[SYCL] Enable stack printing on crashes in post commit (#7934)

The initial attempt to enable LLVM stack printing on crashes(SEGFAULT)
when running SYCL tests.
The motivation is to simplify analysis of sporadic fails in CI.

The patch:
1. If `DSYCL_ENABLE_STACK_PRINTING` `cmake` var is defined:
a. Links the `libsycl.so` with `LLVMSupport` which provides needed
functionality
b. Calls `llvm::sys::PrintStackTraceOnErrorSignal`, which registers
signal handlers,
        in a couple of places in SYCL RT
    c. Adds `llvm-sybmolizer` to the dependencies of `sycl-toolchain`
2. Modifies post-commit workflow to:
    a. build linux job (`linux_default` only) in RelWithDebInfo mode
    b. pass the `cmake` var to the `configure.py`
3. Sets `LLVM_SYMBOLIZER_PATH` in the `lit.cfg.py` for SYCL to the
`llvm-sybmolizer` binary from the build dir

Author: romanovvlad

.github/workflows/sycl_post_commit.yml

@@ -36,6 +36,7 @@ jobs:
       lts_matrix: ${{ needs.test_matrix.outputs.lts_matrix }}
       cts_matrix: ${{ needs.test_matrix.outputs.cts_matrix }}
       lts_aws_matrix: ${{ needs.test_matrix.outputs.lts_aws_matrix }}
+      build_configure_extra_args: --cmake-opt="-DSYCL_ENABLE_STACK_PRINTING=ON" --cmake-opt="-DSYCL_LIB_WITH_DEBUG_SYMBOL=ON"
   linux_no_assert:
     name: Linux (no assert)
     if: github.repository == 'intel/llvm'

sycl/CMakeLists.txt

@@ -9,6 +9,8 @@ option(SYCL_ENABLE_WERROR "Treat all warnings as errors in SYCL project" OFF)
 option(SYCL_DISABLE_STL_ASSERTIONS "Disable assertions in STL containers" ON)
 option(SYCL_ADD_DEV_VERSION_POSTFIX "Adds -V postfix to version string" ON)
 option(SYCL_ENABLE_COVERAGE "Enables code coverage for runtime and unit tests" OFF)
+option(SYCL_ENABLE_STACK_PRINTING "Enables stack printing on crashes of SYCL applications" OFF)
+option(SYCL_LIB_WITH_DEBUG_SYMBOLS "Builds SYCL runtime libraries with debug symbols" OFF)
 
 if (NOT SYCL_COVERAGE_PATH)
   set(SYCL_COVERAGE_PATH "${CMAKE_CURRENT_BINARY_DIR}/profiles")
@@ -327,6 +329,10 @@ if (SYCL_ENABLE_XPTI_TRACING)
   endif()
 endif()
 
+if (SYCL_ENABLE_STACK_PRINTING)
+  add_dependencies(sycl-toolchain llvm-symbolizer)
+endif()
+
 option(SYCL_INCLUDE_TESTS
   "Generate build targets for the SYCL unit tests."
   ${LLVM_INCLUDE_TESTS})

sycl/cmake/modules/AddSYCL.cmake

@@ -24,6 +24,12 @@ function(add_sycl_library LIB_NAME TYPE)
     add_stripped_pdb(${LIB_NAME})
   endif()
 
+  # TODO: Enabled for MSVC
+  if (NOT MSVC AND SYCL_LIB_WITH_DEBUG_SYMBOLS)
+    separate_arguments(CMAKE_CXX_FLAGS_DEBUG_SEPARATED UNIX_COMMAND "${CMAKE_CXX_FLAGS_DEBUG}")
+    target_compile_options(${LIB_NAME} PRIVATE ${CMAKE_CXX_FLAGS_DEBUG_SEPARATED})
+  endif()
+
   # TODO remove add_common_options
   add_common_options(${LIB_NAME})
 endfunction()

sycl/source/CMakeLists.txt

@@ -26,6 +26,23 @@ function(add_sycl_rt_library LIB_NAME LIB_OBJ_NAME)
               $<TARGET_OBJECTS:${LIB_OBJ_NAME}>
               ${CMAKE_CURRENT_BINARY_DIR}/version.rc)
 
+  # Unlike for sycl library, for LLVMSupport we have only one version for a given build,
+  # so, we link LLVMSupport lib to matching sycl version only.
+  if (SYCL_ENABLE_STACK_PRINTING)
+    if(NOT MSVC OR (CMAKE_BUILD_TYPE STREQUAL "Debug" AND ARG_COMPILE_OPTIONS MATCHES ".*MDd.*") OR
+      (NOT CMAKE_BUILD_TYPE STREQUAL "Debug" AND NOT ARG_COMPILE_OPTIONS MATCHES ".*MDd.*"))
+        add_dependencies(${LIB_NAME} LLVMSupport)
+        target_compile_definitions(${LIB_OBJ_NAME} PUBLIC ENABLE_STACK_TRACE)
+        target_link_libraries(${LIB_NAME} PRIVATE LLVMSupport)
+    endif()
+  endif()
+
+  # TODO: Enabled for MSVC
+  if (NOT MSVC AND SYCL_LIB_WITH_DEBUG_SYMBOLS)
+    separate_arguments(CMAKE_CXX_FLAGS_DEBUG_SEPARATED UNIX_COMMAND "${CMAKE_CXX_FLAGS_DEBUG}")
+    target_compile_options(${LIB_NAME} PRIVATE ${CMAKE_CXX_FLAGS_DEBUG_SEPARATED})
+  endif()
+
   if (SYCL_ENABLE_COVERAGE)
     target_compile_options(${LIB_OBJ_NAME} PUBLIC
       -fprofile-instr-generate -fcoverage-mapping

sycl/source/detail/global_handler.cpp

@@ -6,6 +6,11 @@
 //
 //===----------------------------------------------------------------------===//
 
+#ifdef ENABLE_STACK_TRACE
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/Signals.h"
+#endif
+
 #include <detail/config.hpp>
 #include <detail/global_handler.hpp>
 #include <detail/platform_impl.hpp>
@@ -95,9 +100,25 @@ void GlobalHandler::attachScheduler(Scheduler *Scheduler) {
   MScheduler.Inst.reset(Scheduler);
 }
 
+static void enableOnCrashStackPrinting() {
+#ifdef ENABLE_STACK_TRACE
+  static std::once_flag PrintStackFlag;
+  std::call_once(PrintStackFlag, []() {
+    llvm::sys::PrintStackTraceOnErrorSignal(llvm::StringRef());
+  });
+#endif
+}
+
 Scheduler &GlobalHandler::getScheduler() {
   getOrCreate(MScheduler);
   registerSchedulerUsage();
+  // On Windows the registration of the signal handler before main function
+  // (e.g. from DLLMain or from constructors of program scope objects) doesn't
+  // work. So, registering signal handler here because:
+  // 1) getScheduler is likely to be called for any non-trivial application;
+  // 2) first call to getScheduler is likely to be done after main starts.
+  // The same is done in getPlugins.
+  enableOnCrashStackPrinting();
   return *MScheduler.Inst;
 }
 
@@ -132,6 +153,7 @@ std::mutex &GlobalHandler::getFilterMutex() {
   return getOrCreate(MFilterMutex);
 }
 std::vector<plugin> &GlobalHandler::getPlugins() {
+  enableOnCrashStackPrinting();
   return getOrCreate(MPlugins);
 }
 device_filter_list &

sycl/test/Unit/lit.cfg.py

@@ -50,6 +50,9 @@
     if symbolizer in os.environ:
         config.environment[symbolizer] = os.environ[symbolizer]
 
+llvm_symbolizer = os.path.join(config.llvm_tools_dir, 'llvm-symbolizer')
+config.environment['LLVM_SYMBOLIZER_PATH'] = llvm_symbolizer
+
 def find_shlibpath_var():
     if platform.system() in ['Linux', 'FreeBSD', 'NetBSD', 'SunOS']:
         yield 'LD_LIBRARY_PATH'

sycl/test/lit.cfg.py

@@ -93,6 +93,9 @@
 config.substitutions.append( ('%llvm_build_lib_dir',  config.llvm_build_lib_dir ) )
 config.substitutions.append( ('%llvm_build_bin_dir',  config.llvm_build_bin_dir ) )
 
+llvm_symbolizer = os.path.join(config.llvm_build_bin_dir, 'llvm-symbolizer')
+llvm_config.with_environment('LLVM_SYMBOLIZER_PATH', llvm_symbolizer)
+
 config.substitutions.append( ('%fsycl-host-only', '-std=c++17 -Xclang -fsycl-is-host -isystem %s -isystem %s -isystem %s -isystem %s' % (config.sycl_include, config.level_zero_include_dir, config.opencl_include_dir, config.sycl_include + '/sycl/') ) )
 config.substitutions.append( ('%sycl_lib', ' -lsycl6' if platform.system() == "Windows" else '-lsycl') )