nixpkgs/pkgs/build-support/cc-wrapper/default.nix
John Ericson 0f0383394d cc-wrapper: Salt environment variables with LLVM triples
We now (on cross) require per-target flag interposition by putting the
triple in the names of the relevant environment variables, e.g:

export NIX_arm_unknown_linux_gnu_CFLAGS_COMPILE=...

The wrapper also has a `infixSalt` attribute (and "_" prefixed and
suffixed variants) to assist downstream packages.

Note how that the dashes are replaced to keep the identifier valid.
Using names like this allows us to keep the settings for different
compilers seperate.

I think it might be even better to use names like `NIX_{BUILD,HOST}...`
using the platform's role rather than the platform itself, but this
would be more work as the previous stages' tools would have to be re-
wrapped to take on their new role. I therefore didn't do this for now,
but that route should be thoroughly explored in the future.
2017-06-22 17:52:28 -04:00

315 lines
13 KiB
Nix

# The Nixpkgs CC is not directly usable, since it doesn't know where
# the C library and standard header files are. Therefore the compiler
# produced by that package cannot be installed directly in a user
# environment and used from the command line. So we use a wrapper
# script that sets up the right environment variables so that the
# compiler and the linker just "work".
{ name ? "", stdenv, nativeTools, noLibc ? false, nativeLibc, nativePrefix ? ""
, cc ? null, libc ? null, binutils ? null, coreutils ? null, shell ? stdenv.shell
, zlib ? null, extraPackages ? [], extraBuildCommands ? ""
, dyld ? null # TODO: should this be a setup-hook on dyld?
, isGNU ? false, isClang ? cc.isClang or false, gnugrep ? null
, hostPlatform, targetPlatform
}:
with stdenv.lib;
assert nativeTools -> nativePrefix != "";
assert !nativeTools ->
cc != null && binutils != null && coreutils != null && gnugrep != null;
assert !(nativeLibc && noLibc);
assert (noLibc || nativeLibc) == (libc == null);
# For ghdl (the vhdl language provider to gcc) we need zlib in the wrapper.
assert cc.langVhdl or false -> zlib != null;
let
# Prefix for binaries. Customarily ends with a dash separator.
#
# TODO(@Ericson2314) Make unconditional, or optional but always true by
# default.
prefix = stdenv.lib.optionalString (targetPlatform != hostPlatform)
(targetPlatform.config + "-");
ccVersion = (builtins.parseDrvName cc.name).version;
ccName = (builtins.parseDrvName cc.name).name;
libc_bin = if libc == null then null else getBin libc;
libc_dev = if libc == null then null else getDev libc;
libc_lib = if libc == null then null else getLib libc;
cc_solib = getLib cc;
binutils_bin = if nativeTools then "" else getBin binutils;
# The wrapper scripts use 'cat' and 'grep', so we may need coreutils.
coreutils_bin = if nativeTools then "" else getBin coreutils;
default_cxx_stdlib_compile=optionalString (targetPlatform.isLinux && !(cc.isGNU or false))
"-isystem $(echo -n ${cc.gcc}/include/c++/*) -isystem $(echo -n ${cc.gcc}/include/c++/*)/$(${cc.gcc}/bin/gcc -dumpmachine)";
dashlessTarget = stdenv.lib.replaceStrings ["-"] ["_"] targetPlatform.config;
# TODO(@Ericson2314) Make unconditional
infixSalt = stdenv.lib.optionalString (targetPlatform != hostPlatform) dashlessTarget;
infixSalt_ = stdenv.lib.optionalString (targetPlatform != hostPlatform) (dashlessTarget + "_");
_infixSalt = stdenv.lib.optionalString (targetPlatform != hostPlatform) ("_" + dashlessTarget);
in
stdenv.mkDerivation {
name = prefix
+ (if name != "" then name else "${ccName}-wrapper")
+ (stdenv.lib.optionalString (cc != null && ccVersion != "") "-${ccVersion}");
preferLocalBuild = true;
inherit cc shell libc_bin libc_dev libc_lib binutils_bin coreutils_bin;
gnugrep_bin = if nativeTools then "" else gnugrep;
passthru = {
inherit libc nativeTools nativeLibc nativePrefix isGNU isClang default_cxx_stdlib_compile
prefix infixSalt infixSalt_ _infixSalt;
emacsBufferSetup = pkgs: ''
; We should handle propagation here too
(mapc (lambda (arg)
(when (file-directory-p (concat arg "/include"))
(setenv "NIX_${infixSalt_}CFLAGS_COMPILE" (concat (getenv "NIX_${infixSalt_}CFLAGS_COMPILE") " -isystem " arg "/include")))
(when (file-directory-p (concat arg "/lib"))
(setenv "NIX_${infixSalt_}LDFLAGS" (concat (getenv "NIX_${infixSalt_}LDFLAGS") " -L" arg "/lib")))
(when (file-directory-p (concat arg "/lib64"))
(setenv "NIX_${infixSalt_}LDFLAGS" (concat (getenv "NIX_${infixSalt_}LDFLAGS") " -L" arg "/lib64")))) '(${concatStringsSep " " (map (pkg: "\"${pkg}\"") pkgs)}))
'';
};
buildCommand =
''
mkdir -p $out/bin $out/nix-support
wrap() {
local dst="$1"
local wrapper="$2"
export prog="$3"
substituteAll "$wrapper" "$out/bin/$dst"
chmod +x "$out/bin/$dst"
}
''
+ optionalString (libc != null) (if (!targetPlatform.isDarwin) then ''
dynamicLinker="${libc_lib}/lib/$dynamicLinker"
echo $dynamicLinker > $out/nix-support/dynamic-linker
if [ -e ${libc_lib}/lib/32/ld-linux.so.2 ]; then
echo ${libc_lib}/lib/32/ld-linux.so.2 > $out/nix-support/dynamic-linker-m32
fi
# The dynamic linker is passed in `ldflagsBefore' to allow
# explicit overrides of the dynamic linker by callers to gcc/ld
# (the *last* value counts, so ours should come first).
echo "-dynamic-linker" $dynamicLinker > $out/nix-support/libc-ldflags-before
'' else ''
echo $dynamicLinker > $out/nix-support/dynamic-linker
echo "export LD_DYLD_PATH=\"$dynamicLinker\"" >> $out/nix-support/setup-hook
'')
+ optionalString (libc != null) ''
# The "-B${libc_lib}/lib/" flag is a quick hack to force gcc to link
# against the crt1.o from our own glibc, rather than the one in
# /usr/lib. (This is only an issue when using an `impure'
# compiler/linker, i.e., one that searches /usr/lib and so on.)
#
# Unfortunately, setting -B appears to override the default search
# path. Thus, the gcc-specific "../includes-fixed" directory is
# now longer searched and glibc's <limits.h> header fails to
# compile, because it uses "#include_next <limits.h>" to find the
# limits.h file in ../includes-fixed. To remedy the problem,
# another -idirafter is necessary to add that directory again.
echo "-B${libc_lib}/lib/ -idirafter ${libc_dev}/include -idirafter ${cc}/lib/gcc/*/*/include-fixed" > $out/nix-support/libc-cflags
echo "-L${libc_lib}/lib" > $out/nix-support/libc-ldflags
echo "${libc_lib}" > $out/nix-support/orig-libc
echo "${libc_dev}" > $out/nix-support/orig-libc-dev
''
+ (if nativeTools then ''
ccPath="${if targetPlatform.isDarwin then cc else nativePrefix}/bin"
ldPath="${nativePrefix}/bin"
'' else ''
echo $cc > $out/nix-support/orig-cc
# GCC shows ${cc_solib}/lib in `gcc -print-search-dirs', but not
# ${cc_solib}/lib64 (even though it does actually search there...)..
# This confuses libtool. So add it to the compiler tool search
# path explicitly.
if [ -e "${cc_solib}/lib64" -a ! -L "${cc_solib}/lib64" ]; then
ccLDFlags+=" -L${cc_solib}/lib64"
ccCFlags+=" -B${cc_solib}/lib64"
fi
ccLDFlags+=" -L${cc_solib}/lib"
ccCFlags+=" -B${cc_solib}/lib"
${optionalString cc.langVhdl or false ''
ccLDFlags+=" -L${zlib.out}/lib"
''}
# Find the gcc libraries path (may work only without multilib).
${optionalString cc.langAda or false ''
basePath=`echo ${cc_solib}/lib/*/*/*`
ccCFlags+=" -B$basePath -I$basePath/adainclude"
gnatCFlags="-aI$basePath/adainclude -aO$basePath/adalib"
echo "$gnatCFlags" > $out/nix-support/gnat-cflags
''}
if [ -e $ccPath/clang ]; then
# Need files like crtbegin.o from gcc
# It's unclear if these will ever be provided by an LLVM project
ccCFlags="$ccCFlags -B$basePath"
ccCFlags="$ccCFlags -isystem$cc/lib/clang/$ccVersion/include"
fi
echo "$ccLDFlags" > $out/nix-support/cc-ldflags
echo "$ccCFlags" > $out/nix-support/cc-cflags
ccPath="${cc}/bin"
ldPath="${binutils_bin}/bin"
# Propagate the wrapped cc so that if you install the wrapper,
# you get tools like gcov, the manpages, etc. as well (including
# for binutils and Glibc).
echo ${cc} ${cc.man or ""} ${binutils_bin} ${if libc == null then "" else libc_bin} > $out/nix-support/propagated-user-env-packages
echo ${toString extraPackages} > $out/nix-support/propagated-native-build-inputs
''
+ optionalString (targetPlatform.isSunOS && nativePrefix != "") ''
# Solaris needs an additional ld wrapper.
ldPath="${nativePrefix}/bin"
exec="$ldPath/${prefix}ld"
wrap ld-solaris ${./ld-solaris-wrapper.sh}
'')
+ ''
# Create a symlink to as (the assembler). This is useful when a
# cc-wrapper is installed in a user environment, as it ensures that
# the right assembler is called.
if [ -e $ldPath/${prefix}as ]; then
ln -s $ldPath/${prefix}as $out/bin/${prefix}as
fi
wrap ${prefix}ld ${./ld-wrapper.sh} ''${ld:-$ldPath/${prefix}ld}
if [ -e ${binutils_bin}/bin/${prefix}ld.gold ]; then
wrap ${prefix}ld.gold ${./ld-wrapper.sh} ${binutils_bin}/bin/${prefix}ld.gold
fi
if [ -e ${binutils_bin}/bin/ld.bfd ]; then
wrap ${prefix}ld.bfd ${./ld-wrapper.sh} ${binutils_bin}/bin/${prefix}ld.bfd
fi
export real_cc=${prefix}cc
export real_cxx=${prefix}c++
export default_cxx_stdlib_compile="${default_cxx_stdlib_compile}"
if [ -e $ccPath/${prefix}gcc ]; then
wrap ${prefix}gcc ${./cc-wrapper.sh} $ccPath/${prefix}gcc
ln -s ${prefix}gcc $out/bin/${prefix}cc
export real_cc=${prefix}gcc
export real_cxx=${prefix}g++
elif [ -e $ccPath/clang ]; then
wrap ${prefix}clang ${./cc-wrapper.sh} $ccPath/clang
ln -s ${prefix}clang $out/bin/${prefix}cc
export real_cc=clang
export real_cxx=clang++
fi
if [ -e $ccPath/${prefix}g++ ]; then
wrap ${prefix}g++ ${./cc-wrapper.sh} $ccPath/${prefix}g++
ln -s ${prefix}g++ $out/bin/${prefix}c++
elif [ -e $ccPath/clang++ ]; then
wrap ${prefix}clang++ ${./cc-wrapper.sh} $ccPath/clang++
ln -s ${prefix}clang++ $out/bin/${prefix}c++
fi
if [ -e $ccPath/cpp ]; then
wrap ${prefix}cpp ${./cc-wrapper.sh} $ccPath/cpp
fi
''
+ optionalString cc.langFortran or false ''
wrap ${prefix}gfortran ${./cc-wrapper.sh} $ccPath/${prefix}gfortran
ln -sv ${prefix}gfortran $out/bin/${prefix}g77
ln -sv ${prefix}gfortran $out/bin/${prefix}f77
''
+ optionalString cc.langJava or false ''
wrap ${prefix}gcj ${./cc-wrapper.sh} $ccPath/${prefix}gcj
''
+ optionalString cc.langGo or false ''
wrap ${prefix}gccgo ${./cc-wrapper.sh} $ccPath/${prefix}gccgo
''
+ optionalString cc.langAda or false ''
wrap ${prefix}gnatgcc ${./cc-wrapper.sh} $ccPath/${prefix}gnatgcc
wrap ${prefix}gnatmake ${./gnat-wrapper.sh} $ccPath/${prefix}gnatmake
wrap ${prefix}gnatbind ${./gnat-wrapper.sh} $ccPath/${prefix}gnatbind
wrap ${prefix}gnatlink ${./gnatlink-wrapper.sh} $ccPath/${prefix}gnatlink
''
+ optionalString cc.langVhdl or false ''
ln -s $ccPath/${prefix}ghdl $out/bin/${prefix}ghdl
''
+ ''
substituteAll ${./setup-hook.sh} $out/nix-support/setup-hook.tmp
cat $out/nix-support/setup-hook.tmp >> $out/nix-support/setup-hook
rm $out/nix-support/setup-hook.tmp
# some linkers on some platforms don't support specific -z flags
hardening_unsupported_flags=""
if [[ "$($ldPath/${prefix}ld -z now 2>&1 || true)" =~ un(recognized|known)\ option ]]; then
hardening_unsupported_flags+=" bindnow"
fi
if [[ "$($ldPath/${prefix}ld -z relro 2>&1 || true)" =~ un(recognized|known)\ option ]]; then
hardening_unsupported_flags+=" relro"
fi
substituteAll ${./add-flags.sh} $out/nix-support/add-flags.sh
substituteAll ${./add-hardening.sh} $out/nix-support/add-hardening.sh
cp -p ${./utils.sh} $out/nix-support/utils.sh
''
+ extraBuildCommands;
# The dynamic linker has different names on different Linux platforms.
#
# TODO(1b62c9c06173f4d5e6b090e5ae0c68fa5f478faf): This is not the best way to
# do this. I think the reference should be the style in the gcc-cross-wrapper,
# but to keep a stable stdenv now I do this sufficient if/else.
dynamicLinker =
if !nativeLibc then
(if targetPlatform.system == "i686-linux" then "ld-linux.so.2" else
if targetPlatform.system == "x86_64-linux" then "ld-linux-x86-64.so.2" else
# ARM with a wildcard, which can be "" or "-armhf".
if targetPlatform.isArm32 then "ld-linux*.so.3" else
if targetPlatform.system == "aarch64-linux" then "ld-linux-aarch64.so.1" else
if targetPlatform.system == "powerpc-linux" then "ld.so.1" else
if targetPlatform.system == "mips64el-linux" then "ld.so.1" else
if targetPlatform.system == "x86_64-darwin" then "/usr/lib/dyld" else
if stdenv.lib.hasSuffix "pc-gnu" targetPlatform.config then "ld.so.1" else
abort "Don't know the name of the dynamic linker for this platform.")
else "";
crossAttrs = {
shell = shell.crossDrv + shell.crossDrv.shellPath;
libc = stdenv.ccCross.libc;
};
meta =
let cc_ = if cc != null then cc else {}; in
(if cc_ ? meta then removeAttrs cc.meta ["priority"] else {}) //
{ description =
stdenv.lib.attrByPath ["meta" "description"] "System C compiler" cc_
+ " (wrapper script)";
};
}