faa05854f8 util: Remove probably misleading TODO (MarcoFalke)
fac5efe730 util: Add Assume() identity function (MarcoFalke)
fa861569dc util: Allow Assert(...) to be used in all contexts (practicalswift)
Pull request description:
This is needed for #20138. Please refer to the added documentation for motivation.
ACKs for top commit:
practicalswift:
cr ACK faa05854f8
jnewbery:
utACK faa05854f8
hebasto:
ACK faa05854f8, I have reviewed the code and it looks OK, I agree it can be merged.
Tree-SHA512: 72165fbd898b92ab9a79b070993fa1faa86c2e3545b6645e72c652bda295d5107bc298d0482bf3aaf0926fc0c3e6418a445c0e073b08568c44231f547f76a688
Check both failure cases:
- Use a glibc symbol from a version that is too new
- Use a symbol from a library that is not in the allowlist
And also check a conforming binary.
Adding a similar check for Windows PE can be done in a separate PR.
d52f502b1e Fix mock SQLiteDatabases (Andrew Chow)
99309ab3e9 Allow disabling BDB in configure with --without-bdb (Andrew Chow)
ee47f11f73 GUI: Force descriptor wallets when BDB is not compiled (Andrew Chow)
71e40b33bd RPC: Require descriptors=True for createwallet when BDB is not compiled (Andrew Chow)
6ebc41bf9c Enforce salvage is only for BDB wallets (Andrew Chow)
a58b719cf7 Do not compile BDB things when USE_BDB is defined (Andrew Chow)
b33af48210 Include wallet/bdb.h where it is actually being used (Andrew Chow)
Pull request description:
Adds a `--without-bdb` option to `configure` which disables the compilation of the BDB stuff. Legacy wallets will not be created when BDB is not compiled. A legacy-sqlite wallet can be loaded, but we will not create them.
Based on #20156 to resolve the situation where both `--without-sqlite` and `--without-bdb` are provided. In that case, the wallet is disabled and `--disable-wallet` is effectively set.
ACKs for top commit:
laanwj:
Code review ACK d52f502b1e
Tree-SHA512: 5a92ba7a542acc2e27003e9d4e5940e0d02d5c1f110db06cdcab831372bfd83e8d89c269caff31dd5bff062c1cf5f04683becff12bd23a33be731676f346553d
Instead of the ever-messier text parsing of the output of the readelf
tool (which is clearly meant for human consumption not to be machine
parseable), parse the ELF binaries directly.
Add a small dependency-less ELF parser specific to the checks.
This is slightly more secure, too, because it removes potential
ambiguity due to misparsing and changes in the output format of `elfread`. It
also allows for stricter and more specific ELF format checks in the future.
This removes the build-time dependency for `readelf`.
It passes the test-security-check for me locally, though I haven't
checked on all platforms.
8f7b930475 Drop the leading 0 from the version number (Andrew Chow)
Pull request description:
Removes the leading 0 from the version number. The minor version, which we had been using as the major version, is now the major version. The revision, which we had been using as the minor version, is now the minor version. The revision number is dropped. The build number is promoted to being part of the version number. This also avoids issues where it was accidentally not included in the version number.
The CLIENT_VERSION remains the same format as previous as previously, as the Major version was 0 so it never actually got included in it.
The user agent string formatter is updated to follow this new versioning.
***
Honestly I'm just tired of all of the people asking for "1.0" that maybe this'll shut them up. Skip the whole 1.0 thing and go straight to version 22.0!
Also, this means that the terminology we commonly use lines up with how the variables are named. So major versions are actually bumping the major version number, etc.
ACKs for top commit:
jnewbery:
Code review ACK 8f7b930475
MarcoFalke:
review ACK 8f7b930475🎻
Tree-SHA512: b5c3fae14d4c0a9c0ab3b1db7c949ecc0ac3537646306b13d98dd0efc17c489cdd16d43f0a24aaa28e9c4a92ea360500e05480a335b03f9fb308010cdd93a436
Removes the leading 0 from the version number. The minor version, which
we had been using as the major version, is now the major version. The
revision, which we had been using as the minor version, is now the minor
version. The revision number is dropped. The build number is promoted to
being part of the version number. This also avoids issues where it was
accidentally not included in the version number.
The CLIENT_VERSION remains the same format as previous as previously,
the Major version was 0 so that was never a factor in CLIENT_VERSION.
97c738ff1b [tests] Recommend f-strings for formatting, update feature_block to use them (Anthony Towns)
8ae9d314e9 Bump minimum python version to 3.6 (Anthony Towns)
Pull request description:
Python 3.5 has reached [end-of-life](https://devguide.python.org/#status-of-python-branches) as of September 2020, and 3.6 has some moderately nice [features](https://docs.python.org/3/whatsnew/3.6.html):
- `f'x = {x}'` as an alternative to `'x = {}'.format(x)` format strings (cf https://github.com/bitcoin/bitcoin/pull/13718#issuecomment-406591027)
- underscore separators for large numbers, like `1_234_567`
- improvements to async
- improvements to typing module
Note that 3.6 is not available in xenial (16.04), but is available in bionic (18.04), while focal (20.04) has 3.8. CentOS 7 and 8 have 3.6.8, Debian stable has 3.7.3, and [gentoo and arch already had 3.6 and 3.7 in 2018](https://github.com/bitcoin/bitcoin/pull/14954#issuecomment-447118707).
ACKs for top commit:
MarcoFalke:
re-ACK 97c738ff1b
Tree-SHA512: ec7fce68845edde4d61a42de12c065fd49e5217311a6fda1323206f091a0afd50f293645dffc27d420127e4e5deb864e953f1b67eff735a0dfbbedd7899a9d60
0e2a5e448f tests: dumping and minimizing of script assets data (Pieter Wuille)
4567ba034c tests: add generic qa-asset-based script verification unit test (Pieter Wuille)
f06e6d0345 tests: functional tests for Schnorr/Taproot/Tapscript (Pieter Wuille)
3c226639eb tests: add BIP340 Schnorr signature support to test framework (Pieter Wuille)
206fb180ec --- [TAPROOT] Tests --- (Pieter Wuille)
d7ff237f29 Activate Taproot/Tapscript on regtest (BIP 341, BIP 342) (Pieter Wuille)
e9a021d7e6 Make Taproot spends standard + policy limits (Pieter Wuille)
865d2c37e2 --- [TAPROOT] Regtest activation and policy --- (Pieter Wuille)
72422ce396 Implement Tapscript script validation rules (BIP 342) (Johnson Lau)
330de894a9 Use ScriptExecutionData to pass through annex hash (Pieter Wuille)
8bbed4b7ac Implement Taproot validation (BIP 341) (Pieter Wuille)
0664f5fe1f Support for Schnorr signatures and integration in SignatureCheckers (BIP 340) (Pieter Wuille)
5de246ca81 Implement Taproot signature hashing (BIP 341) (Johnson Lau)
9eb590894f Add TaggedHash function (BIP 340) (Pieter Wuille)
450d2b2371 --- [TAPROOT] BIP340/341/342 consensus rules --- (Pieter Wuille)
5d62e3a68b refactor: keep spent outputs in PrecomputedTransactionData (Pieter Wuille)
8bd2b4e784 refactor: rename scriptPubKey in VerifyWitnessProgram to exec_script (Pieter Wuille)
107b57df9f scripted-diff: put ECDSA in name of signature functions (Pieter Wuille)
f8c099e220 --- [TAPROOT] Refactors --- (Pieter Wuille)
Pull request description:
This is an implementation of the Schnorr/taproot consensus rules proposed by BIPs [340](https://github.com/bitcoin/bips/blob/master/bip-0340.mediawiki), [341](https://github.com/bitcoin/bips/blob/master/bip-0340.mediawiki), and [342](https://github.com/bitcoin/bips/blob/master/bip-0340.mediawiki).
See the list of commits [below](https://github.com/bitcoin/bitcoin/pull/19953#issuecomment-691815830). No signing or wallet support of any kind is included, as testing is done entirely through the Python test framework.
This is a successor to https://github.com/bitcoin/bitcoin/pull/17977 (see discussion following [this comment](https://github.com/bitcoin/bitcoin/pull/17977#issuecomment-682285983)), and will have further changes squashed/rebased. The history of this PR can be found in #19997.
ACKs for top commit:
instagibbs:
reACK 0e2a5e448f
benthecarman:
reACK 0e2a5e4
kallewoof:
reACK 0e2a5e448f
jonasnick:
ACK 0e2a5e448f almost only looked at bip340/libsecp related code
jonatack:
ACK 0e2a5e448f modulo the last four commits (tests) that I plan to finish reviewing tomorrow
fjahr:
reACK 0e2a5e448f
achow101:
ACK 0e2a5e448f
Tree-SHA512: 1b00314450a2938a22bccbb4e177230cf08bd365d72055f9d526891f334b364c997e260c10bc19ca78440b6767712c9feea7faad9a1045dd51a5b96f7ca8146e
ba8950ee01 build: optionally skip external warnings (Vasil Dimov)
Pull request description:
Add an option to `./configure` to suppress compilation warnings from
external headers. The option is off by default (no change in behavior,
show warnings from external headers).
This option is useful if e.g. Boost or Qt is installed outside of
`/usr/include` (warnings from headers in `/usr/include` are already
suppressed by default) and those warnings stand in the way of compiling
Bitcoin Core with `-Werror[=...]` or they just clutter the build output
too much and make our own warnings hard to spot.
`-isystem /usr/include` bricks GCC's `#include_next`, so we use
`-idirafter` instead. This way we don't have to treat `/usr/include`
specially.
ACKs for top commit:
practicalswift:
ACK ba8950ee01: diff looks correct!
hebasto:
ACK ba8950ee01, tested on Linux Mint 20 (x86_64).
luke-jr:
utACK ba8950ee01
Tree-SHA512: 9b54fae8590be6c79f2688a5aca09e0a9067f481dabecdd49bb278c08a62ac2b0cc704c894fbd53240e77ac84da0c7a237845df0a696cfbdb0359e1c8e2e10c9
This enables the schnorrsig module in libsecp256k1, adds the relevant types
and functions to src/pubkey, as well as in higher-level `SignatureChecker`
classes. The (verification side of the) BIP340 test vectors is also added.
Add an option to `./configure` to suppress compilation warnings from
external headers. The option is off by default (no change in behavior,
show warnings from external headers).
This option is useful if e.g. Boost or Qt is installed outside of
`/usr/include` (warnings from headers in `/usr/include` are already
suppressed by default) and those warnings stand in the way of compiling
Bitcoin Core with `-Werror[=...]` or they just clutter the build output
too much and make our own warnings hard to spot.
c4b85ba704 Bugfix: Define and use HAVE_FDATASYNC correctly outside LevelDB (Luke Dashjr)
Pull request description:
Fixes a bug introduced in #19614
The LevelDB-specific fdatasync check was only using `AC_SUBST`, which works for Makefiles, but doesn't define anything for C++. Furthermore, the #define is typically 0 or 1, never undefined.
This fixes both issues by defining it and checking its value instead of whether it is merely defined.
Pulled out of #14501 by fanquake's request
ACKs for top commit:
fanquake:
ACK c4b85ba704 - thanks for catching and fixing my mistake.
laanwj:
Code review ACK c4b85ba704
Tree-SHA512: 91d5d426ba000b4f3ee7e2315635e24bbb23ceff16269ddf4f65a63d25fc9e9cf94a3b236eed2f8031cc36ddcf78aeb5916efcb244f415943a8a12f907ede8f9
b536813cef build: add -fstack-clash-protection to hardening flags (fanquake)
076183b36b build: add -fcf-protection=full to hardening options (fanquake)
Pull request description:
Beginning with Ubuntu `19.10`, it's packaged GCC now has some additional hardening options enabled by default (in addition to existing defaults like `-fstack-protector-strong` and reducing the minimum ssp buffer size). The new additions are`-fcf-protection=full` and `-fstack-clash-protection`.
> -fcf-protection=[full|branch|return|none]
> Enable code instrumentation of control-flow transfers to increase program security by checking that target addresses of control-flow transfer instructions (such as indirect function call, function return, indirect jump) are valid. This prevents diverting the flow of control to an unexpected target. This is intended to protect against such threats as Return-oriented Programming (ROP), and similarly call/jmp-oriented programming (COP/JOP).
> -fstack-clash-protection
> Generate code to prevent stack clash style attacks. When this option is enabled, the compiler will only allocate one page of stack space at a time and each page is accessed immediately after allocation. Thus, it prevents allocations from jumping over any stack guard page provided by the operating system.
If your interested you can grab `gcc-9_9.3.0-10ubuntu2.debian.tar.xz` from https://packages.ubuntu.com/focal/g++-9. The relevant changes are part of the `gcc-distro-specs` patches, along with the relevant additions to the gcc manages:
> NOTE: In Ubuntu 19.10 and later versions, -fcf-protection is enabled by default for C, C++, ObjC, ObjC++, if none of -fno-cf-protection nor -fcf-protection=* are found.
> NOTE: In Ubuntu 19.10 and later versions, -fstack-clash-protection is enabled by default for C, C++, ObjC, ObjC++, unless -fno-stack-clash-protection is found.
So, if you're C++ using GCC on Ubuntu 19.10 or later, these options will be active unless you explicitly opt out. This can be observed with a small test:
```c++
int main() { return 0; }
```
```bash
g++ --version
g++ (Ubuntu 9.3.0-10ubuntu2) 9.3.0
g++ test.cpp
objdump -dC a.out
..
0000000000001129 <main>:
1129: f3 0f 1e fa endbr64
112d: 55 push %rbp
112e: 48 89 e5 mov %rsp,%rbp
1131: b8 00 00 00 00 mov $0x0,%eax
1136: 5d pop %rbp
1137: c3 retq
1138: 0f 1f 84 00 00 00 00 nopl 0x0(%rax,%rax,1)
113f: 00
# recompile opting out of control flow protection
g++ test.cpp -fcf-protection=none
objdump -dC a.out
...
0000000000001129 <main>:
1129: 55 push %rbp
112a: 48 89 e5 mov %rsp,%rbp
112d: b8 00 00 00 00 mov $0x0,%eax
1132: 5d pop %rbp
1133: c3 retq
1134: 66 2e 0f 1f 84 00 00 nopw %cs:0x0(%rax,%rax,1)
113b: 00 00 00
113e: 66 90 xchg %ax,%ax
```
Note the insertion of an `endbr64` instruction when compiling and _not_ opting out. This instruction is part of the Intel Control-flow Enforcement Technology [spec](https://software.intel.com/sites/default/files/managed/4d/2a/control-flow-enforcement-technology-preview.pdf), which the GCC control flow implementation is based on.
If we're still doing gitian builds for the `0.21.0` and `0.22.0` releases, we'd likely update the gitian image to Ubuntu Focal, which would mean that the GCC used for gitian builds would also be using these options by default. So we should decide whether we want to explicitly turn these options on as part of our hardening options (although not just for this reason), or, we should be opting-out.
GCC has supported both options since 8.0.0. Clang has supported `-fcf-protection` from 7.0.0 and will support `-fstack-clash-protection` in it's upcoming [11.0.0 release](https://clang.llvm.org/docs/ReleaseNotes.html#id6).
ACKs for top commit:
jamesob:
ACK b536813cef ([`jamesob/ackr/18921.1.fanquake.build_add_stack_clash_an`](https://github.com/jamesob/bitcoin/tree/ackr/18921.1.fanquake.build_add_stack_clash_an))
laanwj:
Code review ACK b536813cef
Tree-SHA512: abc9adf23cdf1be384f5fb9aa5bfffdda86b9ecd671064298d4cda0440828b509f070f9b19c88c7ce50ead9ff32afff9f14c5e78d75f01241568fbfa077be0b7
1ccb9f30c0 Move Win32 defines to configure.ac to ensure they are globally defined (Luke Dashjr)
Pull request description:
#9245 no longer needs this, since the main `_WIN32_WINNT` got bumped by something else.
So rather than just lose it, might as well get it merged in independently.
I'm not aware of any practical effects, but it seems safer to use the same API versions everywhere.
ACKs for top commit:
fanquake:
ACK 1ccb9f30c0 - checked that the binaries produced are the same.
Tree-SHA512: 273e9186579197be01b443b6968e26b9a8031d356fabc5b73aa967fcdb837df195b7ce0fc4e4529c85d9b86da6f2d7ff1bf56a3ff0cbbcd8cee8a9c2bf70a244
2f8a4c9a06 build: Enable some commonly enabled compiler diagnostics (practicalswift)
Pull request description:
Enable some commonly enabled compiler diagnostics as discussed in #17344.
| Compiler diagnostic | no# of emitted unique GCC warnings in `master` | no# of emitted unique Clang warnings in `master` |
| ------------- | ------------- | ------------- |
| `-Wduplicated-branches`: Warn if `if`/`else` branches have duplicated code | 0 | Not supported |
| `-Wduplicated-cond`: Warn if `if`/`else` chain has duplicated conditions | 0 | Not supported |
| `-Wlogical-op`: Warn about logical operations being used where bitwise were probably wanted | 0 | Not supported |
| `-Woverloaded-virtual`: Warn if you overload (not `override`) a virtual function | 0 | 0 |
| ~~`-Wunused-member-function`: Warn on unused member function~~ | Not supported | 2 |
| ~~`-Wunused-template`: Warn on unused template~~ | Not supported | 1 |
There is a large overlap between this list and [Jason Turner's list of recommended compiler diagnostics in the Collaborative Collection of C++ Best Practices (`cppbestpractices`) project](https://github.com/lefticus/cppbestpractices/blob/master/02-Use_the_Tools_Available.md#gcc--clang). There is also an overlap with the recommendations given in the [C++ Core Guidelines](https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines) (with editors Bjarne Stroustrup and Herb Sutter).
Closes#17344.
ACKs for top commit:
jonatack:
ACK 2f8a4c9a06 no warnings for me with these locally on debian 5.7.10-1 (2020-07-26) x86_64 with gcc 10 and clang 12
fanquake:
ACK 2f8a4c9a06 - no-longer seeing any obvious issues with doing this.
hebasto:
ACK 2f8a4c9a06, no new warnings in Travis jobs.
Tree-SHA512: f669ea22b31263a555f999eff6a9d65750662e95831b188c3192a2cf0127fb7b5136deb762a6b0b7bbdfb0dc6a40caf48251a62b164fffb81dd562bdd15ec3c8
70452a070b build: set minimum required Boost to 1.58 (fanquake)
Pull request description:
Any systems which only have an older installable Boost can use depends.
1.58.0 retains compatibility with the packages [installable on Ubuntu 16.04](https://packages.ubuntu.com/xenial/libboost-dev).
The projects usage of Boost wont be going away any time soon, if ever (i.e #15382), and our usage of the test framework.
Fixes: #19506
ACKs for top commit:
practicalswift:
ACK 70452a070b -- patch looks correct
laanwj:
ACK 70452a070b
hebasto:
ACK 70452a070b, tested on Linux Mint 20 (x86_64).
Tree-SHA512: d290415e3c70a394b3d7659c0480a35b4082bdce8d48b1c64a0025f7ad6e21567b4dc85813869513ad246d27f950706930410587c11c1aa3693ae6245084765c
This flag was added to binutils/ld in the 2.30 release,
see commit c11c786f0b45617bb8807ab6a57220d5ff50e414:
> The new "-z separate-code" option will generate separate code LOAD
segment which must be in wholly disjoint pages from any other data.
It was made the default for Linux/x86 targets in the 2.31 release, see commit
f6aec96dce1ddbd8961a3aa8a2925db2021719bb:
> This patch adds --enable-separate-code to ld configure to turn on
-z separate-code by default and enables it by default for Linux/x86.
This avoids mixing code pages with data to improve cache performance
as well as security.
> To reduce x86-64 executable and shared object sizes, the maximum page
size is reduced from 2MB to 4KB when -z separate-code is turned on by
default. Note: -z max-page-size= can be used to set the maximum page
size.
> We compared SPEC CPU 2017 performance before and after this change on
Skylake server. There are no any significant performance changes.
Everything is mostly below +/-1%.
Support was also added to LLVMs lld: https://reviews.llvm.org/D64903, however
there is remains off by default.
There were concerns about an increase in binary size, however in our case, the
increase (1 page worth of bytes) would seem negligible, given we are shipping a
multi-megabyte binary, which then downloads 100's of GBs of data.
Also note that most recent versions of distros are shipping a new enough version
of binutils that this is available and/or on by default (assuming the distro has
not turned it off, I haven't checked everywhere):
CentOS 8: 2.30
Debian Buster 2.31.1
Fedora 29: 2.31.1
FreeBSD: 2.33
GNU Guix: 2.33 / 2.34
Ubuntu 18.04: 2.30
Related threads / discussion:
https://bugzilla.redhat.com/show_bug.cgi?id=1623218
While testing #19530 I noticed that we couldn't call dsymutil after LTO:
```bash
../libtool: line 10643: x86_64-apple-darwin16-dsymutil: command not found
```
This updates configure to call `AC_PATH_TOOL` so that we end up with the
full path to dsymutil, similar to `otool` and `install_name_tool`, ie:
`/bitcoin/depends/x86_64-apple-darwin16/share/../native/bin/x86_64-apple-darwin16-otool`.
Debian GCC ignores -Wformat-security, without -Wformat, which
means when we test for it, 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
```
Fix this by just combining the -Wformat and -Wformat-security checks
together.
92bc268e4a build: Detect missed pkg-config early (Hennadii Stepanov)
1739eb23d8 build: Drop unused use_pkgconfig variable (Hennadii Stepanov)
a661449a2e build: Drop use_pkgconfig check for libmultiprocess check (Hennadii Stepanov)
90b95e7929 build: Drop dead non-pkg-config code for libevent check (Hennadii Stepanov)
44a14afbb8 build: Drop dead non-pkg-config code for qrencode check (Hennadii Stepanov)
10cbae0c39 build: Drop dead non-pkg-config code for ZMQ check (Hennadii Stepanov)
06cfc9cadf build: Fix indentation in UNIVALUE check (Hennadii Stepanov)
6fd2118e77 build: Drop dead non-pkg-config code for UNIVALUE check (Hennadii Stepanov)
e9edbe4dbd build: Always use pkg-config (Hennadii Stepanov)
9e2e753b06 build: Always define ZMQ_STATIC for MinGW (Hennadii Stepanov)
Pull request description:
This PR:
- is based on #18297 (already merged)
- drops all of the non-pkg-config paths from the `configure` script
Ref: #17768
ACKs for top commit:
fanquake:
ACK 92bc268e4a. I re-gitian-built. There are a couple follow-ups that I'll PR shortly. Thanks for addressing my feedback above. I took too long to get back to this.
laanwj:
ACK 92bc268e4a
Tree-SHA512: 83c2d9cf03518867a1ebf7e26a8fc5b6dd8962ef983fe0d84e0c7eb74717f4c36a834da02faf0e503ffd87167005351671cf040c0d4ddae57ee152a6ff84012b
c4ffcf07af build: remove BIP70 configure option (fanquake)
Pull request description:
This was left in after #17165, so that anyone who had been compiling
with (already disabled by default) BIP70 would realise that support
had been completely removed in 0.20.0. However we should be able to
remove it for 0.21.0.
ACKs for top commit:
jnewbery:
utACK c4ffcf07af
MarcoFalke:
ACK c4ffcf07af with or without the "catch-all reject"
Tree-SHA512: a5dd4231ed97c9dd1984fb90d69a8725df2fdda0b963269b0575601c74528e5d820a4a863c428f8ede86eaae2a1606671fe1fcebdeb96b1023f7a5f899270284
9952242c03 build: improve builtin_clz* detection (fanquake)
Pull request description:
Fixes#19402.
The way we currently test for `__builtin_clz*` support with `AC_CHECK_DECLS` does not work with Clang:
```bash
configure:21492: clang++-10 -std=c++11 -c -g -O2 -DHAVE_BUILD_INFO -D__STDC_FORMAT_MACROS conftest.cpp >&5
conftest.cpp💯10: error: builtin functions must be directly called
(void) __builtin_clz;
^
1 error generated.
```
This also removes the `__builtin_clz()` check, as we don't actually use it anywhere, and it's trvial to re-add detection if we do start using it at some point. If this is controversial then I'll add a test for it as well.
ACKs for top commit:
sipa:
ACK 9952242c03
laanwj:
ACK 9952242c03
Tree-SHA512: 695abb1a694a01a25aaa483b4fffa7d598842f2ba4fe8630fbed9ce5450b915c33bf34bb16ad16a16b702dd7c91ebf49fe509a2498b9e28254fe0ec5177bbac0
The way we currently test with AC_CHECK_DECLS do not work with Clang:
```bash
configure:21492: clang++-10 -std=c++11 -c -g -O2 -DHAVE_BUILD_INFO -D__STDC_FORMAT_MACROS conftest.cpp >&5
conftest.cpp💯10: error: builtin functions must be directly called
(void) __builtin_clz;
^
1 error generated.
```
This also removes the __builtin_clz() check, as we don't actually use
it anywhere, and it's trvial to re-add detection if we do start using
it at some point.
On OS X, when searching Homebrew keg-only packages for BDB 4.8, if we find it,
use BDB_CPPFLAGS and BDB_LIBS instead of CFLAGS and LIBS for the result. This
is (1) more correct, and (2) necessary in order to give this location
priority over other directories in the include search path, which may include
system include directories with other versions of BDB.
This option causes the compiler to insert probes whenever stack space
is allocated statically or dynamically to reliably detect stack overflows
and thus mitigate the attack vector that relies on jumping over a stack
guard page as provided by the operating system.
This option is now enabled by default in Ubuntu GCC as of 19.10.
Available in GCC 8 and Clang 11.
8a26848c46 build: Fix m4 escaping (Hennadii Stepanov)
9123ec15db build: Remove extra tokens warning (Hennadii Stepanov)
fded4f48c3 build: Remove duplicated QT_STATICPLUGIN define (Hennadii Stepanov)
05a93d5d96 build: Fix indentation in bitcoin_qt.m4 (Hennadii Stepanov)
ddbb419310 build: Use pkg-config in BITCOIN_QT_CONFIGURE for all hosts (Hennadii Stepanov)
492971de35 build: Fix mingw pkgconfig file and dependency naming (Hennadii Stepanov)
Pull request description:
This PR makes `bitcoin_qt.m4` to use `pkg-config` for all hosts and removes non-pkg-config paths from it. This is a step towards the idea which was clear [stated](https://github.com/bitcoin/bitcoin/pull/8314#issue-76644643) by Cory Fields:
> I believe the consensus is to treat Windows like the others and require pkg-config across the board. We can drop all of the non-pkg-config paths, and simply AC_REQUIRE(PKG_PROG_PKG_CONFIG)
There are two unsolved problems with this PR. If depends is built with `DEBUG=1` the `configure` script fails to pickup Qt:
- for macOS host (similar to, but not the same as #16391)
- for Windows host (regression)
The fix is ~on its way~ submitted in #18298 (as a followup).
Also this PR picks some small improvements from #17820.
ACKs for top commit:
theuni:
Code review ACK 8a26848c46
dongcarl:
Code Review ACK 8a26848c46
laanwj:
Code review ACK 8a26848c46
Tree-SHA512: 3b25990934b939121983df7707997b31d61063b1207d909f539d69494c7cb85212f353092956d09ecffebb9fef28b869914dd1216a596d102fcb9744bb5487f7
This was left in after #17165, so that anyone who had been compiling
with (already disabled by default) BIP70 would realise that support
had been completely removed in 0.20.0. However we should be able to
remove it for 0.21.0.
Fuzzing code uses C++17 specific code (e.g. std::optional), so it is not
possible to compile with --enable-fuzz and without --enable-c++17.
Thus, turn on --enable-c++17 whenever --enable-fuzz is used.
eea8114657 build: Enable unreachable-code-loop-increment (Jonathan Schoeller)
d15db4b1fc refactor: Fix unreachable code in init arg checks (Jonathan Schoeller)
Pull request description:
Closes: #19017
In #19015 it's been suggested that we add some new compiler warnings to our build. Some of these, such as `-Wunreachable-code-loop-increment`, generate warnings. We'll likely want to fix these up if we're going to turn these warnings on.
```shell
init.cpp:969:5: warning: loop will run at most once (loop increment never executed) [-Wunreachable-code-loop-increment]
for (const auto& arg : gArgs.GetUnsuitableSectionOnlyArgs()) {
^~~
1 warning generated.
```
aa8d76806c/src/init.cpp (L968-L972)
To fix this, collect all errors, and output them in a single error message after the loop completes. This resolves the unreachable code warning, and avoids popup hell that could result from outputting a seperate message for each error or warning one by one.
ACKs for top commit:
laanwj:
Code review ACK eea8114657
hebasto:
re-ACK eea8114657, only suggested changes applied since the [previous](https://github.com/bitcoin/bitcoin/pull/19131#pullrequestreview-421772387) review.
Tree-SHA512: 2aa3ceb7fab581b6ba2580900668388d8eba1c3001c8ff9c11c1f4a9a10fbc37f30e590249862676858446e3f4950140a252953ba1643ba3bfd772f8eae20583
facef3d413 doc: Explain that anyone can work on good first issues, move text to CONTRIBUTING.md (MarcoFalke)
fae2fb2a19 doc: Expand section on Getting Started (MarcoFalke)
100000d1b2 doc: Add headings to CONTRIBUTING.md (MarcoFalke)
fab893e0ca doc: Fix unrelated typos reported by codespell (MarcoFalke)
Pull request description:
Some random doc changes:
* Add sections to docs, so that they can be linked to
* Explain that anyone (even maintainers) are allowed to work on good first issues
* Expand section on Getting Started slightly
ACKs for top commit:
hebasto:
ACK facef3d413
fanquake:
ACK facef3d413
Tree-SHA512: 8998e273a76dbf4ca77e79374c14efe4dfcc5c6df6b7d801e1e1e436711dbe6f76b436f9cbc6cacb45a56827babdd6396f3bd376a9426ee7be3bb9b8a3b8e383
While emoji and other symbols in C++ identifers (as accepted by newer
compilers) are fun, they might create confusion during code review, for
example because some symbols look very similar. Forbid such extended
identifiers for now.
This is done by providing `-fno-extended-identifiers`. Thanks to sipa
for suggesting this compiler flag.
e2bab2aa16 multiprocess: add multiprocess travis configuration (Russell Yanofsky)
603fd6a2e7 depends: add MULTIPROCESS depends option (Russell Yanofsky)
5d1377b52b build: multiprocess autotools changes (Russell Yanofsky)
Pull request description:
This PR is part of the [process separation project](https://github.com/bitcoin/bitcoin/projects/10).
---
This PR consists of build changes only. It adds an `--enable-multiprocess` autoconf option (off by default and marked experimental), that builds new `bitcoin-node` and `bitcoin-gui` binaries. These currently function the same as existing `bitcoind` and `bitcoin-qt` binaries, but are extended in #10102 with IPC features to execute node, wallet, and gui functions in separate processes.
In addition to adding the `--enable-multiprocess` config flag, it also adds a depends package and autoconf rules to build with the [libmultiprocess](https://github.com/chaincodelabs/libmultiprocess) library, and it adds new travis configuration to exercise the build code and run functional tests with the new binaries.
The changes in this PR were originally part of #10102 but were moved into #16367 to be able to develop and review the multiprocess build changes independently of the code changes. #16367 was briefly merged and then reverted in #18588. Only change since #16367 has been dropping the `native_boost.mk` depends package which was pointed out to be no longer necessary in https://github.com/bitcoin/bitcoin/pull/16367#issuecomment-596484337 and https://github.com/bitcoin/bitcoin/pull/18588#pullrequestreview-391765649
ACKs for top commit:
practicalswift:
ACK e2bab2aa16
Sjors:
tACK e2bab2aa16 on macOS 10.15.4
hebasto:
ACK e2bab2aa16, tested on Linux Mint 19.3 (x86_64):
Tree-SHA512: b5a76eab5abf63d9d8b6d628cbdff4cc1888eef15cafa0a5d56369e2f9d02595fed623f4b74b2cf2830c42c05a774f0943e700f9c768a82d9d348cad199e135c
Instruct the linker to set the major & minor subsystem versions in the PE
header to 6 & 1 (NT 6.1 which corresponds to Windows 7). Similar to
macOS, the binary will now refuse to run on unsupported versions of
Windows.
a30b0a24e9 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 a30b0a24e9
Empact:
ACK a30b0a24e9
Tree-SHA512: f81b71cf3ee4db88b6f664c571075e0d30800a604f067f44273f256695a1dea533779db2ac859dd0a4cd8b66289c3e45f4aff1cfadfa160a1c354237167b05e2
df6bde031b test: remove glibc fdelt sanity check (fanquake)
8bf1540cc2 build: remove fdelt_chk backwards compatibility code (fanquake)
Pull request description:
ae30d40e50
The return type of [`fdelt_chk`](https://sourceware.org/git/?p=glibc.git;a=blob;f=debug/fdelt_chk.c;h=f62ce7349707cb68f55831c1c591fd7387a90258;hb=HEAD) changed from `unsigned long int` to `long int` in glibc 2.16. See [this commit](https://sourceware.org/git/?p=glibc.git;a=commit;h=ceb9e56b3d1f8c1922e0526c2e841373843460e2). Now that we require [glibc >=2.17](https://github.com/bitcoin/bitcoin/pull/17538) we can remove our back-compat code.
ab7bce584a
While looking at the above changes, I noticed that our glibc fdelt sanity check doesn't seem to be checking anything. `fdelt_warn()` also isn't something we'd want to actually "trigger" at runtime, as doing so would cause `bitcoind` to abort.
The comments:
> // trigger: Call FD_SET to trigger __fdelt_chk. FORTIFY_SOURCE must be defined
> // as >0 and optimizations must be set to at least -O2.
suggest calling FD_SET to check the invocation of `fdelt_chk` (this is [aliased with fdelt_warn in glibc](https://sourceware.org/git/?p=glibc.git;a=blob;f=debug/fdelt_chk.c;h=f62ce7349707cb68f55831c1c591fd7387a90258;hb=HEAD)). However just calling `FD_SET()` will not necessarily cause the compiler to insert a call to `fd_warn()`.
Whether or not GCC (recent Clang should work, but may use different heuristics) inserts a call to `fdelt_warn()` depends on if the compiler can determine if the value passed in is a compile time constant (using [`__builtin_constant_p`](https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html)) and whether the value is < 0 or >= `FD_SETSIZE`. The glibc implementation is [here](https://sourceware.org/git/?p=glibc.git;a=blob;f=misc/bits/select2.h;h=7e17430ed94dd1679af10afa3d74795f9c97c0e8;hb=HEAD). This means our check should never cause a call to be inserted.
Compiling master without `--glibc-back-compat` (if you do pass `--glibc-back-compat` the outcome is still the same; however the abort will only happen with >=`FD_SETSIZE` as that is what our [fdelt_warn()](https://github.com/bitcoin/bitcoin/blob/master/src/compat/glibc_compat.cpp#L24) checks for), there are no calls to `fdelt_warn()` inserted by the compiler:
```bash
objdump -dC bitcoind | grep sanity_fdelt
...
0000000000399d20 <sanity_test_fdelt()>:
399d20: 48 81 ec 98 00 00 00 sub $0x98,%rsp
399d27: b9 10 00 00 00 mov $0x10,%ecx
399d2c: 64 48 8b 04 25 28 00 mov %fs:0x28,%rax
399d33: 00 00
399d35: 48 89 84 24 88 00 00 mov %rax,0x88(%rsp)
399d3c: 00
399d3d: 31 c0 xor %eax,%eax
399d3f: 48 89 e7 mov %rsp,%rdi
399d42: fc cld
399d43: f3 48 ab rep stos %rax,%es:(%rdi)
399d46: 48 8b 84 24 88 00 00 mov 0x88(%rsp),%rax
399d4d: 00
399d4e: 64 48 33 04 25 28 00 xor %fs:0x28,%rax
399d55: 00 00
399d57: 75 0d jne 399d66 <sanity_test_fdelt()+0x46>
399d59: b8 01 00 00 00 mov $0x1,%eax
399d5e: 48 81 c4 98 00 00 00 add $0x98,%rsp
399d65: c3 retq
399d66: e8 85 df c8 ff callq 27cf0 <__stack_chk_fail@plt>
399d6b: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
```
If you modify the sanity test to pass `-1` or `FD_SETSIZE` to `FD_SET`, you'll see calls to `fdelt_warn` inserted, and the runtime behaviour is an abort as expected.
```diff
diff --git a/src/compat/glibc_sanity_fdelt.cpp b/src/compat/glibc_sanity_fdelt.cpp
index 87140d0c7..16974bfa0 100644
--- a/src/compat/glibc_sanity_fdelt.cpp
+++ b/src/compat/glibc_sanity_fdelt.cpp
@@ -20,7 +20,7 @@ bool sanity_test_fdelt()
{
fd_set fds;
FD_ZERO(&fds);
- FD_SET(0, &fds);
+ FD_SET(FD_SETSIZE, &fds);
return FD_ISSET(0, &fds);
}
#endif
```
```bash
0000000000399d20 <sanity_test_fdelt()>:
399d20: 48 81 ec 98 00 00 00 sub $0x98,%rsp
399d27: b9 10 00 00 00 mov $0x10,%ecx
399d2c: 64 48 8b 04 25 28 00 mov %fs:0x28,%rax
399d33: 00 00
399d35: 48 89 84 24 88 00 00 mov %rax,0x88(%rsp)
399d3c: 00
399d3d: 31 c0 xor %eax,%eax
399d3f: 48 89 e7 mov %rsp,%rdi
399d42: fc cld
399d43: f3 48 ab rep stos %rax,%es:(%rdi)
399d46: 48 c7 c7 ff ff ff ff mov $0xffffffffffffffff,%rdi
399d4d: e8 3e ff ff ff callq 399c90 <__fdelt_warn>
399d52: 0f b6 04 24 movzbl (%rsp),%eax
399d56: 83 e0 01 and $0x1,%eax
399d59: 48 8b 94 24 88 00 00 mov 0x88(%rsp),%rdx
399d60: 00
399d61: 64 48 33 14 25 28 00 xor %fs:0x28,%rdx
399d68: 00 00
399d6a: 75 08 jne 399d74 <sanity_test_fdelt()+0x54>
399d6c: 48 81 c4 98 00 00 00 add $0x98,%rsp
399d73: c3 retq
399d74: e8 77 df c8 ff callq 27cf0 <__stack_chk_fail@plt>
399d79: 0f 1f 80 00 00 00 00 nopl 0x0(%rax)
```
```bash
src/bitcoind
*** buffer overflow detected ***: src/bitcoind terminated
Aborted
```
I think the test should should be removed and replaced (if possible) with additional checks in security-check.py. I was thinking about adding a version of [this script](https://github.com/fanquake/core-review/blob/master/fortify.py) as part of the output, but that needs more thought. I'll address this in a follow up.
ACKs for top commit:
laanwj:
ACK df6bde031b
Tree-SHA512: d8b3af4f4eb2d6c767ca6e72ece51d0ab9042e1bbdfcbbdb7ad713414df21489ba3217662b531b8bfdac0265d2ce5431abfae6e861b6187d182ff26c6e59b32d
0c63f80854 build: Suppress -Wdeprecated-copy warnings (Hennadii Stepanov)
Pull request description:
Tomorrow, on Apr 23 the Ubuntu 20.04 release is expected. It packaged with Qt 5.12 LTS that has a nasty peculiarity to cause modern compilers, including Clang 10.0 and GCC 9.3, to emit spammy `-Wdeprecated-copy` warnings (#15822, #18419).
This PR suppress such warnings _temporarily_, until the [upstream is fixed](https://codereview.qt-project.org/c/qt/qtbase/+/272258).
Here are some affected systems (with system packages):
- Ubuntu 20.04 LTS + Qt 5.12.8 LTS + { Clang 10.0 | GCC 9.3 }
- Fedora 32 + Qt 5.13.2 + Clang 10.0
Reference: [QTBUG-75210](https://bugreports.qt.io/browse/QTBUG-75210)
Also see **fanquake**'s [comment](https://github.com/bitcoin/bitcoin/pull/18738#issuecomment-622956100).
ACKs for top commit:
MarcoFalke:
ACK 0c63f80854 seems fine to disable this warning for the 0.21.0 release temporarily and then enable it for 0.22.0, when boost is removed.
fanquake:
ACK 0c63f80854 - I think it's ok to suppress these for now, given that `-Wdeprecated-copy` is enabled (via `-Wextra`) in GCC 9 and Clang 10. The Qt output is pretty noisy, and there's a few warnings from Boost as well.
Tree-SHA512: 7064a3272bc9eae00b73a16c421ac58be148f374cbef87320e8f092f52761f6e98166eff60346b70867f8a69a9698a79455dc16b42d92f8fbe7c56519571ac08
839add193b build: Enable -Wsuggest-override (Hennadii Stepanov)
de5e91c303 refactor: Add BerkeleyDatabaseVersion() function (Hennadii Stepanov)
Pull request description:
From GCC [docs](https://gcc.gnu.org/onlinedocs/gcc-9.2.0/gcc/Warning-Options.html):
> `-Wsuggest-override`
> Warn about overriding virtual functions that are not marked with the override keyword.
~This PR is based on #16722 (the first commit).~ See: https://github.com/bitcoin/bitcoin/pull/16722#issuecomment-584111086
ACKs for top commit:
fanquake:
ACK 839add193b
vasild:
ACK 839add193
practicalswift:
ACK 839add193b assuming Travis is happy: patch looks correct
Tree-SHA512: 1e8cc085da30d41536deff9b181962c1882314ab252c2ad958294087ae1e5a0dfa4886bdbe36f21cf6ae71df776a8420f349f007d4b5b49fd79ba98ce308965a
autoconf and automake changes to support multiprocess gui/node/wallet execution.
This adds a new --enable-multiprocess flag, and build configuration code to
detect libraries needed for multiprocess support. The --enable-multiprocess
flag builds new bitcoin-node and bitcoin-gui executables, which are updated in
https://github.com/bitcoin/bitcoin/pull/10102 to communicate across processes.
But for now they are functionally equivalent to existing bitcoind and
bitcoin-qt executables.
89fea68ffd build: don't pass -w when building for Windows (fanquake)
Pull request description:
This has been around since the introduction of autotools. However at
this point I'm not sure we'd ever want to suppress all warnings when
performing a build, and given that CXX FLAGS will have been overriden
when cross-compiling for Windows (using depends), this would rarely,
if-ever be used anyways.
From https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html:
> -w
>
> Inhibit all warning messages.
ACKs for top commit:
hebasto:
ACK 89fea68ffd
Tree-SHA512: 2b5bdef7fff5c87b28199f5822cab3cdf600c90c01a40db5cd85053eef5dcb5816e2e97ff61a30ff94b4f0c6cb7be22beaef34d82235bdf05ff9da865d40b381
This has been around since the introduction of autotools. However at
this point I'm not sure we'd every want to suppress all warnings when
performing a build, and given that CXX FLAGS will have been overriden
when cross-compiling for Windows (using depends), this would rarely,
if-ever be used anyways.
From https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html:
-w
Inhibit all warning messages.
As is, this sanity check doesn't seem to be testing fdelt_chk, because
passing a value of "0" to FD_SET wont cause the compiler to insert any
calls to fdelt_chk().
The documentation is a little misleading. If we actually triggered fdelt_chk
at runtime, bitcoind would abort. I think this check would be better replaced
(if possible) by additional checks in security-check.py.
The compiler may insert a call to fdelt_warn() (aliased with fdelt_chk
in glibc) at compile time if it can determine that an invalid value is
being passed to FD_SET.
These checks are essentially; value < 0 or value >= FD_SETSIZE along
with a check for wether the value is a compile time constant.
If the compiler can determine an invalid value is being passed, a call
to fdelt_warn will be inserted. Passing 0 should never cause a call to
be inserted.
You can check this after compiling:
```bash
objdump -dC bitcoind | grep sanity_fdelt
...
0000000000399d20 <sanity_test_fdelt()>:
399d20: 48 81 ec 98 00 00 00 sub $0x98,%rsp
399d27: b9 10 00 00 00 mov $0x10,%ecx
399d2c: 64 48 8b 04 25 28 00 mov %fs:0x28,%rax
399d33: 00 00
399d35: 48 89 84 24 88 00 00 mov %rax,0x88(%rsp)
399d3c: 00
399d3d: 31 c0 xor %eax,%eax
399d3f: 48 89 e7 mov %rsp,%rdi
399d42: fc cld
399d43: f3 48 ab rep stos %rax,%es:(%rdi)
399d46: 48 8b 84 24 88 00 00 mov 0x88(%rsp),%rax
399d4d: 00
399d4e: 64 48 33 04 25 28 00 xor %fs:0x28,%rax
399d55: 00 00
399d57: 75 0d jne 399d66 <sanity_test_fdelt()+0x46>
399d59: b8 01 00 00 00 mov $0x1,%eax
399d5e: 48 81 c4 98 00 00 00 add $0x98,%rsp
399d65: c3 retq
399d66: e8 85 df c8 ff callq 27cf0 <__stack_chk_fail@plt>
399d6b: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
```
To test, you could modify this test to pass -1 to FD_SET, and check
that a call to fdelt_warn() is inserted, and that running bitcoind
fails. i.e:
```bash
0000000000399d20 <sanity_test_fdelt()>:
399d20: 48 81 ec 98 00 00 00 sub $0x98,%rsp
399d27: b9 10 00 00 00 mov $0x10,%ecx
399d2c: 64 48 8b 04 25 28 00 mov %fs:0x28,%rax
399d33: 00 00
399d35: 48 89 84 24 88 00 00 mov %rax,0x88(%rsp)
399d3c: 00
399d3d: 31 c0 xor %eax,%eax
399d3f: 48 89 e7 mov %rsp,%rdi
399d42: fc cld
399d43: f3 48 ab rep stos %rax,%es:(%rdi)
399d46: 48 c7 c7 ff ff ff ff mov $0xffffffffffffffff,%rdi
399d4d: e8 3e ff ff ff callq 399c90 <__fdelt_warn>
399d52: 0f b6 04 24 movzbl (%rsp),%eax
399d56: 83 e0 01 and $0x1,%eax
399d59: 48 8b 94 24 88 00 00 mov 0x88(%rsp),%rdx
399d60: 00
399d61: 64 48 33 14 25 28 00 xor %fs:0x28,%rdx
399d68: 00 00
399d6a: 75 08 jne 399d74 <sanity_test_fdelt()+0x54>
399d6c: 48 81 c4 98 00 00 00 add $0x98,%rsp
399d73: c3 retq
399d74: e8 77 df c8 ff callq 27cf0 <__stack_chk_fail@plt>
399d79: 0f 1f 80 00 00 00 00 nopl 0x0(%rax)
```
```bash
./src/bitcoind
*** buffer overflow detected ***: src/bitcoind terminated
Aborted
```
a029805f57 build: remove -Qunused-arguments workaround for clang + ccache (fanquake)
Pull request description:
This was added in 386efb7695 to address spammy Clang warnings when building with ccache.
The issue was addressed in [ccache 3.2](https://bugzilla.samba.org/show_bug.cgi?id=8118), and from a look at most major distros, it's only Debian Jessie that has a version of ccache older than that ([3.1](https://packages.debian.org/jessie/ccache)).
Therefore I think it's acceptable to drop this workaround, and re-enable warnings for unused driver arguments (when compiling using Clang and ccache).
ACKs for top commit:
hebasto:
ACK a029805f57.
vasild:
utACK a029805f57
Tree-SHA512: f887b9bd12f9c1c8d209943b86e8dafe33cfd1572912f2cafabe08ffe403973e48f0f7289280a8c6db9263c57aad43fbd4bb72f42db762eb090f3b1ef0538f43
03da4c7781 build: make linker checks more robust (Cory Fields)
Pull request description:
Check for a flag to turn linker warnings into errors. When flags are passed to
linkers via the compiler driver using a -Wl,-foo flag, linker warnings may be
swallowed rather than bubbling up.
This is one of [Corys commits](b9acd3d33e) that I've modified to also add `-Wl,-fatal_warnings`
for darwin.
ACKs for top commit:
vasild:
re-ACK 03da4c778
Tree-SHA512: 212031d619ed88e52aaae30cf3b711681d72c4d670884406403605d1d86c784c84cb07e2e0d6c30926e659db8f14f8dabd5af3de5291637f8080d6dfee358248
71f183a49b build: warn on potentially uninitialized reads (Vasil Dimov)
Pull request description:
* Enable `conditional-uninitialized` warning class to show potentially uninitialized
reads.
* Fix the sole such warning in Bitcoin Core in `GetRdRand()`: `r1` would be
set to `0` on `rdrand` failure, so initializing it to `0` is a non-functional
change.
ACKs for top commit:
practicalswift:
ACK 71f183a49b
laanwj:
ACK 71f183a49b
Tree-SHA512: 2c1d8caacd86424b16a9d92e5df19e0bedb51ae111eecad7e3bfa46447bc88e5fff1f32dacf6c4a28257ebb3d87e79f80f074ce2c523ce08b1a0c0a67ab44204
Check for a flag to turn linker warnings into errors. When flags are passed to
linkers via the compiler driver using a -Wl,-foo flag, linker warnings may be
swallowed rather than bubbling up.
Co-authored-by: fanquake <fanquake@gmail.com>
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
Enable -Wconditional-uninitialized to warn on potentially uninitialized
reads.
Fix the sole such warning in Bitcoin Core in GetRdRand(): r1 would be
set to 0 on rdrand failure, so initializing it to 0 is a non-functional
change.
From "Intel 64 and IA-32 ArchitecturesSoftware Developer's Manual" [1],
page 1711: "CF=1 indicates that the data in the destination is valid.
Otherwise CF=0 and the data in the destination operand will be returned
as zeros for the specified width."
[1] https://software.intel.com/sites/default/files/managed/39/c5/325462-sdm-vol-1-2abcd-3abcd.pdf
c31cbe7cfe Add C++17 test to Travis (Pieter Wuille)
7829685e27 Add configure option for c++17 (Pieter Wuille)
0fbde488b2 Support conversion between Spans of compatible types (Pieter Wuille)
7cbfebbf3d Update ax_cxx_compile_stdcxx.m4 (Pieter Wuille)
Pull request description:
This adds a `--enable-c++17` option to the configure script, fixes the only C++17 incompatibility (with a commit taken from #18468), and adds a Travis test for it.
This is all off by default, and release builds remain C++11.
It implements the first step of the plan in https://github.com/bitcoin/bitcoin/issues/16684.
ACKs for top commit:
elichai:
tACK c31cbe7cfe
practicalswift:
Tested ACK c31cbe7cfe
hebasto:
ACK c31cbe7cfe, tested on Linux Mint 19.3 both C++11 and C++17 modes. Compiled and passed tests locally.
Tree-SHA512: a4b00776dbceef9c12abbb404c6bcd48f7916ce24c8c7a14116355f64e817578b7fcddbedd5ce435322319d1e4de43429b68553f4d96d970c308fe3e3e59b9d1
182dbdf0f4 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 182dbdf0f4
Tree-SHA512: f9ed4bd661f33ff6b2b1150591e860b3c1f44e12b87c35e870d06a7013c4e841ed2bf17b41ad6b18fe471b0b23a4b5e42cf1400637180888e0bc56c254fe0766
b155fcda51 doc: fix typo in configure.ac (fanquake)
20a30922fb doc: note why we can't use thread_local with glibc back compat (fanquake)
Pull request description:
Given that we went through a [gitian build](https://github.com/bitcoin/bitcoin/pull/18681) to remember why this is the case, we might as well make a note of it in configure.ac.
[From #18681](https://github.com/bitcoin/bitcoin/pull/18681#issuecomment-615526634):
Looking at the Linux build log, this has failed with:
```bash
Checking glibc back compat...
bitcoind: symbol __cxa_thread_atexit_impl from unsupported version GLIBC_2.18
bitcoind: failed IMPORTED_SYMBOLS
bitcoin-cli: symbol __cxa_thread_atexit_impl from unsupported version GLIBC_2.18
bitcoin-cli: failed IMPORTED_SYMBOLS
bitcoin-tx: symbol __cxa_thread_atexit_impl from unsupported version GLIBC_2.18
bitcoin-tx: failed IMPORTED_SYMBOLS
bitcoin-wallet: symbol __cxa_thread_atexit_impl from unsupported version GLIBC_2.18
bitcoin-wallet: failed IMPORTED_SYMBOLS
test/test_bitcoin: symbol __cxa_thread_atexit_impl from unsupported version GLIBC_2.18
test/test_bitcoin: failed IMPORTED_SYMBOLS
bench/bench_bitcoin: symbol __cxa_thread_atexit_impl from unsupported version GLIBC_2.18
bench/bench_bitcoin: failed IMPORTED_SYMBOLS
qt/bitcoin-qt: symbol __cxa_thread_atexit_impl from unsupported version GLIBC_2.18
```
`__cxa_thread_atexit_impl` is used for [thread_local variable destruction](https://sourceware.org/glibc/wiki/Destructor%20support%20for%20thread_local%20variables):
> To implement this support, glibc defines __cxa_thread_atexit_impl exclusively for use by libstdc++ (which has the __cxa_thread_atexit to wrap around it), that registers destructors for thread_local variables in a list. Upon thread or process exit, the destructors are called in reverse order in which they were added.
As suggested, this only became available in glibc 2.18. From the [2.18 release notes](https://sourceware.org/legacy-ml/libc-alpha/2013-08/msg00160.html):
> * Add support for calling C++11 thread_local object destructors on thread
and program exit. This needs compiler support for offloading C++11
destructor calls to glibc.
ACKs for top commit:
hebasto:
ACK b155fcda51
Tree-SHA512: 5b9567e4a70598a4b0b91956f44ae0d93091db17c84cbf9817dac6cfa992c97d3438a8b1bb66644c74891f2149e44984daed445d22de93ca8858c5b0eabefb40
