2x Compile Speed up

CMakeLists.txt

@@ -1,5 +1,9 @@
 cmake_minimum_required(VERSION 3.13 FATAL_ERROR)
 
+# Make sure that we are using the C++11 ABI, if not then there are some weird
+# inconsistencies with our precompiled headers
+add_compile_definitions(_GLIBCXX_USE_CXX11_ABI=1)
+
 # Disable in-source builds to prevent source tree corruption.
 if(" ${CMAKE_SOURCE_DIR}" STREQUAL " ${CMAKE_BINARY_DIR}")
   message(FATAL_ERROR "
@@ -99,6 +103,12 @@ add_definitions( -DMAGICKCORE_HDRI_ENABLE=0 )
 
 find_package(ImageMagick COMPONENTS Magick++ REQUIRED)
 # =============================
+# Build speed up 
+
+# function to enable unity build for a target
+function(set_unity_for_target target_name)
+  set_target_properties(${target_name} PROPERTIES UNITY_BUILD ON UNITY_BUILD_MODE BATCH UNITY_BUILD_BATCH_SIZE 16 UNITY_BUILD_UNIQUE_ID "MY_UNITY_ID")
+endfunction()
 
 # =============================
 # obcpp library & executable

include/stdafx.h

@@ -0,0 +1,15 @@
+#ifndef INCLUDE_STDAFX_H_
+#define INCLUDE_STDAFX_H_
+
+// Commonly used header files to be precompiled in order to speed up compilation
+// In reality this doesn't seem to be doing much in speeding it up...
+// Leaving the infrastructure here in case someone is able to figure out a way to
+// make this actually speed up compilation.
+
+#include <vector>
+#include <unordered_map>
+#include <optional>
+#include <memory>
+#include <string>
+
+#endif  // INCLUDE_STDAFX_H_

src/CMakeLists.txt

@@ -1,3 +1,16 @@
+# DONT REMOVE THE DUMMY FILE!!! IT WILL SEEM LIKE IT IS OKAY BUT IT WILL BREAK THE NEXT TIME
+# YOU RECLONE OR RM -RF THE BUILD DIRECTORY!!! DON'T BE A DUMMY!
+add_library(obcpp_protos STATIC 
+    ${PROJECT_SOURCE_DIR}/build/gen_protos/protos/obc.pb.cc 
+    dummy.c
+)
+
+# LOL
+# https://stackoverflow.com/questions/68735830/cmake-precompiled-headers-issue-with-mixed-c-c-project
+target_precompile_headers(obcpp_protos PUBLIC
+    "$<$<COMPILE_LANGUAGE:CXX>:\"stdafx.h\">"
+    "$<$<COMPILE_LANGUAGE:C>:<stddef.h$<ANGLE-R>>")
+
 add_subdirectory(camera)
 add_subdirectory(core)
 add_subdirectory(cv)
@@ -8,6 +21,7 @@ add_subdirectory(utilities)
 
 add_library(obcpp_lib INTERFACE)
 target_link_libraries(obcpp_lib INTERFACE
+    obcpp_protos
     obcpp_camera
     obcpp_core
     obcpp_cv
@@ -20,6 +34,7 @@ target_link_libraries(obcpp_lib INTERFACE
 # for use in unit tests
 add_library(obcpp_lib_mock INTERFACE)
 target_link_libraries(obcpp_lib_mock INTERFACE
+    obcpp_protos
     obcpp_camera
     obcpp_core
     obcpp_cv

src/camera/CMakeLists.txt

@@ -5,10 +5,21 @@ set(FILES
     mock.cpp
 )
 
-add_library(${LIB_NAME} STATIC ${PROJECT_SOURCE_DIR}/build/gen_protos/protos/obc.pb.cc
+SET(LIB_DEPS
+    obcpp_protos
+)
+
+add_library(${LIB_NAME} STATIC
     ${FILES}
 )
 
+target_link_libraries(${LIB_NAME} PRIVATE
+    ${LIB_DEPS}
+)
+
+target_precompile_headers(${LIB_NAME} REUSE_FROM obcpp_protos)
+set_unity_for_target(${LIB_NAME})
+
 target_add_protobuf(${LIB_NAME})
 target_add_torch(${LIB_NAME})
 # target_add_arena(${LIB_NAME}) # Tyler: currently broken, so we had to comment this out

src/core/CMakeLists.txt

@@ -7,6 +7,7 @@ set(FILES
 )
 
 set(LIB_DEPS
+    obcpp_protos
     obcpp_camera
     obcpp_cv
     obcpp_network
@@ -15,14 +16,17 @@ set(LIB_DEPS
     obcpp_utilities
 )
 
-add_library(${LIB_NAME} STATIC ${PROJECT_SOURCE_DIR}/build/gen_protos/protos/obc.pb.cc
+add_library(${LIB_NAME} STATIC
     ${FILES}
 )
 
 target_link_libraries(${LIB_NAME} PRIVATE
     ${LIB_DEPS}
 )
 
+target_precompile_headers(${LIB_NAME} REUSE_FROM obcpp_protos)
+set_unity_for_target(${LIB_NAME})
+
 target_add_protobuf(${LIB_NAME})
 target_add_torch(${LIB_NAME})
 # target_add_arena(${LIB_NAME}) # Tyler: currently broken, so we had to comment this out

src/cv/CMakeLists.txt

@@ -11,14 +11,22 @@ set(FILES
     utilities.cpp
 )
 
-add_library(${LIB_NAME} STATIC ${PROJECT_SOURCE_DIR}/build/gen_protos/protos/obc.pb.cc
+set(LIB_DEPS
+    obcpp_protos
+    obcpp_utilities
+)
+
+add_library(${LIB_NAME} STATIC
     ${FILES}
 )
 
 target_link_libraries(${LIB_NAME} PRIVATE
-    obcpp_utilities
+    ${LIB_DEPS}
 )
 
+target_precompile_headers(${LIB_NAME} REUSE_FROM obcpp_protos)
+set_unity_for_target(${LIB_NAME})
+
 target_add_protobuf(${LIB_NAME})
 target_add_torch(${LIB_NAME})
 # target_add_arena(${LIB_NAME}) # Tyler: currently broken, so we had to comment this out

src/dummy.c

@@ -0,0 +1,25 @@
+/**
+ * Try and remove this. Just try it, dummy.
+ * 
+ * Ok, but seriously. DON'T DELETE THIS FILE. You might think, "there's no fucking way
+ * this file is actually doing anything." And if you were to remove this file and then
+ * remove the reference to it in src/CMakeLists.txt and recompile, it would look like you
+ * were correct! It will be fine!
+ * 
+ * But if you do do this--and I would encourage you to try!--see what happens if you reclone
+ * the repo or rm -rf your build directory. You will get some unholy error message complaining
+ * about some nonexistent file deep in the bowels of the build directory.
+ * Then you'll come crying back to your daddy and begging for a git restore src/dummy.c,
+ * like the dummy you are.
+ * 
+ * Don't be a dummy, and don't delete this file.
+ * 
+ * (for more information, see the stackoverflow post linked in src/CMakeLists.txt)
+ */
+
+int dummy() {
+    int i = 0;
+    ++i;
+    --i;
+    i = 12;
+}

src/network/CMakeLists.txt

@@ -19,20 +19,24 @@ set(MOCK_FILES
 )
 
 set(LIB_DEPS
+    obcpp_protos
     obcpp_utilities
     obcpp_ticks
     obcpp_core
     obcpp_pathing
 )
 
-add_library(${LIB_NAME} STATIC ${PROJECT_SOURCE_DIR}/build/gen_protos/protos/obc.pb.cc
+add_library(${LIB_NAME} STATIC
     ${FILES}
 )
 
 target_link_libraries(${LIB_NAME} PRIVATE
     ${LIB_DEPS}
 )
 
+target_precompile_headers(${LIB_NAME} REUSE_FROM obcpp_protos)
+set_unity_for_target(${LIB_NAME})
+
 target_add_protobuf(${LIB_NAME})
 target_add_torch(${LIB_NAME})
 # target_add_arena(${LIB_NAME}) # Tyler: currently broken, so we had to comment this out
@@ -57,6 +61,9 @@ target_link_libraries(${LIB_NAME} PRIVATE
     ${LIB_DEPS}
 )
 
+target_precompile_headers(${LIB_NAME} REUSE_FROM obcpp_protos)
+set_unity_for_target(${LIB_NAME})
+
 target_add_protobuf(${LIB_NAME})
 target_add_torch(${LIB_NAME})
 # target_add_arena(${LIB_NAME}) # Tyler: currently broken, so we had to comment this out

src/pathing/CMakeLists.txt

@@ -9,17 +9,21 @@ set(FILES
 )
 
 set (LIB_DEPS
+    obcpp_protos
     obcpp_core
     obcpp_network
     obcpp_utilities
 )
 
-add_library(${LIB_NAME} STATIC ${PROJECT_SOURCE_DIR}/build/gen_protos/protos/obc.pb.cc
+add_library(${LIB_NAME} STATIC
     ${FILES}
 )
 
 target_link_libraries(${LIB_NAME} PRIVATE ${LIB_DEPS})
 
+target_precompile_headers(${LIB_NAME} REUSE_FROM obcpp_protos)
+set_unity_for_target(${LIB_NAME})
+
 target_add_protobuf(${LIB_NAME})
 target_add_torch(${LIB_NAME})
 # target_add_arena(${LIB_NAME}) # Tyler: currently broken, so we had to comment this out

src/ticks/CMakeLists.txt

@@ -17,20 +17,24 @@ set(FILES
 )
 
 set(LIB_DEPS
+    obcpp_protos
     obcpp_pathing
     obcpp_utilities
     obcpp_core
     obcpp_network
 )
 
-add_library(${LIB_NAME} STATIC ${PROJECT_SOURCE_DIR}/build/gen_protos/protos/obc.pb.cc
+add_library(${LIB_NAME} STATIC
     ${FILES}
 )
 
 target_link_libraries(${LIB_NAME} PRIVATE
     ${LIB_DEPS}
 )
 
+target_precompile_headers(${LIB_NAME} REUSE_FROM obcpp_protos)
+set_unity_for_target(${LIB_NAME})
+
 target_add_protobuf(${LIB_NAME})
 target_add_torch(${LIB_NAME})
 # target_add_arena(${LIB_NAME}) # Tyler: currently broken, so we had to comment this out

src/utilities/CMakeLists.txt

@@ -8,10 +8,21 @@ SET(FILES
     rng.cpp
 )
 
-add_library(${LIB_NAME} STATIC ${PROJECT_SOURCE_DIR}/build/gen_protos/protos/obc.pb.cc
+SET(LIB_DEPS
+    obcpp_protos
+)
+
+add_library(${LIB_NAME} STATIC
     ${FILES}
 )
 
+target_link_libraries(${LIB_NAME} PRIVATE
+    ${LIB_DEPS}
+)
+
+target_precompile_headers(${LIB_NAME} REUSE_FROM obcpp_protos)
+set_unity_for_target(${LIB_NAME})
+
 target_add_protobuf(${LIB_NAME})
 target_add_torch(${LIB_NAME})
 # target_add_arena(${LIB_NAME}) # Tyler: currently broken, so we had to comment this out