Skip to main content

Browse the archive

Revision d88785e424aaf18aa3ca291c2299c599c000c6cb authored by Jeff King on 11 May 2016, 13:44:04 UTC, committed by Junio C Hamano on 11 May 2016, 21:03:14 UTC 
test-lib: set BASH_XTRACEFD automatically
 
Passing "-x" to a test script enables the shell's "set -x"
tracing, which can help with tracking down the command that
is causing a failure. Unfortunately, it can also _cause_
failures in some tests that redirect the stderr of a shell
function.  Inside the function the shell continues to
respect "set -x", and the trace output is collected along
with whatever stderr is generated normally by the function.

You can see an example of this by running:

  ./t0040-parse-options.sh -x -i

which will fail immediately in the first test, as it
expects:

  test_must_fail some-cmd 2>output.err

to leave output.err empty (but with "-x" it has our trace
output).

Unfortunately there isn't a portable or scalable solution to
this. We could teach test_must_fail to disable "set -x", but
that doesn't help any of the other functions or subshells.

However, we can work around it by pointing the "set -x"
output to our descriptor 4, which always points to the
original stderr of the test script. Unfortunately this only
works for bash, but it's better than nothing (and other
shells will just ignore the BASH_XTRACEFD variable).

The patch itself is a simple one-liner, but note the caveats
in the accompanying comments.

Automatic tests for our "-x" option may be a bit too meta
(and a pain, because they are bash-specific), but I did
confirm that it works correctly both with regular "-x" and
with "--verbose-only=1". This works because the latter flips
"set -x" off and on for particular tests (if it didn't, we
would get tracing for all tests, as going to descriptor 4
effectively circumvents the verbose flag).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 7654286
Raw File
diffcore-order.c 
/*
 * Copyright (C) 2005 Junio C Hamano
 */
#include "cache.h"
#include "diff.h"
#include "diffcore.h"

static char **order;
static int order_cnt;

static void prepare_order(const char *orderfile)
{
	int cnt, pass;
	struct strbuf sb = STRBUF_INIT;
	void *map;
	char *cp, *endp;
	ssize_t sz;

	if (order)
		return;

	sz = strbuf_read_file(&sb, orderfile, 0);
	if (sz < 0)
		die_errno(_("failed to read orderfile '%s'"), orderfile);
	map = strbuf_detach(&sb, NULL);
	endp = (char *) map + sz;

	for (pass = 0; pass < 2; pass++) {
		cnt = 0;
		cp = map;
		while (cp < endp) {
			char *ep;
			for (ep = cp; ep < endp && *ep != '\n'; ep++)
				;
			/* cp to ep has one line */
			if (*cp == '\n' || *cp == '#')
				; /* comment */
			else if (pass == 0)
				cnt++;
			else {
				if (*ep == '\n') {
					*ep = 0;
					order[cnt] = cp;
				} else {
					order[cnt] = xmemdupz(cp, ep - cp);
				}
				cnt++;
			}
			if (ep < endp)
				ep++;
			cp = ep;
		}
		if (pass == 0) {
			order_cnt = cnt;
			order = xmalloc(sizeof(*order) * cnt);
		}
	}
}

static int match_order(const char *path)
{
	int i;
	static struct strbuf p = STRBUF_INIT;

	for (i = 0; i < order_cnt; i++) {
		strbuf_reset(&p);
		strbuf_addstr(&p, path);
		while (p.buf[0]) {
			char *cp;
			if (!wildmatch(order[i], p.buf, 0, NULL))
				return i;
			cp = strrchr(p.buf, '/');
			if (!cp)
				break;
			*cp = 0;
		}
	}
	return order_cnt;
}

static int compare_objs_order(const void *a_, const void *b_)
{
	struct obj_order const *a, *b;
	a = (struct obj_order const *)a_;
	b = (struct obj_order const *)b_;
	if (a->order != b->order)
		return a->order - b->order;
	return a->orig_order - b->orig_order;
}

void order_objects(const char *orderfile, obj_path_fn_t obj_path,
		   struct obj_order *objs, int nr)
{
	int i;

	if (!nr)
		return;

	prepare_order(orderfile);
	for (i = 0; i < nr; i++) {
		objs[i].orig_order = i;
		objs[i].order = match_order(obj_path(objs[i].obj));
	}
	qsort(objs, nr, sizeof(*objs), compare_objs_order);
}

static const char *pair_pathtwo(void *obj)
{
	struct diff_filepair *pair = (struct diff_filepair *)obj;

	return pair->two->path;
}

void diffcore_order(const char *orderfile)
{
	struct diff_queue_struct *q = &diff_queued_diff;
	struct obj_order *o;
	int i;

	if (!q->nr)
		return;

	o = xmalloc(sizeof(*o) * q->nr);
	for (i = 0; i < q->nr; i++)
		o[i].obj = q->queue[i];
	order_objects(orderfile, pair_pathtwo, o, q->nr);
	for (i = 0; i < q->nr; i++)
		q->queue[i] = o[i].obj;
	free(o);
	return;
}
back to top