nixpkgs/lib/systems/parse.nix
Graham Christensen 152c63c9ff
Convert libs to a fixed-point
This does break the API of being able to import any lib file and get
its libs, however I'm not sure people did this.

I made this while exploring being able to swap out docFn with a stub
in #2305, to avoid functor performance problems. I don't know if that
is going to move forward (or if it is a problem or not,) but after
doing all this work figured I'd put it up anyway :)

Two notable advantages to this approach:

1. when a lib inherits another lib's functions, it doesn't
   automatically get put in to the scope of lib
2. when a lib implements a new obscure functions, it doesn't
   automatically get put in to the scope of lib

Using the test script (later in this commit) I got the following diff
on the API:

  + diff master fixed-lib
  11764a11765,11766
  > .types.defaultFunctor
  > .types.defaultTypeMerge
  11774a11777,11778
  > .types.isOptionType
  > .types.isType
  11781a11786
  > .types.mkOptionType
  11788a11794
  > .types.setType
  11795a11802
  > .types.types

This means that this commit _adds_ to the API, however I can't find a
way to fix these last remaining discrepancies. At least none are
_removed_.

Test script (run with nix-repl in the PATH):

  #!/bin/sh

  set -eux

  repl() {
      suff=${1:-}
      echo "(import ./lib)$suff" \
          | nix-repl 2>&1
  }

  attrs_to_check() {
      repl "${1:-}" \
          | tr ';'  $'\n' \
          | grep "\.\.\." \
          | cut -d' ' -f2 \
          | sed -e "s/^/${1:-}./" \
          | sort
  }

  summ() {
      repl "${1:-}" \
          | tr ' ' $'\n' \
          | sort \
          | uniq
  }

  deep_summ() {
      suff="${1:-}"
      depth="${2:-4}"
      depth=$((depth - 1))
      summ "$suff"

      for attr in $(attrs_to_check "$suff" | grep -v "types.types"); do
          if [ $depth -eq 0 ]; then
              summ "$attr" | sed -e "s/^/$attr./"
          else
              deep_summ "$attr" "$depth" | sed -e "s/^/$attr./"
          fi
      done
  }

  (
      cd nixpkgs

      #git add .
      #git commit -m "Auto-commit, sorry" || true
      git checkout fixed-lib
      deep_summ > ../fixed-lib
      git checkout master
      deep_summ > ../master
  )

  if diff master fixed-lib; then
      echo "SHALLOW MATCH!"
  fi

  (
      cd nixpkgs
      git checkout fixed-lib
      repl .types
  )
2017-09-16 21:36:43 -04:00

174 lines
6.4 KiB
Nix

# Define the list of system with their properties.
#
# See https://clang.llvm.org/docs/CrossCompilation.html and
# http://llvm.org/docs/doxygen/html/Triple_8cpp_source.html especially
# Triple::normalize. Parsing should essentially act as a more conservative
# version of that last function.
{ lib }:
with lib.lists;
with lib.types;
with lib.attrsets;
with (import ./inspect.nix { inherit lib; }).predicates;
let
setTypesAssert = type: pred:
mapAttrs (name: value:
assert pred value;
setType type ({ inherit name; } // value));
setTypes = type: setTypesAssert type (_: true);
in
rec {
isSignificantByte = isType "significant-byte";
significantBytes = setTypes "significant-byte" {
bigEndian = {};
littleEndian = {};
};
isCpuType = isType "cpu-type";
cpuTypes = with significantBytes; setTypesAssert "cpu-type"
(x: elem x.bits [8 16 32 64 128]
&& (if 8 < x.bits
then isSignificantByte x.significantByte
else !(x ? significantByte)))
{
arm = { bits = 32; significantByte = littleEndian; family = "arm"; };
armv5tel = { bits = 32; significantByte = littleEndian; family = "arm"; };
armv6l = { bits = 32; significantByte = littleEndian; family = "arm"; };
armv7a = { bits = 32; significantByte = littleEndian; family = "arm"; };
armv7l = { bits = 32; significantByte = littleEndian; family = "arm"; };
aarch64 = { bits = 64; significantByte = littleEndian; family = "aarch64"; };
i686 = { bits = 32; significantByte = littleEndian; family = "x86"; };
x86_64 = { bits = 64; significantByte = littleEndian; family = "x86"; };
mips64el = { bits = 32; significantByte = littleEndian; family = "mips"; };
powerpc = { bits = 32; significantByte = bigEndian; family = "power"; };
};
isVendor = isType "vendor";
vendors = setTypes "vendor" {
apple = {};
pc = {};
unknown = {};
};
isExecFormat = isType "exec-format";
execFormats = setTypes "exec-format" {
aout = {}; # a.out
elf = {};
macho = {};
pe = {};
unknown = {};
};
isKernelFamily = isType "kernel-family";
kernelFamilies = setTypes "kernel-family" {
bsd = {};
};
isKernel = x: isType "kernel" x;
kernels = with execFormats; with kernelFamilies; setTypesAssert "kernel"
(x: isExecFormat x.execFormat && all isKernelFamily (attrValues x.families))
{
darwin = { execFormat = macho; families = { }; };
freebsd = { execFormat = elf; families = { inherit bsd; }; };
hurd = { execFormat = elf; families = { }; };
linux = { execFormat = elf; families = { }; };
netbsd = { execFormat = elf; families = { inherit bsd; }; };
none = { execFormat = unknown; families = { }; };
openbsd = { execFormat = elf; families = { inherit bsd; }; };
solaris = { execFormat = elf; families = { }; };
windows = { execFormat = pe; families = { }; };
} // { # aliases
# TODO(@Ericson2314): Handle these Darwin version suffixes more generally.
darwin10 = kernels.darwin;
darwin14 = kernels.darwin;
win32 = kernels.windows;
};
isAbi = isType "abi";
abis = setTypes "abi" {
cygnus = {};
gnu = {};
msvc = {};
eabi = {};
androideabi = {};
gnueabi = {};
gnueabihf = {};
unknown = {};
};
isSystem = isType "system";
mkSystem = { cpu, vendor, kernel, abi }:
assert isCpuType cpu && isVendor vendor && isKernel kernel && isAbi abi;
setType "system" {
inherit cpu vendor kernel abi;
};
mkSkeletonFromList = l: {
"2" = # We only do 2-part hacks for things Nix already supports
if elemAt l 1 == "cygwin"
then { cpu = elemAt l 0; kernel = "windows"; abi = "cygnus"; }
else if elemAt l 1 == "gnu"
then { cpu = elemAt l 0; kernel = "hurd"; abi = "gnu"; }
else { cpu = elemAt l 0; kernel = elemAt l 1; };
"3" = # Awkwards hacks, beware!
if elemAt l 1 == "apple"
then { cpu = elemAt l 0; vendor = "apple"; kernel = elemAt l 2; }
else if (elemAt l 1 == "linux") || (elemAt l 2 == "gnu")
then { cpu = elemAt l 0; kernel = elemAt l 1; abi = elemAt l 2; }
else if (elemAt l 2 == "mingw32") # autotools breaks on -gnu for window
then { cpu = elemAt l 0; vendor = elemAt l 1; kernel = "windows"; abi = "gnu"; }
else throw "Target specification with 3 components is ambiguous";
"4" = { cpu = elemAt l 0; vendor = elemAt l 1; kernel = elemAt l 2; abi = elemAt l 3; };
}.${toString (length l)}
or (throw "system string has invalid number of hyphen-separated components");
# This should revert the job done by config.guess from the gcc compiler.
mkSystemFromSkeleton = { cpu
, # Optional, but fallback too complex for here.
# Inferred below instead.
vendor ? assert false; null
, kernel
, # Also inferred below
abi ? assert false; null
} @ args: let
getCpu = name: cpuTypes.${name} or (throw "Unknown CPU type: ${name}");
getVendor = name: vendors.${name} or (throw "Unknown vendor: ${name}");
getKernel = name: kernels.${name} or (throw "Unknown kernel: ${name}");
getAbi = name: abis.${name} or (throw "Unknown ABI: ${name}");
parsed = rec {
cpu = getCpu args.cpu;
vendor =
/**/ if args ? vendor then getVendor args.vendor
else if isDarwin parsed then vendors.apple
else if isWindows parsed then vendors.pc
else vendors.unknown;
kernel = getKernel args.kernel;
abi =
/**/ if args ? abi then getAbi args.abi
else if isLinux parsed then abis.gnu
else if isWindows parsed then abis.gnu
else abis.unknown;
};
in mkSystem parsed;
mkSystemFromString = s: mkSystemFromSkeleton (mkSkeletonFromList (lib.splitString "-" s));
doubleFromSystem = { cpu, vendor, kernel, abi, ... }:
if abi == abis.cygnus
then "${cpu.name}-cygwin"
else "${cpu.name}-${kernel.name}";
tripleFromSystem = { cpu, vendor, kernel, abi, ... } @ sys: assert isSystem sys; let
optAbi = lib.optionalString (abi != abis.unknown) "-${abi.name}";
in "${cpu.name}-${vendor.name}-${kernel.name}${optAbi}";
}