build: Introduce CMake-based build system

.github/workflows/ci.yml

@@ -0,0 +1,69 @@
+name: CI
+on:
+  pull_request:
+  push:
+    branches:
+      - '**'
+    tags-ignore:
+      - '**'
+
+concurrency:
+  group: ${{ github.event_name != 'pull_request' && github.run_id || github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  windows-native:
+    name: ${{ matrix.configuration.job_name }}
+    # See: https://github.com/actions/runner-images#available-images.
+    runs-on: windows-2025
+
+    strategy:
+      fail-fast: false
+      matrix:
+        configuration:
+          - job_name: 'x64 (MSVC): Windows (VS 2022)'
+            build_configuration: 'Release'
+          - job_name: 'x64 (MSVC): Windows (VS 2022, fields=32)'
+            cmake_options: '-DMINISKETCH_FIELDS=32'
+            build_configuration: 'Release'
+          - job_name: 'x64 (MSVC): Windows (VS 2022, debug)'
+            build_configuration: 'Debug'
+            # TODO: Resolve the issue and re-enable benchmark.
+            # See: https://github.com/bitcoin-core/minisketch/pull/96.
+            skip_benchmark: true
+          - job_name: 'x64 (MSVC): Windows (VS 2022, shared)'
+            cmake_options: '-DBUILD_SHARED_LIBS=ON'
+            build_configuration: 'Release'
+          - job_name: 'x64 (clang-cl): Windows (VS 2022)'
+            cmake_options: '-T ClangCL'
+            build_configuration: 'Release'
+            # TODO: Resolve the issue and re-enable benchmark.
+            # See: https://github.com/bitcoin-core/minisketch/pull/96.
+            skip_benchmark: true
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Generate buildsystem
+        env:
+          CXXFLAGS: '/WX'
+        run: cmake -B build -DMINISKETCH_BUILD_BENCHMARK=ON ${{ matrix.configuration.cmake_options }}
+
+      - name: Build
+        run: cmake --build build --config ${{ matrix.configuration.build_configuration }}
+
+      - name: Binaries info
+        shell: bash
+        run: |
+          cd build/bin/${{ matrix.configuration.build_configuration }}
+          file * | grep "\.exe\|\.dll"
+
+      - name: Check
+        working-directory: build
+        run: ctest --output-on-failure -j $env:NUMBER_OF_PROCESSORS -C ${{ matrix.configuration.build_configuration }}
+
+      - name: Benchmark
+        if: ${{ ! matrix.configuration.skip_benchmark }}
+        working-directory: build
+        run: bin\${{ matrix.configuration.build_configuration }}\bench.exe

.gitignore

@@ -33,3 +33,6 @@ stamp-h1
 
 test*
 bench
+
+# CMake build directories.
+/*build*

CMakeLists.txt

@@ -0,0 +1,122 @@
+cmake_minimum_required(VERSION 3.22)
+
+#=============================
+# Project / Package Metadata
+#=============================
+project(minisketch
+  VERSION 0.0.1
+  DESCRIPTION "A library for BCH-based set reconciliation"
+  HOMEPAGE_URL "https://github.com/bitcoin-core/minisketch"
+  LANGUAGES CXX
+)
+
+# ============================================================
+# Project Initialization
+# ============================================================
+enable_testing()
+include(CTestUseLaunchers)
+
+list(APPEND CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/cmake)
+
+if(NOT CMAKE_RUNTIME_OUTPUT_DIRECTORY)
+  set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR}/bin)
+endif()
+if(NOT CMAKE_LIBRARY_OUTPUT_DIRECTORY)
+  set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR}/lib)
+endif()
+if(NOT CMAKE_ARCHIVE_OUTPUT_DIRECTORY)
+  set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR}/lib)
+endif()
+
+# Prevent include directories from parent project from leaking into this one.
+set_property(DIRECTORY PROPERTY INCLUDE_DIRECTORIES "")
+
+#=============================
+# Language Setup
+#=============================
+if(DEFINED CMAKE_CXX_STANDARD)
+  if(CMAKE_CXX_STANDARD EQUAL 98 OR CMAKE_CXX_STANDARD LESS 11)
+    message(FATAL_ERROR "This project requires at least C++11")
+  endif()
+else()
+  set(CMAKE_CXX_STANDARD 11)
+endif()
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+if(NOT DEFINED CMAKE_CXX_EXTENSIONS)
+  set(CMAKE_CXX_EXTENSIONS OFF)
+endif()
+
+#=============================
+# Configurable Options
+#=============================
+option(MINISKETCH_INSTALL "Enable installation." ${PROJECT_IS_TOP_LEVEL})
+if(NOT PROJECT_IS_TOP_LEVEL)
+  mark_as_advanced(MINISKETCH_INSTALL)
+endif()
+
+option(MINISKETCH_BUILD_TESTS "Build tests." ON)
+option(MINISKETCH_BUILD_BENCHMARK "Build benchmark." OFF)
+
+set(supported_fields "")
+set(have_enabled_fields NO)
+set(have_disabled_fields NO)
+foreach(i RANGE 2 64)
+  list(APPEND supported_fields ${i})
+endforeach()
+if(NOT DEFINED MINISKETCH_FIELDS)
+  set(MINISKETCH_FIELDS ${supported_fields} CACHE STRING "Semicolon-separated list of field sizes to build. Default=all. Available sizes: ${supported_fields}.")
+endif()
+foreach(field IN LISTS supported_fields)
+  if(field IN_LIST MINISKETCH_FIELDS)
+    set(have_enabled_fields YES)
+  else()
+    set(have_disabled_fields YES)
+    add_compile_definitions(DISABLE_FIELD_${field})
+  endif()
+endforeach()
+if(NOT have_enabled_fields)
+  message(FATAL_ERROR "No field sizes are enabled.")
+endif()
+unset(have_enabled_fields)
+unset(supported_fields)
+
+#=============================
+# Build Options
+#=============================
+set(CMAKE_CXX_VISIBILITY_PRESET hidden)
+
+if(MSVC)
+  add_compile_options(/Zc:__cplusplus)
+endif()
+
+if(MINGW)
+  add_link_options(-static)
+endif()
+
+#=============================
+# Diagnostics Options
+#=============================
+if(MSVC)
+  # For both MSVC's cl.exe and clang-cl compilers.
+  add_compile_options(/W3)  # Production quality warning level. Enables -Wall Clang's core option.
+else()
+  add_compile_options(-Wall)
+endif()
+
+if(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+  add_compile_options(/wd4060)  # Disable warning C4060 "switch statement contains no 'case' or 'default' labels".
+  add_compile_options(/wd4065)  # Disable warning C4065 "switch statement contains 'default' but no 'case' labels".
+  add_compile_options(/wd4146)  # Disable warning C4146 "unary minus operator applied to unsigned type, result still unsigned".
+  add_compile_options(/wd4244)  # Disable warning C4244 "conversion from 'type1' to 'type2', possible loss of data".
+else()
+  add_compile_options(-Wundef)
+endif()
+
+#=============================
+# Main Processing
+#=============================
+include(SystemIntrospection)
+add_subdirectory(src)
+
+include(PrintConfigureSummary)
+print_configure_summary()

README.md

@@ -66,7 +66,7 @@ Below we compare the PinSketch algorithm (which `libminisketch` is an implementa
 * **Difference type:** PinSketch can only compute the symmetric difference from a merged sketch, while CPISync and IBLT can distinguish which side certain elements were missing on. When the decoder has access to one of the sets, this generally doesn't matter, as he can look up each of the elements in the symmetric difference with one of the sets.
 * **Secure sketch:** Whether the sketch satisfies the definition of a secure sketch<sup>[[1]](#myfootnote1)</sup>, which implies a minimal amount about a set can be extracted from a sketch by anyone who does not know most of the elements already. This makes the algorithm appropriate for applications like fingerprint authentication.
 
-## Building
+## Building with Autotools
 
 The build system is very rudimentary for now, and [improvements](https://github.com/bitcoin-core/minisketch/pulls) are welcome.
 
@@ -78,6 +78,44 @@ cd minisketch
 ./autogen.sh && ./configure && make
 ```
 
+## Building with CMake
+
+To maintain a pristine source tree, CMake encourages performing an out-of-source build by using a separate dedicated build directory.
+
+### Building on POSIX systems
+
+The following commands will produce the same `libminisketch.a` file as in the example [above](#building-with-autotools):
+
+```bash
+cmake -B build -DCMAKE_CXX_FLAGS="-g -O2"  # Generate a build system in subdirectory "build"
+cmake --build build                        # Run the actual build process
+ctest --test-dir build                     # Run the test suite
+sudo cmake --install build                 # Install the library into the system (optional)
+```
+
+Run `cmake -B build -LH` or `ccmake -B build` to see the full list of configurable build options.
+
+### Cross compiling
+
+The following example works on modern Ubuntu/Debian systems:
+
+```bash
+sudo apt install g++-mingw-w64-x86-64-posix
+cmake -B build -DCMAKE_SYSTEM_NAME=Windows -DCMAKE_CXX_COMPILER=x86_64-w64-mingw32-g++-posix
+cmake --build build
+```
+
+### Building on Windows
+
+The following example assumes the use of Visual Studio 2022 and CMake v3.21 or newer.
+
+In "Developer Command Prompt for VS 2022":
+
+```cmd
+cmake -B build
+cmake --build build --config Release
+```
+
 ## Usage
 
 In this section Alice and Bob are trying to find the difference between their sets.

cmake/PrintConfigureSummary.cmake

@@ -0,0 +1,112 @@
+include_guard(GLOBAL)
+
+function(indent_message header content indent_num)
+  if(indent_num GREATER 0)
+    string(REPEAT " " ${indent_num} indentation)
+    string(REPEAT "." ${indent_num} tail)
+    string(REGEX REPLACE "${tail}$" "" header "${header}")
+  endif()
+  message("${indentation}${header} ${content}")
+endfunction()
+
+# Print compiler's flags on best-effort. Include the abstracted
+# CMake flags that we touch ourselves.
+function(print_flags_per_config config indent_num)
+  string(STRIP "${CMAKE_CXX_COMPILER_ARG1} ${CMAKE_CXX_FLAGS}" combined_cxx_flags)
+  string(TOUPPER "${config}" config_uppercase)
+  string(STRIP "${combined_cxx_flags} ${CMAKE_CXX_FLAGS_${config_uppercase}}" combined_cxx_flags)
+  string(STRIP "${combined_cxx_flags} ${CMAKE_CXX${CMAKE_CXX_STANDARD}_STANDARD_COMPILE_OPTION}" combined_cxx_flags)
+  if(CMAKE_POSITION_INDEPENDENT_CODE)
+    string(JOIN " " combined_cxx_flags ${combined_cxx_flags} ${CMAKE_CXX_COMPILE_OPTIONS_PIC})
+  endif()
+  if(CMAKE_CXX_COMPILE_OPTIONS_VISIBILITY AND CMAKE_CXX_VISIBILITY_PRESET)
+    string(JOIN " " combined_cxx_flags ${combined_cxx_flags} ${CMAKE_CXX_COMPILE_OPTIONS_VISIBILITY}${CMAKE_CXX_VISIBILITY_PRESET})
+  endif()
+  get_directory_property(compile_options COMPILE_OPTIONS)
+  string(JOIN " " combined_cxx_flags ${combined_cxx_flags} ${compile_options})
+  indent_message("CXXFLAGS .............................." "${combined_cxx_flags}" ${indent_num})
+endfunction()
+
+function(print_configure_summary)
+  message("")
+  if(PROJECT_IS_TOP_LEVEL)
+    message("Configure summary")
+    message("=================")
+  else()
+    message("minisketch configure summary")
+    message("============================")
+  endif()
+  if(BUILD_SHARED_LIBS)
+    set(library_type "Shared")
+  else()
+    set(library_type "Static")
+  endif()
+  message("Library type .......................... ${library_type}")
+  message("Build options:")
+  if(have_disabled_fields)
+    set(filed_sizes "${MINISKETCH_FIELDS}")
+  else()
+    set(filed_sizes "All")
+  endif()
+  message("  field sizes  ........................ ${filed_sizes}")
+  if(HAVE_CLMUL)
+    set(clmul_status "Enabled")
+  else()
+    set(clmul_status "Disabled")
+  endif()
+  message("  clmul fields ........................ ${clmul_status}")
+  if(CMAKE_CXX_STANDARD GREATER_EQUAL 20)
+    set(clz_status "C++20")
+  elseif(HAVE_CLZ)
+    set(clz_status "Compiler builtin")
+  else()
+    set(clz_status "Default")
+  endif()
+  message("  clz implementation .................. ${clz_status}")
+  message("Optional binaries:")
+  message("  benchmark ........................... ${MINISKETCH_BUILD_BENCHMARK}")
+  message("  tests ............................... ${MINISKETCH_BUILD_TESTS}")
+  message("")
+  if(CMAKE_CROSSCOMPILING)
+    set(cross_status "TRUE, for ${CMAKE_SYSTEM_NAME}, ${CMAKE_SYSTEM_PROCESSOR}")
+  else()
+    set(cross_status "FALSE")
+  endif()
+  message("Cross compiling ....................... ${cross_status}")
+  message("C++ compiler .......................... ${CMAKE_CXX_COMPILER_ID} ${CMAKE_CXX_COMPILER_VERSION}, ${CMAKE_CXX_COMPILER}")
+  get_property(_is_multi_config GLOBAL PROPERTY GENERATOR_IS_MULTI_CONFIG)
+  if(_is_multi_config)
+    list(JOIN CMAKE_CONFIGURATION_TYPES ", " configs)
+    message("Available build configurations ........ ${configs}")
+    if(CMAKE_GENERATOR MATCHES "Visual Studio")
+      set(default_config "Debug")
+    else()
+      list(GET CMAKE_CONFIGURATION_TYPES 0 default_config)
+    endif()
+    message("Default build configuration ........... ${default_config}")
+    foreach(config IN LISTS CMAKE_CONFIGURATION_TYPES)
+      message("'${config}' build configuration:")
+      print_flags_per_config("${config}" 2)
+    endforeach()
+  else()
+    message("CMAKE_BUILD_TYPE ...................... ${CMAKE_BUILD_TYPE}")
+    print_flags_per_config("${CMAKE_BUILD_TYPE}" 0)
+  endif()
+  unset(_is_multi_config)
+
+  message([=[
+
+NOTE: The summary above may not exactly match the final applied build flags
+      if any additional CMAKE_* or environment variables have been modified.
+      To see the exact flags applied, build with the --verbose option.]=]
+  )
+
+  if(have_disabled_fields AND PROJECT_IS_TOP_LEVEL)
+    message("")
+    message(WARNING
+      "Only compiling in support for field sizes: ${MINISKETCH_FIELDS}\n"
+      "This means the library will lack support for other field sizes entirely.\n"
+    )
+  endif()
+  message("")
+endfunction()