[cmake] Fix LLDB_CODESIGN_IDENTITY logic.

[hintonda]

Summary

Consolidate LLDB_CODESIGN_IDENTITY logic in one place and use
SKIP_DEBUGSERVER, which can be set independently, to control
codesigning targets.

Currently, running cmake the first time in a clean directory, without
passing -DLLDB_CODESIGN_IDENTITY='', fails. However, subsequent runs
succeed. That's because LLDB_CODESIGN_IDENTITY gets added to the
CACHE after the initial test. To fix that, the default value must be
set before it's tested.

Here's the error produced on the first run:

CMake Error at tools/lldb/tools/debugserver/source/CMakeLists.txt:215 (add_custom_command):

No TARGET 'debugserver' has been created in this directory.

[vsk]

Thanks, lgtm!

[hintonda]

This is causing test failures due debugserver not found. The fix should be to add DEBUGSERVER_PATH to the cache -- it was originally available in the root scope.

I hope to have a fix in as soon as I validated the fix locally, but if this is causing an issue for anyone, please let me know and I'll revert.

lldb/trunk/CMakeLists.txt

else()
     # Don't set -m when building the framework.
     set(FINISH_EXTRA_ARGS "-m")
   endif()
 
 
   add_subdirectory(scripts)
 endif ()
 
-if(CMAKE_HOST_APPLE)
-  if(LLDB_CODESIGN_IDENTITY)
-    set(DEBUGSERVER_PATH $<TARGET_FILE:debugserver>)
-  else()
-    execute_process(
-      COMMAND xcode-select -p
-      OUTPUT_VARIABLE XCODE_DEV_DIR)
-    string(STRIP ${XCODE_DEV_DIR} XCODE_DEV_DIR)
-    set(DEBUGSERVER_PATH
-      "${XCODE_DEV_DIR}/../SharedFrameworks/LLDB.framework/Resources/debugserver")
-    set(SKIP_DEBUGSERVER True)
-  endif()
-  message(STATUS "Path to the lldb debugserver: ${DEBUGSERVER_PATH}")
-endif()
-
 add_subdirectory(source)
 add_subdirectory(tools)
 
 option(LLDB_INCLUDE_TESTS "Generate build targets for the LLDB unit tests."
   ${LLVM_INCLUDE_TESTS})
 if(LLDB_INCLUDE_TESTS)
   if (TARGET clang)
     set(LLDB_DEFAULT_TEST_C_COMPILER "${LLVM_BINARY_DIR}/${CMAKE_CFG_INTDIR}/bin/clang${CMAKE_EXECUTABLE_SUFFIX}")

lldb/trunk/tools/debugserver/source/CMakeLists.txt

set(lldbDebugserverCommonSources
   MacOSX/MachVMRegion.cpp
   MacOSX/OsLogger.cpp
   ${generated_mach_interfaces}
   ${DEBUGSERVER_VERS_GENERATED_FILE})
 
 add_library(lldbDebugserverCommon ${lldbDebugserverCommonSources})
 
 
+set(LLDB_CODESIGN_IDENTITY "lldb_codesign"
+  CACHE STRING "Identity used for code signing. Set to empty string to skip the signing step.")
+
+if(NOT LLDB_CODESIGN_IDENTITY STREQUAL "")
+  set(DEBUGSERVER_PATH $<TARGET_FILE:debugserver>)
+else()
+  execute_process(
+    COMMAND xcode-select -p
+    OUTPUT_VARIABLE XCODE_DEV_DIR)
+  string(STRIP ${XCODE_DEV_DIR} XCODE_DEV_DIR)
+  set(DEBUGSERVER_PATH
+    "${XCODE_DEV_DIR}/../SharedFrameworks/LLDB.framework/Resources/debugserver")
+  set(SKIP_DEBUGSERVER True)
+endif()
+message(STATUS "Path to the lldb debugserver: ${DEBUGSERVER_PATH}")
+
 if (APPLE)
   if(IOS)
     find_library(BACKBOARD_LIBRARY BackBoardServices
       PATHS ${CMAKE_OSX_SYSROOT}/System/Library/PrivateFrameworks)
     find_library(FRONTBOARD_LIBRARY FrontBoardServices
       PATHS ${CMAKE_OSX_SYSROOT}/System/Library/PrivateFrameworks)
     find_library(SPRINGBOARD_LIBRARY SpringBoardServices
       PATHS ${CMAKE_OSX_SYSROOT}/System/Library/PrivateFrameworks)
add_lldb_tool(debugserver-nonui
     )
 endif()
 
 set(entitlements_xml ${CMAKE_CURRENT_SOURCE_DIR}/debugserver-macosx-entitlements.plist)
 if(IOS)
   set(entitlements_xml ${CMAKE_CURRENT_SOURCE_DIR}/debugserver-entitlements.plist)
 endif()
 
-set(LLDB_CODESIGN_IDENTITY "lldb_codesign"
-  CACHE STRING "Identity used for code signing. Set to empty string to skip the signing step.")
 set(LLDB_USE_ENTITLEMENTS_Default On)
 if("${LLDB_CODESIGN_IDENTITY}" STREQUAL "lldb_codesign")
   set(LLDB_USE_ENTITLEMENTS_Default Off)
 endif()
 option(LLDB_USE_ENTITLEMENTS "Use entitlements when codesigning (Defaults Off when using lldb_codesign identity, otherwise On)" ${LLDB_USE_ENTITLEMENTS_Default})
 
-if ("${LLDB_CODESIGN_IDENTITY}" STREQUAL "")
+if (SKIP_DEBUGSERVER)
   if (CMAKE_HOST_APPLE)
     # If we haven't built a signed debugserver, copy the one from the system.
     add_custom_target(debugserver
       COMMAND ${CMAKE_COMMAND} -E copy_if_different ${DEBUGSERVER_PATH} ${CMAKE_BINARY_DIR}/bin
       VERBATIM
       COMMENT "Copying the system debugserver to LLDB's binaries directory.")
   endif()
 else()