[CMake] Add error to clarify that lldb requires libcxx
Summary:
This adds a specific error message to clarify that lldb requires libcxx when
built together with clang on macOS. In addition, the lldb building docs are also
updated.
Fixes https://bugs.llvm.org/show_bug.cgi?id=41866
Reviewers: sgraenitz, JDevlieghere, EricWF
Reviewed By: sgraenitz
Subscribers: mgorny, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D61877
llvm-svn: 360756
diff --git a/lldb/CMakeLists.txt b/lldb/CMakeLists.txt
index 64807da..af7c312 100644
--- a/lldb/CMakeLists.txt
+++ b/lldb/CMakeLists.txt
@@ -124,6 +124,24 @@
message(WARNING "LLDB test suite requires libc++ in llvm/projects/libcxx or an existing build symlinked to ${cxx_dir}")
endif()
else()
+ # We require libcxx for the test suite, so if we aren't building it,
+ # try to provide a helpful error about how to resolve the situation.
+ if(NOT TARGET cxx)
+ if(LLVM_ENABLE_PROJECTS STREQUAL "")
+ # If `LLVM_ENABLE_PROJECTS` is not being used (implying that we are
+ # using the old layout), suggest checking it out.
+ message(FATAL_ERROR
+ "LLDB test suite requires libc++, but it is currently disabled. "
+ "Please checkout `libcxx` in `llvm/projects` or disable tests "
+ "via `LLDB_INCLUDE_TESTS=OFF`.")
+ else()
+ # If `LLVM_ENABLE_PROJECTS` is being used, suggest adding it.
+ message(FATAL_ERROR
+ "LLDB test suite requires libc++, but it is currently disabled. "
+ "Please add `libcxx` to `LLVM_ENABLE_PROJECTS` or disable tests "
+ "via `LLDB_INCLUDE_TESTS=OFF`.")
+ endif()
+ endif()
list(APPEND LLDB_TEST_DEPS cxx)
endif()
endif()
diff --git a/lldb/docs/resources/build.rst b/lldb/docs/resources/build.rst
index e8d99f7..4c8d242 100644
--- a/lldb/docs/resources/build.rst
+++ b/lldb/docs/resources/build.rst
@@ -151,6 +151,12 @@
LLVM, then you can pass LLVM-specific CMake variables to cmake when building
LLDB.
+If you are building both Clang and LLDB together, be sure to also add libc++,
+which is currently required for testing on macOS:
+
+::
+
+ > cmake -D LLVM_ENABLE_PROJECTS='clang;lldb;libcxx' $PATH_TO_LLVM -G Ninja
Here are some commonly used LLDB-specific CMake variables:
