[CI] Add a clang-tidy build

.github/workflows/clang-tidy.yaml

@@ -0,0 +1,74 @@
+name: clang-tidy
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  clang-tidy:
+    runs-on: ubuntu-24.04
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          submodules: recursive
+
+      - name: Setup Environment
+        env:
+          PROTOBUF_VERSION: '23.3'
+          ABSEIL_CPP_VERSION: '20230125.3'
+          CXX_STANDARD: '14'
+        run: |
+          sudo apt update -y
+          sudo apt install -y --no-install-recommends --no-install-suggests \
+          build-essential
+          sudo -E ./ci/setup_cmake.sh
+          sudo -E ./ci/setup_ci_environment.sh
+          sudo -E ./ci/setup_googletest.sh
+          sudo -E ./ci/install_abseil.sh
+          sudo -E ./ci/install_protobuf.sh
+          sudo -E ./ci/setup_grpc.sh -m -p protobuf -p abseil-cpp
+
+
+      # WITH_OPENTRACING_SHIM and WITH_ETW is not present and will be excluded.
+      - name: Prepare CMake
+        run: |
+          TOPDIR=$(pwd)
+          mkdir -p build && cd build
+          echo "Running cmake..."
+          CC="clang" CXX="clang++" cmake .. \
+          -DCMAKE_CXX_STANDARD=14 \
+          -DWITH_STL=CXX14 \
+          -DWITH_OTLP_HTTP=ON \
+          -DWITH_OTLP_FILE=ON \
+          -DWITH_PROMETHEUS=ON \
+          -DWITH_ZIPKIN=ON \
+          -DWITH_ABSEIL=ON \
+          -DWITH_ELASTICSEARCH=ON \
+          -DWITH_OTLP_HTTP_COMPRESSION=ON \
+          -DWITH_EXAMPLES=ON \
+          -DWITH_EXAMPLES_HTTP=ON \
+          -DBUILD_W3CTRACECONTEXT_TEST=ON \
+          -DWITH_METRICS_EXEMPLAR_PREVIEW=ON \
+          -DWITH_ASYNC_EXPORT_PREVIEW=ON \
+          -DCMAKE_EXPORT_COMPILE_COMMANDS=ON \
+          -DWITH_OTLP_GRPC=ON \
+          -DWITH_OTLP_GRPC_SSL_MTLS_PREVIEW=ON
+          cd ..
+
+      - name: Run Clang-Tidy
+        run: |
+          chmod +x tools/clang-tidy.sh
+          ./tools/clang-tidy.sh | tee clang-tidy-output.log
+
+      - uses: actions/upload-artifact@v4
+        if: success() || failure()
+        with:
+          name: Logs (clang-tidy)
+          path: clang-tidy-output.log
+
+      - name: Count Warnings
+        run: |
+          COUNT=$(grep -c "warning:" clang-tidy-output.log)
+          echo "clang-tidy reported ${COUNT} warning(s)"

CHANGELOG.md

@@ -15,6 +15,9 @@ Increment the:
 
 ## [Unreleased]
 
+* [CI] Added clang-tidy to the CI pipeline, which outputs
+the number of warnings and generates a log file containing the
+details of these warnings [#2051](https://github.com/open-telemetry/opentelemetry-cpp/issues/2051)
 * [SECURITY] Remove OTLP HTTP support for TLS 1.0 and TLS 1.1,
   require TLS 1.2 or better
   [#2721](https://github.com/open-telemetry/opentelemetry-cpp/pull/2721)

tools/clang-tidy.sh

@@ -0,0 +1,59 @@
+#!/bin/bash
+
+# Copyright The OpenTelemetry Authors
+# SPDX-License-Identifier: Apache-2.0
+
+# Define the find command to exclude certain directories and find relevant files
+
+# This command will exclude the following directories: same as format.sh but removing the opentelemetry-shim as well.
+# - third_party
+# - tools
+# - .git
+# - _deps
+# - build
+# - out
+# - .vs
+# - opentelemetry_logo.png
+# - TraceLoggingDynamic.h:
+# - opentelemetry-shim
+
+FIND="find . -name third_party -prune -o -name opentracing-shim -prune -o -name tools -prune -o -name .git -prune -o -name _deps -prune -o -name build -prune -o -name out -prune -o -name .vs -prune -o -name opentelemetry_logo.png -prune -o -name TraceLoggingDynamic.h -prune -o -name '*.h' -o -name '*.cc' -print"
+
+# Define the path to the compile_commands.json
+COMPILE_COMMANDS_PATH="./build/compile_commands.json"
+
+# Define the log file name
+LOG_FILE="clang-tidy-output.log"
+
+
+# Don't require this in the log file as the clang-tidy just want to go into system libraries and produce those warnings as well.
+# This should be probably avioded with header-filter
+FILTER_PATTERN="Suppressed [0-9]* warnings.*|Use -header-filter=.*|Use -system-headers.* | warnings generated."
+
+# Check if the log file is empty or does not exist
+rm -f $LOG_FILE
+
+run_clang_tidy() {
+  file=$1
+  echo "Running clang-tidy on $file" >> $LOG_FILE
+  clang-tidy -p=$COMPILE_COMMANDS_PATH "$file" 2>&1 | grep -Ev "$FILTER_PATTERN" | tee -a $LOG_FILE
+}
+
+NUM_PROCESSORS=$(nproc)
+
+
+export -f run_clang_tidy
+export COMPILE_COMMANDS_PATH
+export LOG_FILE
+export FILTER_PATTERN
+
+# Find all relevant files and store them in a variable
+FILES=$(eval $FIND)
+NUM_FILES=$(echo "$FILES" | wc -l)
+
+
+echo "Number of processors available: $NUM_PROCESSORS"
+echo "Number of files to process: $NUM_FILES"
+
+# Run clang-tidy in parallel on each file found by the find command
+echo "$FILES" | xargs -P $NUM_PROCESSORS -n 1 bash -c 'run_clang_tidy "$@"' _