[Lldb-commits] [PATCH] D64823: [CMake] Default LLDB_PATH_TO_LLVM_BUILD to LLVM_DIR

[Jonas Devlieghere via Phabricator via lldb-commits]

JDevlieghere created this revision.
JDevlieghere added reviewers: sgraenitz, mgorny, xiaobai.
Herald added a subscriber: abidh.
Herald added a project: LLDB.

When doing a standalone build, without setting `LLDB_PATH_TO_LLVM_BUILD` or `LLDB_PATH_TO_CLANG_BUILD`, you get the following error.

  CMake Error at cmake/modules/LLDBStandalone.cmake:23 (find_package):
    Could not find a package configuration file provided by "LLVM" with any of
    the following names:
  
      LLVMConfig.cmake
      llvm-config.cmake
  
    Add the installation prefix of "LLVM" to CMAKE_PREFIX_PATH or set
    "LLVM_DIR" to a directory containing one of the above files.  If "LLVM"
    provides a separate development package or SDK, be sure it has been
    installed.

This suggests setting `LLVM_DIR` to LLVM's install directory. However, LLDBStandalone.cmake takes `LLDB_PATH_TO_LLVM_BUILD` as its hint. As someone who isn't familiar with the standalone process, this is rather confusing. I assume there's good reason to use a separate variable here, so I didn't want to change that. Instead, I propose using `LLVM_DIR` as the default for `LLDB_PATH_TO_LLVM_BUILD`. That way, passing `-DLLVM_DIR=/path/to/llvm` is sufficient to get the standalone build working.


Repository:
  rLLDB LLDB

https://reviews.llvm.org/D64823

Files:
  lldb/cmake/modules/LLDBStandalone.cmake


Index: lldb/cmake/modules/LLDBStandalone.cmake
===================================================================
--- lldb/cmake/modules/LLDBStandalone.cmake
+++ lldb/cmake/modules/LLDBStandalone.cmake
@@ -14,7 +14,7 @@
 
   option(LLVM_INSTALL_TOOLCHAIN_ONLY "Only include toolchain files in the 'install' target." OFF)
 
-  set(LLDB_PATH_TO_LLVM_BUILD "" CACHE PATH "Path to LLVM build tree")
+  set(LLDB_PATH_TO_LLVM_BUILD "${LLVM_DIR}" CACHE PATH "Path to LLVM build tree")
   set(LLDB_PATH_TO_CLANG_BUILD "${LLDB_PATH_TO_LLVM_BUILD}" CACHE PATH "Path to Clang build tree")
 
   file(TO_CMAKE_PATH "${LLDB_PATH_TO_LLVM_BUILD}" LLDB_PATH_TO_LLVM_BUILD)


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