From acb24b4cc4432687e063ae2b5a08f449934e5fbf Mon Sep 17 00:00:00 2001
From: Matthew Bauer <mjbauer95@gmail.com>
Date: Sat, 22 Feb 2020 12:37:46 -0500
Subject: [PATCH 1/7] lib/systems: Assume newlib when no kernel and no libc is
 provided

newlib is the default for most tools when no kernel is provided. Other
exist, but this seems like a safe default.

(cherry picked from commit 8009c2071179ee3490f244b91a49202728efe403)
---
 lib/systems/default.nix | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/lib/systems/default.nix b/lib/systems/default.nix
index 36afdae3866..4ca932d1792 100644
--- a/lib/systems/default.nix
+++ b/lib/systems/default.nix
@@ -36,9 +36,8 @@ rec {
         else if final.isUClibc              then "uclibc"
         else if final.isAndroid             then "bionic"
         else if final.isLinux /* default */ then "glibc"
-        else if final.isMsp430              then "newlib"
-        else if final.isVc4                 then "newlib"
         else if final.isAvr                 then "avrlibc"
+        else if final.isNone                then "newlib"
         else if final.isNetBSD              then "nblibc"
         # TODO(@Ericson2314) think more about other operating systems
         else                                     "native/impure";

From 00afca09295db93bf8bffe3f6f2d92a74eb97b38 Mon Sep 17 00:00:00 2001
From: John Ericson <John.Ericson@Obsidian.Systems>
Date: Thu, 12 Mar 2020 09:56:17 -0400
Subject: [PATCH 2/7] lib: Add armv6l-none to doubles list

---
 lib/systems/doubles.nix | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/lib/systems/doubles.nix b/lib/systems/doubles.nix
index 96e602d0e16..619b0427918 100644
--- a/lib/systems/doubles.nix
+++ b/lib/systems/doubles.nix
@@ -26,7 +26,13 @@ let
 
     "riscv32-linux" "riscv64-linux"
 
-    "aarch64-none" "avr-none" "arm-none" "i686-none" "x86_64-none" "powerpc-none" "msp430-none" "riscv64-none" "riscv32-none" "vc4-none"
+    "arm-none" "armv6l-none" "aarch64-none"
+    "avr-none"
+    "i686-none" "x86_64-none"
+    "powerpc-none"
+    "msp430-none"
+    "riscv64-none" "riscv32-none"
+    "vc4-none"
 
     "js-ghcjs"
   ];

From 783fa4616e044ca33e4841514a180ad1325b48d4 Mon Sep 17 00:00:00 2001
From: John Ericson <John.Ericson@Obsidian.Systems>
Date: Thu, 12 Mar 2020 09:56:55 -0400
Subject: [PATCH 3/7] rustc: Add way to override the arch and config triple for
 rust

Sometimes it is useful for it to be slightly different. Going forward we
should, however, try to make this fallback rarely needed.
---
 pkgs/development/compilers/rust/default.nix | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/pkgs/development/compilers/rust/default.nix b/pkgs/development/compilers/rust/default.nix
index da3421a987d..7dc30f48c50 100644
--- a/pkgs/development/compilers/rust/default.nix
+++ b/pkgs/development/compilers/rust/default.nix
@@ -17,8 +17,9 @@
       "armv7a" = "armv7";
       "armv7l" = "armv7";
       "armv6l" = "arm";
-    }.${cpu.name} or cpu.name;
-  in "${cpu_}-${vendor.name}-${kernel.name}${lib.optionalString (abi.name != "unknown") "-${abi.name}"}";
+    }.${cpu.name} or platform.rustc.arch or cpu.name;
+  in platform.rustc.config
+    or "${cpu_}-${vendor.name}-${kernel.name}${lib.optionalString (abi.name != "unknown") "-${abi.name}"}";
 
   makeRustPlatform = { rustc, cargo, ... }: rec {
     rust = {

From 99c18b34410fe7bbbe3f6417258b06a3d5e3171d Mon Sep 17 00:00:00 2001
From: John Ericson <John.Ericson@Obsidian.Systems>
Date: Wed, 18 Mar 2020 11:28:05 -0400
Subject: [PATCH 4/7] clang-*: Sync wrapping logic

We only want to refer to GCC under these conditions.
---
 pkgs/development/compilers/llvm/5/default.nix | 2 +-
 pkgs/development/compilers/llvm/6/default.nix | 2 +-
 pkgs/development/compilers/llvm/7/default.nix | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/pkgs/development/compilers/llvm/5/default.nix b/pkgs/development/compilers/llvm/5/default.nix
index 05f4dbf6aa0..fd4aaa363bf 100644
--- a/pkgs/development/compilers/llvm/5/default.nix
+++ b/pkgs/development/compilers/llvm/5/default.nix
@@ -23,7 +23,7 @@ let
       ln -s "${cc}/lib/clang/${release_version}/include" "$rsrc"
       ln -s "${targetLlvmLibraries.compiler-rt.out}/lib" "$rsrc/lib"
       echo "-resource-dir=$rsrc" >> $out/nix-support/cc-cflags
-    '' + stdenv.lib.optionalString stdenv.targetPlatform.isLinux ''
+    '' + stdenv.lib.optionalString (stdenv.targetPlatform.isLinux && tools.clang-unwrapped ? gcc && !(stdenv.targetPlatform.useLLVM or false)) ''
       echo "--gcc-toolchain=${tools.clang-unwrapped.gcc}" >> $out/nix-support/cc-cflags
     '';
   in {
diff --git a/pkgs/development/compilers/llvm/6/default.nix b/pkgs/development/compilers/llvm/6/default.nix
index d4745930ed3..85bb00d80c7 100644
--- a/pkgs/development/compilers/llvm/6/default.nix
+++ b/pkgs/development/compilers/llvm/6/default.nix
@@ -23,7 +23,7 @@ let
       ln -s "${cc}/lib/clang/${release_version}/include" "$rsrc"
       ln -s "${targetLlvmLibraries.compiler-rt.out}/lib" "$rsrc/lib"
       echo "-resource-dir=$rsrc" >> $out/nix-support/cc-cflags
-    '' + stdenv.lib.optionalString stdenv.targetPlatform.isLinux ''
+    '' + stdenv.lib.optionalString (stdenv.targetPlatform.isLinux && tools.clang-unwrapped ? gcc && !(stdenv.targetPlatform.useLLVM or false)) ''
       echo "--gcc-toolchain=${tools.clang-unwrapped.gcc}" >> $out/nix-support/cc-cflags
     '';
   in {
diff --git a/pkgs/development/compilers/llvm/7/default.nix b/pkgs/development/compilers/llvm/7/default.nix
index 04e1610fb79..816649e62ad 100644
--- a/pkgs/development/compilers/llvm/7/default.nix
+++ b/pkgs/development/compilers/llvm/7/default.nix
@@ -23,7 +23,7 @@ let
       ln -s "${cc}/lib/clang/${release_version}/include" "$rsrc"
       ln -s "${targetLlvmLibraries.compiler-rt.out}/lib" "$rsrc/lib"
       echo "-resource-dir=$rsrc" >> $out/nix-support/cc-cflags
-    '' + stdenv.lib.optionalString (stdenv.targetPlatform.isLinux && tools.clang-unwrapped ? gcc) ''
+    '' + stdenv.lib.optionalString (stdenv.targetPlatform.isLinux && tools.clang-unwrapped ? gcc && !(stdenv.targetPlatform.useLLVM or false)) ''
       echo "--gcc-toolchain=${tools.clang-unwrapped.gcc}" >> $out/nix-support/cc-cflags
     '';
   in {

From bc054004ac04b2500247c2efe504e6b3da444e61 Mon Sep 17 00:00:00 2001
From: John Ericson <John.Ericson@Obsidian.Systems>
Date: Wed, 18 Mar 2020 11:28:52 -0400
Subject: [PATCH 5/7] cc-wrapper, clang: `libstdcxxHook` should a propagated
 build input

Lumping it in with the target platform libraries was incorrect, and
caused eval failures when gcc couldn't be built for the target platform.
---
 pkgs/build-support/cc-wrapper/default.nix     | 4 ++--
 pkgs/development/compilers/llvm/5/default.nix | 4 +++-
 pkgs/development/compilers/llvm/6/default.nix | 4 +++-
 pkgs/development/compilers/llvm/7/default.nix | 4 +++-
 pkgs/development/compilers/llvm/8/default.nix | 4 +++-
 pkgs/development/compilers/llvm/9/default.nix | 4 +++-
 6 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/pkgs/build-support/cc-wrapper/default.nix b/pkgs/build-support/cc-wrapper/default.nix
index b078bf2fbbd..b7c5ea6e20f 100644
--- a/pkgs/build-support/cc-wrapper/default.nix
+++ b/pkgs/build-support/cc-wrapper/default.nix
@@ -10,7 +10,7 @@
 , cc ? null, libc ? null, bintools, coreutils ? null, shell ? stdenvNoCC.shell
 , nativeTools, noLibc ? false, nativeLibc, nativePrefix ? ""
 , propagateDoc ? cc != null && cc ? man
-, extraPackages ? [], extraBuildCommands ? ""
+, extraTools ? [], extraPackages ? [], extraBuildCommands ? ""
 , isGNU ? false, isClang ? cc.isClang or false, gnugrep ? null
 , buildPackages ? {}
 , libcxx ? null
@@ -212,7 +212,7 @@ stdenv.mkDerivation {
     '';
 
   strictDeps = true;
-  propagatedBuildInputs = [ bintools ];
+  propagatedBuildInputs = [ bintools ] ++ extraTools;
   depsTargetTargetPropagated = extraPackages;
 
   wrapperName = "CC_WRAPPER";
diff --git a/pkgs/development/compilers/llvm/5/default.nix b/pkgs/development/compilers/llvm/5/default.nix
index fd4aaa363bf..3c1b07e7ca7 100644
--- a/pkgs/development/compilers/llvm/5/default.nix
+++ b/pkgs/development/compilers/llvm/5/default.nix
@@ -50,8 +50,10 @@ let
 
     libstdcxxClang = wrapCCWith rec {
       cc = tools.clang-unwrapped;
-      extraPackages = [
+      extraTools = [
         libstdcxxHook
+      ];
+      extraPackages = [
         targetLlvmLibraries.compiler-rt
       ];
       extraBuildCommands = mkExtraBuildCommands cc;
diff --git a/pkgs/development/compilers/llvm/6/default.nix b/pkgs/development/compilers/llvm/6/default.nix
index 85bb00d80c7..ba704f972c3 100644
--- a/pkgs/development/compilers/llvm/6/default.nix
+++ b/pkgs/development/compilers/llvm/6/default.nix
@@ -50,8 +50,10 @@ let
 
     libstdcxxClang = wrapCCWith rec {
       cc = tools.clang-unwrapped;
-      extraPackages = [
+      extraTools = [
         libstdcxxHook
+      ];
+      extraPackages = [
         targetLlvmLibraries.compiler-rt
       ];
       extraBuildCommands = mkExtraBuildCommands cc;
diff --git a/pkgs/development/compilers/llvm/7/default.nix b/pkgs/development/compilers/llvm/7/default.nix
index 816649e62ad..5124a5df00b 100644
--- a/pkgs/development/compilers/llvm/7/default.nix
+++ b/pkgs/development/compilers/llvm/7/default.nix
@@ -57,8 +57,10 @@ let
 
     libstdcxxClang = wrapCCWith rec {
       cc = tools.clang-unwrapped;
-      extraPackages = [
+      extraTools = [
         libstdcxxHook
+      ];
+      extraPackages = [
         targetLlvmLibraries.compiler-rt
       ];
       extraBuildCommands = mkExtraBuildCommands cc;
diff --git a/pkgs/development/compilers/llvm/8/default.nix b/pkgs/development/compilers/llvm/8/default.nix
index d604dda5fe5..105011595c8 100644
--- a/pkgs/development/compilers/llvm/8/default.nix
+++ b/pkgs/development/compilers/llvm/8/default.nix
@@ -57,8 +57,10 @@ let
 
     libstdcxxClang = wrapCCWith rec {
       cc = tools.clang-unwrapped;
-      extraPackages = [
+      extraTools = [
         libstdcxxHook
+      ];
+      extraPackages = [
         targetLlvmLibraries.compiler-rt
       ];
       extraBuildCommands = mkExtraBuildCommands cc;
diff --git a/pkgs/development/compilers/llvm/9/default.nix b/pkgs/development/compilers/llvm/9/default.nix
index 11e44b8bdfa..d42e5187c3c 100644
--- a/pkgs/development/compilers/llvm/9/default.nix
+++ b/pkgs/development/compilers/llvm/9/default.nix
@@ -57,8 +57,10 @@ let
 
     libstdcxxClang = wrapCCWith rec {
       cc = tools.clang-unwrapped;
-      extraPackages = [
+      extraTools = [
         libstdcxxHook
+      ];
+      extraPackages = [
         targetLlvmLibraries.compiler-rt
       ];
       extraBuildCommands = mkExtraBuildCommands cc;

From 0c73297c075cf4fd87922f621fc2358c65b659f3 Mon Sep 17 00:00:00 2001
From: John Ericson <John.Ericson@Obsidian.Systems>
Date: Wed, 18 Mar 2020 12:10:09 -0400
Subject: [PATCH 6/7] compiler-rt-{7,8,9}: Fix cmakeFlags in a few ways

 - Cross to bare metal with GCC works

 - Flags are deduplicated

 - Darwin bootstrapping for 8 and 0 closer.

 - Flags are same across versions.
---
 .../compilers/llvm/7/compiler-rt.nix          | 33 ++++++++++++-----
 .../compilers/llvm/8/compiler-rt.nix          | 36 +++++++++++--------
 .../compilers/llvm/9/compiler-rt.nix          | 34 +++++++++++-------
 3 files changed, 68 insertions(+), 35 deletions(-)

diff --git a/pkgs/development/compilers/llvm/7/compiler-rt.nix b/pkgs/development/compilers/llvm/7/compiler-rt.nix
index ae98940adea..7a5e3d4c8fc 100644
--- a/pkgs/development/compilers/llvm/7/compiler-rt.nix
+++ b/pkgs/development/compilers/llvm/7/compiler-rt.nix
@@ -1,4 +1,13 @@
 { stdenv, version, fetch, cmake, python3, llvm, libcxxabi }:
+
+let
+
+  useLLVM = stdenv.hostPlatform.useLLVM or false;
+  bareMetal = stdenv.hostPlatform.parsed.kernel.name == "none";
+  inherit (stdenv.hostPlatform) isMusl;
+
+in
+
 stdenv.mkDerivation {
   pname = "compiler-rt";
   inherit version;
@@ -11,26 +20,34 @@ stdenv.mkDerivation {
     "-DSCUDO_DEFAULT_OPTIONS=DeleteSizeMismatch=0:DeallocationTypeMismatch=0"
   ];
 
-  cmakeFlags = stdenv.lib.optionals (stdenv.hostPlatform.useLLVM or false || stdenv.isDarwin) [
+  cmakeFlags = stdenv.lib.optionals (useLLVM || stdenv.isDarwin) [
     "-DCOMPILER_RT_DEFAULT_TARGET_ONLY=ON"
     "-DCMAKE_C_COMPILER_TARGET=${stdenv.hostPlatform.config}"
     "-DCMAKE_ASM_COMPILER_TARGET=${stdenv.hostPlatform.config}"
-  ] ++ stdenv.lib.optionals (stdenv.hostPlatform.useLLVM or false) [
-    "-DCMAKE_C_FLAGS=-nodefaultlibs"
-    "-DCMAKE_CXX_COMPILER_WORKS=ON"
-    "-DCOMPILER_RT_BUILD_BUILTINS=ON"
+  ] ++ stdenv.lib.optionals (useLLVM || bareMetal || isMusl) [
     "-DCOMPILER_RT_BUILD_SANITIZERS=OFF"
     "-DCOMPILER_RT_BUILD_XRAY=OFF"
     "-DCOMPILER_RT_BUILD_LIBFUZZER=OFF"
     "-DCOMPILER_RT_BUILD_PROFILE=OFF"
+  ] ++ stdenv.lib.optionals (useLLVM || bareMetal) [
+    "-DCMAKE_C_COMPILER_WORKS=ON"
+    "-DCMAKE_CXX_COMPILER_WORKS=ON"
     "-DCOMPILER_RT_BAREMETAL_BUILD=ON"
+    "-DCMAKE_SIZEOF_VOID_P=${toString (stdenv.hostPlatform.parsed.cpu.bits / 8)}"
+  ] ++ stdenv.lib.optionals (useLLVM) [
+    "-DCOMPILER_RT_BUILD_BUILTINS=ON"
+    "-DCMAKE_C_FLAGS=-nodefaultlibs"
+    #https://stackoverflow.com/questions/53633705/cmake-the-c-compiler-is-not-able-to-compile-a-simple-test-program
+    "-DCMAKE_TRY_COMPILE_TARGET_TYPE=STATIC_LIBRARY"
+  ] ++ stdenv.lib.optionals (bareMetal) [
+    "-DCOMPILER_RT_OS_DIR=baremetal"
   ];
 
   outputs = [ "out" "dev" ];
 
   patches = [
     ./compiler-rt-codesign.patch # Revert compiler-rt commit that makes codesign mandatory
-  ] ++ stdenv.lib.optional (stdenv.hostPlatform.useLLVM or false) ./crtbegin-and-end.patch
+  ] ++ stdenv.lib.optional (useLLVM) ./crtbegin-and-end.patch
     ++ stdenv.lib.optional stdenv.hostPlatform.isMusl ./sanitizers-nongnu.patch;
 
   # TSAN requires XPC on Darwin, which we have no public/free source files for. We can depend on the Apple frameworks
@@ -41,7 +58,7 @@ stdenv.mkDerivation {
   postPatch = stdenv.lib.optionalString stdenv.isDarwin ''
     substituteInPlace cmake/config-ix.cmake \
       --replace 'set(COMPILER_RT_HAS_TSAN TRUE)' 'set(COMPILER_RT_HAS_TSAN FALSE)'
-  '' + stdenv.lib.optionalString (stdenv.hostPlatform.useLLVM or false) ''
+  '' + stdenv.lib.optionalString (useLLVM) ''
     substituteInPlace lib/builtins/int_util.c \
       --replace "#include <stdlib.h>" ""
     substituteInPlace lib/builtins/clear_cache.c \
@@ -53,7 +70,7 @@ stdenv.mkDerivation {
   # Hack around weird upsream RPATH bug
   postInstall = stdenv.lib.optionalString stdenv.isDarwin ''
     ln -s "$out/lib"/*/* "$out/lib"
-  '' + stdenv.lib.optionalString (stdenv.hostPlatform.useLLVM or false) ''
+  '' + stdenv.lib.optionalString (useLLVM) ''
     ln -s $out/lib/*/clang_rt.crtbegin-*.o $out/lib/linux/crtbegin.o
     ln -s $out/lib/*/clang_rt.crtend-*.o $out/lib/linux/crtend.o
     ln -s $out/lib/*/clang_rt.crtbegin_shared-*.o $out/lib/linux/crtbeginS.o
diff --git a/pkgs/development/compilers/llvm/8/compiler-rt.nix b/pkgs/development/compilers/llvm/8/compiler-rt.nix
index 9c0829146f7..795c81f4219 100644
--- a/pkgs/development/compilers/llvm/8/compiler-rt.nix
+++ b/pkgs/development/compilers/llvm/8/compiler-rt.nix
@@ -1,4 +1,13 @@
 { stdenv, version, fetch, cmake, python3, llvm, libcxxabi }:
+
+let
+
+  useLLVM = stdenv.hostPlatform.useLLVM or false;
+  bareMetal = stdenv.hostPlatform.parsed.kernel.name == "none";
+  inherit (stdenv.hostPlatform) isMusl;
+
+in
+
 stdenv.mkDerivation {
   pname = "compiler-rt";
   inherit version;
@@ -11,27 +20,26 @@ stdenv.mkDerivation {
     "-DSCUDO_DEFAULT_OPTIONS=DeleteSizeMismatch=0:DeallocationTypeMismatch=0"
   ];
 
-  cmakeFlags = stdenv.lib.optionals (stdenv.hostPlatform.useLLVM or false) [
+  cmakeFlags = stdenv.lib.optionals (useLLVM || stdenv.isDarwin) [
     "-DCOMPILER_RT_DEFAULT_TARGET_ONLY=ON"
     "-DCMAKE_C_COMPILER_TARGET=${stdenv.hostPlatform.config}"
     "-DCMAKE_ASM_COMPILER_TARGET=${stdenv.hostPlatform.config}"
-    "-DCMAKE_C_FLAGS=-nodefaultlibs"
-    "-DCMAKE_CXX_COMPILER_WORKS=ON"
+  ] ++ stdenv.lib.optionals (useLLVM || bareMetal || isMusl) [
     "-DCOMPILER_RT_BUILD_SANITIZERS=OFF"
     "-DCOMPILER_RT_BUILD_XRAY=OFF"
     "-DCOMPILER_RT_BUILD_LIBFUZZER=OFF"
     "-DCOMPILER_RT_BUILD_PROFILE=OFF"
+  ] ++ stdenv.lib.optionals (useLLVM || bareMetal) [
+    "-DCMAKE_C_COMPILER_WORKS=ON"
+    "-DCMAKE_CXX_COMPILER_WORKS=ON"
     "-DCOMPILER_RT_BAREMETAL_BUILD=ON"
+    "-DCMAKE_SIZEOF_VOID_P=${toString (stdenv.hostPlatform.parsed.cpu.bits / 8)}"
+  ] ++ stdenv.lib.optionals (useLLVM) [
+    "-DCOMPILER_RT_BUILD_BUILTINS=ON"
+    "-DCMAKE_C_FLAGS=-nodefaultlibs"
     #https://stackoverflow.com/questions/53633705/cmake-the-c-compiler-is-not-able-to-compile-a-simple-test-program
     "-DCMAKE_TRY_COMPILE_TARGET_TYPE=STATIC_LIBRARY"
-    "-DCMAKE_SIZEOF_VOID_P=${toString (stdenv.hostPlatform.parsed.cpu.bits / 8)}"
-  ] ++ stdenv.lib.optionals stdenv.hostPlatform.isMusl [
-    "-DCOMPILER_RT_BUILD_SANITIZERS=OFF"
-    "-DCOMPILER_RT_BUILD_XRAY=OFF"
-    "-DCOMPILER_RT_BUILD_LIBFUZZER=OFF"
-    "-DCOMPILER_RT_BUILD_PROFILE=OFF"
-  ] ++ stdenv.lib.optionals (stdenv.hostPlatform.parsed.kernel.name == "none") [
-    "-DCOMPILER_RT_BAREMETAL_BUILD=ON"
+  ] ++ stdenv.lib.optionals (bareMetal) [
     "-DCOMPILER_RT_OS_DIR=baremetal"
   ];
 
@@ -40,7 +48,7 @@ stdenv.mkDerivation {
   patches = [
     ./compiler-rt-codesign.patch # Revert compiler-rt commit that makes codesign mandatory
   ]# ++ stdenv.lib.optional stdenv.hostPlatform.isMusl ./sanitizers-nongnu.patch
-    ++ stdenv.lib.optional (stdenv.hostPlatform.useLLVM or false) ./crtbegin-and-end.patch;
+    ++ stdenv.lib.optional (useLLVM) ./crtbegin-and-end.patch;
 
   # TSAN requires XPC on Darwin, which we have no public/free source files for. We can depend on the Apple frameworks
   # to get it, but they're unfree. Since LLVM is rather central to the stdenv, we patch out TSAN support so that Hydra
@@ -50,7 +58,7 @@ stdenv.mkDerivation {
   postPatch = stdenv.lib.optionalString stdenv.isDarwin ''
     substituteInPlace cmake/config-ix.cmake \
       --replace 'set(COMPILER_RT_HAS_TSAN TRUE)' 'set(COMPILER_RT_HAS_TSAN FALSE)'
-  '' + stdenv.lib.optionalString (stdenv.hostPlatform.useLLVM or false) ''
+  '' + stdenv.lib.optionalString (useLLVM) ''
     substituteInPlace lib/builtins/int_util.c \
       --replace "#include <stdlib.h>" ""
     substituteInPlace lib/builtins/clear_cache.c \
@@ -62,7 +70,7 @@ stdenv.mkDerivation {
   # Hack around weird upsream RPATH bug
   postInstall = stdenv.lib.optionalString (stdenv.hostPlatform.isDarwin || stdenv.hostPlatform.isWasm) ''
     ln -s "$out/lib"/*/* "$out/lib"
-  '' + stdenv.lib.optionalString (stdenv.hostPlatform.useLLVM or false) ''
+  '' + stdenv.lib.optionalString (useLLVM) ''
     ln -s $out/lib/*/clang_rt.crtbegin-*.o $out/lib/crtbegin.o
     ln -s $out/lib/*/clang_rt.crtend-*.o $out/lib/crtend.o
     ln -s $out/lib/*/clang_rt.crtbegin_shared-*.o $out/lib/crtbeginS.o
diff --git a/pkgs/development/compilers/llvm/9/compiler-rt.nix b/pkgs/development/compilers/llvm/9/compiler-rt.nix
index 037953bb23d..0cfd8d7c9e7 100644
--- a/pkgs/development/compilers/llvm/9/compiler-rt.nix
+++ b/pkgs/development/compilers/llvm/9/compiler-rt.nix
@@ -1,4 +1,13 @@
 { stdenv, version, fetch, cmake, python3, llvm, libcxxabi }:
+
+let
+
+  useLLVM = stdenv.hostPlatform.useLLVM or false;
+  bareMetal = stdenv.hostPlatform.parsed.kernel.name == "none";
+  inherit (stdenv.hostPlatform) isMusl;
+
+in
+
 stdenv.mkDerivation rec {
   pname = "compiler-rt";
   inherit version;
@@ -11,27 +20,26 @@ stdenv.mkDerivation rec {
     "-DSCUDO_DEFAULT_OPTIONS=DeleteSizeMismatch=0:DeallocationTypeMismatch=0"
   ];
 
-  cmakeFlags = stdenv.lib.optionals (stdenv.hostPlatform.useLLVM or false) [
+  cmakeFlags = stdenv.lib.optionals (useLLVM || stdenv.isDarwin) [
     "-DCOMPILER_RT_DEFAULT_TARGET_ONLY=ON"
     "-DCMAKE_C_COMPILER_TARGET=${stdenv.hostPlatform.config}"
     "-DCMAKE_ASM_COMPILER_TARGET=${stdenv.hostPlatform.config}"
-    "-DCMAKE_C_FLAGS=-nodefaultlibs"
-    "-DCMAKE_CXX_COMPILER_WORKS=ON"
+  ] ++ stdenv.lib.optionals (useLLVM || bareMetal || isMusl) [
     "-DCOMPILER_RT_BUILD_SANITIZERS=OFF"
     "-DCOMPILER_RT_BUILD_XRAY=OFF"
     "-DCOMPILER_RT_BUILD_LIBFUZZER=OFF"
     "-DCOMPILER_RT_BUILD_PROFILE=OFF"
+  ] ++ stdenv.lib.optionals (useLLVM || bareMetal) [
+    "-DCMAKE_C_COMPILER_WORKS=ON"
+    "-DCMAKE_CXX_COMPILER_WORKS=ON"
     "-DCOMPILER_RT_BAREMETAL_BUILD=ON"
+    "-DCMAKE_SIZEOF_VOID_P=${toString (stdenv.hostPlatform.parsed.cpu.bits / 8)}"
+  ] ++ stdenv.lib.optionals (useLLVM) [
+    "-DCOMPILER_RT_BUILD_BUILTINS=ON"
+    "-DCMAKE_C_FLAGS=-nodefaultlibs"
     #https://stackoverflow.com/questions/53633705/cmake-the-c-compiler-is-not-able-to-compile-a-simple-test-program
     "-DCMAKE_TRY_COMPILE_TARGET_TYPE=STATIC_LIBRARY"
-    "-DCMAKE_SIZEOF_VOID_P=${toString (stdenv.hostPlatform.parsed.cpu.bits / 8)}"
-  ] ++ stdenv.lib.optionals stdenv.hostPlatform.isMusl [
-    "-DCOMPILER_RT_BUILD_SANITIZERS=OFF"
-    "-DCOMPILER_RT_BUILD_XRAY=OFF"
-    "-DCOMPILER_RT_BUILD_LIBFUZZER=OFF"
-    "-DCOMPILER_RT_BUILD_PROFILE=OFF"
-  ] ++ stdenv.lib.optionals (stdenv.hostPlatform.parsed.kernel.name == "none") [
-    "-DCOMPILER_RT_BAREMETAL_BUILD=ON"
+  ] ++ stdenv.lib.optionals (bareMetal) [
     "-DCOMPILER_RT_OS_DIR=baremetal"
   ];
 
@@ -49,7 +57,7 @@ stdenv.mkDerivation rec {
   postPatch = stdenv.lib.optionalString stdenv.isDarwin ''
     substituteInPlace cmake/config-ix.cmake \
       --replace 'set(COMPILER_RT_HAS_TSAN TRUE)' 'set(COMPILER_RT_HAS_TSAN FALSE)'
-  '' + stdenv.lib.optionalString (stdenv.hostPlatform.useLLVM or false) ''
+  '' + stdenv.lib.optionalString (useLLVM) ''
     substituteInPlace lib/builtins/int_util.c \
       --replace "#include <stdlib.h>" ""
     substituteInPlace lib/builtins/clear_cache.c \
@@ -61,7 +69,7 @@ stdenv.mkDerivation rec {
   # Hack around weird upsream RPATH bug
   postInstall = stdenv.lib.optionalString (stdenv.hostPlatform.isDarwin || stdenv.hostPlatform.isWasm) ''
     ln -s "$out/lib"/*/* "$out/lib"
-  '' + stdenv.lib.optionalString (stdenv.hostPlatform.useLLVM or false) ''
+  '' + stdenv.lib.optionalString (useLLVM) ''
     ln -s $out/lib/*/clang_rt.crtbegin-*.o $out/lib/crtbegin.o
     ln -s $out/lib/*/clang_rt.crtend-*.o $out/lib/crtend.o
     ln -s $out/lib/*/clang_rt.crtbegin_shared-*.o $out/lib/crtbeginS.o

From 7c0d3f6f70c7a55e8c988e9d6882820b9d26171d Mon Sep 17 00:00:00 2001
From: John Ericson <John.Ericson@Obsidian.Systems>
Date: Wed, 18 Mar 2020 17:43:11 -0400
Subject: [PATCH 7/7] lib: Fix systems test for new `armv6l-none`

---
 lib/tests/systems.nix | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/tests/systems.nix b/lib/tests/systems.nix
index 6f52912994d..dd2b9575fc2 100644
--- a/lib/tests/systems.nix
+++ b/lib/tests/systems.nix
@@ -14,7 +14,7 @@ let
 in with lib.systems.doubles; lib.runTests {
   testall = mseteq all (linux ++ darwin ++ freebsd ++ openbsd ++ netbsd ++ illumos ++ wasi ++ windows ++ embedded ++ js);
 
-  testarm = mseteq arm [ "armv5tel-linux" "armv6l-linux" "armv7a-linux" "armv7l-linux" "arm-none" "armv7a-darwin" ];
+  testarm = mseteq arm [ "armv5tel-linux" "armv6l-linux" "armv6l-none" "armv7a-linux" "armv7l-linux" "arm-none" "armv7a-darwin" ];
   testi686 = mseteq i686 [ "i686-linux" "i686-freebsd" "i686-netbsd" "i686-openbsd" "i686-cygwin" "i686-windows" "i686-none" "i686-darwin" ];
   testmips = mseteq mips [ "mipsel-linux" ];
   testx86_64 = mseteq x86_64 [ "x86_64-linux" "x86_64-darwin" "x86_64-freebsd" "x86_64-openbsd" "x86_64-netbsd" "x86_64-cygwin" "x86_64-solaris" "x86_64-windows" "x86_64-none" ];