treat warnings as errors in CI

In the past, when we build on travis and appveyor, we would detect this,
and turn on -Werror (treating warnings as errors). Somewhere along the
line - that got lost.

Re-enable that for azure pipelines, and document it in the README

At the same time, turn on the equivilent for the cmake files themselves.

Signed-off-by: Robin Getz <[email protected]>

CI/azure/ci-ubuntu.sh

@@ -3,6 +3,6 @@ set -x
 uname -a
 echo "$PWD"
 mkdir build && cd build
-cmake .. -DWITH_HWMON=ON -DWITH_SERIAL_BACKEND=ON -DWITH_EXAMPLES=ON -DPYTHON_BINDINGS=ON -DENABLE_PACKAGING=ON -DCPACK_SYSTEM_NAME="${ARTIFACTNAME}"
+cmake .. -Werror=dev -DCOMPILE_WARNING_AS_ERROR=ON -DWITH_HWMON=ON -DWITH_SERIAL_BACKEND=ON -DWITH_EXAMPLES=ON -DPYTHON_BINDINGS=ON -DENABLE_PACKAGING=ON -DCPACK_SYSTEM_NAME="${ARTIFACTNAME}"
 make
 make package

CI/build_win.ps1

@@ -10,7 +10,7 @@ mkdir build-x64
 cp .\libiio.iss.cmakein .\build-x64
 cd build-x64
 
-cmake -G "$COMPILER" -DCMAKE_SYSTEM_PREFIX_PATH="C:" -DENABLE_IPV6=ON -DWITH_USB_BACKEND=ON -DWITH_SERIAL_BACKEND=ON -DPYTHON_BINDINGS=ON -DCSHARP_BINDINGS:BOOL=ON -DLIBXML2_LIBRARIES="C:\\libs\\64\\libxml2.lib" -DLIBUSB_LIBRARIES="C:\\libs\\64\\libusb-1.0.lib" -DLIBSERIALPORT_LIBRARIES="C:\\libs\\64\\libserialport.dll.a" -DLIBUSB_INCLUDE_DIR="C:\\include\\libusb-1.0" -DLIBXML2_INCLUDE_DIR="C:\\include\\libxml2" ..
+cmake -G "$COMPILER" -DCMAKE_SYSTEM_PREFIX_PATH="C:" -Werror=dev -DCOMPILE_WARNING_AS_ERROR=ON -DENABLE_IPV6=ON -DWITH_USB_BACKEND=ON -DWITH_SERIAL_BACKEND=ON -DPYTHON_BINDINGS=ON -DCSHARP_BINDINGS:BOOL=ON -DLIBXML2_LIBRARIES="C:\\libs\\64\\libxml2.lib" -DLIBUSB_LIBRARIES="C:\\libs\\64\\libusb-1.0.lib" -DLIBSERIALPORT_LIBRARIES="C:\\libs\\64\\libserialport.dll.a" -DLIBUSB_INCLUDE_DIR="C:\\include\\libusb-1.0" -DLIBXML2_INCLUDE_DIR="C:\\include\\libxml2" ..
 cmake --build . --config Release
 if ( $LASTEXITCODE -ne 0 ) {
 		throw "[*] cmake build failure"

CMakeLists.txt

@@ -184,13 +184,14 @@ endif()
 
 # make sure all check_symbol_exists are before this point, otherwise they fail
 # on some versions of compilers
+option(COMPILE_WARNING_AS_ERROR "Make all warnings into errors" OFF)
 if (MSVC)
 	# why can't different CIs use the same flags?
 	# Travis CI      : CI=True & TRAVIS=True
 	# Appveyor       : CI=True & APPVEYOR=True
 	# Azure Pipelines: TF_BUILD=True
-	if(DEFINED ENV{TF_BUILD} OR (DEFINED ENV{CI} AND DEFINED ENV{APPVEYOR}))
-		message(STATUS "Running in an Azure or AppVeyor environment, setting -Werror")
+	if(COMPILE_WARNING_AS_ERROR)
+		message(STATUS "Setting -Werror")
 		add_compile_options(/WX)
 	endif()
 elseif (CMAKE_COMPILER_IS_GNUCC OR CMAKE_C_COMPILER_ID STREQUAL "Clang")
@@ -200,8 +201,8 @@ elseif (CMAKE_COMPILER_IS_GNUCC OR CMAKE_C_COMPILER_ID STREQUAL "Clang")
 		SET(CMAKE_EXE_LINKER_FLAGS  "${CMAKE_EXE_LINKER_FLAGS} -fprofile-arcs -ftest-coverage")
 		SET(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS}  -fprofile-arcs -ftest-coverage")
 	endif()
-	if(DEFINED ENV{TF_BUILD} OR (DEFINED ENV{CI} AND (DEFINED ENV{TRAVIS} OR DEFINED ENV{APPVEYOR})))
-		message(STATUS "Running in CI environment (Azure, Travis or AppVeyor), setting -Werror")
+	if(COMPILE_WARNING_AS_ERROR)
+		message(STATUS "Setting -Werror")
 		set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Werror")
 	endif()
 else()

README_BUILD.md

@@ -39,6 +39,7 @@ The recommendation is to leave things to the default.
 Cmake Options          | Default | Target | Description                                    |
 ---------------------- | ------- | -------| ---------------------------------------------- |
 `BUILD_SHARED_LIBS`    |  ON |        All | Build shared libraries            |
+'COMPILE_WARNING_AS_ERROR' | OFF |    All | Make all C warnings into errors     |
 `PYTHON_BINDINGS`      | OFF |        All | Install PYTHON bindings                            |
 `WITH_TESTS`           |  ON |        All | Build the test programs (iio-utils)                |
 `WITH_EXAMPLES`        | OFF |        All | Build the example programs                         |

azure-pipelines.yml

@@ -50,7 +50,7 @@ stages:
     - script: |
         set -e
         mkdir build && cd build
-        cmake .. -DENABLE_PACKAGING=ON -DPYTHON_BINDINGS=ON -DWITH_DOC=ON -DWITH_MAN=ON -DCPACK_SYSTEM_NAME=${ARTIFACTNAME}
+        cmake .. -Werror=dev -DCOMPILE_WARNING_AS_ERROR=ON -DENABLE_PACKAGING=ON -DPYTHON_BINDINGS=ON -DWITH_DOC=ON -DWITH_MAN=ON -DCPACK_SYSTEM_NAME=${ARTIFACTNAME}
         make
         make package
       displayName: 'Build'
@@ -208,23 +208,23 @@ stages:
     - script: |
         set -e
         mkdir build && cd build
-        cmake .. -DOSX_PACKAGE=ON -DPYTHON_BINDINGS=ON -DWITH_EXAMPLES=ON -DWITH_SERIAL_BACKEND=OFF -DWITH_ZSTD=OFF
+        cmake .. -Werror=dev -DCOMPILE_WARNING_AS_ERROR=ON -DOSX_PACKAGE=ON -DPYTHON_BINDINGS=ON -DWITH_EXAMPLES=ON -DWITH_SERIAL_BACKEND=OFF -DWITH_ZSTD=OFF
         make
         sudo make install
         cd ..
       displayName: 'Build'
     - script: |
         set -e
         mkdir build_tar && cd build_tar
-        cmake .. -DOSX_PACKAGE=OFF -DENABLE_PACKAGING=ON -DPYTHON_BINDINGS=ON -DWITH_SERIAL_BACKEND=OFF -DWITH_ZSTD=OFF -DCPACK_SYSTEM_NAME=${ARTIFACTNAME}
+        cmake .. -Werror=dev -DCOMPILE_WARNING_AS_ERROR=ON -DOSX_PACKAGE=OFF -DENABLE_PACKAGING=ON -DPYTHON_BINDINGS=ON -DWITH_SERIAL_BACKEND=OFF -DWITH_ZSTD=OFF -DCPACK_SYSTEM_NAME=${ARTIFACTNAME}
         make
         make package
         cd ..
       displayName: 'Build tar'
     - script: |
         set -e
         cd build
-        cmake .. -DPYTHON_BINDINGS=ON -DWITH_DOC=ON
+        cmake .. -Werror=dev -DCOMPILE_WARNING_AS_ERROR=ON -DPYTHON_BINDINGS=ON -DWITH_DOC=ON
         make
         cd ..
       displayName: 'Build With Doc'