We use TAL_USE_TALLOC to use libtalloc as the backend: you can test that with
ccanlint --compiler="cc -DTAL_USE_TALLOC".
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

We can't really tell if non-ccan dependencies are used, so don't try.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

David Gibson points out that a project may already be using talloc, so
this gives a simple adapter if one module uses tal.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

It may interfere with other at_exit() calls, so let them call it manually.
Also, use memset to zero, which really does make valgrind notice any leaks.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

In this case, CCAN_CFLAGS should be "".
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Since we never post-add a length property, we can save some cycles by
allocating it together with the object itself:

Before:
	$ ./samba-allocs talloc.dump --tal
	Tal time:                6058997-6215211(6102645)ns
	Tal_free time:           4791112-4968964(4824814)ns
	Single tal_free time:    3173647-3331584(3200183)ns
	$ ./samba-allocs talloc.dump --tal-size
	Virtual size = 9809920, RSS = 3952640

After:
	$ ./samba-allocs talloc.dump --tal
	Tal time:                5911994-6043808(5956914)ns
	Tal_free time:           4676026-4834598(4719908)ns
	Single tal_free time:    2888195-3067365(2922298)ns
	$ ./samba-allocs talloc.dump --tal-size
	Virtual size = 9809920, RSS = 3948544
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Since we added the length property, this penalizes us with an extra
alloc.  Unfortunately, we can't tell from the talloc.dump which are
array tallocs and which are single tallocs, but grepping the sources
gives a rate of 1 in 27.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

The first ok() line was actually failing, because sigaction returns 0
on success, but because the program exit(0) out the abort handler,
that wasn't being seen.

So remove tap and just abort and assert our way through the test,
which I think is clearer.

We use macros to mug the talloc entry points, since talloc_set_allocator()
is not in mainline talloc.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Now it's a useful little command line utility, with tests.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

We weren't using the compiler and cflags options in tools/compile.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

We can use tal_count.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

eg:
	tal/str: Module's tests cover all the code (tests_coverage): PASS (+3/6)
	tal/str: Total score: 55/58
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Slowly removing the talloc dependency.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Tests and example copied from talloc_link, which I also wrote.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

They are far too convenient, despite their inefficiency.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Shorter, sweeter, and less legacy.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Useful for joining two strings.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Helper to reallocate and append to an array.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

They don't need anything internal to tal, they're just helpers.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

It's short, and much clearer.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Unlike talloc, we don't have a count on everything, just on array
allocations.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

You don't need write access to the context to attach a destructor;
it's meta.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

$ for i in `seq 10`; do ./samba-allocs talloc.dump --tal; done | stats.c --trim-outliers
Before:
Read 25998 nodes
Tal time:                2857988-2981158(2904324)ns
Tal_free time:           2417170-2582088(2470931)ns
Single tal_free time:    1551654-1609583(1575984)ns

After:
Read 25998 nodes
Tal time:                2780974-2901323(2839352)ns
Tal_free time:           2241725-2355309(2285165)ns
Single tal_free time:    1549908-1612485(1566609)ns
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

We sanity check tal headers by ensuring that the pointers are in the
bounds of things we've allocated.  But the first one we check is the
prop ptr, which may also be a literal: this is_literal() dereferences
the pointer, which means we usually crash here if it's not a tal
object.

Move that last, and we have far more success with our sanity checking.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

All the effort trying to keep the header size down to 2 pointers turns
out to be wasted.  In addition, getting the parent of a tal pointer is
now much faster.

./samba-allocs talloc.dump --tal-size:
Before:
	Virtual size = 9633792, RSS = 3952640
After:
	Virtual size = 9793536, RSS = 3948544

And we're much faster now, esp. on free.

./samba-allocs talloc.dump --tal:
Before:
	Tal time:                2718068ns
	Tal_free time:           3360258ns
	Single tal_free time:    1667412ns
After:
	Tal time:                2788287ns
	Tal_free time:           2290167ns
	Single tal_free time:    1566998ns
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>


Header from folded patch 'tal-fix-set-destroying-bit.patch':

tal: fix destroying bit usage.

Actually looking at a destroying contexts' parent didn't work, and a couple
of places didn't filter out the destroying bit.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

If we see an ccan include line in an example, we add that to the
dependencies to try to build the example, but we didn't handle nested
modules.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

ccanlint would abort with 'Malformed line 53' if there was a bad header.
That's very poor, and deeply unhelpful.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>