Deprecate unified build in favor of unity build.

.github/workflows/ci-p4tools.yml

@@ -20,7 +20,7 @@ jobs:
     env:
       CTEST_PARALLEL_LEVEL: 4
       IMAGE_TYPE: test
-      ENABLE_UNIFIED_COMPILATION: ON
+      CMAKE_UNITY_BUILD: ON
       ENABLE_TEST_TOOLS: ON
     steps:
     - uses: actions/checkout@v3
@@ -30,7 +30,7 @@ jobs:
     - name: ccache
       uses: hendrikmuhs/ccache-action@v1
       with:
-        key: test-tools-${{ matrix.unified }}-${{ runner.os }}
+        key: test-tools-${{ runner.os }}
         max-size: 1000M
 
     - name: Build (Ubuntu 20.04)

.github/workflows/ci-ptf-kernels-weekly.yml

@@ -41,7 +41,6 @@ jobs:
             kernel_version: 5.15.0-48
             os: ubuntu-20.04
     env:
-      UNIFIED: ON
       # Used by virt-builder and virt-install, for valid values see `virt-builder --list`.
       OS_TYPE: ${{ matrix.os }}
       # List of kernels to use in a single job
@@ -78,7 +77,7 @@ jobs:
 
       - name: Build (Linux)
         run: |
-          docker build --network host -t p4c --build-arg MAKEFLAGS=-j8 --build-arg IMAGE_TYPE=test --build-arg ENABLE_UNIFIED_COMPILATION=$UNIFIED --build-arg INSTALL_PTF_EBPF_DEPENDENCIES=ON --build-arg KERNEL_VERSIONS="$KERNEL_VERSIONS" .
+          docker build --network host -t p4c --build-arg MAKEFLAGS=-j8 --build-arg IMAGE_TYPE=test --build-arg CMAKE_UNITY_BUILD=ON --build-arg INSTALL_PTF_EBPF_DEPENDENCIES=ON --build-arg KERNEL_VERSIONS="$KERNEL_VERSIONS" .
           ./tools/export_ccache.sh
 
       - name: Install VM

.github/workflows/ci-ptf.yml

@@ -34,7 +34,7 @@ jobs:
     env:
       CTEST_PARALLEL_LEVEL: 4
       IMAGE_TYPE: test
-      ENABLE_UNIFIED_COMPILATION: ON
+      CMAKE_UNITY_BUILD: ON
       MAKEFLAGS: -j8
       INSTALL_PTF_EBPF_DEPENDENCIES: ON
     steps:

.github/workflows/ci-static-build-test.yml

@@ -20,7 +20,7 @@ jobs:
     runs-on: ubuntu-20.04
     env:
       IMAGE_TYPE: test
-      ENABLE_UNIFIED_COMPILATION: ON
+      CMAKE_UNITY_BUILD: ON
       BUILD_STATIC_RELEASE: ON
     steps:
     - uses: actions/checkout@v3

.github/workflows/ci-test.yml

@@ -20,7 +20,6 @@ jobs:
     env:
       CTEST_PARALLEL_LEVEL: 4
       IMAGE_TYPE: test
-      ENABLE_UNIFIED_COMPILATION: ON
     steps:
     - uses: actions/checkout@v3
       with:
@@ -44,16 +43,16 @@ jobs:
 
   # Build with gcc and test p4c on Ubuntu 20.04.
   test-ubuntu20:
-    name: test-ubuntu20 (Unified ${{ matrix.unified }})
+    name: test-ubuntu20 (Unity ${{ matrix.unity }})
     strategy:
       fail-fast: false
       matrix:
-        unified: [ON, OFF]
+        unity: [ON, OFF]
     runs-on: ubuntu-20.04
     env:
       CTEST_PARALLEL_LEVEL: 4
       IMAGE_TYPE: test
-      ENABLE_UNIFIED_COMPILATION: ${{ matrix.unified }}
+      CMAKE_UNITY_BUILD: ${{ matrix.unity }}
     steps:
     - uses: actions/checkout@v3
       with:
@@ -63,7 +62,7 @@ jobs:
     - name: ccache
       uses: hendrikmuhs/ccache-action@v1
       with:
-        key: test-${{ matrix.unified }}-${{ runner.os }}-gcc
+        key: test-${{ matrix.unity }}-${{ runner.os }}-gcc
         max-size: 1000M
 
     - name: Build (Ubuntu 20.04, GCC)
@@ -74,7 +73,7 @@ jobs:
       # Need to use sudo for the eBPF kernel tests.
       run: sudo -E ctest --output-on-failure --schedule-random
       working-directory: ./build
-      if: matrix.unified == 'ON'
+      if: matrix.unity == 'ON'
 
   # Build with clang and test p4c on Ubuntu 20.04.
   test-ubuntu20-clang-sanitizers:
@@ -84,7 +83,6 @@ jobs:
     env:
       CTEST_PARALLEL_LEVEL: 2
       IMAGE_TYPE: test
-      ENABLE_UNIFIED_COMPILATION: ON
       COMPILE_WITH_CLANG: ON
       BUILD_AUTO_VAR_INIT_PATTERN: ON
       ENABLE_SANITIZERS: ON
@@ -117,7 +115,6 @@ jobs:
     runs-on: ubuntu-latest
     env:
       CTEST_PARALLEL_LEVEL: 4
-      ENABLE_UNIFIED_COMPILATION: ON
     steps:
     - uses: actions/checkout@v3
       with:
@@ -132,7 +129,7 @@ jobs:
 
     - name: Build (Ubuntu 18.04, GCC)
       run: |
-        docker build -t p4c --build-arg BASE_IMAGE=ubuntu:18.04 --build-arg IMAGE_TYPE=test --build-arg ENABLE_UNIFIED_COMPILATION=ON .
+        docker build -t p4c --build-arg BASE_IMAGE=ubuntu:18.04 --build-arg IMAGE_TYPE=test .
         ./tools/export_ccache.sh
 
       # run with sudo (...) --privileged
@@ -172,9 +169,8 @@ jobs:
 
     - name: Build p4c (Fedora Linux)
       run: |
-        ./bootstrap.sh -DCMAKE_BUILD_TYPE=RELEASE -DENABLE_UNIFIED_COMPILATION=ON
-         make -j2 -C build
-
+        ./bootstrap.sh -DCMAKE_BUILD_TYPE=RELEASE -DCMAKE_UNITY_BUILD=ON
+        make -j2 -C build
 
     - name: Run p4c tests (Fedora Linux)
       # Need to use sudo for the eBPF kernel tests.
@@ -213,7 +209,7 @@ jobs:
       run: |
           PROTOBUF=`brew --prefix --installed protobuf`
           ./bootstrap.sh -DENABLE_GC=ON -DCMAKE_BUILD_TYPE=RELEASE \
-              -DENABLE_UNIFIED_COMPILATION=ON \
+              -DCMAKE_UNITY_BUILD=ON \
               -DProtobuf_INCLUDE_DIR=$PROTOBUF/include \
               -DProtobuf_LIBRARY=$PROTOBUF/lib/libprotobuf.dylib \
               -DENABLE_PROTOBUF_STATIC=OFF

.github/workflows/ci-validation.yml

@@ -19,7 +19,6 @@ jobs:
     env:
       CTEST_PARALLEL_LEVEL: 4
       IMAGE_TYPE: test
-      ENABLE_UNIFIED_COMPILATION: ON
       VALIDATION: ON
     runs-on: ubuntu-20.04
     steps:
@@ -38,5 +37,6 @@ jobs:
         tools/ci-build.sh
 
     - name: Validate
-      run: ctest -R toz3-validate-p4c --output-on-failure --schedule-random
+      run: |
+          ctest  -R toz3-validate-p4c --output-on-failure --schedule-random
       working-directory: ./build

CMakeLists.txt

@@ -12,8 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# This is the CMake version supplied by Ubuntu 18.04.
-cmake_minimum_required (VERSION 3.10.2 FATAL_ERROR)
+# This is the CMake version supplied by Ubuntu 20.04.
+cmake_minimum_required (VERSION 3.16.3 FATAL_ERROR)
 
 find_program(CCACHE_PROGRAM ccache)
 if(CCACHE_PROGRAM)
@@ -47,6 +47,8 @@ OPTION (ENABLE_SANITIZERS "Enable sanitizers" OFF)
 OPTION (BUILD_STATIC_RELEASE "Build a statically linked release binary" OFF)
 OPTION (BUILD_AUTO_VAR_INIT_PATTERN "Initialize variables with pattern during build" OFF)
 OPTION (ENABLE_IWYU "Enable checking includes with IWYU" OFF)
+# Support a legacy option. TODO: Remove?
+OPTION (ENABLE_UNIFIED_COMPILATION "Enable CMAKE_UNITY_BUILD" OFF)
 
 set (P4C_DRIVER_NAME "p4c" CACHE STRING "Customize the name of the driver script")
 
@@ -83,13 +85,26 @@ else()
   set (P4C_VERSION "${P4C_SEM_VERSION_STRING} (SHA: ${P4C_GIT_SHA} BUILD: ${CMAKE_BUILD_TYPE})")
 endif()
 include(P4CUtils)
-include(UnifiedBuild)
 
 # # search in /usr/local first
 # set (CMAKE_FIND_ROOT_PATH "/usr/local/bin" "${CMAKE_FIND_ROOT_PATH}")
 set (P4C_CXX_FLAGS "")
 set (P4C_LIB_DEPS)
 
+
+# Support the legacy unified build option.
+if(ENABLE_UNIFIED_COMPILATION)
+  message(
+    WARNING
+      "Using deprecated option \"ENABLE_UNIFIED_COMPILATION\". Please use \"CMAKE_UNITY_BUILD\" instead."
+  )
+  set(CMAKE_UNITY_BUILD ON)
+endif()
+
+# If unity builds are enabled, choose an aggressive batch size.
+if (CMAKE_UNITY_BUILD)
+  set(CMAKE_UNITY_BUILD_BATCH_SIZE 16 CACHE UNINITIALIZED "Set the unity build batch size.")
+endif ()
 # set the required options for a static release build
 if (BUILD_STATIC_RELEASE)
   message(STATUS "Building static release binaries")

Dockerfile

@@ -13,8 +13,8 @@ ARG IN_DOCKER=TRUE
 # testing; in this case, the source code and build-only dependencies will not be
 # removed from the image.
 ARG IMAGE_TYPE=build
-# Whether to do a unified build.
-ARG ENABLE_UNIFIED_COMPILATION=ON
+# Whether to do a unity build.
+ARG CMAKE_UNITY_BUILD=ON
 # Whether to enable translation validation
 ARG VALIDATION=OFF
 # This creates a release build that includes link time optimization and links

README.md

@@ -230,7 +230,7 @@ use them, but YMMV.
 
 - `git` for version control
 
-- CMake 3.10.2 or higher
+- CMake 3.16.3 or higher
 
 - Boehm-Weiser garbage-collector C++ library
 
@@ -283,6 +283,9 @@ Please note that while all Protobuf versions newer than 3.0 should work for
 `p4c` itself, you may run into trouble with some extensions and other p4lang
 projects unless you install version 3.18.1.
 
+### CMake
+p4c requires a CMake version of at least 3.16.3 or higher. On older systems, a newer version of CMake can be installed using `pip3 install --user cmake==3.16.3`. We have a CI test on Ubuntu 18.04 that uses this option, but there is no guarantee that this will lead to a successful build.
+
 ## Fedora dependencies
 
 ```bash

backends/bmv2/CMakeLists.txt

@@ -82,17 +82,14 @@ set (BMV2_BACKEND_COMMON_HDRS
 
 set (IR_DEF_FILES ${IR_DEF_FILES} ${CMAKE_CURRENT_SOURCE_DIR}/bmv2.def PARENT_SCOPE)
 
-build_unified(BMV2_BACKEND_COMMON_SRCS)
 add_library(bmv2backend ${P4C_STATIC_BUILD} ${BMV2_BACKEND_COMMON_SRCS})
 add_dependencies(bmv2backend genIR frontend)
 
-build_unified(BMV2_SIMPLE_SWITCH_SRCS)
 add_executable(p4c-bm2-ss ${BMV2_SIMPLE_SWITCH_SRCS})
 target_link_libraries (p4c-bm2-ss bmv2backend ${P4C_LIBRARIES} ${P4C_LIB_DEPS})
 
 install(TARGETS p4c-bm2-ss RUNTIME DESTINATION ${P4C_RUNTIME_OUTPUT_DIRECTORY})
 
-build_unified(BMV2_PSA_SWITCH_SRCS)
 add_executable(p4c-bm2-psa ${BMV2_PSA_SWITCH_SRCS})
 target_link_libraries (p4c-bm2-psa bmv2backend ${P4C_LIBRARIES} ${P4C_LIB_DEPS})
 install(TARGETS p4c-bm2-psa RUNTIME DESTINATION ${P4C_RUNTIME_OUTPUT_DIRECTORY})

backends/ebpf/CMakeLists.txt

@@ -90,7 +90,6 @@ set (P4C_EBPF_HDRS
 
 set (P4C_EBPF_DIST_HEADERS p4include/ebpf_model.p4)
 
-build_unified(P4C_EBPF_SRCS)
 add_executable(p4c-ebpf ${P4C_EBPF_SRCS})
 target_link_libraries (p4c-ebpf ${P4C_LIBRARIES} ${P4C_LIB_DEPS})
 add_dependencies(p4c-ebpf genIR frontend)

backends/graphs/CMakeLists.txt

@@ -30,7 +30,7 @@ set (GRAPHS_HDRS
   graph_visitor.h
   )
 
-build_unified(GRAPHS_SRCS ALL)
+
 add_executable(p4c-graphs ${GRAPHS_SRCS} ${EXTENSION_P4_14_CONV_SOURCES})
 target_link_libraries (p4c-graphs ${P4C_LIBRARIES} ${P4C_LIB_DEPS})
 add_dependencies(p4c-graphs genIR frontend)

backends/p4test/CMakeLists.txt

@@ -25,7 +25,7 @@ set (P4TEST_HDRS
   midend.h
   )
 
-build_unified(P4TEST_SRCS ALL)
+
 add_executable(p4test ${P4TEST_SRCS} ${EXTENSION_P4_14_CONV_SOURCES})
 target_link_libraries (p4test ${P4C_LIBRARIES} ${P4C_LIB_DEPS})
 add_dependencies(p4test genIR frontend)

backends/p4tools/modules/testgen/register.h.in

@@ -7,10 +7,10 @@ namespace P4Tools {
 
 namespace P4Testgen {
 
-void registerCompilerTargets() {
+inline void registerCompilerTargets() {
 @compiler_targets_var@}
 
-void registerTestgenTargets() {
+inline void registerTestgenTargets() {
 @testgen_targets_var@}
 
 }  // namespace P4Tools

backends/p4tools/modules/testgen/targets/bmv2/backend/protobuf/protobuf.cpp

@@ -277,7 +277,7 @@ inja::json Protobuf::getVerify(const TestSpec *testSpec) {
     return verifyData;
 }
 
-static std::string getTestCase() {
+std::string Protobuf::getTestCaseTemplate() {
     static std::string TEST_CASE(
         R"""(# A P4TestGen-generated test case for {{test_name}}.p4
 metadata: "p4testgen seed: {{ default(seed, "none") }}"
@@ -429,7 +429,7 @@ void Protobuf::outputTest(const TestSpec *testSpec, cstring selectedBranches, si
     auto incrementedTestName = testName + "_" + std::to_string(testIdx);
 
     protobufFile = std::ofstream(incrementedTestName + ".proto");
-    std::string testCase = getTestCase();
+    std::string testCase = getTestCaseTemplate();
     emitTestcase(testSpec, selectedBranches, testIdx, testCase, currentCoverage);
 }
 

backends/p4tools/modules/testgen/targets/bmv2/backend/protobuf/protobuf.h

@@ -63,6 +63,9 @@ class Protobuf : public TF {
     void emitTestcase(const TestSpec *testSpec, cstring selectedBranches, size_t testId,
                       const std::string &testCase, float currentCoverage);
 
+    /// @returns the inja test case template as a string.
+    static std::string getTestCaseTemplate();
+
     /// Converts all the control plane objects into Inja format.
     static inja::json getControlPlane(const TestSpec *testSpec);
 

backends/p4tools/modules/testgen/targets/bmv2/backend/ptf/ptf.cpp

@@ -282,7 +282,7 @@ void PTF::emitPreamble(const std::string &preamble) {
     ptfFile.flush();
 }
 
-static std::string getTestCase() {
+std::string PTF::getTestCaseTemplate() {
     static std::string TEST_CASE(
         R"""(
 class Test{{test_id}}(AbstractTest):
@@ -419,7 +419,7 @@ void PTF::outputTest(const TestSpec *testSpec, cstring selectedBranches, size_t
         emitPreamble(preamble);
         preambleEmitted = true;
     }
-    std::string testCase = getTestCase();
+    std::string testCase = getTestCaseTemplate();
     emitTestcase(testSpec, selectedBranches, testIdx, testCase, currentCoverage);
 }
 

backends/p4tools/modules/testgen/targets/bmv2/backend/ptf/ptf.h

@@ -58,6 +58,9 @@ class PTF : public TF {
     void emitTestcase(const TestSpec *testSpec, cstring selectedBranches, size_t testId,
                       const std::string &testCase, float currentCoverage);
 
+    /// @returns the inja test case template as a string.
+    static std::string getTestCaseTemplate();
+
     /// Converts all the control plane objects into Inja format.
     static inja::json getControlPlane(const TestSpec *testSpec);
 

backends/p4tools/modules/testgen/targets/bmv2/backend/stf/stf.cpp

@@ -235,7 +235,7 @@ inja::json::array_t STF::getClone(const std::map<cstring, const TestObject *> &c
     return cloneJson;
 }
 
-static std::string getTestCase() {
+std::string STF::getTestCaseTemplate() {
     static std::string TEST_CASE(
         R"""(# p4testgen seed: {{ default(seed, "none") }}
 # Date generated: {{timestamp}}
@@ -328,7 +328,7 @@ void STF::outputTest(const TestSpec *testSpec, cstring selectedBranches, size_t
     auto incrementedTestName = testName + "_" + std::to_string(testIdx);
 
     stfFile = std::ofstream(incrementedTestName + ".stf");
-    std::string testCase = getTestCase();
+    std::string testCase = getTestCaseTemplate();
     emitTestcase(testSpec, selectedBranches, testIdx, testCase, currentCoverage);
 }
 

backends/p4tools/modules/testgen/targets/bmv2/backend/stf/stf.h

@@ -52,6 +52,9 @@ class STF : public TF {
     void emitTestcase(const TestSpec *testSpec, cstring selectedBranches, size_t testId,
                       const std::string &testCase, float currentCoverage);
 
+    /// @returns the inja test case template as a string.
+    static std::string getTestCaseTemplate();
+
     /// Converts all the control plane objects into Inja format.
     static inja::json getControlPlane(const TestSpec *testSpec);
 

backends/p4tools/modules/testgen/targets/bmv2/register.h

@@ -13,10 +13,10 @@ namespace P4Tools {
 namespace P4Testgen {
 
 /// Register the BMv2 compiler target with the tools framework.
-void bmv2_registerCompilerTarget() { Bmv2::BMv2_V1ModelCompilerTarget::make(); }
+inline void bmv2_registerCompilerTarget() { Bmv2::BMv2_V1ModelCompilerTarget::make(); }
 
 /// Register the BMv2 testgen target with the testgen framework.
-void bmv2_registerTestgenTarget() { Bmv2::BMv2_V1ModelTestgenTarget::make(); }
+inline void bmv2_registerTestgenTarget() { Bmv2::BMv2_V1ModelTestgenTarget::make(); }
 
 }  // namespace P4Testgen