Restore temporary configurations

.github/scripts/strategy-matrix/generate.py

@@ -196,11 +196,22 @@ def generate_strategy_matrix(all: bool, config: Config) -> list:
         # Enable code coverage for Debian Bookworm using GCC 15 in Debug on
         # linux/amd64
         if (
-            f"{os['compiler_name']}-{os['compiler_version']}" == "gcc-15"
+            f"{os['distro_name']}-{os['distro_version']}" == "debian-bookworm"
+            and f"{os['compiler_name']}-{os['compiler_version']}" == "gcc-15"
             and build_type == "Debug"
             and architecture["platform"] == "linux/amd64"
         ):
-            cmake_args = f"-Dcoverage=ON -Dcoverage_format=xml -DCODE_COVERAGE_VERBOSE=ON -DCMAKE_C_FLAGS=-O0 -DCMAKE_CXX_FLAGS=-O0 {cmake_args}"
+            cmake_args = f"{cmake_args} -Dcoverage=ON -Dcoverage_format=xml -DCODE_COVERAGE_VERBOSE=ON -DCMAKE_C_FLAGS=-O0 -DCMAKE_CXX_FLAGS=-O0"
+
+        # Enable unity build for Ubuntu Jammy using GCC 12 in Debug on
+        # linux/amd64.
+        if (
+            f"{os['distro_name']}-{os['distro_version']}" == "ubuntu-jammy"
+            and f"{os['compiler_name']}-{os['compiler_version']}" == "gcc-12"
+            and build_type == "Debug"
+            and architecture["platform"] == "linux/amd64"
+        ):
+            cmake_args = f"{cmake_args} -Dunity=ON"
 
         # Generate a unique name for the configuration, e.g. macos-arm64-debug
         # or debian-bookworm-gcc-12-amd64-release.
@@ -217,6 +228,8 @@ def generate_strategy_matrix(all: bool, config: Config) -> list:
         config_name += f"-{build_type.lower()}"
         if "-Dcoverage=ON" in cmake_args:
             config_name += "-coverage"
+        if "-Dunity=ON" in cmake_args:
+            config_name += "-unity"
 
         # Add the configuration to the list, with the most unique fields first,
         # so that they are easier to identify in the GitHub Actions UI, as long

BUILD.md

@@ -575,10 +575,16 @@ See [Sanitizers docs](./docs/build/sanitizers.md) for more details.
 | `assert`   | OFF           | Enable assertions.                                             |
 | `coverage` | OFF           | Prepare the coverage report.                                   |
 | `tests`    | OFF           | Build tests.                                                   |
+| `unity`    | OFF           | Configure a unity build.                                       |
 | `xrpld`    | OFF           | Build the xrpld application, and not just the libxrpl library. |
 | `werr`     | OFF           | Treat compilation warnings as errors                           |
 | `wextra`   | OFF           | Enable additional compilation warnings                         |
 
+[Unity builds][5] may be faster for the first build (at the cost of much more
+memory) since they concatenate sources into fewer translation units. Non-unity
+builds may be faster for incremental builds, and can be helpful for detecting
+`#include` omissions.
+
 ## Troubleshooting
 
 ### Conan
@@ -645,6 +651,7 @@ If you want to experiment with a new package, follow these steps:
 [1]: https://github.com/conan-io/conan-center-index/issues/13168
 [2]: https://en.cppreference.com/w/cpp/compiler_support/20
 [3]: https://docs.conan.io/en/latest/getting_started.html
+[5]: https://en.wikipedia.org/wiki/Unity_build
 [6]: https://github.com/boostorg/beast/issues/2648
 [7]: https://github.com/boostorg/beast/issues/2661
 [gcovr]: https://gcovr.com/en/stable/getting-started.html

cmake/XrplAddTest.cmake

@@ -9,5 +9,9 @@ function (xrpl_add_test name)
 
     isolate_headers(${target} "${CMAKE_SOURCE_DIR}" "${CMAKE_SOURCE_DIR}/tests/${name}" PRIVATE)
 
+    # Disable unity build for the test target to avoid potential conflicts
+    # between test source files.
+    set_target_properties(${target} PROPERTIES UNITY_BUILD_MODE GROUP UNITY_BUILD_BATCH_SIZE 0)
+
     add_test(NAME ${target} COMMAND ${target})
 endfunction ()

cmake/XrplCore.cmake

@@ -4,7 +4,12 @@
 
 include(target_protobuf_sources)
 
+# Protocol buffers cannot participate in a unity build,
+# because all the generated sources
+# define a bunch of `static const` variables with the same names,
+# so we just build them as a separate library.
 add_library(xrpl.libpb)
+set_target_properties(xrpl.libpb PROPERTIES UNITY_BUILD OFF)
 target_protobuf_sources(xrpl.libpb xrpl/proto LANGUAGE cpp IMPORT_DIRS include/xrpl/proto
                         PROTOS include/xrpl/proto/xrpl.proto)
 

cmake/XrplSettings.cmake

@@ -30,6 +30,14 @@ if (tests)
     endif ()
 endif ()
 
+option(unity "Creates a build using UNITY support in cmake." OFF)
+if (unity)
+    if (NOT is_ci)
+        set(CMAKE_UNITY_BUILD_BATCH_SIZE 15 CACHE STRING "")
+    endif ()
+    set(CMAKE_UNITY_BUILD ON CACHE BOOL "Do a unity build")
+endif ()
+
 if (is_clang AND is_linux)
     option(voidstar "Enable Antithesis instrumentation." OFF)
 endif ()

conanfile.py

@@ -23,6 +23,7 @@ class Xrpl(ConanFile):
         "shared": [True, False],
         "static": [True, False],
         "tests": [True, False],
+        "unity": [True, False],
         "xrpld": [True, False],
     }
 
@@ -54,6 +55,7 @@ class Xrpl(ConanFile):
         "shared": False,
         "static": True,
         "tests": False,
+        "unity": False,
         "xrpld": False,
         "date/*:header_only": True,
         "ed25519/*:shared": False,
@@ -166,6 +168,7 @@ class Xrpl(ConanFile):
         tc.variables["rocksdb"] = self.options.rocksdb
         tc.variables["BUILD_SHARED_LIBS"] = self.options.shared
         tc.variables["static"] = self.options.static
+        tc.variables["unity"] = self.options.unity
         tc.variables["xrpld"] = self.options.xrpld
         tc.generate()
 

src/libxrpl/net/RegisterSSLCerts.cpp

@@ -85,8 +85,7 @@ registerSSLCerts(boost::asio::ssl::context& ctx, boost::system::error_code& ec,
 // There is a very unpleasant interaction between <wincrypt> and
 // openssl x509 types (namely the former has macros that stomp
 // on the latter), these undefs allow this TU to be safely used in
-// unity builds without messing up subsequent TUs. Although we
-// no longer use unity builds, leaving the undefs here does no harm.
+// unity builds without messing up subsequent TUs.
 #if BOOST_OS_WINDOWS
 #undef X509_NAME
 #undef X509_EXTENSIONS