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

[Yoann Congal via llvm-commits]

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

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

>From c547879623079717c76222c1cbe2f6c322b76c0b 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                    | 6 +++++-
 clang-tools-extra/clangd/test/CMakeLists.txt               | 7 +++++--
 clang-tools-extra/clangd/test/lit.site.cfg.py.in           | 1 +
 .../gn/secondary/clang-tools-extra/clangd/test/BUILD.gn    | 6 +++++-
 4 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/clang-tools-extra/clangd/CMakeLists.txt b/clang-tools-extra/clangd/CMakeLists.txt
index 6f10afe4a5625..279515d635d38 100644
--- a/clang-tools-extra/clangd/CMakeLists.txt
+++ b/clang-tools-extra/clangd/CMakeLists.txt
@@ -220,4 +220,8 @@ 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)
+
+option(CLANGD_BUILD_DEXP "Build the dexp tool as part of Clangd" ON)
+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@
diff --git a/llvm/utils/gn/secondary/clang-tools-extra/clangd/test/BUILD.gn b/llvm/utils/gn/secondary/clang-tools-extra/clangd/test/BUILD.gn
index 9d42409f1973f..8bfcb1282f0e5 100644
--- a/llvm/utils/gn/secondary/clang-tools-extra/clangd/test/BUILD.gn
+++ b/llvm/utils/gn/secondary/clang-tools-extra/clangd/test/BUILD.gn
@@ -77,7 +77,6 @@ group("test") {
   deps = [
     ":lit_site_cfg",
     ":lit_unit_site_cfg",
-    "//clang-tools-extra/clangd/index/dex/dexp",
     "//clang-tools-extra/clangd/indexer:clangd-indexer",
     "//clang-tools-extra/clangd/tool:clangd",
     "//clang-tools-extra/clangd/unittests:ClangdTests",
@@ -92,6 +91,11 @@ group("test") {
       "//clang-tools-extra/clangd/xpc/test-client:clangd-xpc-test-client",
     ]
   }
+  if (clangd_build_dexp) {
+    deps += [
+      "//clang-tools-extra/clangd/index/dex/dexp",
+    ]
+  }
   testonly = true
 }