feat: download msgpack (#2885)

Downloads msgpack-c with same content using commit hash, from
https://github.com/AztecProtocol/msgpack-c. As this is not our code (a
few small patches to error-handling aside) and it's somewhat large at
7mb of code, itself bundling dependencies., so it's cleaner to not have
it in tree.

barretenberg/cpp/CMakeLists.txt

@@ -141,6 +141,7 @@ include(cmake/threading.cmake)
 include(cmake/gtest.cmake)
 include(cmake/benchmark.cmake)
 include(cmake/module.cmake)
+include(cmake/msgpack.cmake)
 add_subdirectory(src)
 if (ENABLE_ASAN AND NOT(FUZZING))
     find_program(LLVM_SYMBOLIZER_PATH NAMES llvm-symbolizer-16)

barretenberg/cpp/cmake/module.cmake

@@ -55,6 +55,10 @@ function(barretenberg_module MODULE_NAME)
             ${ARGN}
             ${TBB_IMPORTED_TARGETS}
         )
+
+        # enable msgpack downloading via dependency (solves race condition)
+        add_dependencies(${MODULE_NAME} msgpack-c)
+        add_dependencies(${MODULE_NAME}_objects msgpack-c)
         list(APPEND lib_targets ${MODULE_NAME})
 
         set(MODULE_LINK_NAME ${MODULE_NAME})
@@ -117,6 +121,9 @@ function(barretenberg_module MODULE_NAME)
             ${TBB_IMPORTED_TARGETS}
         )
 
+        # enable msgpack downloading via dependency (solves race condition)
+        add_dependencies(${MODULE_NAME}_test_objects msgpack-c)
+        add_dependencies(${MODULE_NAME}_tests msgpack-c)
         if(NOT WASM AND NOT CI)
             # If collecting coverage data, set profile
             # For some reason processor affinity doesn't work, so the developer has to set it manually anyway
@@ -219,6 +226,9 @@ function(barretenberg_module MODULE_NAME)
             ${TBB_IMPORTED_TARGETS}
         )
 
+        # enable msgpack downloading via dependency (solves race condition)
+        add_dependencies(${MODULE_NAME}_bench_objects msgpack-c)
+        add_dependencies(${MODULE_NAME}_bench msgpack-c)
         add_custom_target(
             run_${MODULE_NAME}_bench
             COMMAND ${MODULE_NAME}_bench

barretenberg/cpp/cmake/msgpack.cmake

@@ -0,0 +1,16 @@
+include(ExternalProject)
+
+# External project: Download msgpack-c from GitHu
+set(MSGPACK_PREFIX "${CMAKE_BINARY_DIR}/_deps/msgpack-c")
+set(MSGPACK_INCLUDE "${MSGPACK_PREFIX}/src/msgpack-c/include")
+
+ExternalProject_Add(
+    msgpack-c
+    PREFIX ${MSGPACK_PREFIX}
+    GIT_REPOSITORY "https://github.com/AztecProtocol/msgpack-c.git"
+    GIT_TAG af447c28f0bafe761290a72754212436e530941b
+    CONFIGURE_COMMAND ""  # No configure step
+    BUILD_COMMAND ""      # No build step
+    INSTALL_COMMAND ""    # No install step
+    UPDATE_COMMAND ""     # No update step
+)

barretenberg/cpp/src/CMakeLists.txt

@@ -37,13 +37,12 @@ if(WASM)
     add_link_options(-Wl,--export-memory,--import-memory,--stack-first,-z,stack-size=1048576,--max-memory=4294967296)
 endif()
 
-include_directories(${CMAKE_CURRENT_SOURCE_DIR} ${CMAKE_CURRENT_SOURCE_DIR}/msgpack-c/include)
-
+include_directories(${CMAKE_CURRENT_SOURCE_DIR} ${MSGPACK_INCLUDE})
 
 # I feel this should be limited to ecc, however it's currently used in headers that go across libraries,
 # and there currently isn't an easy way to inherit the DDISABLE_SHENANIGANS parameter.
 if(DISABLE_ASM)
-    message(STATUS "Using fallback non-assembly methods for field multiplications.")
+    message("Using fallback non-assembly methods for field multiplications.")
     add_definitions(-DDISABLE_SHENANIGANS=1)
 else()
     message(STATUS "Using optimized assembly for field arithmetic.")