[cmake][wip] Add support for setting crash report directory

[paulkirth]

Summary

Crash reports and reproducers can be saved to a directory through
-fcrash-diagnostics-dir. This patch adds a CMAKE variable and plumbs
it through to the runtimes build targets in addition to Clang/LLVM

[paulkirth]

Actually passthrough/update the variable in the runtimes build.
Remove debugging code.

[paulkirth]

Is there a way to write a test for CMAKE?

[Mordante]

This seems to solve the same issue as D133082, have you seen that patch?

[paulkirth]

@Mordante I had not seen that, so thanks for pointing this out.

[paulkirth]

D133082 has landed, making this change redundant

compiler-rt/lib/sanitizer_common/sanitizer_hash.h

 //===-- sanitizer_common.h --------------------------------------*- C++ -*-===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements a simple hash function.
 //===----------------------------------------------------------------------===//
 
 #ifndef SANITIZER_HASH_H
 #define SANITIZER_HASH_H
 
+#pragma clang __debug crash
+
 #include "sanitizer_internal_defs.h"
 
 namespace __sanitizer {
 class MurMur2HashBuilder {
   static const u32 m = 0x5bd1e995;
   static const u32 seed = 0x9747b28c;
   static const u32 r = 24;
   u32 h;
public:
   }
   u32 get() {
     u32 x = h;
     x ^= x >> 13;
     x *= m;
     x ^= x >> 15;
     return x;
   }
-};
+}
 
 class MurMur2Hash64Builder {
   static const u64 m = 0xc6a4a7935bd1e995ull;
   static const u64 seed = 0x9747b28c9747b28cull;
   static const u64 r = 47;
   u64 h;
 
  public:

llvm/CMakeLists.txt

 
 set(LLVM_ENABLE_NEW_PASS_MANAGER TRUE CACHE BOOL
   "Enable the new pass manager by default.")
 if(NOT LLVM_ENABLE_NEW_PASS_MANAGER)
   message(FATAL_ERROR "Enabling the legacy pass manager on the cmake level is"
                       " no longer supported.")
 endif()
 
+set(LLVM_CRASH_REPORT_DIR "" CACHE STRING "Define directory name for crash reports" )
+
 include(HandleLLVMOptions)
 
 ######
 
 # Configure all of the various header file fragments LLVM uses which depend on
 # configuration variables.
 set(LLVM_ENUM_TARGETS "")
 set(LLVM_ENUM_ASM_PRINTERS "")

 
 add_subdirectory(projects)
 
 if( LLVM_INCLUDE_TOOLS )
   add_subdirectory(tools)
 endif()
 
 if( LLVM_INCLUDE_RUNTIMES )
+  message("LLVM_ENABLE_CRASH_REPORT_DIR = ${LLVM_ENABLE_CRASH_REPORT_DIR}")
+  message("LLVM_CRASH_REPORT_DIR = ${LLVM_CRASH_REPORT_DIR}")
   add_subdirectory(runtimes)
 endif()
 
 if( LLVM_INCLUDE_EXAMPLES )
   add_subdirectory(examples)
 endif()
 
 if( LLVM_INCLUDE_TESTS )

llvm/cmake/modules/HandleLLVMOptions.cmake

if (MSVC)
           CMAKE_C_FLAGS_MINSIZEREL)
         string (REGEX REPLACE "(^| )[/-]D *NDEBUG($| )" " "
           "${flags_var_to_scrub}" "${${flags_var_to_scrub}}")
       endforeach()
      endif()
   endif()
 endif()
 
+if(DEFINED LLVM_CRASH_REPORT_DIR AND CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+  append("-fcrash-diagnostics-dir=${LLVM_CRASH_REPORT_DIR}" CMAKE_CXX_FLAGS CMAKE_C_FLAGS)
+endif()
+
 if(LLVM_ENABLE_EXPENSIVE_CHECKS)
   add_definitions(-DEXPENSIVE_CHECKS)
 
   # In some libstdc++ versions, std::min_element is not constexpr when
   # _GLIBCXX_DEBUG is enabled.
   CHECK_CXX_SOURCE_COMPILES("
     #define _GLIBCXX_DEBUG
     #include <algorithm>

llvm/runtimes/CMakeLists.txt

llvm_ExternalProject_Add(builtins
                                       -DLLVM_ENABLE_PER_TARGET_RUNTIME_DIR=${LLVM_ENABLE_PER_TARGET_RUNTIME_DIR_default}
                                       -DCMAKE_C_COMPILER_WORKS=ON
                                       -DCMAKE_ASM_COMPILER_WORKS=ON
                                       ${COMMON_CMAKE_ARGS}
                                       ${BUILTINS_CMAKE_ARGS}
                            PASSTHROUGH_PREFIXES COMPILER_RT
                                                 DARWIN
                                                 SANITIZER
+                                                LLVM_CRASH_REPORT_DIR
                            USE_TOOLCHAIN
                            TARGET_TRIPLE ${LLVM_TARGET_TRIPLE}
                            ${EXTRA_ARGS})
 endfunction()
 
 function(builtin_register_target compiler_rt_path target)
   cmake_parse_arguments(ARG "" "" "DEPENDS" ${ARGN})
 
llvm_ExternalProject_Add(runtimes
                                       -DLLVM_BUILD_TOOLS=${LLVM_BUILD_TOOLS}
                                       -DCMAKE_C_COMPILER_WORKS=ON
                                       -DCMAKE_CXX_COMPILER_WORKS=ON
                                       -DCMAKE_ASM_COMPILER_WORKS=ON
                                       ${COMMON_CMAKE_ARGS}
                                       ${RUNTIMES_CMAKE_ARGS}
                            PASSTHROUGH_PREFIXES LLVM_ENABLE_RUNTIMES
                                                 LLVM_USE_LINKER
+                                                LLVM_CRASH_REPORT_DIR
                                                 ${ARG_PREFIXES}
                            EXTRA_TARGETS ${extra_targets}
                                          ${test_targets}
                                          ${SUB_COMPONENTS}
                                          ${SUB_CHECK_TARGETS}
                                          ${SUB_INSTALL_TARGETS}
                            USE_TOOLCHAIN
                            TARGET_TRIPLE ${LLVM_TARGET_TRIPLE}

runtimes/CMakeLists.txt

 # This file handles building LLVM runtime sub-projects.
 cmake_minimum_required(VERSION 3.13.4)
 project(Runtimes C CXX ASM)
 
 # Add path for custom and the LLVM build's modules to the CMake module path.
 set(LLVM_COMMON_CMAKE_UTILS "${CMAKE_CURRENT_SOURCE_DIR}/../cmake")
 list(INSERT CMAKE_MODULE_PATH 0
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake"
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules"
   "${LLVM_COMMON_CMAKE_UTILS}"
   "${LLVM_COMMON_CMAKE_UTILS}/Modules"
   "${CMAKE_CURRENT_SOURCE_DIR}/../llvm/cmake"
   "${CMAKE_CURRENT_SOURCE_DIR}/../llvm/cmake/modules"
 )
 
+  message("LLVM_ENABLE_CRASH_REPORT_DIR = ${LLVM_ENABLE_CRASH_REPORT_DIR}")
+  message("LLVM_CRASH_REPORT_DIR = ${LLVM_CRASH_REPORT_DIR}")
+
 # We order libraries to mirror roughly how they are layered, except that compiler-rt can depend
 # on libc++, so we put it after.
 set(LLVM_DEFAULT_RUNTIMES "libc;libunwind;libcxxabi;pstl;libcxx;compiler-rt;openmp")
 set(LLVM_SUPPORTED_RUNTIMES "${LLVM_DEFAULT_RUNTIMES};llvm-libgcc")
 set(LLVM_ENABLE_RUNTIMES "" CACHE STRING
   "Semicolon-separated list of runtimes to build, or \"all\" (${LLVM_DEFAULT_RUNTIMES}). Supported runtimes are ${LLVM_SUPPORTED_RUNTIMES}.")
 if(LLVM_ENABLE_RUNTIMES STREQUAL "all" )
   set(LLVM_ENABLE_RUNTIMES ${LLVM_DEFAULT_RUNTIMES})