On 3/28/22 18:23, Sebastian Huber wrote:
On 24/03/2022 13:03, Martin Liška wrote:
On 3/24/22 11:51, Sebastian Huber wrote:
Maybe we could add the file path into the gcov information stream using a new
tag:
#define GCOV_TAG_GCDA_FILE_NAME ((gcov_unsigned_t)0xa5000000)
Then the complete gcov information can be dumped using a single base64 encoded
stream. We could add some support to the gcov-tool to read this stream and
merge it into gcda files.
I would support such patch!
Ok, good. I work currently on a prototype implementation. My use case would be
like this.
Great, the suggested scheme works for me.
Run a test executable which dumps all gcov info objects in a serial data stream. It could
be encoded as base64. It could be also compressed. On the host you unpack the encoded
data stream and feed it into gcov-tool using the new "merge-stream" subcommand:
gcov-tool --help
Usage: gcov-tool [OPTION]... SUB_COMMAND [OPTION]...
Offline tool to handle gcda counts
-h, --help Print this help, then exit
-v, --version Print version number, then exit
merge-stream [options] [stream-file] Merge coverage stream file (or stdin)
and coverage file contents
-v, --verbose Verbose mode
-w, --weight <w1,w2> Set weights (float point values)
Example:
base64 -d log.txt | gcov-tool merge-stream
The gcov-tool uses a new tag which contains the filename of the associated gcov
info file:
gcov-dump b-xilinx_zynq_a9_qemu/init.gcda
b-xilinx_zynq_a9_qemu/init.gcda:data:magic `gcda':version `B20 '
b-xilinx_zynq_a9_qemu/init.gcda:stamp 3496756572
b-xilinx_zynq_a9_qemu/init.gcda:checksum 137326246
b-xilinx_zynq_a9_qemu/init.gcda: a5000000: 62:FILENAME
`/home/EB/sebastian_h/src/lwip/b-xilinx_zynq_a9_qemu/init.gcda'
b-xilinx_zynq_a9_qemu/init.gcda: a1000000: 8:OBJECT_SUMMARY runs=0, sum_max=0
b-xilinx_zynq_a9_qemu/init.gcda: 01000000: 12:FUNCTION ident=1016818396,
lineno_checksum=0xd31791e7, cfg_checksum=0x4529789a
b-xilinx_zynq_a9_qemu/init.gcda: 01a10000: 232:COUNTERS arcs 29 counts
Should I generate this filename tag to all configurations or just in case
inhibit_libc is defined?
I would emit it unconditionally. Btw. why do you need the tag?
Cheers,
Martin
Advantage:
* No dependency on the GCC configuration
Disadvantages:
* Bigger files
* Actual filename and the filename of the tag differ if file is moved
* Potential information leak
In any case, I would add the support for the (optional) filename tag to all
readers.
