build: fix static linking with a hack

This causes libstore, libexpr, libfetchers, and libutil to be linked
with -Wl,--whole-archive to executables, when building statically.

libstore for the store backends, libexpr for the primops, libfetchers
for the fetcher backends I assume(?), and libutil for the nix::logger
initializer (which notably shows in pre-main constructors when HOME is
not owned by the user. cursed.).

This workaround should be removed when #359 is fixed.

Fixes #306.

Change-Id: Ie9ef0154e09a6ed97920ee8ab23810ca5e2de84c

7 files changed, 66 insertions, 11 deletions

diff --git a/meson.build b/meson.build
index 9db764f00..b98b1fb15 100644
--- a/meson.build
+++ b/meson.build
@@ -17,6 +17,19 @@
 #
 # Finally, src/nix/meson.build defines the Nix command itself, relying on all prior meson files.
 #
+# libstore, libexpr, and libfetchers have some special handling to make static builds work.
+# Their use static constructors for dynamic registration of primops, store backends, etc
+# gets borked during static link. We can't simply wholesale apply `link_whole :` either,
+# because these libraries get linked multiple times since Lix's components are transitively
+# dependent. So instead, each of those libraries have two dependency objects:
+# liblix{store,expr,fetchers,util} and liblix{store,expr,fetchers,util}_mstatic ("maybe static").
+# The _mstatic versions should be used in the `dependencies :` arguments to ALL EXECUTABLES
+# but executables ONLY. When we are not building statically (default_library != 'static'),
+# they are equivalent. When we are building statically, the _mstatic version will be
+# `link_whole :` rather than `link_with :`.
+# FIXME: This hack should be removed when https://git.lix.systems/lix-project/lix/issues/359
+# is fixed.
+#
 # Unit tests are setup in tests/unit/meson.build, under the test suite "check".
 #
 # Functional tests are a bit more complicated. Generally they're defined in
@@ -79,6 +92,8 @@ if not fs.is_absolute(sysconfdir)
   sysconfdir = '/' / sysconfdir
 endif
 
+is_static = get_option('default_library') == 'static'
+
 # All of this has to go before the rest of the dependency checking,
 # so that internal-api-docs can be built with -Denable-build=false
 
diff --git a/src/libexpr/meson.build b/src/libexpr/meson.build
index 9a18c7ab3..e60a85b5d 100644
--- a/src/libexpr/meson.build
+++ b/src/libexpr/meson.build
@@ -162,6 +162,16 @@ liblixexpr = declare_dependency(
   link_with : libexpr,
 )
 
+# FIXME: remove when https://git.lix.systems/lix-project/lix/issues/359 is fixed.
+if is_static
+  liblixexpr_mstatic = declare_dependency(
+    include_directories : include_directories('.'),
+    link_whole : libexpr,
+  )
+else
+  liblixexpr_mstatic = liblixexpr
+endif
+
 # FIXME: not using the pkg-config module because it creates way too many deps
 # while meson migration is in progress, and we want to not include boost here
 configure_file(
diff --git a/src/libfetchers/meson.build b/src/libfetchers/meson.build
index 365bcd4a7..ee38b6cda 100644
--- a/src/libfetchers/meson.build
+++ b/src/libfetchers/meson.build
@@ -56,3 +56,13 @@ liblixfetchers = declare_dependency(
   include_directories : include_directories('.'),
   link_with : libfetchers,
 )
+
+# FIXME: remove when https://git.lix.systems/lix-project/lix/issues/359 is fixed.
+if is_static
+  liblixfetchers_mstatic = declare_dependency(
+    include_directories : include_directories('.'),
+    link_whole : libfetchers,
+  )
+else
+  liblixfetchers_mstatic = liblixfetchers
+endif
diff --git a/src/libstore/meson.build b/src/libstore/meson.build
index 65ecacc20..7a129d22c 100644
--- a/src/libstore/meson.build
+++ b/src/libstore/meson.build
@@ -234,6 +234,16 @@ liblixstore = declare_dependency(
   link_with : libstore,
 )
 
+# FIXME: remove when https://git.lix.systems/lix-project/lix/issues/359 is fixed.
+if is_static
+  liblixstore_mstatic = declare_dependency(
+    include_directories : include_directories('.'),
+    link_whole : libstore,
+  )
+else
+  liblixstore_mstatic = liblixstore
+endif
+
 # FIXME: not using the pkg-config module because it creates way too many deps
 # while meson migration is in progress, and we want to not include boost here
 configure_file(
diff --git a/src/libutil/meson.build b/src/libutil/meson.build
index cfdd0e52c..8c3377e76 100644
--- a/src/libutil/meson.build
+++ b/src/libutil/meson.build
@@ -155,3 +155,13 @@ liblixutil = declare_dependency(
   include_directories : include_directories('.'),
   link_with : libutil
 )
+
+# FIXME: remove when https://git.lix.systems/lix-project/lix/issues/359 is fixed.
+if is_static
+  liblixutil_mstatic = declare_dependency(
+    include_directories : include_directories('.'),
+    link_whole : libutil,
+  )
+else
+  liblixutil_mstatic = liblixutil
+endif
diff --git a/src/nix/meson.build b/src/nix/meson.build
index 45303641f..8115a3d08 100644
--- a/src/nix/meson.build
+++ b/src/nix/meson.build
@@ -81,10 +81,10 @@ nix = executable(
   nix2_commands_sources,
   dependencies : [
     liblixcmd,
-    liblixutil,
-    liblixstore,
-    liblixexpr,
-    liblixfetchers,
+    liblixutil_mstatic,
+    liblixstore_mstatic,
+    liblixexpr_mstatic,
+    liblixfetchers_mstatic,
     liblixmain,
     boehm,
     nlohmann_json,
diff --git a/tests/unit/meson.build b/tests/unit/meson.build
index d8d4a00d1..06aff4626 100644
--- a/tests/unit/meson.build
+++ b/tests/unit/meson.build
@@ -64,7 +64,7 @@ libutil_tester = executable(
     gtest,
     boehm,
     liblixutil,
-    liblixexpr,
+    liblixexpr_mstatic,
     liblixutil_test_support,
     nlohmann_json,
   ],
@@ -131,7 +131,7 @@ libstore_tester = executable(
   dependencies : [
     liblixstore_test_support,
     liblixutil_test_support,
-    liblixstore,
+    liblixstore_mstatic,
     liblixutil,
     rapidcheck,
     gtest,
@@ -194,10 +194,10 @@ libexpr_tester = executable(
   dependencies : [
     liblixexpr_test_support,
     liblixstore_test_support,
-    liblixstore,
+    liblixstore_mstatic,
     liblixutil,
-    liblixexpr,
-    liblixfetchers,
+    liblixexpr_mstatic,
+    liblixfetchers_mstatic,
     rapidcheck,
     boehm,
     gtest,
@@ -225,8 +225,8 @@ libcmd_tester = executable(
     liblixcmd,
     liblixutil,
     liblixmain,
-    liblixexpr,
-    liblixstore,
+    liblixexpr_mstatic,
+    liblixstore_mstatic,
     gtest,
     boost,
   ],