Support for armv7a-bionic (android)

This adds support to haskell.nix for building for armv7a-android.
It includes
- various minor fixes
- a lot of bionic (libc) patches for ghc
- no gold on 32bit android
- android overlay: mostly static
- disable KTLS on openssl for android

Author: angerman

compiler/ghc/default.nix

@@ -44,9 +44,9 @@ let self =
 
 , enableDWARF ? false
 
-, enableTerminfo ?
+, enableTerminfo ? !stdenv.targetPlatform.isAndroid &&
     # Terminfo does not work on older ghc cross arm and windows compilers
-     (!haskell-nix.haskellLib.isCrossTarget || !(stdenv.targetPlatform.isAarch64 || stdenv.targetPlatform.isWindows) || builtins.compareVersions ghc-version "8.10" >= 0)
+     (!haskell-nix.haskellLib.isCrossTarget || !(stdenv.targetPlatform.isAarch32 || stdenv.targetPlatform.isAarch64 || stdenv.targetPlatform.isWindows) || builtins.compareVersions ghc-version "8.10" >= 0)
 
 , # Wheter to build in NUMA support
   enableNUMA ? true
@@ -323,7 +323,10 @@ stdenv.mkDerivation (rec {
         export NIX_LDFLAGS+=" -rpath $out/lib/${targetPrefix}ghc-${ghc-version}"
     '' + lib.optionalString stdenv.isDarwin ''
         export NIX_LDFLAGS+=" -no_dtrace_dof"
-    '' + lib.optionalString targetPlatform.useAndroidPrebuilt ''
+    '' + 
+    # we really want "+armv7-a,+soft-float,+neon" as features, but llvm will 
+    # fail with those :facepalm:
+    lib.optionalString targetPlatform.useAndroidPrebuilt ''
         sed -i -e '5i ,("armv7a-unknown-linux-androideabi", ("e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64", "cortex-a8", ""))' llvm-targets
     '' + lib.optionalString targetPlatform.isMusl ''
         echo "patching llvm-targets for musl targets..."
@@ -393,7 +396,7 @@ stdenv.mkDerivation (rec {
                    ++ lib.optional stdenv.targetPlatform.isAarch32 "pic"
                    ++ lib.optional stdenv.targetPlatform.isMusl "pie";
 
-  postInstall = lib.optionalString (enableNUMA && targetPlatform.isLinux) ''
+  postInstall = lib.optionalString (enableNUMA && targetPlatform.isLinux && !targetPlatform.isAarch32 && !targetPlatform.isAndroid) ''
     # Patch rts.conf to ensure libnuma can be found
 
     for file in $(find "$out/lib" -name "rts*.conf"); do

lib/call-cabal-project-to-nix.nix

@@ -467,8 +467,8 @@ let
         cabal.project.freeze
       chmod +w cabal.project.freeze
     ''}
-    export SSL_CERT_FILE=${cacert}/etc/ssl/certs/ca-bundle.crt
-    export GIT_SSL_CAINFO=${cacert}/etc/ssl/certs/ca-bundle.crt
+    export SSL_CERT_FILE=${evalPackages.cacert}/etc/ssl/certs/ca-bundle.crt
+    export GIT_SSL_CAINFO=${evalPackages.cacert}/etc/ssl/certs/ca-bundle.crt
 
     echo "Using index-state ${index-state-found}"
     CABAL_DIR=${

overlays/android.nix

@@ -11,18 +11,31 @@ final: prev: prev.lib.optionalAttrs prev.stdenv.hostPlatform.isAndroid ({
     '';
     # my current thinking is that this is due to the android toolchain using r23, api30.
   });
-  libffi = prev.libffi.overrideAttrs (_: {
+  libffi = prev.libffi.overrideAttrs ( old: {
     dontDisableStatic = true;
+    configureFlags = old.configureFlags ++ [ "--disable-shared" ];
 
     hardeningDisable = [ "fortify" "stackprotector" "format" ];
+  } // prev.lib.optionalAttrs (prev.stdenv.hostPlatform.isAarch32 || prev.stdenv.hostPlatform.isAarch64) {
     # see libiconv. We want to target a lower minsdk
     postConfigure = ''
-      echo "#undef HAVE_MEMFD_CREATE" >> aarch64-unknown-linux-android/fficonfig.h
+      echo "#undef HAVE_MEMFD_CREATE" >> ${prev.stdenv.hostPlatform.config}/fficonfig.h
     '';
   });
-  gmp6 = (prev.gmp6.override { withStatic = true; }).overrideAttrs(_: {
+  gmp6 = (prev.gmp6.override { withStatic = true; }).overrideAttrs(old: {
     hardeningDisable = [ "fortify" "stackprotector" "format" ];
+    configureFlags = old.configureFlags ++ [ "--disable-shared" ];
   });
+  zlib = prev.zlib.override { shared = false; static = true; };
+  # kernel tls (ktls) doesn't work with the android kernel. And will complain
+  # about lots of implicitly declared functions and undeclared identifiers,
+  # because the android (linux) kernel doesn't expose those.
+  openssl = prev.openssl.override { static = true; enableKTLS = false; };
+  
 }) // prev.lib.optionalAttrs prev.stdenv.targetPlatform.isAndroid ({
-  bionic = prev.bionic.override { enableStatic = true; };
+  # we still need the shared libraries to link against on the platform.  GHC
+  # has been neutered to not even try loading shared libs and will use dynamic ones.
+  # We also link iserv against the static libs, so that we have a fully static
+  # android (bionic/linux) iserv we can execute on glibc/linux.
+  bionic = prev.bionic.override { enableStatic = true; enableShared = true; };
 })

overlays/bootstrap.nix

@@ -150,8 +150,9 @@ in {
                 ++ fromUntil "8.10.2" "8.10.3" ./patches/ghc/MR3714-backported-to-8.10.2.patch
 
                 # See https://github.com/input-output-hk/haskell.nix/issues/1027
+                ++ final.lib.optional (versionAtLeast "8.10.3" && versionLessThan "9.2" && final.stdenv.targetPlatform.isAarch32) ./patches/ghc/ghc-8.10-3434-armv7a.patch
                 ++ final.lib.optional (versionAtLeast "8.10.3" && versionLessThan "9.2" && final.stdenv.targetPlatform.isAarch64) ./patches/ghc/ghc-8.10-3434.patch
-                ++ final.lib.optional (versionAtLeast "9.2.1"  && versionLessThan "9.3" && final.stdenv.targetPlatform.isAarch64) ./patches/ghc/ghc-9.2-3434.patch
+                ++ final.lib.optional (versionAtLeast "9.2.1"  && versionLessThan "9.3" && (final.stdenv.targetPlatform.isAarch64 || final.stdenv.targetPlatform.isAndroid)) ./patches/ghc/ghc-9.2-3434.patch
 
                 ++ fromUntil "8.10.1" "9.4"    ./patches/ghc/ghc-acrt-iob-func.patch
                 ++ fromUntil "8.10.1" "9.4"    ./patches/ghc/ghc-mprotect-nonzero-len.patch
@@ -186,18 +187,28 @@ in {
                 ++ fromUntil "9.6.1"  "9.8"    ./patches/ghc/MR10116.patch
                 ++ fromUntil "9.4.1"  "9.6"    ./patches/ghc/hadrian-build-deriveConstants-genprimopcode-ghc94.patch
                 ++ fromUntil "9.6.1"  "9.8"    ./patches/ghc/hadrian-build-deriveConstants-genprimopcode.patch
+                ++ final.lib.optional (versionAtLeast "8.10"   && versionLessThan "9.4" && final.stdenv.targetPlatform != final.stdenv.hostPlatform) ./patches/ghc/ghc-make-stage-1-lib-ghc.patch
 
                 # the following is a partial reversal of https://gitlab.haskell.org/ghc/ghc/-/merge_requests/4391, to address haskell.nix#1227
                 ++ final.lib.optional (versionAtLeast "8.10.6" && versionLessThan "9.0" && final.stdenv.targetPlatform.isAarch64) ./patches/ghc/mmap-next.patch
                 ++ final.lib.optional (versionAtLeast "8.10.6" && versionLessThan "9.0" && final.stdenv.targetPlatform.isAarch64) ./patches/ghc/m32_alloc.patch
+
+                # Android
                 ++ final.lib.optional (versionAtLeast "8.10.6" && versionLessThan "9.0" && final.stdenv.targetPlatform.isAndroid) ./patches/ghc/rts-android-jemalloc-qemu.patch
                 ++ final.lib.optional (versionAtLeast "8.10.6" && versionLessThan "9.0" && final.stdenv.targetPlatform.isAndroid) ./patches/ghc/stack-protector-symbols.patch
-                ++ final.lib.optional (versionAtLeast "8.10.6" && versionLessThan "9.0" && final.stdenv.targetPlatform.isAndroid) ./patches/ghc/libraries-prim-os-android.patch
+                ++ final.lib.optional (versionAtLeast "8.10.6" && versionLessThan "9.0" && final.stdenv.targetPlatform.isAndroid && final.stdenv.targetPlatform.isAarch32) ./patches/ghc/libraries-prim-os-android-armv7a.patch
+                ++ final.lib.optional (versionAtLeast "8.10.6" && versionLessThan "9.0" && final.stdenv.targetPlatform.isAndroid && final.stdenv.targetPlatform.isAarch64) ./patches/ghc/libraries-prim-os-android.patch
                 ++ final.lib.optional (versionAtLeast "8.10.6" && versionLessThan "9.0" && final.stdenv.targetPlatform.isAndroid) ./patches/ghc/ghc-rts-linker-condbr.patch
-                ++ final.lib.optional (versionAtLeast "8.10.6" && versionLessThan "9.0" && final.stdenv.targetPlatform.isAndroid) ./patches/ghc/ghc-8.10.7-linker-weak-and-common.patch
-                ++ final.lib.optional (versionAtLeast "8.10.6" && versionLessThan "9.0" && final.stdenv.targetPlatform.isAndroid) ./patches/ghc/libc-memory-symbols.patch
+                # due to mmap-next renaming we need different ones for aarch64 and aarch32 m(
+                ++ final.lib.optional (versionAtLeast "8.10.6" && versionLessThan "9.0" && final.stdenv.targetPlatform.isAndroid && final.stdenv.targetPlatform.isAarch32) ./patches/ghc/ghc-8.10.7-linker-weak-and-common-armv7a.patch
+                ++ final.lib.optional (versionAtLeast "8.10.6" && versionLessThan "9.0" && final.stdenv.targetPlatform.isAndroid && final.stdenv.targetPlatform.isAarch64) ./patches/ghc/ghc-8.10.7-linker-weak-and-common.patch
+                ++ final.lib.optional (versionAtLeast "8.10.6" && versionLessThan "9.0" && final.stdenv.targetPlatform.isAndroid && final.stdenv.targetPlatform.isAarch32) ./patches/ghc/libc-memory-symbols-armv7a.patch
+                ++ final.lib.optional (versionAtLeast "8.10.6" && versionLessThan "9.0" && final.stdenv.targetPlatform.isAndroid && final.stdenv.targetPlatform.isAarch64) ./patches/ghc/libc-memory-symbols.patch
                 ++ final.lib.optional (versionAtLeast "8.10.6" && versionLessThan "9.0" && final.stdenv.targetPlatform.isAndroid) ./patches/ghc/android-base-needs-iconv.patch
-                ++ final.lib.optional (versionAtLeast "8.10"   && versionLessThan "9.4" && final.stdenv.targetPlatform != final.stdenv.hostPlatform) ./patches/ghc/ghc-make-stage-1-lib-ghc.patch
+                ++ final.lib.optional (versionAtLeast "8.10.6" && versionLessThan "9.2" && final.stdenv.targetPlatform.isAndroid && final.stdenv.targetPlatform.isAarch32) ./patches/ghc/ghc-8.10-android.patch
+                ++ final.lib.optional (versionAtLeast "8.10.6" && versionLessThan "9.2" && final.stdenv.targetPlatform.isAndroid && final.stdenv.targetPlatform.isAarch32) ./patches/ghc/ghc-8.10.7-android-bionic-symbols.patch
+                ++ final.lib.optional (versionAtLeast "8.10.6" && versionLessThan "9.2" && final.stdenv.targetPlatform.isAndroid && final.stdenv.targetPlatform.isAarch32) ./patches/ghc/ghc-8.10.7-bionic-libc.patch
+                ++ final.lib.optional (versionAtLeast "8.10.6" && versionLessThan "9.2" && final.stdenv.targetPlatform.isAndroid && final.stdenv.targetPlatform.isAarch32) ./patches/ghc/ghc-8.10.7-cross-dont-build-stage2-tools.patch
                 ;
         in ({
             ghc865 = final.callPackage ../compiler/ghc (traceWarnOld "8.6" {

overlays/linux-cross.nix

@@ -27,6 +27,22 @@ in
 let
 
   # we want this to hold only for arm (32 and 64bit) for now.
+  # For 32bit android, we need to pass -no-pie, as we otherwise
+  # get -pie injected into the linker flags. We don't want that.
+  # If we target 32bit android, we need remote-iserv to be runnable
+  # in a 32bit linux (via qemu-arm user mode emulation).  If we have
+  # -pie enabled, it will produce a static-pie executable, which
+  # seems a lot like what we want but will crash on launch.  It appears
+  # the the __stack_chk_guard lookups go through some lookup table, and
+  # while the relocations for the lookup table are correct, the __stack_chk_guard
+  # address isn't properly relocated.  This could also be because libc isn't
+  # supposed to be staticlly linked really.  However because we are lacking
+  # the loader for arm on linux, we can't used dynamically linked executables
+  # until one in /system/bin/linker is provided.
+  #
+  # We also need to run armv7a-android in unshare --user --pid --fork, to
+  # ensure that we get a low pid < 65535 for android (If we run outside)
+  # of nix build envs.
   isLinuxCross = buildPlatform != hostPlatform && hostPlatform.isLinux && (hostPlatform.isAarch32 || hostPlatform.isAarch64);
   qemuIservWrapper = writeScriptBin "iserv-wrapper" ''
     #!${stdenv.shell}
@@ -35,7 +51,7 @@ let
     unset configureFlags
     PORT=$((5000 + $RANDOM % 5000))
     (>&2 echo "---> Starting ${iserv-proxy-interpreter.exeName} on port $PORT")
-    ${qemu}/bin/qemu-${qemuSuffix} ${iserv-proxy-interpreter.override (lib.optionalAttrs hostPlatform.isAndroid { setupBuildFlags = ["--ghc-option=-optl-static" ];})}/bin/${iserv-proxy-interpreter.exeName} tmp $PORT &
+    ${qemu}/bin/qemu-${qemuSuffix} ${iserv-proxy-interpreter.override (lib.optionalAttrs hostPlatform.isAndroid { setupBuildFlags = ["--ghc-option=-optl-static" ] ++ lib.optional hostPlatform.isAarch32 "--ghc-option=-optl-no-pie";})}/bin/remote-iserv tmp $PORT &
     (>&2 echo "---| ${iserv-proxy-interpreter.exeName} should have started on $PORT")
     RISERV_PID="$!"
     ${iserv-proxy}/bin/iserv-proxy $@ 127.0.0.1 "$PORT"

overlays/patches/ghc/ghc-8.10-3434-armv7a.patch

@@ -0,0 +1,68 @@
+diff --git a/libraries/ghc-prim/ghc-prim.cabal b/libraries/ghc-prim/ghc-prim.cabal
+index c633124..2bd51c0 100644
+--- a/libraries/ghc-prim/ghc-prim.cabal
++++ b/libraries/ghc-prim/ghc-prim.cabal
+@@ -70,7 +70,7 @@ Library
+     if os(linux)
+         -- we need libm, but for musl and other's we might need libc, as libm
+         -- is just an empty shell.
+-        extra-libraries: c, m
++        extra-libraries: c, m
+
+     c-sources:
+         cbits/atomic.c
+diff --git a/rts/RtsSymbols.c b/rts/RtsSymbols.c
+index 9ca696c..b4a85e5 100644
+--- a/rts/RtsSymbols.c
++++ b/rts/RtsSymbols.c
+@@ -1000,6 +1000,18 @@
+ #define RTS_LIBGCC_SYMBOLS
+ #endif
+
++
++#if !defined(DYNAMIC) && defined(linux_HOST_OS)
++// we need these for static musl builds. However when
++// linking shared objects (DLLs) this will fail, hence
++// we do not include them when building with -DDYNAMIC
++#define RTS_LINKER_SYMBOLS                             \
++      SymI_NeedsProto(__fini_array_start)              \
++      SymI_NeedsProto(__fini_array_end)
++#else
++#define RTS_LINKER_SYMBOLS
++#endif
++
+ /* entirely bogus claims about types of these symbols */
+ #define SymI_NeedsProto(vvv)  extern void vvv(void);
+ #define SymI_NeedsDataProto(vvv)  extern StgWord vvv[];
+@@ -1028,6 +1040,7 @@ RTS_DARWIN_ONLY_SYMBOLS
+ RTS_OPENBSD_ONLY_SYMBOLS
+ RTS_LIBGCC_SYMBOLS
+ RTS_LIBFFI_SYMBOLS
++RTS_LINKER_SYMBOLS
+ #undef SymI_NeedsProto
+ #undef SymI_NeedsDataProto
+ #undef SymI_HasProto
+@@ -1068,6 +1081,8 @@ RTS_LIBFFI_SYMBOLS
+ #define SymI_HasProto_deprecated(vvv)   \
+    { #vvv, (void*)0xBAADF00D, true },
+
++void *RTS_DYNAMIC = NULL;
++
+ RtsSymbolVal rtsSyms[] = {
+       RTS_SYMBOLS
+       RTS_RET_SYMBOLS
+@@ -1078,6 +1093,7 @@ RtsSymbolVal rtsSyms[] = {
+       RTS_OPENBSD_ONLY_SYMBOLS
+       RTS_LIBGCC_SYMBOLS
+       RTS_LIBFFI_SYMBOLS
++      RTS_LINKER_SYMBOLS
+       SymI_HasDataProto(nonmoving_write_barrier_enabled)
+ #if defined(darwin_HOST_OS) && defined(i386_HOST_ARCH)
+       // dyld stub code contains references to this,
+@@ -1085,5 +1101,6 @@ RtsSymbolVal rtsSyms[] = {
+       // lazy pointers as nonlazy.
+       { "dyld_stub_binding_helper", (void*)0xDEADBEEF, false },
+ #endif
++      { "_DYNAMIC", (void*)(&RTS_DYNAMIC), false },
+       { 0, 0, false } /* sentinel */
+ };