From 12fa9511b5fba18e83f88b7b831906595bcf2116 Mon Sep 17 00:00:00 2001
From: Cory Fields <cory-nospam-@coryfields.com>
Date: Mon, 16 Sep 2024 17:43:49 +0000
Subject: [PATCH] build: simplify dependency graph

Allow the objects of static libs to be built in parallel rather than serially
based on their dependency ordering.

For more detail, see:
https://cmake.org/cmake/help/latest/prop_tgt/OPTIMIZE_DEPENDENCIES.html
---
 CMakeLists.txt          | 7 +++++++
 cmake/minisketch.cmake  | 3 +++
 src/util/CMakeLists.txt | 3 +++
 3 files changed, 13 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index b002641415..edfb63926a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -71,6 +71,13 @@ set(CMAKE_CXX_EXTENSIONS OFF)
 
 list(APPEND CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/cmake/module)
 
+# Flatten static lib dependencies.
+# Without this, if libfoo.a depends on libbar.a, libfoo's objects can't begin
+# to be compiled until libbar.a has been created.
+if (NOT DEFINED CMAKE_OPTIMIZE_DEPENDENCIES)
+  set(CMAKE_OPTIMIZE_DEPENDENCIES TRUE)
+endif()
+
 #=============================
 # Configurable options
 #=============================
diff --git a/cmake/minisketch.cmake b/cmake/minisketch.cmake
index bb93c80467..7407739ed9 100644
--- a/cmake/minisketch.cmake
+++ b/cmake/minisketch.cmake
@@ -74,6 +74,9 @@ add_library(minisketch STATIC EXCLUDE_FROM_ALL
   ${PROJECT_SOURCE_DIR}/src/minisketch/src/fields/generic_8bytes.cpp
 )
 
+# Workaround for https://gitlab.kitware.com/cmake/cmake/-/issues/24058
+set_target_properties(minisketch PROPERTIES OPTIMIZE_DEPENDENCIES OFF)
+
 target_include_directories(minisketch
   PUBLIC
     $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/src/minisketch/include>
diff --git a/src/util/CMakeLists.txt b/src/util/CMakeLists.txt
index 4999dbf13f..9ca26a9e27 100644
--- a/src/util/CMakeLists.txt
+++ b/src/util/CMakeLists.txt
@@ -36,6 +36,9 @@ add_library(bitcoin_util STATIC EXCLUDE_FROM_ALL
   ../sync.cpp
 )
 
+# Workaround for https://gitlab.kitware.com/cmake/cmake/-/issues/24058
+set_target_properties(bitcoin_util PROPERTIES OPTIMIZE_DEPENDENCIES OFF)
+
 target_link_libraries(bitcoin_util
   PRIVATE
     core_interface