mm-xmm-read.cpp -o %t
 # RUN: %lldb -b -s %s %t | FileCheck %s
 process launch
diff --git a/lldb/lit/lit.cfg.py b/lldb/lit/lit.cfg.py
index e1db762..f96152e 100644
--- a/lldb/lit/lit.cfg.py
+++ b/lldb/lit/lit.cfg.py
@@ -73,3 +73,17 @@ for i in ['module-cache-clang', 'module-cache-lldb']:
     if os.path.isdir(cachedir):
         print("Deleting module cache at %s."%cachedir)
         shutil.rmtree(cachedir)
+
+# If running tests natively, check for CPU features needed for some tests.
+
+if 'native' in config.available_features:
+    cpuid_exe = lit.util.which('lit-cpuid', config.lldb_tools_dir)
+    if cpuid_exe is None:
+        lit_config.warning("lit-cpuid not found, tests requiring CPU extensions will be skipped")
+    else:
+        out, err, exitcode = lit.util.executeCommand([cpuid_exe])
+        if exitcode == 0:
+            for x in out.split():
+                config.available_features.add('native-cpu-%s' % x)
+        else:
+            lit_config.warning("lit-cpuid failed: %s" % err)
diff --git a/lldb/utils/lit-cpuid/CMakeLists.txt b/lldb/utils/lit-cpuid/CMakeLists.txt
new file mode 100644
index 0000000..b3af817
--- /dev/null
+++ b/lldb/utils/lit-cpuid/CMakeLists.txt
@@ -0,0 +1,5 @@
+add_llvm_utility(lit-cpuid
+  lit-cpuid.cpp
+  )
+
+target_link_libraries(lit-cpuid PRIVATE LLVMSupport)
diff --git a/lldb/utils/lit-cpuid/lit-cpuid.cpp b/lldb/utils/lit-cpuid/lit-cpuid.cpp
new file mode 100644
index 0000000..65c552b
--- /dev/null
+++ b/lldb/utils/lit-cpuid/lit-cpuid.cpp
@@ -0,0 +1,33 @@
+//===- lit-cpuid.cpp - Get CPU feature flags for lit exported features ----===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// lit-cpuid obtains the feature list for the currently running CPU, and outputs
+// those flags that are interesting for LLDB lit tests.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/StringMap.h"
+#include "llvm/Support/Host.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+
+int main(int argc, char **argv) {
+#if defined(__i386__) || defined(_M_IX86) || \
+    defined(__x86_64__) || defined(_M_X64)
+  StringMap<bool> features;
+
+  if (!sys::getHostCPUFeatures(features))
+    return 1;
+
+  if (features["sse"])
+    outs() << "sse\n";
+#endif
+
+  return 0;
+}
-- 
2.7.4