0fef60c63d6d2f4df8e698936221e2330ef3a244 build: improved output of configure for build OS (sachinkm77)
Pull request description:
The purpose of this fix is to improve output of the configure script by providing the build OS. This is done by leveraging the build_os set by the script config.sub / config.guess. #18966
ACKs for top commit:
fanquake:
ACK 0fef60c63d6d2f4df8e698936221e2330ef3a244 - thanks for following up.
Tree-SHA512: b9f49df901a9d37eb16c67c063bb3611602a84391aa54d097a52b740f474c2785c24bf405522d15d724fde25070d354bf20b885add2ee4405a71cbe9ebab5ff3
a30b0a24e97eae7f6d1428c5bf339a579872f28e build: enable -Werror=gnu (Vasil Dimov)
Pull request description:
Stop the build if a warning is emitted due to `-Wgnu` and
`--enable-werror` has been used. As usual - this would help notice such
a warning that is about to be introduced in new code.
This is a followup to
https://github.com/bitcoin/bitcoin/pull/18088 build: ensure we aren't using GNU extensions
ACKs for top commit:
practicalswift:
ACK a30b0a24e97eae7f6d1428c5bf339a579872f28e
Empact:
ACK a30b0a24e9
Tree-SHA512: f81b71cf3ee4db88b6f664c571075e0d30800a604f067f44273f256695a1dea533779db2ac859dd0a4cd8b66289c3e45f4aff1cfadfa160a1c354237167b05e2
68537275bd91d1dc14a69609ae443f955bfdbd64 build: Enable -Werror=sign-compare (Ben Woosley)
eac6a3080d38cfd4eb7204ecd327df213958e51a refactor: Rework asmap Interpret to avoid ptrdiff_t (Ben Woosley)
df37377e30678ac9b8338ea920e50b7296da6bd5 test: Fix outstanding -Wsign-compare errors (Ben Woosley)
Pull request description:
Disallowing sign-comparison mismatches can help to prevent the introduction of overflow and interpretation bugs.
In this case, ~all~ most existing violations are in the tests, and most simply required annotating the literal as unsigned for comparison.
This was previously prevented by violations in leveldb which were fixed upstream and merged in #17398. You can test that by building this branch against: 22d11187ee3c7abfe9d43c9eb68f102498cc2b9a vs 75fb37ce68289eb7e00e2ccdd2ef7f9271332545
ACKs for top commit:
fjahr:
re-ACK 68537275bd91d1dc14a69609ae443f955bfdbd64
practicalswift:
ACK 68537275bd91d1dc14a69609ae443f955bfdbd64
Tree-SHA512: 14b5daa38c496fb51548feb30fb4dd179e6f76a8d355f52bc8e2a18f2f9340f0bc98dcf36d8b3d6521045d013891c3103749a4eda88ceef00202a6a0cf93f73c
5a157eb3703e1e65ed285f13a824562ab12aa3ff Bugfix: configure: Only avoid -isystem for exact /usr/include path (Luke Dashjr)
556ee6f2fa0e2da2bb12fe05a885431f61db2e47 Bugfix: configure: Quote SUPPRESS_WARNINGS sufficiently to preserve brackets (Luke Dashjr)
Pull request description:
The regex includes `[/ ]` which is supposed to match either a forward slash or a space, but m4 treats the brackets as special characters and effectively strips them out, leading to -isystem /usr/include paths except for in the typical scenario where it is the final parameter in the flag string.
ACKs for top commit:
hebasto:
ACK 5a157eb3703e1e65ed285f13a824562ab12aa3ff, tested on Ubuntu 22.04 with clang 14.0.
vasild:
ACK 5a157eb3703e1e65ed285f13a824562ab12aa3ff
Tree-SHA512: 5c8c282b647b7853b8fad1b5b473703c4a0635073d2685a8ac984151046e2c6a859e6972465419d27356dd29a47f21a2a3a6ad402ec434fe1f9882e5a35f0749
061accfddd2d27ad584c826413c68857d2be9ced build: require libtool 2.4.2 (fanquake)
Pull request description:
Every system we support has 2.4.6 available, except for OpenBSD, which
[currently ships with 2.4.2](https://github.com/openbsd/ports/blob/master/devel/libtool/Makefile) (released 2011). For now, set our minimum
required version to that.
After a 7 year hitus, 2.4.7 has also very recently been released:
https://savannah.gnu.org/forum/forum.php?forum_id=10139.
Partially motivated by comments in https://github.com/bitcoin/bitcoin/pull/24615.
See also: https://repology.org/project/libtool/versions
ACKs for top commit:
achow101:
ACK 061accfddd2d27ad584c826413c68857d2be9ced
hebasto:
ACK 061accfddd2d27ad584c826413c68857d2be9ced
prusnak:
ACK 061accfddd2d27ad584c826413c68857d2be9ced
Tree-SHA512: bc032022b8609b73253ff1c4fd480f4d09be761b8fec295f39319f9499ee2df116f55295da476be551c43ed88fbb0bfed7bb5a188b9979b34147fe39737ec76f
3d70c058684727cd036314014ec0a9208d3e9168 build: remove faketime unsetting and comments from configure.ac (fanquake)
Pull request description:
We no-longer use [`faketime`](https://github.com/wolfcw/libfaketime) (it used to be required in gitian), so as far as I'm aware, there is no need for us to unset `FAKETIME` or mention it in our build docs.
ACKs for top commit:
laanwj:
Code review ACK 3d70c058684727cd036314014ec0a9208d3e9168
prusnak:
Approach ACK 3d70c05
hebasto:
ACK 3d70c058684727cd036314014ec0a9208d3e9168, I have reviewed the code and it looks OK, I agree it can be merged.
Tree-SHA512: 9cf89d63b81119f3d2f02975a66ec0b93e861993fdb0e4f70538e3be6e0047dc09ce87ef2de40cbf877647a21706b39ddf07240c77765278d383d7a7878cc7eb
e46287853f3a41c3f0772d3448d8df4ea01a156f build: remove --enable-determinism configure option (fanquake)
Pull request description:
This was added by me a while back, with the intention of expanding what this did. That hasn't happened, and this hasn't gained much use. There's also been some discussion of some configure option fatigue, so just remove it for now. Note that `-Wl,--no-insert-timestamp` is also already used in the Guix build.
ACKs for top commit:
MarcoFalke:
review ACK e46287853f3a41c3f0772d3448d8df4ea01a156f
jarolrod:
Code Review ACK e46287853f3a41c3f0772d3448d8df4ea01a156f
Tree-SHA512: ac976f88203eca2a49e296a98693dbe53330e0cb0e273c5ff1fcded30daeb6070cc5beeae35cf9acfdc2279cd64c274d5aeb588aef077aa9bfde39bb23570491
8f7704d0321a71c1691837a6bd3b4e05f84d3031 build: improve detection of eBPF support (fanquake)
Pull request description:
Just checking for the `sys/sdt.h` header isn't enough, as systems like macOS have the header, but it doesn't actually have the `DTRACE_PROBE*` probes, which leads to [compile failures](https://github.com/bitcoin/bitcoin/pull/22006#issuecomment-859559004). The contents of `sys/sdt.h` in the macOS SDK is:
```bash
#ifndef _SYS_SDT_H
#define _SYS_SDT_H
/*
* This is a wrapper header that wraps the mach visible sdt.h header so that
* the header file ends up visible where software expects it to be. We also
* do the C/C++ symbol wrapping here, since Mach headers are technically C
* interfaces.
*
* Note: The process of adding USDT probes to code is slightly different
* than documented in the "Solaris Dynamic Tracing Guide".
* The DTRACE_PROBE*() macros are not supported on Mac OS X -- instead see
* "BUILDING CODE CONTAINING USDT PROBES" in the dtrace(1) manpage
*
*/
#include <sys/cdefs.h>
__BEGIN_DECLS
#include <mach/sdt.h>
__END_DECLS
#endif /* _SYS_SDT_H */
```
The `BUILDING CODE CONTAINING USDT PROBES` section from the dtrace manpage is available [here](https://gist.github.com/fanquake/e56c9866d53b326646d04ab43a8df9e2), and outlines the more involved process of using USDT probes on macOS.
ACKs for top commit:
jb55:
utACK 8f7704d0321a71c1691837a6bd3b4e05f84d3031
practicalswift:
cr ACK 8f7704d0321a71c1691837a6bd3b4e05f84d3031
hebasto:
ACK 8f7704d0321a71c1691837a6bd3b4e05f84d3031, tested on macOS Big Sur 11.4 (20F71) and on Linux Mint 20.1 (x86_64) with depends.
Tree-SHA512: 5f1351d0ac2e655fccb22a5454f415906404fdaa336fd89b54ef49ca50a442c44ab92d063cba3f161cb8ea0679c92ae3cd6cfbbcb19728cac21116247a017df5
1111457d7433c2cca1d7e98946f6954e3a0280ef build: Disable deprecated-copy warning only when external warnings are enabled (MarcoFalke)
Pull request description:
Fixes https://github.com/bitcoin/bitcoin/issues/18967
Alternative to https://github.com/bitcoin/bitcoin/pull/22240
ACKs for top commit:
fanquake:
tACK 1111457d7433c2cca1d7e98946f6954e3a0280ef
Tree-SHA512: 0fc826f26ebbeab662fa7eed2a5cc1630c6c4e612deb91734885fc8bae0352be657ec48ae94ff55a984ac36d27b95cea8d947cc5cf408231d56addecf79db83f
9bac71350d98580cc7441957fc7c3fa2f4158553 build: make HAVE_O_CLOEXEC available outside LevelDB (bugfix) (Sebastian Falbesoner)
584fd91d2d294883e6896dbd64a2176528e94581 init: only use pipe2 if availabile, check in configure (Sebastian Falbesoner)
Pull request description:
The result of the O_CLOEXEC availability check is currently only set in the Makefile and passed to LevelDB (see `LEVELDB_CPPFLAGS_INT` in `src/Makefile.leveldb.include`), but not defined to be used in our codebase. This means that code within the preprocessor conditional `#if HAVE_O_CLOEXEC` was actually never compiled. On the master branch this is currently used for pipe creation in `src/shutdown.cpp`, PR #21007 moves this part to a new module (I found the issue while testing that PR).
The fix is similar to the one in #19803, which solved the same problem for HAVE_FDATASYNC.
In the course of working on the PR it turned out that pipe2 is not available an all platforms, hence a configure check and a corresponding define HAVE_PIPE2 is introduced and used.
The PR can be tested by anyone with a system that has pipe2 and O_CLOEXEC available by putting gibberish into the HAVE_O_CLOEXEC block: on master, everything should compile fine, on PR, the compiler should abort with an error. At least that's my naive way of testing preprocessor logic, happy to hear more sophisticated ways :-)
ACKs for top commit:
laanwj:
Code review ACK 9bac71350d98580cc7441957fc7c3fa2f4158553
Tree-SHA512: aec89faf6ba52b6f014c610ebef7b725d9e967207d58b42a4a71afc9f1268fcb673ecc85b33a2a3debba8105a304dd7edaba4208c5373fcef2ab83e48a170051
d51f0fa4b7b19281efe65aacf414845c661d0a13 doc: add release notes for 26896 (fanquake)
2b248798d96f794db08b7725730b5fb4e00b9b10 build: remove --enable-upnp-default from configure (fanquake)
02f5a5e7b5fd7ba35e407d4409202a0e0fed003c build: remove --enable-natpmp-default from configure (fanquake)
25a0e8ba0b31d8bd265df0589fe49241a60d0fc2 Remove configure-time setting of DEFAULT_UPNP (fanquake)
06562e5fa771dab275a9cab4914cd64d961a52bc Remove configure-time setting of DEFAULT_NATPMP (fanquake)
Pull request description:
This PR removes the `--enable-upnp-default` and `--enable-natpmp-default` options from configure.
It's odd to me that we maintain configure-time options for setting the default port-forwarding runtime state (but no other similar options), and I'm not sure what use-case it satisfies, that can't be achieved by multiple other means. I also doubt that we'll ever restart using these in release builds, or turning on any of this by default.
I think the only scenario these options would be used is when you want to compile your own binaries (we don't use them in Guix), with port-forwarding on by default, but otherwise can't or don't want to use a `.conf` file, can't or don't want to pass command line options at runtime, and also don't want to modify the source code?
ACKs for top commit:
hebasto:
ACK d51f0fa4b7b19281efe65aacf414845c661d0a13, rebased and comments have been addressed since my recent [review](https://github.com/bitcoin/bitcoin/pull/26896#pullrequestreview-1273910740).
TheCharlatan:
ACK d51f0fa4b7b19281efe65aacf414845c661d0a13
Tree-SHA512: 481decd8bddd8b03b7319591e3acf189f7b6b96c9a9a8c5bc1a3f8ec00d0b8f9b52d2f5c28a298a2ec947cfe9611cfd184e393ccb2e4e21bfce86ca7d4de60d3
## Issue being fixed or feature implemented
Bump develop version to v20.1.0; v21 features should not yet be merged
into develop; when the time is come to begin merging v21 features into
develop, we can then bump version again.
## What was done?
Bump version
## How Has This Been Tested?
## Breaking Changes
## Checklist:
_Go over all the following points, and put an `x` in all the boxes that
apply._
- [ ] I have performed a self-review of my own code
- [ ] I have commented my code, particularly in hard-to-understand areas
- [ ] I have added or updated relevant unit/integration/functional/e2e
tests
- [ ] I have made corresponding changes to the documentation
- [x] I have assigned this pull request to a milestone _(for repository
code-owners and collaborators only)_
4446ef0a549d567a88d82b606aa8c47f115673f9 build: remove support for weak linking getauxval() (fanquake)
e56100c5b4daf2285dde9807bf654599aa19bd6b build: remove arm includes from getauxval() check (fanquake)
Pull request description:
It was [pointed out in #23030](https://github.com/bitcoin/bitcoin/pull/23030#issuecomment-922893367) that we might be able to get rid of our weak linking of [`getauxval()`](https://man7.org/linux/man-pages/man3/getauxval.3.html) (`HAVE_WEAK_GETAUXVAL`) entirely, with only Android being a potential holdout:
> I wonder if it's time to get rid of HAVE_WEAK_GETAUXVAL. I think it's confusing. Either we build against a C library that has this functionality, or not. We don't do this weak linking thing for any other symbols and recently got rid of the other glibc backwards compatibility stuff.
> Unless there is still a current platform that really needs it (Android?), I'd prefer to remove it from the build system, it has caused enough issues.
After looking at Android further, it would seem that given we are moving to using `std::filesystem`, which [requires NDK version 22 and later](https://github.com/android/ndk/wiki/Changelog-r22), and `getauxval` has been available in the since [API version 18](https://developer.android.com/ndk/guides/cpu-features#features_using_libcs_getauxval3), that shouldn't really be an issue. Support for API levels < 19 will be dropped with the NDK 24 release, and according to [one website](https://apilevels.com/), supporting API level 18+ will cover ~99% of devices. Note that in the CI we currently build with NDK version 22 and API level 28.
The other change in this PR is removing the include of headers for ARM intrinsics, from the check for strong `getauxval()` support in configure, as they shouldn't be needed. Including these headers also meant that the check would basically only succeed when building for ARM. This would be an issue if we remove weak linking, as we wouldn't detect `getauxval()` as supported on other platforms. Note that we also use `getauxval()` in our RNG when it's available.
I've checked that with these changes we detect support for strong `getauxval()` on Alpine (muslibc). On Linux, previously we'd be detecting support for weak getauxval(), now we detect strong support. Note that we already require glibc 2.17, and `getauxval()` was introduced in `2.16`.
This is an alternative / supersedes #23030.
ACKs for top commit:
laanwj:
Code review and tested ACK 4446ef0a549d567a88d82b606aa8c47f115673f9
Tree-SHA512: 5f2a9e9cc2d63bddab73f0dcb169d4d6beda74622af82bc0439722f1189f81d052e2fc1eaf27056a7a606320d5ddc4c11075f0d051dd93d77c5e1c15337f354a
## Issue being fixed or feature implemented
Bump version
## What was done?
## How Has This Been Tested?
Na
## Breaking Changes
Na
## Checklist:
_Go over all the following points, and put an `x` in all the boxes that
apply._
- [ ] I have performed a self-review of my own code
- [ ] I have commented my code, particularly in hard-to-understand areas
- [ ] I have added or updated relevant unit/integration/functional/e2e
tests
- [ ] I have made corresponding changes to the documentation
- [x] I have assigned this pull request to a milestone _(for repository
code-owners and collaborators only)_
## Issue being fixed or feature implemented
Bump version to rc.1
## What was done?
bump version
## How Has This Been Tested?
## Breaking Changes
## Checklist:
_Go over all the following points, and put an `x` in all the boxes that
apply._
- [x] I have performed a self-review of my own code
- [ ] I have commented my code, particularly in hard-to-understand areas
- [ ] I have added or updated relevant unit/integration/functional/e2e
tests
- [ ] I have made corresponding changes to the documentation
- [x] I have assigned this pull request to a milestone _(for repository
code-owners and collaborators only)_
01a3392b1b778fa4fcf568013326d6ea1de4fb3b Drop bitcoin-wallet dependency on libevent (Russell Yanofsky)
0660119ac372c2863d14060ac1bc9bc243771f94 Drop unintended bitcoin-tx dependency on libevent (Russell Yanofsky)
Pull request description:
This fixes compile errors trying to build bitcoin-tx and bitcoin-wallet without libevent, which were reported by Luke Dashjr in https://github.com/bitcoin/bitcoin/issues/18465
The fix avoiding `bitcoin-tx` dependency on libevent just adds a conditional build rule. This is implemented in the first commit (more details in commit description).
The fix avoiding `bitcoin-wallet` dependency on libevent requires minor code changes, because `bitcoin-wallet` (unlike `bitcoin-tx`) links against code that calls `urlDecode` / `evhttp_uridecode`. This fix is implemented in the second commit (again details in the commit description).
ACKs for top commit:
jonasschnelli:
utACK 01a3392b1b778fa4fcf568013326d6ea1de4fb3b.
Tree-SHA512: d2245e912ab494cccceeb427a1eca8e55b01a0006ff93eebcfb5461ae7cecd1083ac2de443d9db036b18bdc6f0fb615546caaa20c585046f66d234937f74870a
ef712298c3f8bc2afdad783f05080443b72b3f77 util: Check for file being NULL in DirectoryCommit (Luke Dashjr)
457490403853321d308c6ca6aaa90d6f8f29b4cf Fix possible data race when committing block files (Evan Klitzke)
220bb16cbee5b91d0bc0fcc6c71560d631295fa5 util: Introduce DirectoryCommit commit function to sync a directory (Evan Klitzke)
ce5cbaea63ad4ea78e533bdb14f47f414061ae7f util.h: Document FileCommit function (Evan Klitzke)
844d650eea3bd809884cc5dd996a388bdc58314e util: Prefer Mac-specific F_FULLSYNC over fdatasync in FileCommit (Evan Klitzke)
f6cec0bcaf560fa310853ad3fe17022602b63d5f util: Refactor FileCommit from an #if sequence nested in #else, to a sequence of #elif (Evan Klitzke)
Pull request description:
Reviving #12696
ACKs for top commit:
laanwj:
Code review ACK ef712298c3f8bc2afdad783f05080443b72b3f77
Tree-SHA512: 07d650990ef4c18d645dee3f9a199a940683ad17557d79d93979a76c4e710d8d70e6eae01d1a5991494a24a7654eb7db868be0c34a31e70b2509945d95bc9cce
## Issue being fixed or feature implemented
The order of members in a class/struct definition and the order of their
initialization should match. This ensures that the code is more
error-proof in cases where the order of member initializations is
important, as they may depend on each other.
Instead manual checking of member initialization better let CI handle
it.
Last PR where it's noticed:
https://github.com/dashpay/dash/pull/5531#discussion_r1299404387
## What was done?
New flag "-Werror=reorder" for `configure.ac` and fixes existing code.
## How Has This Been Tested?
Build code with `--enable-werror`
## Breaking Changes
N/A
## Checklist:
- [x] I have performed a self-review of my own code
- [ ] I have commented my code, particularly in hard-to-understand areas
- [ ] I have added or updated relevant unit/integration/functional/e2e
tests
- [ ] I have made corresponding changes to the documentation
- [x] I have assigned this pull request to a milestone
904d875cf5aecc337daa6a2243a803033cf4eee3 configure: output notice that test binary is disabled by fuzzing (Andrew Poelstra)
Pull request description:
I wasted a bit of time today running a stale `test_bitcoin` and not understanding why, until I remembered that I'd ./configured my working directory with --enable-fuzz.
Top commit has no ACKs.
Tree-SHA512: 6cbe30547332114ad3fe61c67e224f5a28aac4b1b58e0acecb29cb04f5a34f792c927797aa8000449aae076435bd45acf209b7323b0b48fa971705d6ed3e6529
faf7d4fa86b700ec272806cd2bd8666a92405619 build: Add cov_fuzz target (MarcoFalke)
fac71e364e4bbaeffc35e45aff8c8c2c6f2b5c67 build: link fuzz/test_runner.py for out-of-tree builds (MarcoFalke)
faf2c5aca01643eb560287e08f9c0a7ca0ac9c88 build: Remove unused USE_COVERAGE (MarcoFalke)
Pull request description:
Only libFuzzer is supported right now, so clang is required. Thus, this needs a workaround such as https://github.com/bitcoin/bitcoin/issues/12602#issuecomment-562788247
Can be tested with:
```
mkdir build && cd build
../configure --enable-fuzz --with-sanitizers=fuzzer --enable-lcov --enable-lcov-branch-coverage CC=clang CXX=clang++
make $MAKEJOBS
make cov_fuzz
ACKs for top commit:
practicalswift:
ACK faf7d4fa86b700ec272806cd2bd8666a92405619
Tree-SHA512: 6828f8f81d95f6781713d0b09d7eba2ffdb50217e09ca839db61791a4ed70024859c7a0cb01d9eede79166d574dd57ece01f9d9fe2610d4a72a4ca4a4ce0b838
cd04286825c6512b46bf59ab7b3dfffb0e36d65b build: Fix typo in EVENT_CFLAGS variable (Hennadii Stepanov)
f709ad0c907d87d03002455967cc30ae7d704d80 build: Fix libevent linking for bench_bitcoin binary (Hennadii Stepanov)
Pull request description:
This change fixes `libevent` linking error for the `bench_bitcoin` binary.
This PR is an alternative to #18377.
Fix#18373.
Also fixed a typo in `EVENT_CFLAGS` variable noted by **brakmic**.
ACKs for top commit:
fanquake:
ACK cd04286825c6512b46bf59ab7b3dfffb0e36d65b
Tree-SHA512: a62f7457e86b11d3a55d603ea5d83f3a413792e2f28a0c72300e54d12591bd6f0acc1d76a4bd4b591e0223bc6d530e7a4b9a8b939fe2fdbf2dddfda5b1b537be
## Issue being fixed or feature implemented
gmp can't be detected on macos when installed via `brew` atm
## What was done?
detect package prefix and adjust CPPFLAGS and LDFLAGS accordingly
## How Has This Been Tested?
`./configure`
before: `configure: error: libgmp headers missing`
after: passes
## Breaking Changes
n/a
## Checklist:
- [x] I have performed a self-review of my own code
- [ ] I have commented my code, particularly in hard-to-understand areas
- [ ] I have added or updated relevant unit/integration/functional/e2e
tests
- [ ] I have made corresponding changes to the documentation
- [x] I have assigned this pull request to a milestone _(for repository
code-owners and collaborators only)_
b6aadcd5b4350a6ebcd57e88e7a0853cedf7c2fb build: Add -Werror=mismatched-tags (Hennadii Stepanov)
1485124291368c4a2ca8ea09c18e813f1dbabf5c Fix -Wmismatched-tags warnings (Hennadii Stepanov)
Pull request description:
Warnings were introduced in #20749:
```
./validation.h:43:1: warning: class 'CCheckpointData' was previously declared as a struct; this is valid, but may result in linker errors under the Microsoft C++ ABI [-Wmismatched-tags]
class CCheckpointData;
^
./chainparams.h:24:8: note: previous use is here
struct CCheckpointData {
^
./validation.h:43:1: note: did you mean struct here?
class CCheckpointData;
^~~~~
struct
1 warning generated.
```
This change fixes AppVeyor build: https://ci.appveyor.com/project/DrahtBot/bitcoin/builds/37547435
ACKs for top commit:
glozow:
utACK b6aadcd5b4🚗
practicalswift:
cr ACK b6aadcd5b4350a6ebcd57e88e7a0853cedf7c2fb: patch looks correct
Tree-SHA512: 3ac887ebdbf9a1ae33c1fd5381b3b8d83388ad557ddeb55013acd42bb9752a5bd009e3a0eed52644a023a7a0dda1c159277981af82f58fb0abfe60b84e01bf29
6cef3652d143a1dddad1254cab0953561d24c1fa build: fix -Wformat-security check when compiling with GCC (fanquake)
Pull request description:
GCC expects `-Wformat` to be passed with [`-Wformat-security`](https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html), which means
when we test for it in configure it currently fails:
```bash
checking whether C++ compiler accepts -Wformat-security... no
...
configure:15907: checking whether C++ compiler accepts -Wformat-security
configure:15926: g++ -std=c++11 -c -g -O2 -Werror -Wformat-security conftest.cpp >&5
cc1plus: error: '-Wformat-security' ignored without '-Wformat' [-Werror=format-security]
cc1plus: all warnings being treated as errors
```
and never gets added to our CXX flags. Note that Clang does not have this requirement and the check is working correctly there.
The change in this PR is the simple fix, however we might want to consider using something like `-Wformat=2` in future, which in GCC is equivalent to `-Wformat -Wformat-nonliteral -Wformat-security -Wformat-y2k.` and similar [in Clang](https://clang.llvm.org/docs/DiagnosticsReference.html#wformat-2).
ACKs for top commit:
practicalswift:
ACK 6cef3652d143a1dddad1254cab0953561d24c1fa
laanwj:
ACK 6cef3652d143a1dddad1254cab0953561d24c1fa
Tree-SHA512: f9230d42af39f85ea9d2f55dbbebd2bae4740fe59b0da2e092af3ac9ef7e6799d3a4cf83eb64574c63982e5f6b14e226d44c84fa0335255d65c9947d86a1ea38
182dbdf0f4b6e6484b0d4588aaefacc75862a99c util: Detect posix_fallocate() instead of assuming (Vasil Dimov)
Pull request description:
Don't assume that `posix_fallocate()` is available on Linux and not
available on other operating systems. At least FreeBSD has it and we
are not using it.
Properly check whether `posix_fallocate()` is present and use it if it
is.
ACKs for top commit:
laanwj:
ACK 182dbdf0f4b6e6484b0d4588aaefacc75862a99c
Tree-SHA512: f9ed4bd661f33ff6b2b1150591e860b3c1f44e12b87c35e870d06a7013c4e841ed2bf17b41ad6b18fe471b0b23a4b5e42cf1400637180888e0bc56c254fe0766
