gcov coverage limited to test files

Question

I have the following CMakeLists.txt file:

cmake_minimum_required(VERSION 3.16)
project(first_coverage)

set(CXX_STANDARD 20)
set(CXX_STANDARD_REQUIRED True)
set(CMAKE_BUILD_TYPE Debug)
set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
set(CMAKE_CXX_OUTPUT_EXTENSION_REPLACE ON)

include (FetchContent)

enable_testing()

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} --coverage -O0 -fprofile-arcs -fprofile-abs-path -ftest-coverage -fno-inline -fno-inline-small-functions -fno-default-inline")

file(GLOB_RECURSE sources "src/**.cpp")

file(GLOB_RECURSE test_cases "test/**.cpp")

message(flags: ${CMAKE_CXX_FLAGS})

add_library(first_coverage_deps INTERFACE)
target_link_libraries(first_coverage_deps INTERFACE
    ${CONAN_LIBS}
)

target_compile_options(first_coverage_deps INTERFACE
    -Werror=return-type
    -Werror=unused
    -Werror=pessimizing-move
    -Werror=redundant-move
)

target_include_directories(first_coverage_deps
    INTERFACE src
    INTERFACE external
)

add_library(first_coverage
    ${sources}
)

set(FETCHCONTENT_BASE_DIR "${CMAKE_SOURCE_DIR}/external/")

FetchContent_Declare(
    googletest
    URL https://github.com/google/googletest/archive/609281088cfefc76f9d0ce82e1ff6c30cc3591e5.zip
)

FetchContent_MakeAvailable(googletest)

add_executable(first_coverage_test
    ${test_cases}
)

target_link_libraries(first_coverage first_coverage_deps)
target_link_libraries(first_coverage_test first_coverage gtest_main)

include(GoogleTest)
gtest_discover_tests(first_coverage_test)

and a src folder with a header and a source file: QuickMaths.hpp:

#include <cstdint>

using size_t = std::size_t;

size_t
multiply(size_t a, size_t b);

inline size_t
add(size_t a, size_t b)
{
  return a + b;
}

class QuickMaths
{
public:
  size_t operator*() const;
  friend QuickMaths operator+(QuickMaths const&, QuickMaths const&);

  QuickMaths(size_t x);

private:
  size_t x;
};

and

#include "QuickMaths.hpp"

size_t
multiply(size_t a, size_t b)
{
  return a * b;
}

size_t
QuickMaths::operator*() const
{
  return x;
}

QuickMaths::QuickMaths(size_t x)
  : x(x)
{}

QuickMaths
operator+(QuickMaths const& a, QuickMaths const& b)
{
  return a.x + b.x;
}

I have a test folder with a QuickMaths.cpp file:

#include <gtest/gtest.h>

#include <QuickMaths.hpp>

TEST(AddTest, shouldAdd)
{
  EXPECT_EQ(add(1UL, 1UL), 2UL);
}

TEST(MultiplyTest, shouldMultiply)
{
  EXPECT_EQ(multiply(2UL, 4UL), 8UL);
}

TEST(QuickMathTest, haveValue)
{
  auto v = QuickMaths{ 4UL };
  EXPECT_EQ(*v, 4UL);
}

Steps I use to build the project, run test, generate coverage are as following:

mkdir external && mkdir build && cd build

cmake ../

make && make test

gcovr -r ../ .

It successfully creates coverage output, however the coverage only shows executed lines for the external/gtest as well as the file in test, but shows 0 lines executed for the files that I really want to test, which are the header and the source-file in the src directory.

The output of make test is as follows:

Running tests...
Test project /home/pete/dev/sandbox/coverage_sbs/first_coverage/build
    Start 1: AddTest.shouldAdd
1/3 Test #1: AddTest.shouldAdd ................   Passed    0.01 sec
    Start 2: MultiplyTest.shouldMultiply
2/3 Test #2: MultiplyTest.shouldMultiply ......   Passed    0.00 sec
    Start 3: QuickMathTest.haveValue
3/3 Test #3: QuickMathTest.haveValue ..........   Passed    0.00 sec

100% tests passed, 0 tests failed out of 3

Total Test time (real) =   0.03 sec

And here's the output of gcovr -r ../ .

------------------------------------------------------------------------------
                           GCC Code Coverage Report
Directory: ../
------------------------------------------------------------------------------
File                                       Lines    Exec  Cover   Missing
------------------------------------------------------------------------------
external/googletest-src/googletest/include/gtest/gtest-printers.h
                                              20       0     0%   212,215,306,312,333-334,413,415,440-441,665,674,833-834,902,906,942-945
external/googletest-src/googletest/include/gtest/gtest.h
                                              17       0     0%   324,333-334,337,427,435,440-441,522,1522,1529,1541,1545-1546,1549,1561,1564
external/googletest-src/googletest/include/gtest/internal/gtest-internal.h
                                              19       1     5%   454,461,493-494,506,508,521,525,527,529,532,534,542,546,548,550,553,555
external/googletest-src/googletest/include/gtest/internal/gtest-port.h
                                               1       0     0%   970
src/QuickMaths.cpp                             8       0     0%   4,6,10,12,15-16,20,22
src/QuickMaths.hpp                             2       0     0%   9,11
test/QuickMaths.cpp                            7       3    42%   7,12,17-18
------------------------------------------------------------------------------
TOTAL                                         74       4     5%
------------------------------------------------------------------------------

How do I get the coverage to be correctly recognized for these files?

Answer 1

In my case this turned out to be a version-mismatch between gcc and gcov (See comment under answer to related-thread )

If the default gcov does not match the compiler you used, you must tell gcovr. You can do this either via a command line flag gcovr --gcov-executable gcov-11 -r ../ or via an environment variable GCOV=gcov-11 gcovr -r ../