[CMake] Simplify lldb-server handling

[JDevlieghere]

Summary

We can piggyback off the existing add_lldb_tool_subdirectory to decide whether or not lldb-server should be built.

[davide]

LGTM

[davide]

lldb/tools/CMakeLists.txt

12 ↗

(On Diff #199327)

This probably predates the use of add_lldb_tool_subdirectory in lldb.

cmake/modules/LLDBConfig.cmake

 if(NOT PURE_WINDOWS)
   set(CMAKE_THREAD_PREFER_PTHREAD TRUE)
   find_package(Threads REQUIRED)
   list(APPEND system_libs ${CMAKE_THREAD_LIBS_INIT})
 endif()
 
 list(APPEND system_libs ${CMAKE_DL_LIBS})
 
-SET(SKIP_LLDB_SERVER_BUILD OFF CACHE BOOL "Skip building lldb-server")
-
 # Figure out if lldb could use lldb-server.  If so, then we'll
 # ensure we build lldb-server when an lldb target is being built.
-if (CMAKE_SYSTEM_NAME MATCHES "Android|Darwin|FreeBSD|Linux|NetBSD")
-    set(LLDB_CAN_USE_LLDB_SERVER 1)
-else()
-    set(LLDB_CAN_USE_LLDB_SERVER 0)
+if (NOT CMAKE_SYSTEM_NAME MATCHES "Android|Darwin|FreeBSD|Linux|NetBSD")
+  set(LLDB_TOOL_LLDB_SERVER_BUILD OFF)
 endif()
 
 # Figure out if lldb could use debugserver.  If so, then we'll
 # ensure we build debugserver when we build lldb.
 if ( CMAKE_SYSTEM_NAME MATCHES "Darwin" )
     set(LLDB_CAN_USE_DEBUGSERVER 1)
 else()
     set(LLDB_CAN_USE_DEBUGSERVER 0)

tools/CMakeLists.txt

 add_subdirectory(argdumper)
 add_subdirectory(driver)
 add_subdirectory(intel-features)
 
 # We want lldb-test to be built only when it's needed,
 # i.e. if a target requires it as dependency. The typical
 # example is `check-lldb`. So, we pass EXCLUDE_FROM_ALL here.
 add_subdirectory(lldb-test EXCLUDE_FROM_ALL)
 
 add_lldb_tool_subdirectory(lldb-instr)
 add_lldb_tool_subdirectory(lldb-mi)
+add_lldb_tool_subdirectory(lldb-server)
 add_lldb_tool_subdirectory(lldb-vscode)
 
 if (CMAKE_SYSTEM_NAME MATCHES "Darwin")
   add_subdirectory(darwin-debug)
   add_subdirectory(debugserver)
 endif()
-
-if (LLDB_CAN_USE_LLDB_SERVER AND NOT SKIP_LLDB_SERVER_BUILD)
-  add_subdirectory(lldb-server)
-endif()

unittests/tools/CMakeLists.txt

+if(LLDB_TOOL_LLDB_MI_BUILD)
   add_subdirectory(lldb-mi)
-if(CMAKE_SYSTEM_NAME MATCHES "Android|Darwin|Linux|NetBSD")
-  if ((CMAKE_SYSTEM_NAME MATCHES "Darwin" AND SKIP_TEST_DEBUGSERVER) OR (NOT CMAKE_SYSTEM_NAME MATCHES "Darwin" AND SKIP_LLDB_SERVER_BUILD))
-    # These tests are meant to test lldb-server/debugserver in isolation, and
-    # don't provide any value if run against a server copied from somewhere.
-  else()
-    add_subdirectory(lldb-server)
-  endif()
+if(LLDB_TOOL_LLDB_SERVER_BUILD)
+  add_subdirectory(lldb-server)
 endif()