The Autoconf macro AC_USE_SYSTEM_EXTENSIONS defines preprocessor macros
which turn on extensions to C and POSIX. The macro also makes it easier
for developers to use the extensions without needing (or forgetting) to
define them manually.
The macro can be safely used because it was introduced in Autoconf 2.60
and Tor requires Autoconf 2.63 and above.
This is a big-ish patch, but it's very straightforward. Under this
clang warning, we're not actually allowed to have a global variable
without a previous extern declaration for it. The cases where we
violated this rule fall into three roughly equal groups:
* Stuff that should have been static.
* Stuff that was global but where the extern was local to some
other C file.
* Stuff that was only global when built for the unit tests, that
needed a conditional extern in the headers.
The first two were IMO genuine problems; the last is a wart of how
we build tests.
This warning, IIUC, means that the compiler doesn't like it when it
sees a NULL check _after_ we've already dereferenced the
variable. In such cases, it considers itself free to eliminate the
NULL check.
There are a couple of tricky cases:
One was the case related to the fact that tor_addr_to_in6() can
return NULL if it gets a non-AF_INET6 address. The fix was to
create a variant which asserts on the address type, and never
returns NULL.
So, back long ago, XXX012 meant, "before Tor 0.1.2 is released, we
had better revisit this comment and fix it!"
But we have a huge pile of such comments accumulated for a large
number of released versions! Not cool.
So, here's what I tried to do:
* 0.2.9 and 0.2.8 are retained, since those are not yet released.
* XXX+ or XXX++ or XXX++++ or whatever means, "This one looks
quite important!"
* The others, after one-by-one examination, are downgraded to
plain old XXX. Which doesn't mean they aren't a problem -- just
that they cannot possibly be a release-blocking problem.
We need to define this function when compiling with clang -m32 -ftrapv,
since otherwise we get link errors, since apparently some versions
of libclang_rt.builtins don't define a version of it that works? Or
clang doesn't know to look for it?
This definition is taken from the LLVM source at
https://llvm.org/svn/llvm-project/compiler-rt/trunk/lib/builtins/mulodi4.c
I've also included the license (dual BSD-ish/MIT-ish).
We know there are overflows in curve25519-donna-c32, so we'll have
to have that one be fwrapv.
Only apply the asan, ubsan, and trapv options to the code that does
not need to run in constant time. Those options introduce branches
to the code they instrument.
(These introduced branches should never actually be taken, so it
might _still_ be constant time after all, but branch predictors are
complicated enough that I'm not really confident here. Let's aim for
safety.)
Closes 17983.
* SHA-3/SHAKE use little endian for certain things, so byteswap as
needed.
* The code was written under the assumption that unaligned access to
quadwords is allowed, which isn't true particularly on non-Intel.
Yes, we could cast to unsigned char first, but it's probably safest
to just use our own (in test_util), or remove bad-idea features that
we don't use (in readpassphrase.c).
Fixes 18728.
The digest routines use init/update/sum, where sum will automatically
copy the internal state to support calculating running digests.
The XOF routines use init/absorb/squeeze, which behave exactly as stated
on the tin.
Apparently this only happens with clang (or with some particular
clang versions), and only on i386.
Fixes 16970; bug not in any released Tor.
Found by Teor; fix from Yawning.
This probably requires the user to manually set CFLAGS, but should
result in a net gain on 32 bit x86. Enabling SSE2 support would be
possible on x86_64, but will result in slower performance.
Implements feature #16535.
The code was always in our Ed25519 wrappers, so enable it when using
the ed25519-donna backend, and deal with the mocking related
crypto_rand silliness.
Implements feature 16533.
The only reason 16 byte alignment is required is for SSE2 load and
store operations, so only align datastructures to 16 byte boundaries
when building with SSE2 support.
This fixes builds with GCC SSP on platforms that don't have special
case code to do dynamic stack re-alignment (everything not x86/x86_64).
Fixes bug #16666.
