Add an includes-check CI workflow

.github/workflows/includes-check.yml

@@ -0,0 +1,96 @@
+name: Check includes
+on: [push, pull_request]
+
+defaults:
+  run:
+    shell: bash
+
+jobs:
+  includes-check:
+    runs-on: ubuntu-latest
+    container:
+      image: "debian:13"
+      options: --user 0
+    strategy:
+      matrix:
+        board: ['HACKRF_ONE', 'JAWBREAKER', 'RAD1O', 'PRALINE']
+        cmake: ['3.10.0', 'latest']
+
+      # Don't cancel all builds when one fails
+      fail-fast: false
+
+    steps:
+
+    - name: Make it work on debian
+      run: |
+        apt update
+        apt install -y git python3 python3-pip python3-venv nodejs
+        # actions/checkout insists on putting the checkout in the
+        # working directory rather than ${{ github.workspace }}.
+        #
+        # This may just be because the 'runner' user does not exist
+        # in the docker image at startup.
+        #
+        # also see: https://github.com/actions/runner/issues/878
+        useradd -ms /bin/bash runner
+        ln -s /__w /home/runner/work
+
+    - name: Checkout repository
+      uses: actions/checkout@v6
+      with:
+        submodules: true
+
+    - name: Setup cmake
+      uses: jwlawson/actions-setup-cmake@v2
+      with:
+        cmake-version: ${{ matrix.cmake }}
+
+    - name: Install Arm GNU Toolchain
+      uses: carlosperate/arm-none-eabi-gcc-action@v1
+
+    - name: Install dependencies
+      run: |
+        python3 -m venv environment && source environment/bin/activate
+        python3 -m pip install PyYAML
+        apt install -y iwyu
+        iwyu --version
+
+    - name: Build libopencm3
+      working-directory: ${{github.workspace}}/firmware/libopencm3/
+      run: |
+        source ../../environment/bin/activate
+        make
+
+    - name: Create Build Environment
+      run: cmake -E make_directory ${{github.workspace}}/firmware/build
+
+    - name: Configure CMake
+      working-directory: ${{github.workspace}}/firmware/build
+      run: cmake ${{github.workspace}}/firmware/ -DCMAKE_BUILD_TYPE=Release -DBOARD=${{ matrix.board }} -DCHECK_INCLUDES=1
+
+    - name: Build
+      working-directory: ${{github.workspace}}/firmware/build
+      run: |
+        source ../../environment/bin/activate
+        output="$(cmake --build . --config Release 2>&1)"
+        while IFS= read -r line
+        do
+            if [[ "${line}" == "Warning: include-what-you-use"* ]]; then
+                exit_code=1
+                dump=1
+                echo
+            elif [[ "${line}" == "---" ]]; then
+                dump=0
+                echo
+            fi
+            if [[ ${dump} == "1" ]]; then
+                echo "${line}"
+            fi
+        done <<< ${output}
+        if [[ ${exit_code} == "1" ]]; then
+            echo "Includes check failed for board target: ${{ matrix.board }}"
+        else
+            echo "Includes check succeeded for board target: ${{ matrix.board }}"
+        fi
+        echo $(include-what-you-use --version)
+        exit ${exit_code}

firmware/CMakeLists.txt

@@ -20,10 +20,17 @@
 
 # Top directory CMake project for HackRF firmware
 
+option(CHECK_INCLUDES
+	   "Check firmware sources for unused includes and transitive dependencies. (Requires iwyu)" OFF)
+
 cmake_minimum_required(VERSION 3.10.0)
 set(CMAKE_TOOLCHAIN_FILE toolchain-arm-cortex-m.cmake)
 
 project (hackrf_firmware_all C)
 
+if(CHECK_INCLUDES)
+	include(include-what-you-use.cmake)
+endif()
+
 add_subdirectory(blinky)
 add_subdirectory(hackrf_usb)

firmware/include-what-you-use.cmake

@@ -0,0 +1,38 @@
+# Copyright 2026 Great Scott Gadgets <info@greatscottgadgets.com>
+#
+# This file is part of HackRF.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; see the file COPYING.  If not, write to
+# the Free Software Foundation, Inc., 51 Franklin Street,
+# Boston, MA 02110-1301, USA.
+#
+
+cmake_minimum_required(VERSION 3.10.0)
+
+find_program(IWYU_COMMAND NAMES include-what-you-use)
+if(NOT IWYU_COMMAND)
+	message(FATAL_ERROR "Could not find the include-what-you-use executable.")
+endif()
+
+# include-what-you-use arguments:
+#
+#   --no_fwd_decls  - Disable forward declaration suggestions.
+#   --mapping_file  - Specify mapping files for excluding suggestions.
+#
+list(APPEND IWYU_COMMAND
+			-Xiwyu --no_fwd_decls
+			-Xiwyu --mapping_file=${CMAKE_SOURCE_DIR}/libopencm3.imp)
+
+set(CMAKE_C_INCLUDE_WHAT_YOU_USE ${IWYU_COMMAND})
+set(CMAKE_CXX_INCLUDE_WHAT_YOU_USE ${IWYU_COMMAND})