c++ - Gcov 报告未命中 return 语句

Question

gcov 提示我的一种算法:

File 'Algorithm.h'
Lines executed:95.00% of 20
Algorithm.h:creating 'Algorithm.h.gcov'

   17:   25:inline std::vector<std::string> starts_with(const std::vector<std::string>& input, const std::string& startsWith)
    -:   26:{
   17:   27:    std::vector<std::string> output;
   17:   28:    std::remove_copy_if(input.begin(), input.end(), std::back_inserter(output), !boost::bind(&boost::starts_with<std::string,std::string>, _1, startsWith));
#####:   29:    return output;
    -:   30:}

我的测试看起来像这样，它通过了:

TEST (TestAlgorithm, starts_with)
{
    std::vector<std::string> input = boost::assign::list_of("1")("2")("22")("33")("222");
    EXPECT_TRUE(starts_with(input,"22") == boost::assign::list_of("22")("222"));
}

可能是什么问题？我没有使用优化。

更新:

我的 CMakeList.txt 包含:

if(CMAKE_COMPILER_IS_GNUCXX)
    set(CMAKE_CXX_FLAGS "-O0")        ## Optimize
endif()

Answer 1

尝试在 g++ 中使用 -fno-elide-constructors 开关

来自 GCC 权威指南:

-fno-elide-constructors: This option when compiling C++ options causes GCC not to omit creating temporary objects when initializing objects of the same type, as permitted by the C++ standard. Specifying this option causes GCC to explicitly call the copy constructor in all cases.

这里有一些讨论: How can I get more accurate results from gcov?在这里:http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12076