I want to analyze code coverage datas. I want to create gcov files from OpenSSL (and from other projects), but I can only create them in the same directory of the project, and only for the files in the current folder.

I want to create them in a different directory, preserve the source original directory structure, and make the whole process as automatic as possible.

source: ~/mygcovproject/projects/openssl-1.0.0

output: ~/mygcovproject/gcovdata/openssl-1.0.0

Currently I can create the files only in this way:

$ cd ~/mygcovproject/projects/openssl-1.0.0
$ make clean
$ export CC="gcc -fprofile-arcs -ftest-coverage"; ./config
$ make
$ make tests

$ cd test
$ gcov *.c
$ mv *.gcov ~/mygcovproject/gcovdata/openssl-1.0.0/test/
$ cd ..

$ cd apps
$ gcov *.c
$ mv *.gcov ~/mygcovproject/gcovdata/openssl-1.0.0/apps/
$ cd ..

$cd crypto
... (for all the folders)

But there is 2 big problem with this method:

1) There are many folders and subfolders.

2) I have to move the files manually.

How should I do this? Can you help me please?


Thanks Gilles, it helped me a lot, but I still struggle with the last part. I get error messages from gcov:

$ cat dothemagic.sh 
shopt -s globstar
mkdir -p "$gcov_data_dir"
#make tests
for x in ./**/*.c; do
  gcov "$gcov_data_dir/${x%/*}/$x"

$ ./dothemagic.sh 
../../gcovdata/openssl-1.0.0/./apps/./apps/app_rand.gcno:cannot open notes file
../../gcovdata/openssl-1.0.0/./apps/./apps/apps.gcno:cannot open notes file
../../gcovdata/openssl-1.0.0/./apps/./apps/asn1pars.gcno:cannot open notes file
../../gcovdata/openssl-1.0.0/./apps/./apps/ca.gcno:cannot open notes file
../../gcovdata/openssl-1.0.0/./apps/./apps/ciphers.gcno:cannot open notes file
../../gcovdata/openssl-1.0.0/./apps/./apps/cms.gcno:cannot open notes file
../../gcovdata/openssl-1.0.0/./apps/./apps/crl2p7.gcno:cannot open notes file

I tried this too, but it did not work, i get errors:

for x in ./**/*.c; do
  echo $x
  gcov $x

$ ./run_tests.sh openssl-1.0.0

File 'app_rand.c'
Lines executed:37.50% of 40
Creating 'app_rand.c.gcov'
Cannot open source file app_rand.c

File 'apps.c'
Lines executed:33.76% of 939
Creating 'apps.c.gcov'
Cannot open source file apps.c


I tried a single command:

$ gcov ./apps/app_rand.c
File 'app_rand.c'
Lines executed:37.50% of 40
Creating 'app_rand.c.gcov'
Cannot open source file app_rand.c

Looks like I can only run gcov on the files in the same folder. How should I solve this? Should I cd in the directories in the loop, then move the files? Or am I doing something wrong?

I tried in the folders with the -o options, but it did not worked:

$ pwd
$ ls bftest.*
bftest.c  bftest.c.gcov  bftest.gcda  bftest.gcno  bftest.o
$ gcov -o ~/gcov_project/gcov/ bftest.c
/home/blackcat/gcov_project/gcov/bftest.gcno:cannot open notes file
$ gcov bftest.c
File 'bftest.c'
Lines executed:47.52% of 101
Creating 'bftest.c.gcov'

File '/usr/include/x86_64-linux-gnu/bits/stdio2.h'
Lines executed:100.00% of 1
Creating 'stdio2.h.gcov'

File '/usr/include/x86_64-linux-gnu/bits/string3.h'
Lines executed:100.00% of 2
Creating 'string3.h.gcov'

Upd2: Starting from Gilles solution I created a working code. Thanks. In the end I put all of them in the same directory, but I created a prefix from their path.

### Generate and copy gcov files ###

mkdir -p "$OUTPUT_DIR"

for x in **/*.c; do
  if [ "$CDIR" != "$TARGET_DIR/${x%/*}" ]; then
    cd $CDIR
    gcov -p *.c


    for f in *.gcov; do
        if [[ $f == \#* ]] ;
           cp $f "$OUTPUT_DIR/$f"
           cp $f "$OUTPUT_DIR/$PREFIX#$f"

You have the commands, so put them in a script!

To run a bunch of commands on different data, put the changing data in a variable.

To run gcov and mv on all the files, there are several possible methods, including:

  • Run gcov on all files, then move them.
  • Run gcov on one file, then move its output.
  • Run gconv on the files in a directory, then move them.

The first approach doesn't work because gcov needs to be executed in the directory containing the source files. The third directory-based approach is in fact the most complicated of the three: the simplest method would be to run gcov on one file at a time.

In bash, you can enumerate all the C files in a directory and its subdirectories recursively with the wildcard pattern **/*.c. The ** wildcard needs to be enabled with the globstar option. To iterate over the files, use a for loop.

To change into a directory just to run one command, run cd and that command in a subshell: (cd … && gcov …).

You need one more type of shell construct: a bit of manipulation of file names to extract the directory part. The parameter expansion construct ${x%/*} expands to the value of the variable x with the shortest suffix matching the pattern /* removed. In other words, that's the directory part of the file name stored in x. This wouldn't work if x consisted only of a file name with no directory part (i.e. foo as opposed to bar/foo); it so happens that there's no .c file at the root of the OpenSSL source tree, but a simple way to make sure the file name starts with ./, which designates the current directory.

Invoke this script at the root of the OpenSSL source tree, after running ./config with your desired options.

shopt -s globstar
make tests
for x in ./**/*.c; do
  mkdir -p "$gcov_data_dir/${x%/*}"
  (cd "${x%/*}" && gcov "${x##*/}") &&
  mv "$x.gcov" "$gcov_data_dir/${x%/*}"

To avoid having to move the .gcov files, an alternative approach would be to create a forest of symbolic links to the compilation directory, and run gcov in the gcovdata directory. With GNU coreutils (i.e. on non-embedded Linux or Cygwin), you can do that with cp -al.

cp -al openssl-1.0.0 gcovdata
cd gcovdata
for x in ./**/*.c; do
  (cd "${x%/*}" && gcov "${x##*/}")
  • Thanks Gilles, it helped me a lot, but I still struggle with the last part. I've updated my question. – BlackCat Jul 26 '15 at 11:32
  • @BlackCat Sorry for the delay. I hadn't realized that gcov always writes to the current directory. I've updated my answer. – Gilles Aug 3 '15 at 1:15

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