On Fri, Mar 30 2018, Johannes Schindelin wrote [expressing frustrations
about Windows test suite slowness]:
I've wondered for a while whether it wouldn't be a viable approach to
make something like an interpreter for our test suite to get around this
problem, i.e. much of it's very repetitive and just using a few shell
functions we've defined, what if we had C equivalents of those?
Duy had a WIP patch set a while ago to add C test suite support, but I
thought what if we turn that inside-out, and instead have a shell
interpreter that knows about the likes of test_cmp, and executes them
directly?
Here's proof of concept as a patch to the dash shell:
u dash (debian/master=) $ git diff
diff --git a/src/builtins.def.in b/src/builtins.def.in
index 4441fe4..b214a17 100644
--- a/src/builtins.def.in
+++ b/src/builtins.def.in
@@ -92,3 +92,4 @@ ulimitcmd ulimit
#endif
testcmd test [
killcmd -u kill
+testcmpcmd test_cmp
diff --git a/src/jobs.c b/src/jobs.c
index c2c2332..905563f 100644
--- a/src/jobs.c
+++ b/src/jobs.c
@@ -1502,3 +1502,12 @@ getstatus(struct job *job) {
jobno(job), job->nprocs, status, retval));
return retval;
}
+
+#include <stdio.h>
+int
+testcmpcmd(argc, argv)
+ int argc;
+ char **argv;
+{
+ fprintf(stderr, "Got %d arguments\n", argc);
+}
I just added that to jobs.c because it was easiest, then test_cmp
becomes a builtin:
u dash (debian/master=) $ src/dash -c 'type test_cmp'
test_cmp is a shell builtin
u dash (debian/master=) $ src/dash -c 'echo foo && test_cmp 1 2 3'
foo
Got 4 arguments
I.e. it's really easy to add new built in commands to the dash shell
(and probably other shells, but dash is really small & fast).
We could carry some patch like that to dash, and also patch it so
test-lib.sh could know that that was our own custom shell, and we'd then
skip defining functions like test_cmp, and instead use that new builtin.
Similarly, it could then be linked to our own binaries, and the
test-tool would be a builtin that would appropriately dispatch, and we
could even eventually make "git" a shell builtin.
I don't have time or interest to work on this now, but thought it was
interesting to share. This assumes that something in shellscript like:
while echo foo; do echo bar; done
Is no slower on Windows than *nix, since it's purely using built-ins, as
opposed to something that would shell out.
