[clangd] Fix build failures observed on build bots for missing libs

[saghir]

Summary

This was broken by 56ac9d46a7c1468d587ccec02a781e52d0bb298a.
There were some changes made to fix it in
a20d57e83441a69fa2bab86593b18cc0402095d2, but that did not quite
fix everything.

[saghir]

This is to fix failures in the build bot: https://lab.llvm.org/buildbot/#/builders/57/builds/28356

[saghir]

@mstorsjo @ivanmurashko Can you please take a look at this? This is blocking our builds on the PowerPC buildbots. Thanks a lot for your time!

[nemanjai]

Lets get this committed to unblock the bots and if it is not the correct/desired fix, the author can subsequently provide the more appropriate fix.

[mstorsjo]

To clarify the issue - the kind of builds that seems to be broken is builds with BUILD_SHARED_LIBS=ON. The reason is that these libraries are needed is because the clangd target includes $<TARGET_OBJECTS:obj.clangDaemonTweaks>, so all the dependencies of clangDaemonTweaks would need to be included here as well. Please include that in the commit message description. (Is there a way to pull in those instead of duplicating the list?)

This looks mostly ok to me, but it does add slightly more libraries than what's needed. As the list of libraries that now are linked into clangdMain is the list of libraries that previously was linked for the two components that now are clangd and clangdMain, so some of the dependencies only need to be moved, not duplicated.

A more minimal set of dependencies, which seems to link successfully with BUILD_SHARED_LIBS=ON, is achieved with this diff on top of current git main:

diff --git a/clang-tools-extra/clangd/tool/CMakeLists.txt b/clang-tools-extra/clangd/tool/CMakeLists.txt
index ddf9c2488819..6c21175d7687 100644
--- a/clang-tools-extra/clangd/tool/CMakeLists.txt
+++ b/clang-tools-extra/clangd/tool/CMakeLists.txt
@@ -26,11 +26,7 @@ clang_target_link_libraries(clangdMain
   clangBasic
   clangFormat
   clangFrontend
-  clangLex
-  clangSema
   clangTooling
-  clangToolingCore
-  clangToolingRefactoring
   clangToolingSyntax
   )
 
@@ -44,7 +40,20 @@ target_link_libraries(clangdMain
   ${CLANGD_XPC_LIBS}
   )
 
+clang_target_link_libraries(clangd
+  PRIVATE
+  clangAST
+  clangBasic
+  clangLex
+  clangSema
+  clangToolingCore
+  clangToolingRefactoring
+  clangToolingSyntax
+  )
+
 target_link_libraries(clangd
   PRIVATE
   clangdMain
+  clangDaemon
+  clangdSupport
   )

Not sure if it's good hygiene to only link specifically to exactly those libraries that are needed and nothing else, or if it's just making things slightly more brittle?

[saghir]

In D155111#4495131, @mstorsjo wrote:

To clarify the issue - the kind of builds that seems to be broken is builds with BUILD_SHARED_LIBS=ON. The reason is that these libraries are needed is because the clangd target includes $<TARGET_OBJECTS:obj.clangDaemonTweaks>, so all the dependencies of clangDaemonTweaks would need to be included here as well. Please include that in the commit message description. (Is there a way to pull in those instead of duplicating the list?)

This looks mostly ok to me, but it does add slightly more libraries than what's needed. As the list of libraries that now are linked into clangdMain is the list of libraries that previously was linked for the two components that now are clangd and clangdMain, so some of the dependencies only need to be moved, not duplicated.

A more minimal set of dependencies, which seems to link successfully with BUILD_SHARED_LIBS=ON, is achieved with this diff on top of current git main:

diff --git a/clang-tools-extra/clangd/tool/CMakeLists.txt b/clang-tools-extra/clangd/tool/CMakeLists.txt
index ddf9c2488819..6c21175d7687 100644
--- a/clang-tools-extra/clangd/tool/CMakeLists.txt
+++ b/clang-tools-extra/clangd/tool/CMakeLists.txt
@@ -26,11 +26,7 @@ clang_target_link_libraries(clangdMain
   clangBasic
   clangFormat
   clangFrontend
-  clangLex
-  clangSema
   clangTooling
-  clangToolingCore
-  clangToolingRefactoring
   clangToolingSyntax
   )
 
@@ -44,7 +40,20 @@ target_link_libraries(clangdMain
   ${CLANGD_XPC_LIBS}
   )
 
+clang_target_link_libraries(clangd
+  PRIVATE
+  clangAST
+  clangBasic
+  clangLex
+  clangSema
+  clangToolingCore
+  clangToolingRefactoring
+  clangToolingSyntax
+  )
+
 target_link_libraries(clangd
   PRIVATE
   clangdMain
+  clangDaemon
+  clangdSupport
   )

Not sure if it's good hygiene to only link specifically to exactly those libraries that are needed and nothing else, or if it's just making things slightly more brittle?

Thanks for reviewing and providing suggestions. I have put up a follow up patch for review: https://reviews.llvm.org/D155540

clang-tools-extra/clangd/tool/CMakeLists.txt

target_link_libraries(clangdMain
   clangTidy
 
   clangDaemon
   clangdRemoteIndex
   clangdSupport
   ${CLANGD_XPC_LIBS}
   )
 
+clang_target_link_libraries(clangd
+  PRIVATE
+  clangAST
+  clangBasic
+  clangFormat
+  clangFrontend
+  clangLex
+  clangSema
+  clangTooling
+  clangToolingCore
+  clangToolingRefactoring
+  clangToolingSyntax
+  )
+
 target_link_libraries(clangd
   PRIVATE
   clangdMain
+  clangDaemon
+  clangdSupport
   )