title: Makefile//Shell command, what is it doing and how? How to see what is happening
body: <p>I am trying to understand/use a pre-defined Makefile (from CppUTest, <a href="https://github.com/cpputest/cpputest/blob/master/build/MakefileWorker.mk" rel="nofollow">MakefileWorker.mk</a>).
  Around line 515 there is a <code>gcov</code> command available. However, when I use <code>make gcov</code> gcov is (once) invoked with apparantly invalid parameters as it (once) prints its usage:</p>
  
  <pre><code>D:\devel\ctest&gt;make gcov
  Running ctest_tests
  ..............................................
  OK (46 tests, 46 ran, 407 checks, 0 ignored, 0 filtered out, 0 ms)
  
  ./../cpputest/scripts/filterGcov.sh gcov_output.txt gcov_error.txt gcov_report.txt ctest_tests.txt
  
    0.00%
    0.00%   -a, --all-blocks Show information for every basic block
    0.00%   -b, --branch-probabilities Include branch probabilities in output
    0.00%   -c, --branch-counts Output counts of branches taken
    0.00%   -d, --display-progress Display progress information
    0.00%   -f, --function-summaries Output summaries for each function
    0.00%   -h, --help Print this help, then exit
    0.00%   -i, --intermediate-format Output .gcov file in intermediate text format
    0.00%   -l, --long-file-names Use long output file names for included
    0.00%   -m, --demangled-names Output demangled function names
    0.00%   -n, --no-output Do not create an output file
    0.00%   -o, --object-directory DIR|FILE Search for object files in DIR or called FILE
    0.00%   -p, --preserve-paths Preserve all pathname components
    0.00%   -r, --relative-only Only show data for relative sources
    0.00%   -s, --source-prefix DIR Source prefix to elide
    0.00%   -u, --unconditional-branches Show unconditional branch counts too
    0.00%   -v, --version Print version number, then exit
    0.00%   &lt;http://sourceforge.net/projects/mingw-w64&gt;.
    0.00%   For bug reporting instructions, please see:
    0.00%   Print code coverage information.
    0.00%   rather than percentages
    0.00%   source files
    0.00%   Usage: gcov [OPTION]... SOURCE|OBJ...
   96.97%   src/HomeAutomation/LightScheduler.c
  100.00%   src/HomeAutomation/RandomMinute.c
  File src/HAL/UART/hal_uart_baudrate.c   Lines executed:97.22% of 72
  See gcov directory for details
  
  D:\devel\ctest&gt;
  </code></pre>
  
  <p>But I am all but skilled in unravelling Makefiles/bash scripts and have no clue where things might go wrong.
  As for the settings used:</p>
  
  <pre><code>CPPUTEST_USE_VPATH = N
  SRC_DIRS = \
      src/util\
      src/HomeAutomation\
      src/HAL/UART
  SRC_FILES is empty
  </code></pre>
  
  <p>It is going "wrong" at the <code>gcov --object-directory etc</code> invocation, but that is all I know.</p>