[llvm] [llvm][cmake] Error if lldb project is enabled without clang (PR #149055)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-lldb

Author: David Spickett (DavidSpickett)

<details>
<summary>Changes</summary>

Fixes https://github.com/llvm/llvm-project/issues/54555

We could do what flang does and enable clang automatically, but I personally prefer making the user make the choice.

Also from a buld requirements perspective, flang is a bigger build than clang. So if you're already set on building flang, clang should be within your budget too. lldb is smaller than clang.

---
Full diff: https://github.com/llvm/llvm-project/pull/149055.diff


1 Files Affected:

- (modified) llvm/CMakeLists.txt (+6) 


``````````diff
diff --git a/llvm/CMakeLists.txt b/llvm/CMakeLists.txt
index 3f8201fa426fe..bf52533abe525 100644
--- a/llvm/CMakeLists.txt
+++ b/llvm/CMakeLists.txt
@@ -179,6 +179,12 @@ if ("flang" IN_LIST LLVM_ENABLE_PROJECTS)
   endif ()
 endif()
 
+if ("lldb" IN_LIST LLVM_ENABLE_PROJECTS)
+  if (NOT "clang" IN_LIST LLVM_ENABLE_PROJECTS)
+    message(FATAL_ERROR "Clang is not enabled, but is required for lldb.")
+  endif ()
+endif ()
+
 if ("libc" IN_LIST LLVM_ENABLE_PROJECTS)
   message(WARNING "Using LLVM_ENABLE_PROJECTS=libc is deprecated.  Please use "
     "-DLLVM_ENABLE_RUNTIMES=libc or see the instructions at "

``````````

</details>


https://github.com/llvm/llvm-project/pull/149055