[XRay] Clean up XRay build configuration

[dberris]

Summary

This change spans both LLVM and compiler-rt, where we do the following:

• Add XRay to the LLVMBuild system, to allow for distributing the XRay trace loading library along with the LLVM distributions.

• Use llvm-config better in the compiler-rt XRay implementation, to depend on the potentially already-distributed LLVM XRay library.

While this is tested with the standalone compiler-rt build, it does
require that the LLVMXRay library (and LLVMSupport as well) are
available during the build. In case the static libraries are available,
the unit tests will build and work fine. We're still having issues with
attempting to use a shared library version of the LLVMXRay library since
the shared library might not be accessible from the standard shared
library lookup paths.

The larger change here is the inclusion of the LLVMXRay library in the
distribution, which allows for building tools around the XRay traces and
profiles that the XRay runtime already generates.

[dberris]

Fixup description.

[dberris]

Update LLVMBuild.txt header in llvm/lib/XRay/.

[mboerger]

LGTM

[mgorny]

compiler-rt/trunk/cmake/Modules/CompilerRTUtils.cmake

242 ↗

(On Diff #166672)

I'm sorry but this can't really work properly with stand-alone builds since LLVMTestingSupport is not installed. You need to build it from the source tree, and that's true PITA. I've just spent two hours trying to fix this and I've reached peak level of frustration where I give up.

compiler-rt/cmake/Modules/CompilerRTUtils.cmake

if (LLVM_CONFIG_PATH)
     list(GET CONFIG_OUTPUT 4 INCLUDE_DIR)
 
     set(LLVM_BINARY_DIR ${BINARY_DIR} CACHE PATH "Path to LLVM build tree")
     set(LLVM_LIBRARY_DIR ${LIBRARY_DIR} CACHE PATH "Path to llvm/lib")
     set(LLVM_MAIN_SRC_DIR ${MAIN_SRC_DIR} CACHE PATH "Path to LLVM source tree")
     set(LLVM_TOOLS_BINARY_DIR ${TOOLS_BINARY_DIR} CACHE PATH "Path to llvm/bin")
     set(LLVM_INCLUDE_DIR ${INCLUDE_DIR} CACHE PATH "Paths to LLVM headers")
 
+    # Detect if we have the LLVMXRay and TestingSupport library installed and
+    # available from llvm-config.
+    execute_process(
+      COMMAND ${LLVM_CONFIG_PATH} "--ldflags" "--libs" "xray" "testingsupport"
+      RESULT_VARIABLE HAD_ERROR
+      OUTPUT_VARIABLE CONFIG_OUTPUT)
+    if (HAD_ERROR)
+      message(WARNING "llvm-config finding xray failed with status ${HAD_ERROR}")
+      set(COMPILER_RT_HAS_LLVMXRAY FALSE)
+    else()
+      string(REGEX REPLACE "[ \t]*[\r\n]+[ \t]*" ";" CONFIG_OUTPUT ${CONFIG_OUTPUT})
+      list(GET CONFIG_OUTPUT 0 LDFLAGS)
+      list(GET CONFIG_OUTPUT 1 LIBLIST)
+      set(LLVM_XRAY_LDFLAGS ${LDFLAGS} CACHE STRING "Linker flags for LLVMXRay library")
+      set(LLVM_XRAY_LIBLIST ${LIBLIST} CACHE STRING "Library list for LLVMXRay")
+      set(COMPILER_RT_HAS_LLVMXRAY TRUE)
+    endif()
+
     # Make use of LLVM CMake modules.
     # --cmakedir is supported since llvm r291218 (4.0 release)
     execute_process(
       COMMAND ${LLVM_CONFIG_PATH} --cmakedir
       RESULT_VARIABLE HAD_ERROR
       OUTPUT_VARIABLE CONFIG_OUTPUT)
     if(NOT HAD_ERROR)
       string(STRIP "${CONFIG_OUTPUT}" LLVM_CMAKE_PATH_FROM_LLVM_CONFIG)

compiler-rt/lib/xray/tests/CMakeLists.txt

else()
     set(tgt_name "RTXRay.test.${arch}")
   endif()
   set(${lib} "${tgt_name}" PARENT_SCOPE)
 endfunction()
 
 set(XRAY_TEST_ARCH ${XRAY_SUPPORTED_ARCH})
 set(XRAY_UNITTEST_LINK_FLAGS
   ${CMAKE_THREAD_LIBS_INIT}
-  -l${SANITIZER_CXX_ABI_LIBRARY}
-  -fxray-instrument
-  )
+  -l${SANITIZER_CXX_ABI_LIBRARY})
+
 if (NOT APPLE)
   append_list_if(COMPILER_RT_HAS_LIBM -lm XRAY_UNITTEST_LINK_FLAGS)
   append_list_if(COMPILER_RT_HAS_LIBRT -lrt XRAY_UNITTEST_LINK_FLAGS)
   append_list_if(COMPILER_RT_HAS_LIBDL -ldl XRAY_UNITTEST_LINK_FLAGS)
   append_list_if(COMPILER_RT_HAS_LIBPTHREAD -pthread XRAY_UNITTEST_LINK_FLAGS)
 
   # Needed by LLVMSupport.
   append_list_if(
     COMPILER_RT_HAS_TERMINFO
     -l${COMPILER_RT_TERMINFO_LIB} XRAY_UNITTEST_LINK_FLAGS)
+
+  if (COMPILER_RT_STANDALONE_BUILD)
+    append_list_if(COMPILER_RT_HAS_LLVMXRAY ${LLVM_XRAY_LDFLAGS} XRAY_UNITTEST_LINK_FLAGS)
+    append_list_if(COMPILER_RT_HAS_LLVMXRAY ${LLVM_XRAY_LIBLIST} XRAY_UNITTEST_LINK_FLAGS)
+  else()
+    # We add the library directories one at a time in our CFLAGS.
+    foreach (DIR ${LLVM_LIBRARY_DIR})
+      list(APPEND XRAY_UNITTEST_LINK_FLAGS -L${DIR})
+    endforeach()
+
+    # We also add the actual libraries to link as dependencies.
+    list(APPEND XRAY_UNITTEST_LINK_FLAGS -lLLVMXRay -lLLVMSupport -lLLVMTestingSupport)
+  endif()
 endif()
 
 macro(add_xray_unittest testname)
   cmake_parse_arguments(TEST "" "" "SOURCES;HEADERS" ${ARGN})
   if(UNIX AND NOT APPLE)
     set(CMAKE_DL_LIBS_INIT "")
     foreach(arch ${XRAY_TEST_ARCH})
       set(TEST_OBJECTS)
       get_xray_lib_for_arch(${arch} XRAY_RUNTIME_LIBS)
       generate_compiler_rt_tests(TEST_OBJECTS
         XRayUnitTests "${testname}-${arch}-Test" "${arch}"
         SOURCES ${TEST_SOURCES} ${COMPILER_RT_GTEST_SOURCE}
                 ${COMPILER_RT_GMOCK_SOURCE}
 
         # Note that any change in the implementations will cause all the unit
         # tests to be re-built. This is by design, but may be cumbersome during
         # the build/test cycle.
         COMPILE_DEPS ${TEST_SOURCES} ${COMPILER_RT_GTEST_SOURCE}
         ${XRAY_HEADERS} ${XRAY_ALL_SOURCE_FILES_ABS_PATHS}
         RUNTIME "${XRAY_RUNTIME_LIBS}"
         DEPS gtest xray llvm-xray LLVMXRay LLVMTestingSupport
         CFLAGS ${XRAY_UNITTEST_CFLAGS}
         LINK_FLAGS ${TARGET_LINK_FLAGS} ${XRAY_UNITTEST_LINK_FLAGS}
-        -lLLVMXRay -lLLVMSupport -lLLVMTestingSupport)
+        )
       set_target_properties(XRayUnitTests
         PROPERTIES
         RUNTIME_OUTPUT_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
     endforeach()
   endif()
 endmacro()
 
 if(COMPILER_RT_CAN_EXECUTE_TESTS)

compiler-rt/lib/xray/tests/unit/CMakeLists.txt

-add_xray_unittest(XRayBufferQueueTest SOURCES
-  buffer_queue_test.cc xray_unit_test_main.cc)
-add_xray_unittest(XRayAllocatorTest SOURCES
-  allocator_test.cc xray_unit_test_main.cc)
-add_xray_unittest(XRaySegmentedArrayTest SOURCES
-  segmented_array_test.cc xray_unit_test_main.cc)
-add_xray_unittest(XRayFunctionCallTrieTest SOURCES
-  function_call_trie_test.cc xray_unit_test_main.cc)
-add_xray_unittest(XRayProfileCollectorTest SOURCES
-  profile_collector_test.cc xray_unit_test_main.cc)
-
-add_xray_unittest(XRayFDRLoggingTest SOURCES
+add_xray_unittest(XRayTest SOURCES
+  buffer_queue_test.cc
+  allocator_test.cc
+  segmented_array_test.cc
+  function_call_trie_test.cc
+  profile_collector_test.cc
   fdr_log_writer_test.cc
   xray_unit_test_main.cc)

llvm/lib/LLVMBuild.txt

  ProfileData
  Support
  TableGen
  Target
  Testing
  ToolDrivers
  Transforms
  WindowsManifest
+ XRay
 
 [component_0]
 type = Group
 name = Libraries
 parent = $ROOT

llvm/lib/XRay/LLVMBuild.txt

-;===- ./lib/LLVMBuild.txt --------------------------------------*- Conf -*--===;
+;===- ./lib/Support/LLVMBuild.txt ------------------------------*- Conf -*--===;
 ;
 ;                     The LLVM Compiler Infrastructure
 ;
 ; This file is distributed under the University of Illinois Open Source
 ; License. See LICENSE.TXT for details.
 ;
 ;===------------------------------------------------------------------------===;
 ;
 ; This is an LLVMBuild description file for the components in this subdirectory.
 ;
 ; For more information on the LLVMBuild system, please see:
 ;
 ;   http://llvm.org/docs/LLVMBuild.html
 ;
 ;===------------------------------------------------------------------------===;
 
-[common]
-subdirectories =
- Analysis
- AsmParser
- Bitcode
- CodeGen
- DebugInfo
- Demangle
- ExecutionEngine
- FuzzMutate
- LineEditor
- Linker
- IR
- IRReader
- LTO
- MC
- Object
- BinaryFormat
- ObjectYAML
- Option
- Passes
- ProfileData
- Support
- TableGen
- Target
- Testing
- ToolDrivers
- Transforms
- WindowsManifest
-
 [component_0]
-type = Group
-name = Libraries
-parent = $ROOT
+type = Library
+name = XRay
+parent = Libraries
+required_libraries = Support Object
+installed = 1