smmintrin.h uses #if __cplusplus rather than #ifdef __cplusplus which
trips up warnings.

Change-Id: Ic2e0a64f0485a6e1d807c1e2d9d7f5bf8c64e296
Reviewed-on: https://boringssl-review.googlesource.com/5450
Reviewed-by: Adam Langley <agl@google.com>

See TODO comment being removed.

Change-Id: I92ce7018f88c24b3e2e61441397fda36b977d3b8
Reviewed-on: https://boringssl-review.googlesource.com/5435
Reviewed-by: Adam Langley <agl@google.com>

Rather, take a leaf out of Chromium's book and use MSVC's __cpuid and
_xgetbv built-in, with an inline assembly emulated version for other
compilers.

This preserves the behavior of the original assembly with the following
differences:

- CPUs without cpuid aren't support. Chromium's base/cpu.cc doesn't
  check, and SSE2 support is part of our baseline; the perlasm code
  is always built with OPENSSL_IA32_SSE2.

- The clear_xmm block in cpu-x86-asm.pl is removed. This was used to
  clear some XMM-using features if OSXSAVE was set but XCR0 reports the
  OS doesn't use XSAVE to store SSE state. This wasn't present in the
  x86_64 and seems wrong. Section 13.5.2 of the Intel manual, volume 1,
  explicitly says SSE may still be used in this case; the OS may save
  that state in FXSAVE instead. A side discussion on upstream's RT#2633
  agrees.

- The old code ran some AMD CPUs through the "intel" codepath and some
  went straight to "generic" after duplicating some, but not all, logic.
  The AMD copy didn't clear some reserved bits and didn't query CPUID 7
  for AVX2 support. This is moot since AMD CPUs today don't support
  AVX2, but it seems they're expected to in the future?

- Setting bit 10 is dropped. This doesn't appear to be queried anywhere,
  was 32-bit only, and seems a remnant of upstream's
  14e21f863a.

Change-Id: I0548877c97e997f7beb25e15f3fea71c68a951d2
Reviewed-on: https://boringssl-review.googlesource.com/5434
Reviewed-by: Adam Langley <agl@google.com>

Beyond generally eliminating unnecessary includes, eliminate as many
includes of headers that declare/define particularly error-prone
functionality like strlen, malloc, and free. crypto/err/internal.h was
added to remove the dependency on openssl/thread.h from the public
openssl/err.h header. The include of <stdlib.h> in openssl/mem.h was
retained since it defines OPENSSL_malloc and friends as macros around
the stdlib.h functions. The public x509.h, x509v3.h, and ssl.h headers
were not changed in order to minimize breakage of source compatibility
with external code.

Change-Id: I0d264b73ad0a720587774430b2ab8f8275960329
Reviewed-on: https://boringssl-review.googlesource.com/4220
Reviewed-by: Adam Langley <agl@google.com>

Including string.h in base.h causes any file that includes a BoringSSL
header to include string.h. Generally this wouldn't be a problem,
although string.h might slow down the compile if it wasn't otherwise
needed. However, it also causes problems for ipsec-tools in Android
because OpenSSL didn't have this behaviour.

This change removes string.h from base.h and, instead, adds it to each
.c file that requires it.

Change-Id: I5968e50b0e230fd3adf9b72dd2836e6f52d6fb37
Reviewed-on: https://boringssl-review.googlesource.com/3200
Reviewed-by: David Benjamin <davidben@chromium.org>
Reviewed-by: Adam Langley <agl@google.com>

This is an initial cut at aarch64 support. I have only qemu to test it
however—hopefully hardware will be coming soon.

This also affects 32-bit ARM in that aarch64 chips can run 32-bit code
and we would like to be able to take advantage of the crypto operations
even in 32-bit mode. AES and GHASH should Just Work in this case: the
-armx.pl files can be built for either 32- or 64-bit mode based on the
flavour argument given to the Perl script.

SHA-1 and SHA-256 don't work like this however because they've never
support for multiple implementations, thus BoringSSL built for 32-bit
won't use the SHA instructions on an aarch64 chip.

No dedicated ChaCha20 or Poly1305 support yet.

Change-Id: Ib275bc4894a365c8ec7c42f4e91af6dba3bd686c
Reviewed-on: https://boringssl-review.googlesource.com/2801
Reviewed-by: Adam Langley <agl@google.com>

Change-Id: Idec1cda87b0a58e9350d0e10c3251a2c47ac1929
Reviewed-on: https://boringssl-review.googlesource.com/1790
Reviewed-by: Adam Langley <agl@google.com>

Chromium does not like static initializers, and the CPU logic uses one to
initialize CPU bits. However, the crypto library lacks an explicit
initialization function, which could complicate (no compile-time errors)
porting existing code which uses crypto/, but not ssl/.

Add an explicit CRYPTO_library_init function, but make it a no-op by default.
It only does anything (and is required) if building with
BORINGSSL_NO_STATIC_INITIALIZER.

Change-Id: I6933bdc3447fb382b1f87c788e5b8142d6f3fe39
Reviewed-on: https://boringssl-review.googlesource.com/1770
Reviewed-by: Adam Langley <agl@google.com>

Apart from the obvious little issues, this also works around a
(seeming) libtool/linker:

a.c defines a symbol:

int kFoo;

b.c uses it:

extern int kFoo;

int f() {
  return kFoo;
}

compile them:

$ gcc -c a.c
$ gcc -c b.c

and create a dummy main in order to run it, main.c:

int f();

int main() {
  return f();
}

this works as expected:

$ gcc main.c a.o b.o

but, if we make an archive:

$ ar q lib.a a.o b.o

and use that:

$ gcc main.c lib.a
Undefined symbols for architecture x86_64
  "_kFoo", referenced from:
    _f in lib.a(b.o)

(It doesn't matter what order the .o files are put into the .a)

Linux and Windows don't seem to have this problem.

nm on a.o shows that the symbol is of type "C", which is a "common symbol"[1].
Basically the linker will merge multiple common symbol definitions together.

If ones makes a.c read:

int kFoo = 0;

Then one gets a type "D" symbol - a "data section symbol" and everything works
just fine.

This might actually be a libtool bug instead of an ld bug: Looking at `xxd
lib.a | less`, the __.SYMDEF SORTED index at the beginning of the archive
doesn't contain an entry for kFoo unless initialised.

Change-Id: I4cdad9ba46e9919221c3cbd79637508959359427

Initial fork from f2d678e6e8 (1.0.2 beta).

(This change contains substantial changes from the original and
effectively starts a new history.)