Merge pull request #6514 from bulbazord/cherrypick/20221013/103194447

[lldb] Introduce CMake variable LLDB_ENFORCE_STRICT_TEST_REQUIREMENTS

Author: bulbazord

lldb/cmake/modules/AddLLDB.cmake

@@ -404,6 +404,25 @@ function(lldb_find_system_debugserver path)
   endif()
 endfunction()
 
+function(lldb_find_python_module module)
+  set(MODULE_FOUND PY_${module}_FOUND)
+  if (DEFINED ${MODULE_FOUND})
+    return()
+  endif()
+
+  execute_process(COMMAND "${Python3_EXECUTABLE}" "-c" "import ${module}"
+    RESULT_VARIABLE status
+    ERROR_QUIET)
+
+  if (status)
+    set(${MODULE_FOUND} OFF CACHE BOOL "Failed to find python module '${module}'")
+    message(STATUS "Could NOT find Python module '${module}'")
+  else()
+    set(${MODULE_FOUND} ON CACHE BOOL "Found python module '${module}'")
+    message(STATUS "Found Python module '${module}'")
+  endif()
+endfunction()
+
 # Removes all module flags from the current CMAKE_CXX_FLAGS. Used for
 # the Objective-C++ code in lldb which we don't want to build with modules.
 # Reasons for this are that modules with Objective-C++ would require that

lldb/cmake/modules/LLDBConfig.cmake

@@ -82,6 +82,8 @@ option(LLDB_NO_INSTALL_DEFAULT_RPATH "Disable default RPATH settings in binaries
 option(LLDB_USE_SYSTEM_DEBUGSERVER "Use the system's debugserver for testing (Darwin only)." OFF)
 option(LLDB_SKIP_STRIP "Whether to skip stripping of binaries when installing lldb." OFF)
 option(LLDB_SKIP_DSYM "Whether to skip generating a dSYM when installing lldb." OFF)
+option(LLDB_ENFORCE_STRICT_TEST_REQUIREMENTS
+  "Fail to configure if certain requirements are not met for testing." OFF)
 
 # BEGIN SWIFT MOD
 option(LLDB_ENABLE_SWIFT_SUPPORT "Enable swift support" ON)

lldb/test/CMakeLists.txt

@@ -1,5 +1,30 @@
 # Test runner infrastructure for LLDB. This configures the LLDB test trees
 # for use by Lit, and delegates to LLVM's lit test handlers.
+# Lit requires a Python3 interpreter, let's be careful and fail early if it's
+# not present.
+if (NOT DEFINED Python3_EXECUTABLE)
+  message(FATAL_ERROR
+    "LLDB test suite requires a Python3 interpreter but none "
+    "was found. Please install Python3 or disable tests with "
+    "`LLDB_INCLUDE_TESTS=OFF`.")
+endif()
+
+if(LLDB_ENFORCE_STRICT_TEST_REQUIREMENTS)
+  message(STATUS "Enforcing strict test requirements for LLDB")
+  set(useful_python_modules
+    psutil # Lit uses psutil to do per-test timeouts.
+  )
+  foreach(module ${useful_python_modules})
+    lldb_find_python_module(${module})
+    if (NOT PY_${module}_FOUND)
+      message(FATAL_ERROR
+        "Python module '${module}' not found. Please install it via pip or via "
+        "your operating system's package manager. Alternatively, disable "
+        "strict testing requirements with "
+        "`LLDB_ENFORCE_STRICT_TEST_REQUIREMENTS=OFF`")
+    endif()
+  endforeach()
+endif()
 
 if(LLDB_BUILT_STANDALONE)
   # In order to run check-lldb-* we need the correct map_config directives in