[llvm] Guard cmake JOB_POOL property against duplicate entries if … (PR #169052)

[Jonas Rickert via llvm-commits]

https://github.com/jorickert created https://github.com/llvm/llvm-project/pull/169052

…  HandleLLVMOptions gets included multiple times.

Otherwise including HandleLLVMOptions  multiple times and setting -DLLVM_PARALLEL_LINK_JOBS=SOME_NUMBER leads to the following ninja error : `duplicate pool 'link_job_pool'`

>From 00c388f177f233ed397f6d1373e3a381155f68b9 Mon Sep 17 00:00:00 2001
From: "Rickert, Jonas" <Jonas.Rickert at amd.com>
Date: Fri, 21 Nov 2025 14:45:24 +0000
Subject: [PATCH] Guard cmake JOB_POOL property against duplicate entries if
 HandleLLVMOptions gets included multiple times

Signed-off-by: Rickert, Jonas <Jonas.Rickert at amd.com>
---
 llvm/cmake/modules/HandleLLVMOptions.cmake | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/llvm/cmake/modules/HandleLLVMOptions.cmake b/llvm/cmake/modules/HandleLLVMOptions.cmake
index 2d78626d953c9..a9b394292eab2 100644
--- a/llvm/cmake/modules/HandleLLVMOptions.cmake
+++ b/llvm/cmake/modules/HandleLLVMOptions.cmake
@@ -57,7 +57,10 @@ if(LLVM_PARALLEL_COMPILE_JOBS)
   if(NOT CMAKE_GENERATOR MATCHES "Ninja")
     message(WARNING "Job pooling is only available with Ninja generators.")
   else()
-    set_property(GLOBAL APPEND PROPERTY JOB_POOLS compile_job_pool=${LLVM_PARALLEL_COMPILE_JOBS})
+    get_property(_existing_compile_job_pool GLOBAL PROPERTY JOB_POOLS)
+    if(NOT _existing_compile_job_pool MATCHES "compile_job_pool=")
+      set_property(GLOBAL APPEND PROPERTY JOB_POOLS compile_job_pool=${LLVM_PARALLEL_COMPILE_JOBS})
+    endif()
     set(CMAKE_JOB_POOL_COMPILE compile_job_pool)
   endif()
 endif()
@@ -81,7 +84,10 @@ if(CMAKE_GENERATOR MATCHES "Ninja")
     set(LLVM_PARALLEL_LINK_JOBS "2")
   endif()
   if(LLVM_PARALLEL_LINK_JOBS)
-    set_property(GLOBAL APPEND PROPERTY JOB_POOLS link_job_pool=${LLVM_PARALLEL_LINK_JOBS})
+    get_property(_existing_job_pools GLOBAL PROPERTY JOB_POOLS)
+    if(NOT _existing_job_pools MATCHES "link_job_pool=")
+      set_property(GLOBAL APPEND PROPERTY JOB_POOLS link_job_pool=${LLVM_PARALLEL_LINK_JOBS})
+    endif()
     set(CMAKE_JOB_POOL_LINK link_job_pool)
   endif()
 elseif(LLVM_PARALLEL_LINK_JOBS)
@@ -105,7 +111,10 @@ if(LLVM_PARALLEL_TABLEGEN_JOBS)
   if(NOT CMAKE_GENERATOR MATCHES "Ninja")
     message(WARNING "Job pooling is only available with Ninja generators.")
   else()
-    set_property(GLOBAL APPEND PROPERTY JOB_POOLS tablegen_job_pool=${LLVM_PARALLEL_TABLEGEN_JOBS})
+    get_property(_existing_tablegen_job_pool GLOBAL PROPERTY JOB_POOLS)
+    if(NOT _existing_tablegen_job_pool MATCHES "tablegen_job_pool=")
+      set_property(GLOBAL APPEND PROPERTY JOB_POOLS tablegen_job_pool=${LLVM_PARALLEL_TABLEGEN_JOBS})
+    endif()
     # Job pool for tablegen is set on the add_custom_command
   endif()
 endif()