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bfd, opcodes: Init separate derivations for binutils libraries #30484

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merged 8 commits into from
Nov 14, 2017

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@Ericson2314 Ericson2314 commented Oct 16, 2017

Motivation for this change

This is intended to be reviewed commit by commit.

On most distros, these are just built and distributed as part of binutils. We don't use binutils across the board, however, but rather switch between binutils and a cctools-binutils mashup, and change the
outputs on binutils too. This creates a combinatorial conditional soup which is hard to maintain.

My hope is to lower the the state space. While my patch isn't the most maintainable, they make downstream packages become more maintainable to compensate. The additional derivations themselves are completely platform-agnostic, always they always supports all possible target
platforms, and always yield "out" and "dev" outputs. That, in turn, allows downstream packages to not worry about a dependency shape-shifting under them.

In fact, the actual binutils package can avoid needing multiple outputs now that these serve the requisite libraries, so that also can become simpler on all platforms, too, removing the original wart this PR circumnavigates for now. Actually changing the binutils package to leverage is a mass rebuild, however, so I'll leave that for a separate PR.

I do hope to upstream something like my patch too, but until then I'll make myself maintainer of these derivations.

Things done
  • Tested using sandboxing (nix.useSandbox on NixOS, or option build-use-sandbox in nix.conf on non-NixOS)
  • Built stdenv on platform(s)
    • NixOS
    • macOS
    • other Linux distributions
  • Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
  • Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
  • Tested execution of all binary files (usually in ./result/bin/)
  • Fits CONTRIBUTING.md.

CC @bgamari @orivej

@Ericson2314 Ericson2314 added the 6.topic: cross-compilation Building packages on a different platform than they will be used on label Oct 16, 2017
# providing the linker and related tools. The two we use now are GNU
# Binutils, and Apple's "cctools"; "binutils" as an attempt to find an
# unused middle-ground name that evokes both.
bintools = binutils_bin;
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@copumpkin I ended up going with "bintools" rather than "utils", for the reasons above, but the concept is the same as what I mentioned in #29396 (comment) .

@@ -1,4 +1,4 @@
{ stdenv, fetchurl, binutils }:
{ stdenv, fetchurl, libbfd, binutilsOpcodes }:
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don't need libbfd here, oops

@@ -7796,6 +7800,10 @@ with pkgs;

belle-sip = callPackage ../development/libraries/belle-sip { };

libbfd = callPackage ../development/libraries/libbfd { };
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bfd? libbfd? binutils-bfd? Help me bikeshed!

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Maybe rename binutils-opcodes to libopcodes for consistency with libbfd? It seems to be known under this name, e.g. in http://mkfs.github.io/ and https://pypi.python.org/pypi/pybfd

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Ah, good precedence finding!

@@ -7796,6 +7800,10 @@ with pkgs;

belle-sip = callPackage ../development/libraries/belle-sip { };

libbfd = callPackage ../development/libraries/libbfd { };

binutilsOpcodes = callPackage ../development/libraries/binutils-opcodes { };
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opcodes? libopcodes? binutils-opcodes? Help me bikeshed!

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I vote binutils-opcodes!

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Yes, binutils-opcodes. We don't do camelCase in package names anymore.

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We don't do camelCase in package names anymore.

Oh, glad I asked! I saw a vague trend but had no idea that was the policy. Kebob FTW!

@@ -0,0 +1,13 @@
--- a/opcodes/configure.ac
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Oops. this file can go.

@Ericson2314 Ericson2314 changed the title bfd, opcodes: Init separate derivations for binutils libraries bfd, opcodes: WIP Init separate derivations for binutils libraries Oct 16, 2017
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I'm not familiar with the problem; why do we have those conditional outputs in binutils in the first place?

@@ -7796,6 +7800,10 @@ with pkgs;

belle-sip = callPackage ../development/libraries/belle-sip { };

libbfd = callPackage ../development/libraries/libbfd { };

binutilsOpcodes = callPackage ../development/libraries/binutils-opcodes { };
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I vote binutils-opcodes!

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@abbradar Some of the Darwin ones might just be because nobody bothered to muck through the allowedRequisites, but the cross ones are because of real build systems bugs, it seems (I got failures once trying to make them unconditional).

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Good, 👍 then! Conditional outputs are not something nice to deal with.

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In principle, building the libraries separately is nice, but: 1) The patch will probably make maintaining binutils significantly harder. 2) Applying the patch to binutils would cause a dependency on autoconf/automake during early stdenv bootstrap. 3) I don't really understand the motivation. What is the "combinatorial conditional soup"?

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Ericson2314 commented Oct 17, 2017

Applying the patch to binutils would cause a dependency on autoconf/automake during early stdenv bootstrap.

Right now, binutils itself is built the same as before---stock, rebuilding those libs. This is also gross, but means stdenv avoids those issues. If I successfully upstream the patch or something like it, then we won't need to regenerate anything avoiding the dep. That would be a good time to make the binutils and gdb use these.

The patch will probably make maintaining binutils significantly harder.

That's why I'm committing to maintain these new derivations and upstreaming the patch. If I suddenly go missing, well, one can revert and alias the new derivations to binutils. That's the best insurance I can offer :).

I don't really understand the motivation. What is the "combinatorial conditional soup"?

  1. The multiple outputs mess: https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/tools/misc/binutils/default.nix#L53-L56 . Do note I want to soon™ get Linux<->Darwin cross compiling working; I fear even more logic will be needed for the outputs for that.

    If binutils is just for the binaries, we can scrap all those and just do "out". I'd statically link to prevent derivations using libs from binutils, and then switch back to dynamic linking once the patch is upstreamed and binutils can depend on these new derivations.

  2. binutils vs binutils-raw: https://github.com/NixOS/nixpkgs/blob/master/pkgs/top-level/all-packages.nix#L6930-L6933 We don't fake gcc, for example, on Darwin, so this strikes me as unnecessarily incongruous and confusing.

    That binutils executables are usually wrapped in cc-wrapper makes it all the more so. That's a lot of indirection to wrap one's mind around on Darwin!

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@Ericson2314 Thanks! Regarding

Right now, binutils itself is built the same as before

we would want to have binutils use the separate libraries, because otherwise we end up duplicating them. Which could lead to confusion if (say) both binutils and libbfd are in the build inputs.

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Ericson2314 commented Oct 17, 2017

@edolstra Sure, I'll look into doing that as part of this then. Thanks!

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The changes to ghc make sense to me within the rationale of this patch.

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Based on that @edolstra said, this will have to go to staging instead. I made #30549 for the master-ready parts.

@Ericson2314 Ericson2314 changed the base branch from master to staging October 18, 2017 18:30
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Ah, thanks. That's because the dev output is not the default for those antiquotations. Should be fixed now. @nixborg build

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@nixborg build

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nixborg commented Nov 13, 2017

Jobset created at https://hydra.mayflower.de/jobset/nixos/pr-30484

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@nixborg build

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nixborg commented Nov 14, 2017

Jobset created at https://hydra.mayflower.de/jobset/nixos/pr-30484

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I just added a commit to make myself a binutils maintainer too, since we'll eventually want binutils to use the libbfd and libopcodes derivations, which will require coordination with upstream just like merging the patch the build those separately in the first place.

That doesn't change any hashes, so my old build still stands (I though the nixborg build would be a noop but staging changed in the interum). Merging, then.

@Ericson2314 Ericson2314 merged commit 728446f into NixOS:staging Nov 14, 2017
@Ericson2314 Ericson2314 deleted the libbfd branch November 14, 2017 17:10
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orivej commented Nov 18, 2017

This has broken rustc tests for Linux on staging. The first failed build: https://hydra.nixos.org/build/64149296 .

The test run-make/atomic-lock-free runs rustc with --target= i686-unknown-linux-gnu, x86_64-unknown-linux-gnu, arm-unknown-linux-gnueabi and runs nm for each output. The expected output looks like this:

atomic_lock_free.0.o:
00000000 T _ZN16atomic_lock_free10atomic_i1617h2e4fcd96500dd9adE
00000000 T _ZN16atomic_lock_free10atomic_i3217hf3342aa248394428E
…
nm: rust.metadata.bin: File format not recognized
nm: atomic_lock_free.0.bytecode.deflate: File format not recognized

i686 and x86_64 output is expected, but arm output is different and it fails the test:

nm: atomic_lock_free.0.o: File format is ambiguous
nm: Matching formats: elf32-littlearm elf32-littlearm-symbian elf32-littlearm-vxworks
nm: rust.metadata.bin: File format not recognized
nm: atomic_lock_free.0.bytecode.deflate: File format not recognized

/cc @vcunat

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orivej commented Nov 19, 2017

Here is the object file produced by rust that the staging nm fails to decode: atomic_lock_free.0.o.gz

$ gunzip atomic_lock_free.0.o.gz
$ nm atomic_lock_free.0.o
nm: atomic_lock_free.0.o: File format is ambiguous
nm: Matching formats: elf32-littlearm elf32-littlearm-symbian elf32-littlearm-vxworks

It works with the master nm or when the staging nm is called with nm --target=elf32-little.

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orivej commented Nov 19, 2017

I'm going to apply this patch: https://sourceware.org/ml/binutils/2013-05/msg00271.html

orivej added a commit that referenced this pull request Nov 19, 2017
#30484 (comment)

Since [1] libbfd is compiled with support for all available targets. However, it
can not choose whether an ARM ELF file is elf32-littlearm,
elf32-littlearm-symbian, or elf32-littlearm-vxworks, and fails with the "File
format is ambiguous" error.  Here [2] Alan Modra intended to prioritize the
first of the three, but although his patch was merged and reportedly solved the
issue, currently glibc 2.28.1 and 2.29.1 again fail to disambiguate these
targets.  This commit makes it prioritize elf32-littlearm over the other two.

[1] f8741c3
[2] https://sourceware.org/ml/binutils/2013-05/msg00271.html
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orivej commented Nov 19, 2017

Actually that patch was merged and reportedly solved the issue. Glibc must have regressed since then. I've commited the following patch to staging: c76890f . It is worth fixing the issue upstream (I've confirmed that 2.29.1 is affected too) and my patch is not worth upstreaming as it is, but it is safe and it works.

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orivej commented Nov 19, 2017

Reported upstream: https://sourceware.org/bugzilla/show_bug.cgi?id=22458

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orivej commented Nov 19, 2017

pybfd also needs fixing on staging: #31818
First failed build: https://hydra.nixos.org/build/64179131

orivej added a commit to orivej/nixpkgs that referenced this pull request Nov 19, 2017
PR NixOS#30484 (f8741c3) has split libbfd and
libopcodes from binutils and gdb.  The original pybfd setup.py is completely
unsuitable to handle that.  This commit replaces the original source with a fork
with a patched setup.py.
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@orivej This is extremely thorough troubleshooting and patching. Thank you so much!

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orivej commented Nov 21, 2017

@Ericson2314 You are welcome!

After this PR (not in master yet), binutils ship windres utility. These packages attempt to use it and fail to build:

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orivej commented Nov 21, 2017

I've fixed pdf2djvu in 0b9cd7a and forced the others to expect that windres is missing without testing in 4f73b31. (Feel free to fix the latter without setting internal autoconf variables if you want to.)

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My ultimate plan is single binutils always (we still pass --target for the moment) and arch-specific bintools-wrapper. Maybe we should just not define WINDRES outside of windows, then.

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orivej commented Nov 21, 2017

Only pdf2djvu had correct logic that was overridden by the presence of WINDRES environment variable; other projects just assumed that if windres is in PATH they are on Windows. Since this affects just 5 projects, let's keep it as it is.

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Ah ok, I misunderstood. Good choice then.

@orivej orivej mentioned this pull request Dec 31, 2017
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1.severity: mass-darwin-rebuild This PR causes a large number of packages to rebuild on Darwin 1.severity: mass-rebuild This PR causes a large number of packages to rebuild 6.topic: cross-compilation Building packages on a different platform than they will be used on 10.rebuild-darwin: 0 This PR does not cause any packages to rebuild on Darwin 10.rebuild-darwin-stdenv This PR causes stdenv to rebuild 10.rebuild-linux: 0 This PR does not cause any packages to rebuild on Linux 10.rebuild-linux-stdenv This PR causes stdenv to rebuild
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