introduce code coverage to the cpp sdk

.github/actions/gcovr/action.yaml

@@ -0,0 +1,58 @@
+name: Gcovr
+description: Generate code coverage reports with gcovr and llvm-cov
+
+inputs:
+  build-directory:
+    description: Build directory containing coverage data (.gcda / .gcno)
+    required: false
+    default: build
+  source-root:
+    description: Source root for gcovr --root
+    required: false
+    default: ${{ github.workspace }}
+  gcov-executable:
+    description: gcov executable passed to gcovr (e.g. llvm-cov-16 gcov for Clang)
+    required: false
+    default: llvm-cov-16 gcov
+  gcovr-version:
+    description: gcovr PyPI version to install
+    required: false
+    default: "8.4"
+  output-directory:
+    description: Directory for generated coverage reports
+    required: false
+    default: build/coverage
+  fail-under-line:
+    description: Fail if line coverage is below this percent (0 disables the gate)
+    required: false
+    default: "0"
+
+runs:
+  using: composite
+  steps:
+    - name: Install gcovr
+      shell: bash
+      run: |
+        python3 -m pip install --user "gcovr==${{ inputs.gcovr-version }}"
+        echo "$HOME/.local/bin" >> "$GITHUB_PATH"
+
+    - name: Verify llvm-cov
+      shell: bash
+      run: |
+        llvm_cov="${{ inputs.gcov-executable }}"
+        llvm_cov_bin="${llvm_cov%% *}"
+        if ! command -v "${llvm_cov_bin}" >/dev/null 2>&1; then
+          echo "::error::${llvm_cov_bin} not found; install LLVM or adjust gcov-executable"
+          exit 1
+        fi
+
+    - name: Generate coverage report
+      shell: bash
+      run: |
+        chmod +x "${{ github.action_path }}/run_gcovr.sh"
+        SOURCE_ROOT="${{ inputs.source-root }}" \
+        BUILD_DIR="${{ github.workspace }}/${{ inputs.build-directory }}" \
+        OUTPUT_DIR="${{ github.workspace }}/${{ inputs.output-directory }}" \
+        GCOV_EXECUTABLE="${{ inputs.gcov-executable }}" \
+        FAIL_UNDER_LINE="${{ inputs.fail-under-line }}" \
+        "${{ github.action_path }}/run_gcovr.sh"

.github/actions/gcovr/run_gcovr.sh

@@ -0,0 +1,32 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+: "${SOURCE_ROOT:?SOURCE_ROOT is required}"
+: "${BUILD_DIR:?BUILD_DIR is required}"
+: "${OUTPUT_DIR:?OUTPUT_DIR is required}"
+: "${GCOV_EXECUTABLE:=llvm-cov-16 gcov}"
+
+mkdir -p "${OUTPUT_DIR}"
+
+gcovr_args=(
+  --root "${SOURCE_ROOT}"
+  --object-directory "${BUILD_DIR}"
+  --gcov-executable "${GCOV_EXECUTABLE}"
+  --print-summary
+  --json-summary "${OUTPUT_DIR}/summary.json"
+  --html --html-details
+  -o "${OUTPUT_DIR}/index.html"
+  --cobertura "${OUTPUT_DIR}/cobertura.xml"
+  --exclude '.*contrib/.*'
+  --exclude '.*tests/.*'
+  --exclude '.*/_deps/.*'
+  --filter 'src/'
+  --filter 'include/ydb-cpp-sdk/'
+  --filter 'plugins/'
+)
+
+if [[ -n "${FAIL_UNDER_LINE:-}" && "${FAIL_UNDER_LINE}" != "0" ]]; then
+  gcovr_args+=(--fail-under-line "${FAIL_UNDER_LINE}")
+fi
+
+gcovr "${gcovr_args[@]}"

.github/workflows/coverage.yml

@@ -0,0 +1,89 @@
+name: Coverage
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    types: [opened, synchronize, reopened, ready_for_review]
+    branches:
+      - main
+
+concurrency:
+  group: coverage-${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  coverage:
+    runs-on: ubuntu-22.04
+    permissions:
+      contents: read
+      id-token: write
+    services:
+      ydb:
+        image: ydbplatform/local-ydb:24.4
+        ports:
+          - 2135:2135
+          - 2136:2136
+          - 8765:8765
+        volumes:
+          - /tmp/ydb_certs:/ydb_certs
+        env:
+          YDB_LOCAL_SURVIVE_RESTART: true
+          YDB_USE_IN_MEMORY_PDISKS: true
+          YDB_TABLE_ENABLE_PREPARED_DDL: true
+        options: '-h localhost'
+    steps:
+      - name: Checkout PR
+        uses: actions/checkout@v4
+        if: github.event.pull_request.head.sha != ''
+        with:
+          submodules: true
+          ref: ${{ github.event.pull_request.head.sha }}
+
+      - name: Checkout
+        uses: actions/checkout@v4
+        if: github.event.pull_request.head.sha == ''
+        with:
+          submodules: true
+
+      - name: Install dependencies
+        uses: ./.github/actions/prepare_vm
+
+      - name: Configure and build with coverage
+        shell: bash
+        run: |
+          mkdir -p build
+          rm -rf build/*
+          cmake --preset coverage-test-gcc
+          cmake --build build -j"$(nproc)"
+
+      - name: Test
+        shell: bash
+        run: |
+          ctest -j1 --preset coverage-all --output-on-failure
+
+      - name: Generate coverage report
+        uses: ./.github/actions/gcovr
+        with:
+          build-directory: build
+          source-root: ${{ github.workspace }}
+          gcov-executable: gcov-13
+
+      - name: Upload coverage to Codecov
+        uses: codecov/codecov-action@v5
+        with:
+          use_oidc: true
+          files: build/coverage/cobertura.xml
+          disable_search: true
+          flags: sdk
+          name: ydb-cpp-sdk
+          fail_ci_if_error: true
+          verbose: true
+
+      - name: Upload coverage reports
+        uses: actions/upload-artifact@v4
+        with:
+          name: coverage-report
+          path: build/coverage/
+          retention-days: 14

CMakeLists.txt

@@ -43,6 +43,7 @@ include(CMakePackageConfigHelpers)
 list(APPEND CMAKE_MODULE_PATH ${YDB_SDK_SOURCE_DIR}/cmake)
 
 include(cmake/global_flags.cmake)
+include(cmake/coverage.cmake)
 include(cmake/global_vars.cmake)
 include(cmake/install.cmake)
 include(cmake/common.cmake)

CMakePresets.json

@@ -118,6 +118,21 @@
       "name": "debug-test-gcc",
       "inherits": ["debug-base", "gcc-toolchain", "test"],
       "displayName": "Default Debug Test Config (GCC)"
+    },
+    {
+      "name": "coverage-base",
+      "inherits": ["release-base", "test"],
+      "hidden": true,
+      "cacheVariables": {
+        "YDB_SDK_COVERAGE": "ON",
+        "ARCADIA_ROOT": "${sourceDir}",
+        "ARCADIA_BUILD_ROOT": "${sourceDir}/build"
+      }
+    },
+    {
+      "name": "coverage-test-gcc",
+      "inherits": ["coverage-base", "gcc-toolchain"],
+      "displayName": "Coverage Test Config (GCC)"
     }
   ],
   "buildPresets": [
@@ -173,6 +188,25 @@
         "YDB_ENDPOINT": "localhost:2136",
         "YDB_DATABASE": "/local"
       }
+    },
+    {
+      "name": "coverage-all",
+      "inherits": "all",
+      "displayName": "Run All Tests (coverage CI)",
+      "configurePreset": "coverage-test-gcc",
+      "execution": {
+        "timeout": 1800
+      },
+      "filter": {
+        "exclude": {
+          "name": "(ManyMessages|DiscoveryHang|DescribeHang)"
+        }
+      },
+      "environment": {
+        "YDB_ENDPOINT": "localhost:2136",
+        "YDB_DATABASE": "/local",
+        "YDB_VERSION": "24.4"
+      }
     }
   ]
 }

README.md

@@ -1,5 +1,7 @@
 # YDB C++ SDK: driver for [YDB](https://github.com/ydb-platform/ydb)
 
+[![Codecov](https://codecov.io/gh/ydb-platform/ydb-cpp-sdk/branch/main/graph/badge.svg)](https://app.codecov.io/gh/ydb-platform/ydb-cpp-sdk)
+
 ## Building YDB C++ SDK from sources
 
 ### Prerequisites

cmake/ccache.cmake

@@ -1,5 +1,7 @@
 find_program(CCACHE_PATH ccache)
-if (NOT CCACHE_PATH)
+if (YDB_SDK_COVERAGE)
+  message(STATUS "YDB_SDK_COVERAGE is ON: ccache compiler launchers disabled")
+elseif (NOT CCACHE_PATH)
   message(AUTHOR_WARNING
     "Ccache is not found, that will increase the re-compilation time; "
     "pass -DCCACHE_PATH=path/to/bin to specify the path to the `ccache` binary file."

cmake/common.cmake

@@ -216,6 +216,7 @@ function(_ydb_sdk_add_library Tgt)
   target_compile_definitions(${Tgt} ${includeMode}
     YDB_SDK_OSS
   )
+  _ydb_sdk_apply_coverage(${Tgt})
 
 endfunction()
 
@@ -462,4 +463,3 @@ function(_ydb_sdk_validate_public_headers)
   )
   target_include_directories(validate_public_interface PUBLIC ${YDB_SDK_BINARY_DIR}/__validate_headers_dir/include)
 endfunction()
-

cmake/coverage.cmake

@@ -0,0 +1,21 @@
+option(YDB_SDK_COVERAGE "Instrument SDK and tests for gcov/llvm-cov coverage" OFF)
+
+if (YDB_SDK_COVERAGE)
+  add_link_options(--coverage)
+endif()
+
+function(_ydb_sdk_apply_coverage target)
+  if (NOT YDB_SDK_COVERAGE)
+    return()
+  endif()
+  get_target_property(is_iface ${target} TYPE)
+  if (is_iface STREQUAL "INTERFACE_LIBRARY")
+    return()
+  endif()
+  # Do not use -fprofile-abs-path: it expands __FILE__/__LOCATION__ to absolute paths
+  # and breaks util/system/src_location_ut and src_root_ut (and similar assertions).
+  # gcovr --root maps profile data to the source tree without it.
+  set(_coverage_compile_flags --coverage -O0 -g -fno-inline)
+  target_compile_options(${target} PRIVATE ${_coverage_compile_flags})
+  target_link_options(${target} PRIVATE --coverage)
+endfunction()

cmake/testing.cmake

@@ -51,6 +51,7 @@ function(add_ydb_test)
   endif()
 
   add_executable(${YDB_TEST_NAME})
+  _ydb_sdk_apply_coverage(${YDB_TEST_NAME})
   target_include_directories(${YDB_TEST_NAME} PRIVATE ${YDB_TEST_INCLUDE_DIRS})
   target_link_libraries(${YDB_TEST_NAME} PRIVATE ${YDB_TEST_LINK_LIBRARIES})
   target_sources(${YDB_TEST_NAME} PRIVATE ${YDB_TEST_SOURCES})