使用Gcovr对多个文件进行代码覆盖

Question

我对gcovr很陌生。我的代码中有3个文件，即main.cpp、math.cpp和math.hpp，我使用以下命令用g++编译它

g++ -fprofile-arcs -ftest-coverage -fPIC -O0 main.cpp  math.cpp math.hpp -o math

我的代码已经编译并成功运行。当我为代码覆盖率运行以下命令时

 gcovr -r .

它产生这样的输出

------------------------------------------------------------------------------
                       GCC Code Coverage Report
Directory: .
------------------------------------------------------------------------------
File                                       Lines    Exec  Cover   Missing
------------------------------------------------------------------------------
main.cpp                                       6       6   100%
------------------------------------------------------------------------------
TOTAL                                          6       6   100%
------------------------------------------------------------------------------ 

它只显示了main.cpp的代码覆盖率。我想知道其他文件的代码覆盖率，too.How，我能得到它吗？如果您提前can.Thanks，请帮助我。

这是我的代码main.cpp

#include "math.hpp"
int main( int argc, char **argv)
{
    Math m;
    m.Multiply(20, 50);
    m.Divide(40, 5);
}

Math.cpp

#include "math.hpp"

using namespace std;
int Math::Multiply(int Num1, int Num2){
    Mul= Num1 * Num2;
    std::cout << "Multiplication of "<<Num1<< " * " <<Num2<< " = "<< Mul<<endl;
    return Mul;
}

int Math::Divide(int Num1, int Num2){
    Div = Num1/Num2;
    std::cout << "Division of "<<Num1<< " / " <<Num2 <<" = "<< Div<<endl;
    return Div;
}

math.hpp

#include <ctime>
#include<iostream>
class Math
{
  int Num1;
  int Num2;
  int Fact, Mul, Div, Num, i;

public:
  int Multiply(int Num1,int Num2);
  int Divide(int Num1, int Num2);
};

运行命令gcovr -v -r时。如下所示

C:\Users\user\Desktop\Gcovr>gcovr -v -r .
Filters for --root: (1)
- <_sre.SRE_Pattern object at 0x01C206A0>
Filters for --filter: (1)
- DirectoryPrefixFilter(C\:\/Users\/user\/Desktop\/Gcovr\/)
Filters for --exclude: (0)
Filters for --gcov-filter: (1)
- AlwaysMatchFilter()
Filters for --gcov-exclude: (0)
Filters for --exclude-directories: (0)
Scanning directory . for gcda/gcno files...
Found 4 files (and will process 2)
Pool started with 1 threads
Processing file: C:\Users\user\Desktop\Gcovr\main.gcda
Running gcov: 'gcov C:\Users\user\Desktop\Gcovr\main.gcda --branch-counts -- 
branch-probabilities --preserve-paths --object-directory 
C:\Users\user\Desktop\Gcovr' in 'c:\users\user\appdata\local\temp\tmpyekiry'
Running gcov: 'gcov C:\Users\user\Desktop\Gcovr\main.gcda --branch-counts -- 
branch-probabilities --preserve-paths --object-directory 
C:\Users\user\Desktop\Gcovr' in 'C:\Users\user\Desktop\Gcovr'
Finding source file corresponding to a gcov data file
  currdir      C:\Users\user\Desktop\Gcovr
  gcov_fname   c:\users\user\appdata\local\temp\tmpyekiry\main.cpp.gcov
           [u'        -', u'    0', u'Source', u'main.cpp\n']
  source_fname C:\Users\user\Desktop\Gcovr\main.gcda
  root         C:\Users\user\Desktop\Gcovr
  fname        C:\Users\user\Desktop\Gcovr\main.cpp
Parsing coverage data for file C:\Users\user\Desktop\Gcovr\main.cpp
uncovered: set([])
covered:   {2: 1, 5: 1, 6: 1, 7: 4}
branches:  {5: {1: 1, 2: 0}, 6: {1: 1, 2: 0}, 7: {1: 1, 2: 0, 3: 1, 4: 0}}
noncode:   set([3])
Finding source file corresponding to a gcov data file
  currdir      C:\Users\user\Desktop\Gcovr
  gcov_fnamec:\users\user\appdata\local\temp\tmpyekiry\c~#mingw#lib#gcc#mingw32#6.3.0#include#c++#iostream.gcov
           [u'        -', u'    0', u'Source', 
u'c:/mingw/lib/gcc/mingw32/6.3.0/include/c++/iostream\n']
  source_fname C:\Users\user\Desktop\Gcovr\main.gcda
  root         C:\Users\user\Desktop\Gcovr
  fname        c:\mingw\lib\gcc\mingw32\6.3.0\include\c++\iostream
Parsing coverage data for file c:\mingw\lib\gcc\mingw32\6.3.0\include\c++\iostream
  Filtering coverage data for file c:\mingw\lib\gcc\mingw32\6.3.0\include\c++\iostream
Processing file: C:\Users\user\Desktop\Gcovr\math.gcda
Running gcov: 'gcov C:\Users\user\Desktop\Gcovr\math.gcda --branch-counts --branch-probabilities --preserve-paths --object-directory C:\Users\user\Desktop\Gcovr' in 'c:\users\user\appdata\local\temp\tmpyekiry'
Gathered coveraged data for 1 files

Answer 1

问题是，您正在显式地将头文件math.hpp传递给编译器。这不包含任何会产生对象代码的定义，这会导致以下事件序列：

1. main.cpp是编译的。创建一个文件main.gcno，允许gcov解释覆盖数据main.gcda。
2. math.cpp是编译的，它创建了一个math.gcno文件。
3. math.hpp是编译的，它用空文件覆盖math.gcno。

因此，不识别math.cpp的覆盖率数据，并且该文件被排除在覆盖范围之外。

没有必要将math.hpp传递给编译器，因为源文件#include这个文件。如果从编译器调用中删除标头，我们将得到以下gcovr输出：

------------------------------------------------------------------------------
                           GCC Code Coverage Report
Directory: .
------------------------------------------------------------------------------
File                                       Lines    Exec  Cover   Missing
------------------------------------------------------------------------------
main.cpp                                       4       4   100%   
math.cpp                                       9       9   100%   
------------------------------------------------------------------------------
TOTAL                                         13      13   100%
------------------------------------------------------------------------------

( math.hpp文件仍未列出，但包含的语句为零。)