[clang-tools-extra] clangd: Add a build option to disable building dexp (PR #133124)

[Yoann Congal via cfe-commits]

https://github.com/ycongal-smile updated https://github.com/llvm/llvm-project/pull/133124

>From 895bf3da0236bc6bf9f814ab3e00d1a4f52a9397 Mon Sep 17 00:00:00 2001
From: Yoann Congal <yoann.congal at smile.fr>
Date: Tue, 25 Mar 2025 22:25:55 +0100
Subject: [PATCH] clangd: Add a build option to disable building dexp

Building dexp on Debian 11 currently causes intermittent failure[0][1].

Adding the CLANGD_BUILD_DEXP option to disable dexp from the build
allows Debian 11 users to build clang (albeit without the dexp tool).

This option is set to "Build Dexp" by default so, no change is expected
without manual setting.

[0]: https://bugzilla.yoctoproject.org/show_bug.cgi?id=15803
[1]: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1101322
---
 clang-tools-extra/clangd/CMakeLists.txt          | 8 +++++++-
 clang-tools-extra/clangd/test/CMakeLists.txt     | 7 +++++--
 clang-tools-extra/clangd/test/lit.site.cfg.py.in | 1 +
 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/clang-tools-extra/clangd/CMakeLists.txt b/clang-tools-extra/clangd/CMakeLists.txt
index 6f10afe4a5625..a1e9da41b4b32 100644
--- a/clang-tools-extra/clangd/CMakeLists.txt
+++ b/clang-tools-extra/clangd/CMakeLists.txt
@@ -210,6 +210,9 @@ if (CLANGD_ENABLE_REMOTE)
   include(AddGRPC)
 endif()
 
+option(CLANGD_BUILD_DEXP "Build the dexp tool as part of Clangd" ON)
+llvm_canonicalize_cmake_booleans(CLANGD_BUILD_DEXP)
+
 if(CLANG_INCLUDE_TESTS)
   add_subdirectory(test)
   add_subdirectory(unittests)
@@ -220,4 +223,7 @@ option(CLANGD_ENABLE_REMOTE "Use gRPC library to enable remote index support for
 set(GRPC_INSTALL_PATH "" CACHE PATH "Path to gRPC library manual installation.")
 
 add_subdirectory(index/remote)
-add_subdirectory(index/dex/dexp)
+
+if(CLANGD_BUILD_DEXP)
+  add_subdirectory(index/dex/dexp)
+endif()
diff --git a/clang-tools-extra/clangd/test/CMakeLists.txt b/clang-tools-extra/clangd/test/CMakeLists.txt
index b51f461a49866..42fc3506641f2 100644
--- a/clang-tools-extra/clangd/test/CMakeLists.txt
+++ b/clang-tools-extra/clangd/test/CMakeLists.txt
@@ -3,8 +3,6 @@ set(CLANGD_TEST_DEPS
   ClangdTests
   clangd-indexer
   split-file
-  # No tests for it, but we should still make sure they build.
-  dexp
   )
 
 if(CLANGD_BUILD_XPC)
@@ -12,6 +10,11 @@ if(CLANGD_BUILD_XPC)
   list(APPEND CLANGD_TEST_DEPS ClangdXpcUnitTests)
 endif()
 
+if(CLANGD_BUILD_DEXP)
+  # No tests for it, but we should still make sure they build.
+  list(APPEND CLANGD_TEST_DEPS dexp)
+endif()
+
 if(CLANGD_ENABLE_REMOTE)
   list(APPEND CLANGD_TEST_DEPS clangd-index-server clangd-index-server-monitor)
 endif()
diff --git a/clang-tools-extra/clangd/test/lit.site.cfg.py.in b/clang-tools-extra/clangd/test/lit.site.cfg.py.in
index 1fe7c8d0f3244..a0bb3561e19ee 100644
--- a/clang-tools-extra/clangd/test/lit.site.cfg.py.in
+++ b/clang-tools-extra/clangd/test/lit.site.cfg.py.in
@@ -15,6 +15,7 @@ config.llvm_shlib_dir = "@SHLIBDIR@"
 config.clangd_source_dir = "@CMAKE_CURRENT_SOURCE_DIR@/.."
 config.clangd_binary_dir = "@CMAKE_CURRENT_BINARY_DIR@/.."
 config.clangd_build_xpc = @CLANGD_BUILD_XPC@
+config.clangd_build_dexp = @CLANGD_BUILD_DEXP@
 config.clangd_enable_remote = @CLANGD_ENABLE_REMOTE@
 config.clangd_tidy_checks = @CLANGD_TIDY_CHECKS@
 config.have_zlib = @LLVM_ENABLE_ZLIB@