Brief Description of gcov Data Files#
gcov uses two files for profiling. The names of these files
are derived from the original object file by substituting the
file suffix with either .gcno
, or .gcda
. The files
contain coverage and profile data stored in a platform-independent format.
The .gcno
files are placed in the same directory as the object
file. By default, the .gcda
files are also stored in the same
directory as the object file, but the GCC -fprofile-dir
option
may be used to store the .gcda
files in a separate directory.
The .gcno
notes file is generated when the source file is compiled
with the GCC -ftest-coverage
option. It contains information to
reconstruct the basic block graphs and assign source line numbers to
blocks.
The .gcda
count data file is generated when a program containing
object files built with the GCC -fprofile-arcs
option is executed.
A separate .gcda
file is created for each object file compiled with
this option. It contains arc transition counts, value profile counts, and
some summary information.
It is not recommended to access the coverage files directly.
Consumers should use the intermediate format that is provided
by gcov tool via --json-format
option.