[flang-commits] [flang] 083c683 - [flang] Add FLANG_PARALLEL_COMPILE_JOBS option (#95672)

[via flang-commits]

Author: Tom Stellard
Date: 2024-06-18T08:26:11-07:00
New Revision: 083c683969b2436afdc45becadc955841f5f4d31

URL: https://github.com/llvm/llvm-project/commit/083c683969b2436afdc45becadc955841f5f4d31
DIFF: https://github.com/llvm/llvm-project/commit/083c683969b2436afdc45becadc955841f5f4d31.diff

LOG: [flang] Add FLANG_PARALLEL_COMPILE_JOBS option (#95672)

This works the same way as LLVM_PARALLEL_COMPILE_JOBS except that it is
specific to the flang source rather than for the whole project.

Configuring with -DFLANG_PARALLEL_COMPILE_JOBS=1 would mean that there
would only ever be one flang source being compiled at a time.

Some of the flang sources require large amounts of memory to compile, so
this option can be used to avoid OOM erros when compiling those files
while still allowing the rest of the project to compile using the
maximum number of jobs.

---------

Co-authored-by: Nikita Popov <github at npopov.com>

Added: 
    

Modified: 
    flang/CMakeLists.txt
    flang/cmake/modules/AddFlang.cmake

Removed: 
    


################################################################################
diff  --git a/flang/CMakeLists.txt b/flang/CMakeLists.txt
index cbe8f1186236a..75db5b93d4dbe 100644
--- a/flang/CMakeLists.txt
+++ b/flang/CMakeLists.txt
@@ -445,6 +445,18 @@ if (APPLE)
   endif()
 endif()
 
+# Set up job pools for flang.  Some of the flang sources take a lot of memory to
+# compile, so allow users to limit the number of parallel flang jobs.  This is
+# useful for building flang alongside several other projects since you can use
+# the maximum number of build jobs for the other projects while limiting the
+# number of flang compile jobs.
+#
+# We want this set to infinity by default
+set(FLANG_PARALLEL_COMPILE_JOBS 0 CACHE STRING
+  "The maximum number of concurrent compilation jobs (Ninja only)")
+
+set_property(GLOBAL APPEND PROPERTY JOB_POOLS flang_compile_job_pool=${FLANG_PARALLEL_COMPILE_JOBS})
+
 include(CMakeParseArguments)
 include(AddFlang)
 

diff  --git a/flang/cmake/modules/AddFlang.cmake b/flang/cmake/modules/AddFlang.cmake
index 3a5119b83831f..c4b957324ea1c 100644
--- a/flang/cmake/modules/AddFlang.cmake
+++ b/flang/cmake/modules/AddFlang.cmake
@@ -89,6 +89,7 @@ function(add_flang_library name)
       set_property(GLOBAL APPEND PROPERTY FLANG_LIBS ${name})
     endif()
     set_property(GLOBAL APPEND PROPERTY FLANG_EXPORTS ${name})
+    set_property(TARGET obj.${name} PROPERTY JOB_POOL_COMPILE flang_compile_job_pool)
   else()
     # Add empty "phony" target
     add_custom_target(${name})