zlib: Properly clean up static/shared distinction

This improves what commit

    e999def1 zlib: clean up static/shared distincion

described as "kind of a mess" and "confusing". And indeed it was confusing.

Now, the concept whether or not the .a file is moved to a split output
is controlled by a clean variable.

The defaults remain unchanged.

The new approach also finally cleanly allows building statically but NOT
using a split output, like all other autoconf-based projects in nixpkgs do
(using the `dontDisableStatic` setting).
That is important for overlays that want to enable static libs for all
packages in one go, without having to hand-patch idiosynchrasies like zlib
had until now.

Until now, if you wanted the .a in the main output, the only way was to go via
`static=false, shared=true` -- which made no sense, because you had to say
`static=false` even though you want a static lib. That is fixed now.
This commit is contained in:
Niklas Hambüchen 2019-08-11 22:03:56 +02:00
parent 2240c5c858
commit aa99a263cc

View file

@ -1,24 +1,19 @@
{ stdenv
, fetchurl
# Regarding static/shared libaries, the current behaviour is:
#
# - static=true, shared=true: builds both and moves .a to the .static output;
# in this case `pkg-config` auto detection will
# not work if the .static output is given as
# buildInputs to another package (#66461)
# - static=true, shared=false: builds .a only and leaves it in the main output
# - static=false, shared=true: builds shared only
#
# To get both `.a` and shared libraries in one output,
# you currently have to use
# static=false, shared=true
# and use
# .overrideAttrs (old: { dontDisableStatic = true; })
# This is because by default, upstream zlib ./configure builds both.
, static ? true
# Note: If `{ static = false; shared = false; }`, upstream's default is used
# (which is building both static and shared as of zlib 1.2.11).
, shared ? true
, static ? true
# If true, a separate .static ouput is created and the .a is moved there.
# In this case `pkg-config` will auto detection will currently not work if the
# .static output is given as `buildInputs` to another package (#66461), because
# the `.pc` file lists only the main output's lib dir.
# If false, and if `{ static = true; }`, the .a stays in the main output.
, splitStaticOutput ? static
}:
assert splitStaticOutput -> static;
stdenv.mkDerivation (rec {
name = "zlib-${version}";
version = "1.2.11";
@ -41,14 +36,35 @@ stdenv.mkDerivation (rec {
'';
outputs = [ "out" "dev" ]
++ stdenv.lib.optional (shared && static) "static";
++ stdenv.lib.optional splitStaticOutput "static";
setOutputFlags = false;
outputDoc = "dev"; # single tiny man3 page
configureFlags = stdenv.lib.optional shared "--shared"
++ stdenv.lib.optional (static && !shared) "--static";
# For zlib's ./configure (as of verion 1.2.11), the order
# of --static/--shared flags matters!
# `--shared --static` builds only static libs, while
# `--static --shared` builds both.
# So we use the latter order to be able to build both.
# Also, giving just `--shared` builds both,
# giving just `--static` builds only static,
# and giving nothing builds both.
# So we have 3 possible ways to build both:
# `--static --shared`, `--shared` and giving nothing.
# Of these, we choose `--shared`, only because that's
# what we did in the past and we can avoid mass rebuilds this way.
# As a result, we pass `--static` only when we want just static.
configureFlags = stdenv.lib.optional (static && !shared) "--static"
++ stdenv.lib.optional shared "--shared";
postInstall = stdenv.lib.optionalString (shared && static) ''
# Note we don't need to set `dontDisableStatic`, because static-disabling
# works by grepping for `enable-static` in the `./configure` script
# (see `pkgs/stdenv/generic/setup.sh`), and zlib's handwritten one does
# not have such.
# It wouldn't hurt setting `dontDisableStatic = static && !splitStaticOutput`
# here (in case zlib ever switches to autoconf in the future),
# but we don't do it simply to avoid mass rebuilds.
postInstall = stdenv.lib.optionalString splitStaticOutput ''
moveToOutput lib/libz.a "$static"
''
# jww (2015-01-06): Sometimes this library install as a .so, even on
@ -69,6 +85,8 @@ stdenv.mkDerivation (rec {
# to the bootstrap-tools libgcc (as uses to happen on arm/mips)
NIX_CFLAGS_COMPILE = stdenv.lib.optionalString (!stdenv.hostPlatform.isDarwin) "-static-libgcc";
# We don't strip on static cross-compilation because of reports that native
# stripping corrupted the target library; see commit 12e960f5 for the report.
dontStrip = stdenv.hostPlatform != stdenv.buildPlatform && static;
configurePlatforms = [];