This also adds coverage support to the new test framework, which due to
reduction in scope, no longer needs aggregation and can be much
simpler. Really all we need to do is pass --coverage to GCC, which
builds its .gcda files during testing in a multi-process-safe manner.
The addition of branch coverage leverages information that was available
in both lcov and gcov.
This was made easier with the addition of the --json-format to gcov
in GCC 9.0, however the lax backwards compatibility for gcov's
intermediary options is a bit concerning. Hopefully --json-format
sticks around for a while.
GCC is a bit annoying here, it can't generate .cgi files without
generating the related .o files, though I suppose the alternative risks
duplicating a large amount of compilation work (littlefs is really
a small project).
Previously we rebuilt the .o files anytime we needed .cgi files
(callgraph info used for stack.py). This changes it so we always
built .cgi files as a side-effect of compilation. This is similar
to the .d file generation, though may be annoying if the system
cc doesn't support --callgraph-info.
A small mistake in test.py's control flow meant the failing test job
would succesfully kill all other test jobs, but then humorously start
up a new process to continue testing.
A full summary of static measurements (code size, stack usage, etc) can now
be found with:
make summary
This is done through the combination of a new ./scripts/summary.py
script and the ability of existing scripts to merge into existing csv
files, allowing multiple results to be merged either in a pipeline, or
in parallel with a single ./script/summary.py call.
The ./scripts/summary.py script can also be used to quickly compare
different builds or configurations. This is a proper implementation
of a similar but hacky shell script that has already been very useful
for making optimization decisions:
$ ./scripts/structs.py new.csv -d old.csv --summary
name (2 added, 0 removed) code stack structs
TOTAL 28648 (-2.7%) 2448 1012
Also some other small tweaks to scripts:
- Removed state saving diff rules. This isn't the most useful way to
handle comparing changes.
- Added short flags for --summary (-Y) and --files (-F), since these
are quite often used.
- Added -L/--depth argument to show dependencies for scripts/stack.py,
this replaces calls.py
- Additional internal restructuring to avoid repeated code
- Removed incorrect diff percentage when there is no actual size
- Consistent percentage rendering in test.py
This required a patch to the --diff flag for the scripts to ignore
a missing file. This enables the useful one liner for making comparisons
with potentially missing previous versions:
./scripts/code.py lfs.o -d lfs.o.code.csv -o lfs.o.code.csv
function (0 added, 0 removed) old new diff
TOTAL 25476 25476 +0
One downside, these previous files are easy to delete as a part of make
clean, which limits their usefulness for comparing configuration
changes...
Note this detects loops (recursion), and renders this as infinity.
Currently littlefs does have a single recursive function and you can see
how this infects the full call graph. Eventually this should be removed.
