Added test code coverage report
diff --git a/.gitignore b/.gitignore
index f3be78e..9b3ffd0 100644
--- a/.gitignore
+++ b/.gitignore
@@ -27,3 +27,5 @@
 install_manifest.txt
 /bbasm
 /ImportExecutables.cmake
+*-coverage/
+*-coverage.info
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0cf55eb..d7c8796 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -5,6 +5,7 @@
 option(BUILD_GUI "Build GUI" ON)
 option(BUILD_PYTHON "Build Python Integration" ON)
 option(BUILD_TESTS "Build GUI" OFF)
+option(COVERAGE "Add code coverage info" OFF)
 option(STATIC_BUILD "Create static build" OFF)
 
 set(link_param "")
@@ -50,7 +51,11 @@
 endif()
 set(CMAKE_DEFIN)
 
-set(CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}/3rdparty/sanitizers-cmake/cmake" ${CMAKE_MODULE_PATH})
+set(CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}/3rdparty/sanitizers-cmake/cmake;." ${CMAKE_MODULE_PATH})
+
+if (COVERAGE)
+    include(CodeCoverage)
+endif()
 
 if(NOT DEFINED CMAKE_SUPPRESS_DEVELOPER_WARNINGS)
      set(CMAKE_SUPPRESS_DEVELOPER_WARNINGS 1 CACHE INTERNAL "No dev warnings")
@@ -192,6 +197,16 @@
         
     # Add any new per-architecture targets here
     if (BUILD_TESTS)
+        if (COVERAGE)
+            APPEND_COVERAGE_COMPILER_FLAGS()
+            set(COVERAGE_LCOV_EXCLUDES '/usr/include/*' '3rdparty/*' 'generated/*' 'bba/*')
+            SETUP_TARGET_FOR_COVERAGE_LCOV(
+                NAME ${family}-coverage 
+                EXECUTABLE nextpnr-${family}-test
+                DEPENDENCIES nextpnr-${family}-test
+            )
+        endif()
+
         aux_source_directory(tests/${family}/ ${ufamily}_TEST_FILES)
         if (BUILD_GUI)
             aux_source_directory(tests/gui/ GUI_TEST_FILES)
diff --git a/CodeCoverage.cmake b/CodeCoverage.cmake
new file mode 100644
index 0000000..1028522
--- /dev/null
+++ b/CodeCoverage.cmake
@@ -0,0 +1,303 @@
+# Copyright (c) 2012 - 2017, Lars Bilke
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without modification,
+# are permitted provided that the following conditions are met:
+#
+# 1. Redistributions of source code must retain the above copyright notice, this
+#    list of conditions and the following disclaimer.
+#
+# 2. Redistributions in binary form must reproduce the above copyright notice,
+#    this list of conditions and the following disclaimer in the documentation
+#    and/or other materials provided with the distribution.
+#
+# 3. Neither the name of the copyright holder nor the names of its contributors
+#    may be used to endorse or promote products derived from this software without
+#    specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+# ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+# ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+# CHANGES:
+#
+# 2012-01-31, Lars Bilke
+# - Enable Code Coverage
+#
+# 2013-09-17, Joakim Söderberg
+# - Added support for Clang.
+# - Some additional usage instructions.
+#
+# 2016-02-03, Lars Bilke
+# - Refactored functions to use named parameters
+#
+# 2017-06-02, Lars Bilke
+# - Merged with modified version from github.com/ufz/ogs
+#
+#
+# USAGE:
+#
+# 1. Copy this file into your cmake modules path.
+#
+# 2. Add the following line to your CMakeLists.txt:
+#      include(CodeCoverage)
+#
+# 3. Append necessary compiler flags:
+#      APPEND_COVERAGE_COMPILER_FLAGS()
+#
+# 4. If you need to exclude additional directories from the report, specify them
+#    using the COVERAGE_LCOV_EXCLUDES variable before calling SETUP_TARGET_FOR_COVERAGE_LCOV.
+#    Example:
+#      set(COVERAGE_LCOV_EXCLUDES 'dir1/*' 'dir2/*')
+#
+# 5. Use the functions described below to create a custom make target which
+#    runs your test executable and produces a code coverage report.
+#
+# 6. Build a Debug build:
+#      cmake -DCMAKE_BUILD_TYPE=Debug ..
+#      make
+#      make my_coverage_target
+#
+
+include(CMakeParseArguments)
+
+# Check prereqs
+find_program( GCOV_PATH gcov )
+find_program( LCOV_PATH  NAMES lcov lcov.bat lcov.exe lcov.perl)
+find_program( GENHTML_PATH NAMES genhtml genhtml.perl genhtml.bat )
+find_program( GCOVR_PATH gcovr PATHS ${CMAKE_SOURCE_DIR}/scripts/test)
+find_program( SIMPLE_PYTHON_EXECUTABLE python )
+
+if(NOT GCOV_PATH)
+    message(FATAL_ERROR "gcov not found! Aborting...")
+endif() # NOT GCOV_PATH
+
+if("${CMAKE_CXX_COMPILER_ID}" MATCHES "(Apple)?[Cc]lang")
+    if("${CMAKE_CXX_COMPILER_VERSION}" VERSION_LESS 3)
+        message(FATAL_ERROR "Clang version must be 3.0.0 or greater! Aborting...")
+    endif()
+elseif(NOT CMAKE_COMPILER_IS_GNUCXX)
+    message(FATAL_ERROR "Compiler is not GNU gcc! Aborting...")
+endif()
+
+set(COVERAGE_COMPILER_FLAGS "-g -O0 --coverage -fprofile-arcs -ftest-coverage"
+    CACHE INTERNAL "")
+
+set(CMAKE_CXX_FLAGS_COVERAGE
+    ${COVERAGE_COMPILER_FLAGS}
+    CACHE STRING "Flags used by the C++ compiler during coverage builds."
+    FORCE )
+set(CMAKE_C_FLAGS_COVERAGE
+    ${COVERAGE_COMPILER_FLAGS}
+    CACHE STRING "Flags used by the C compiler during coverage builds."
+    FORCE )
+set(CMAKE_EXE_LINKER_FLAGS_COVERAGE
+    ""
+    CACHE STRING "Flags used for linking binaries during coverage builds."
+    FORCE )
+set(CMAKE_SHARED_LINKER_FLAGS_COVERAGE
+    ""
+    CACHE STRING "Flags used by the shared libraries linker during coverage builds."
+    FORCE )
+mark_as_advanced(
+    CMAKE_CXX_FLAGS_COVERAGE
+    CMAKE_C_FLAGS_COVERAGE
+    CMAKE_EXE_LINKER_FLAGS_COVERAGE
+    CMAKE_SHARED_LINKER_FLAGS_COVERAGE )
+
+if(NOT CMAKE_BUILD_TYPE STREQUAL "Debug")
+    message(WARNING "Code coverage results with an optimised (non-Debug) build may be misleading")
+endif() # NOT CMAKE_BUILD_TYPE STREQUAL "Debug"
+
+if(CMAKE_C_COMPILER_ID STREQUAL "GNU")
+    link_libraries(gcov)
+else()
+    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} --coverage")
+endif()
+
+# Defines a target for running and collection code coverage information
+# Builds dependencies, runs the given executable and outputs reports.
+# NOTE! The executable should always have a ZERO as exit code otherwise
+# the coverage generation will not complete.
+#
+# SETUP_TARGET_FOR_COVERAGE_LCOV(
+#     NAME testrunner_coverage                    # New target name
+#     EXECUTABLE testrunner -j ${PROCESSOR_COUNT} # Executable in PROJECT_BINARY_DIR
+#     DEPENDENCIES testrunner                     # Dependencies to build first
+# )
+function(SETUP_TARGET_FOR_COVERAGE_LCOV)
+
+    set(options NONE)
+    set(oneValueArgs NAME)
+    set(multiValueArgs EXECUTABLE EXECUTABLE_ARGS DEPENDENCIES)
+    cmake_parse_arguments(Coverage "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
+
+    if(NOT LCOV_PATH)
+        message(FATAL_ERROR "lcov not found! Aborting...")
+    endif() # NOT LCOV_PATH
+
+    if(NOT GENHTML_PATH)
+        message(FATAL_ERROR "genhtml not found! Aborting...")
+    endif() # NOT GENHTML_PATH
+
+    # Setup target
+    add_custom_target(${Coverage_NAME}
+
+        # Cleanup lcov
+        COMMAND ${LCOV_PATH} --gcov-tool ${GCOV_PATH} -directory . --zerocounters
+        # Create baseline to make sure untouched files show up in the report
+        COMMAND ${LCOV_PATH} --gcov-tool ${GCOV_PATH} -c -i -d . -o ${Coverage_NAME}.base
+
+        # Run tests
+        COMMAND ${Coverage_EXECUTABLE}
+
+        # Capturing lcov counters and generating report
+        COMMAND ${LCOV_PATH} --gcov-tool ${GCOV_PATH} --directory . --capture --output-file ${Coverage_NAME}.info
+        # add baseline counters
+        COMMAND ${LCOV_PATH} --gcov-tool ${GCOV_PATH} -a ${Coverage_NAME}.base -a ${Coverage_NAME}.info --output-file ${Coverage_NAME}.total
+        COMMAND ${LCOV_PATH} --gcov-tool ${GCOV_PATH} --remove ${Coverage_NAME}.total ${COVERAGE_LCOV_EXCLUDES} --output-file ${PROJECT_BINARY_DIR}/${Coverage_NAME}.info.cleaned
+        COMMAND ${GENHTML_PATH} -o ${Coverage_NAME} ${PROJECT_BINARY_DIR}/${Coverage_NAME}.info.cleaned
+        COMMAND ${CMAKE_COMMAND} -E remove ${Coverage_NAME}.base ${Coverage_NAME}.total ${PROJECT_BINARY_DIR}/${Coverage_NAME}.info.cleaned
+
+        WORKING_DIRECTORY ${PROJECT_BINARY_DIR}
+        DEPENDS ${Coverage_DEPENDENCIES}
+        COMMENT "Resetting code coverage counters to zero.\nProcessing code coverage counters and generating report."
+    )
+
+    # Show where to find the lcov info report
+    add_custom_command(TARGET ${Coverage_NAME} POST_BUILD
+        COMMAND ;
+        COMMENT "Lcov code coverage info report saved in ${Coverage_NAME}.info."
+    )
+
+    # Show info where to find the report
+    add_custom_command(TARGET ${Coverage_NAME} POST_BUILD
+        COMMAND ;
+        COMMENT "Open ./${Coverage_NAME}/index.html in your browser to view the coverage report."
+    )
+
+endfunction() # SETUP_TARGET_FOR_COVERAGE_LCOV
+
+# Defines a target for running and collection code coverage information
+# Builds dependencies, runs the given executable and outputs reports.
+# NOTE! The executable should always have a ZERO as exit code otherwise
+# the coverage generation will not complete.
+#
+# SETUP_TARGET_FOR_COVERAGE_GCOVR_XML(
+#     NAME ctest_coverage                    # New target name
+#     EXECUTABLE ctest -j ${PROCESSOR_COUNT} # Executable in PROJECT_BINARY_DIR
+#     DEPENDENCIES executable_target         # Dependencies to build first
+# )
+function(SETUP_TARGET_FOR_COVERAGE_GCOVR_XML)
+
+    set(options NONE)
+    set(oneValueArgs NAME)
+    set(multiValueArgs EXECUTABLE EXECUTABLE_ARGS DEPENDENCIES)
+    cmake_parse_arguments(Coverage "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
+
+    if(NOT SIMPLE_PYTHON_EXECUTABLE)
+        message(FATAL_ERROR "python not found! Aborting...")
+    endif() # NOT SIMPLE_PYTHON_EXECUTABLE
+
+    if(NOT GCOVR_PATH)
+        message(FATAL_ERROR "gcovr not found! Aborting...")
+    endif() # NOT GCOVR_PATH
+
+    # Combine excludes to several -e arguments
+    set(GCOVR_EXCLUDES "")
+    foreach(EXCLUDE ${COVERAGE_GCOVR_EXCLUDES})
+        list(APPEND GCOVR_EXCLUDES "-e")
+        list(APPEND GCOVR_EXCLUDES "${EXCLUDE}")
+    endforeach()
+
+    add_custom_target(${Coverage_NAME}
+        # Run tests
+        ${Coverage_EXECUTABLE}
+
+        # Running gcovr
+        COMMAND ${GCOVR_PATH} --xml
+            -r ${PROJECT_SOURCE_DIR} ${GCOVR_EXCLUDES}
+            --object-directory=${PROJECT_BINARY_DIR}
+            -o ${Coverage_NAME}.xml
+        WORKING_DIRECTORY ${PROJECT_BINARY_DIR}
+        DEPENDS ${Coverage_DEPENDENCIES}
+        COMMENT "Running gcovr to produce Cobertura code coverage report."
+    )
+
+    # Show info where to find the report
+    add_custom_command(TARGET ${Coverage_NAME} POST_BUILD
+        COMMAND ;
+        COMMENT "Cobertura code coverage report saved in ${Coverage_NAME}.xml."
+    )
+
+endfunction() # SETUP_TARGET_FOR_COVERAGE_GCOVR_XML
+
+# Defines a target for running and collection code coverage information
+# Builds dependencies, runs the given executable and outputs reports.
+# NOTE! The executable should always have a ZERO as exit code otherwise
+# the coverage generation will not complete.
+#
+# SETUP_TARGET_FOR_COVERAGE_GCOVR_HTML(
+#     NAME ctest_coverage                    # New target name
+#     EXECUTABLE ctest -j ${PROCESSOR_COUNT} # Executable in PROJECT_BINARY_DIR
+#     DEPENDENCIES executable_target         # Dependencies to build first
+# )
+function(SETUP_TARGET_FOR_COVERAGE_GCOVR_HTML)
+
+    set(options NONE)
+    set(oneValueArgs NAME)
+    set(multiValueArgs EXECUTABLE EXECUTABLE_ARGS DEPENDENCIES)
+    cmake_parse_arguments(Coverage "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
+
+    if(NOT SIMPLE_PYTHON_EXECUTABLE)
+        message(FATAL_ERROR "python not found! Aborting...")
+    endif() # NOT SIMPLE_PYTHON_EXECUTABLE
+
+    if(NOT GCOVR_PATH)
+        message(FATAL_ERROR "gcovr not found! Aborting...")
+    endif() # NOT GCOVR_PATH
+
+    # Combine excludes to several -e arguments
+    set(GCOVR_EXCLUDES "")
+    foreach(EXCLUDE ${COVERAGE_GCOVR_EXCLUDES})
+        list(APPEND GCOVR_EXCLUDES "-e")
+        list(APPEND GCOVR_EXCLUDES "${EXCLUDE}")
+    endforeach()
+
+    add_custom_target(${Coverage_NAME}
+        # Run tests
+        ${Coverage_EXECUTABLE}
+
+        # Create folder
+        COMMAND ${CMAKE_COMMAND} -E make_directory ${PROJECT_BINARY_DIR}/${Coverage_NAME}
+
+        # Running gcovr
+        COMMAND ${GCOVR_PATH} --html --html-details
+            -r ${PROJECT_SOURCE_DIR} ${GCOVR_EXCLUDES}
+            --object-directory=${PROJECT_BINARY_DIR}
+            -o ${Coverage_NAME}/index.html
+        WORKING_DIRECTORY ${PROJECT_BINARY_DIR}
+        DEPENDS ${Coverage_DEPENDENCIES}
+        COMMENT "Running gcovr to produce HTML code coverage report."
+    )
+
+    # Show info where to find the report
+    add_custom_command(TARGET ${Coverage_NAME} POST_BUILD
+        COMMAND ;
+        COMMENT "Open ./${Coverage_NAME}/index.html in your browser to view the coverage report."
+    )
+
+endfunction() # SETUP_TARGET_FOR_COVERAGE_GCOVR_HTML
+
+function(APPEND_COVERAGE_COMPILER_FLAGS)
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${COVERAGE_COMPILER_FLAGS}" PARENT_SCOPE)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${COVERAGE_COMPILER_FLAGS}" PARENT_SCOPE)
+    message(STATUS "Appending code coverage compiler flags: ${COVERAGE_COMPILER_FLAGS}")
+endfunction() # APPEND_COVERAGE_COMPILER_FLAGS
diff --git a/README.md b/README.md
index ceb16ed..010acd8 100644
--- a/README.md
+++ b/README.md
@@ -152,6 +152,9 @@
   - `-DSANITIZE_THREAD=ON`
   - `-DSANITIZE_UNDEFINED=ON`
 - Running valgrind example `valgrind --leak-check=yes --tool=memcheck ./nextpnr-ice40 --json ice40/blinky.json`
+- Running tests with code coverage use `-DBUILD_TESTS=ON -DCOVERAGE` and after `make` run `make ice40-coverage` 
+- After that open `ice40-coverage/index.html` in your browser to view the coverage report
+- Note that `lcov` is needed in order to generate reports
 
 Links and references
 --------------------