gprbuild, xmlada: init at 21.0.0

GPRbuild is a multi language build system developed by AdaCore which
is mostly used for build Ada-related projects using GNAT.

Since GPRbuild is used to build itself and its dependency library
XML/Ada we first build a bootstrap version of it using the provided
bash build script bootstrap.sh as the gprbuild-boot derivation.
gprbuild-boot is then used to build xmlada and the proper gprbuild
derivation.

GPRbuild has its own search path mechanism via GPR_PROJECT_PATH which
we address via a setupHook. It currently works quite similar to the
pkg-config one: It accumulates all inputs into GPR_PROJECT_PATH,
GPR_PROJECT_PATH_FOR_BUILD etc. However this is quite limited at the
moment as we don't have a gprbuild wrapper yet which understands the
_FOR_BUILD suffix. However, we'll need to address this in the future
as it is currently basically impossible to test since the distinction
only affects cross-compilation, but it is not possible to build a GNAT
cross-compiler in nixpkgs at the moment (I'm working on changing that,
however).

Another issue we had to solve was GPRbuild not finding the right GNAT
via its gprconfig tool: GPRbuild has a knowledge base with compiler
definitions which run some checks and collect info about binaries
which are in PATH. In the end the first compiler in PATH that supports
the desired language is selected.

We want GPRbuild to discover our wrapped GNAT since the unwrapped one
is incapable of producing working binaries since it won't find the
crt*.o objects distributed with libc. GPRbuild however needs to find
the Ada runtime distributed with GNAT which is not part of the wrapper
derivation, so it will skip the wrapper and select the unwrapped GNAT.
Symlinking the unwrapped's lib directory into the wrapper fixes this
problem, but breaks linking in some cases (e. g. when linking against
OMP from gcc, the runtime variant will shadow the problem dynamic lib
from buildInputs). Additionally it uses gnatls as an indicator it has
found GNAT which is not part of the wrapper.

The solution we opted to adopt here is to install a custom compiler
description into gprbuild's knowledge base which properly detects the
nixpkgs GNAT wrapper: It uses gnatmake to detect GNAT instead of
gnatls and discovers the runtime via a symlink we add to
`$out/nix-support`. This additional definition is enough to properly
detect GNAT, since the plain wrapped gcc detection works out of the
box. It may, however, be necessary to add special definitions for
other languages in the future where gprbuild also needs to discover
the runtime.

One future improvement would be to install libgpr into a separate
output or split it into a separate derivation (which would require to
link gprbuild statically always since otherwise we end up with a
cyclical dependency).
This commit is contained in:
sternenseemann 2021-07-22 13:52:40 +02:00 committed by sterni
parent 04de1306ba
commit c3c4ef859a
7 changed files with 265 additions and 0 deletions

View file

@ -234,6 +234,11 @@ stdenv.mkDerivation {
wrap ${targetPrefix}gnatmake ${./gnat-wrapper.sh} $ccPath/${targetPrefix}gnatmake
wrap ${targetPrefix}gnatbind ${./gnat-wrapper.sh} $ccPath/${targetPrefix}gnatbind
wrap ${targetPrefix}gnatlink ${./gnat-wrapper.sh} $ccPath/${targetPrefix}gnatlink
# this symlink points to the unwrapped gnat's output "out". It is used by
# our custom gprconfig compiler description to find GNAT's ada runtime. See
# ../../development/tools/build-managers/gprbuild/{boot.nix, nixpkgs-gnat.xml}
ln -sf ${cc} $out/nix-support/gprconfig-gnat-unwrapped
''
+ optionalString cc.langD or false ''

View file

@ -0,0 +1,35 @@
{ stdenv
, lib
, fetchFromGitHub
, gnat
# use gprbuild-boot since gprbuild proper depends
# on this xmlada derivation.
, gprbuild-boot
}:
stdenv.mkDerivation rec {
pname = "xmlada";
version = "21.0.0";
src = fetchFromGitHub {
name = "xmlada-${version}-src";
owner = "AdaCore";
repo = "xmlada";
rev = "v${version}";
sha256 = "00vljkvck951nj853v9sda5qbfm1mp8y2k61ja2595rmp8qcrazw";
};
nativeBuildInputs = [
gnat
gprbuild-boot
];
meta = with lib; {
description = "XML/Ada: An XML parser for Ada";
homepage = "https://github.com/AdaCore/xmlada";
maintainers = [ maintainers.sternenseemann ];
license = licenses.gpl3Plus;
platforms = platforms.all;
};
}

View file

@ -0,0 +1,90 @@
{ stdenv
, lib
, fetchFromGitHub
, gnat
, which
, xmlada # for src
}:
let
version = "21.0.0";
gprConfigKbSrc = fetchFromGitHub {
name = "gprconfig-kb-${version}-src";
owner = "AdaCore";
repo = "gprconfig_kb";
rev = "v${version}";
sha256 = "11qmzfdd0ipmhxl4k2hjidqc9i40bywrfkbiivd3lhscxca5pxpg";
};
in
stdenv.mkDerivation {
pname = "gprbuild-boot";
inherit version;
src = fetchFromGitHub {
name = "gprbuild-${version}";
owner = "AdaCore";
repo = "gprbuild";
rev = "v${version}";
sha256 = "1knpwasbrz6sxh3dhkc4izchcz4km04j77r4vxxhi23fbd8v1ynj";
};
nativeBuildInputs = [
gnat
which
];
postPatch = ''
# The Makefile uses gprbuild to build gprbuild which
# we can't do at this point, delete it to prevent the
# default phases from failing.
rm Makefile
# make sure bootstrap script runs
patchShebangs --build bootstrap.sh
'';
# This setupHook populates GPR_PROJECT_PATH which is used by
# gprbuild to find dependencies. It works quite similar to
# the pkg-config setupHook in the sense that it also splits
# dependencies into GPR_PROJECT_PATH and GPR_PROJECT_PATH_FOR_BUILD,
# but gprbuild itself doesn't support this, so we'll need to
# introducing a wrapper for it in the future remains TODO.
# For the moment this doesn't matter since we have no situation
# were gprbuild is used to build something used at build time.
setupHook = ./gpr-project-path-hook.sh;
installPhase = ''
runHook preInstall
./bootstrap.sh \
--with-xmlada=${xmlada.src} \
--with-kb=${gprConfigKbSrc} \
--prefix=$out
# Install custom compiler description which can detect nixpkgs'
# GNAT wrapper as a proper Ada compiler. The default compiler
# description expects the runtime library to be installed in
# the same prefix which isn't the case for nixpkgs. As a
# result, it would detect the unwrapped GNAT as a proper
# compiler which is unable to produce working binaries.
#
# Our compiler description is very similar to the upstream
# GNAT description except that we use a symlink in $out/nix-support
# created by the cc-wrapper to find the associated runtime
# libraries and use gnatmake instead of gnatls to find GNAT's
# bin directory.
install -m644 ${./nixpkgs-gnat.xml} $out/share/gprconfig/nixpkgs-gnat.xml
runHook postInstall
'';
meta = with lib; {
description = "Multi-language extensible build tool";
homepage = "https://github.com/AdaCore/gprbuild";
license = licenses.gpl3Plus;
maintainers = [ maintainers.sternenseemann ];
platforms = platforms.all;
};
}

View file

@ -0,0 +1,65 @@
{ lib
, stdenv
, fetchFromGitHub
, fetchpatch
, gprbuild-boot
, which
, gnat
, xmlada
}:
stdenv.mkDerivation {
pname = "gprbuild";
# See ./boot.nix for an explanation of the gprbuild setupHook,
# our custom knowledge base entry and the situation wrt a
# (future) gprbuild wrapper.
inherit (gprbuild-boot)
version
src
setupHook
meta
;
nativeBuildInputs = [
gnat
gprbuild-boot
which
];
propagatedBuildInputs = [
xmlada
];
makeFlags = [
"ENABLE_SHARED=${if stdenv.hostPlatform.isStatic then "no" else "yes"}"
"PROCESSORS=$(NIX_BUILD_CORES)"
# confusingly, for gprbuild --target is autoconf --host
"TARGET=${stdenv.hostPlatform.config}"
"prefix=${placeholder "out"}"
] ++ lib.optionals (!stdenv.hostPlatform.isStatic) [
"LIBRARY_TYPE=relocatable"
];
# Fixes gprbuild being linked statically always
patches = lib.optional (!stdenv.hostPlatform.isStatic) (fetchpatch {
name = "gprbuild-relocatable-build.patch";
url = "https://aur.archlinux.org/cgit/aur.git/plain/relocatable-build.patch?h=gprbuild&id=1d4e8a5cb982e79135a0aaa3ef87654bed1fe4f0";
sha256 = "1r3xsp1pk9h666mm8mdravkybmd5gv2f751x2ffb1kxnwq1rwiyn";
});
buildFlags = [ "all" "libgpr.build" ];
installFlags = [ "all" "libgpr.install" ];
# link gprconfig_kb db from gprbuild-boot into build dir,
# the install process copies its contents to $out
preInstall = ''
ln -sf ${gprbuild-boot}/share/gprconfig share/gprconfig
'';
# no need for the install script
postInstall = ''
rm $out/doinstall
'';
}

View file

@ -0,0 +1,8 @@
addAdaObjectsPath() {
local role_post
getHostRoleEnvHook
addToSearchPath "GPR_PROJECT_PATH${role_post}" "$1/share/gpr"
}
addEnvHooks "$targetOffset" addAdaObjectsPath

View file

@ -0,0 +1,56 @@
<?xml version="1.0" ?>
<gprconfig>
<!-- This differs from the default GNAT compiler description
in the following ways:
* gnatmake is used over gnatls to detect the GNAT version
since the latter is not part of the wrapper.
* to find the runtime libraries, we rely on the symlink
../nix-support/gprconfig-gnat-unwrapped which is a
gprconfig-specific addition to the cc-wrapper we employ
for Ada compilers (which is only GNAT at the moment).
For documentation on this file format and its use refer to
https://docs.adacore.com/gprbuild-docs/html/gprbuild_ug/companion_tools.html#the-gprconfig-knowledge-base
-->
<compiler_description>
<!-- We would like to name this something different, so users
of gprconfig know this is something custom, nixpkgs-related,
but unfortunately the knowledge base depends on the name of
the compiler for e. g. linker settings.
-->
<name>GNAT</name>
<executable prefix="1">(.*-.*-.*)?gnatmake</executable>
<version>
<external>${PREFIX}gnatmake -v</external>
<grep regexp="^GNATMAKE.+?(\d+(\.\d+)?)" group="1"></grep>
</version>
<languages>Ada</languages>
<variable name="gcc_version">
<external>${PREFIX}gcc -v</external>
<grep regexp="^[-\w]*gcc \S+ (\S+)" group="1"></grep>
</variable>
<!-- The ada runtime libraries and objects are only part of the unwrapped
GNAT derivation. We can't symlink them into the wrapper derivation
(at least not the canonical location) since that screws with linking
against libraries distributed with gcc.
As a workaround, we create a symlink to the unwrapped GNAT's "out"
output in the cc-wrapper which we can read into a variable here and
use to find GNAT's Ada runtime.
-->
<variable name="gnat_unwrapped">
<external>readlink -n ${PATH}/../nix-support/gprconfig-gnat-unwrapped</external>
</variable>
<runtimes default="default,kernel,native">
<directory group="default" >$gnat_unwrapped/lib/gcc(-lib)?/$TARGET/$gcc_version/adalib/</directory>
<directory group="default" contents="^rts-">$gnat_unwrapped/lib/gcc(-lib)?/$TARGET/$gcc_version/ada_object_path</directory>
<directory group="2" >$gnat_unwrapped/lib/gcc(-lib)?/$TARGET/$gcc_version/rts-(.*)/adalib/</directory>
<directory group="1" >$gnat_unwrapped/$TARGET/lib/gnat/(.*)/adalib/</directory>
</runtimes>
<target>
<external>${PREFIX}gcc -dumpmachine</external>
<grep regexp="[^\r\n]+"></grep>
</target>
</compiler_description>
</gprconfig>

View file

@ -13772,6 +13772,10 @@ in
gotty = callPackage ../servers/gotty { };
gprbuild-boot = callPackage ../development/tools/build-managers/gprbuild/boot.nix { };
gprbuild = callPackage ../development/tools/build-managers/gprbuild { };
gputils = callPackage ../development/tools/misc/gputils { };
gpuvis = callPackage ../development/tools/misc/gpuvis { };
@ -19098,6 +19102,8 @@ in
];
};
xmlada = callPackage ../development/libraries/ada/xmlada { };
xmlrpc_c = callPackage ../development/libraries/xmlrpc-c { };
xmlsec = callPackage ../development/libraries/xmlsec { };