Merge pull request #153790 from sternenseemann/cross-bootstrap-logic

Cross bootstrapping logic fixes benefitting llvmPackages

pkgs/development/compilers/llvm/10/default.nix

@@ -89,7 +89,11 @@ let
     #   python3 = pkgs.python3;  # don't use python-boot
     # });
 
-    clang = if stdenv.cc.isGNU then tools.libstdcxxClang else tools.libcxxClang;
+    # pick clang appropriate for package set we are targeting
+    clang =
+      /**/ if stdenv.targetPlatform.useLLVM or false then tools.clangUseLLVM
+      else if (pkgs.targetPackages.stdenv or stdenv).cc.isGNU then tools.libstdcxxClang
+      else tools.libcxxClang;
 
     libstdcxxClang = wrapCCWith rec {
       cc = tools.clang-unwrapped;

pkgs/development/compilers/llvm/11/default.nix

@@ -104,7 +104,11 @@ let
     #   python3 = pkgs.python3;  # don't use python-boot
     # });
 
-    clang = if stdenv.cc.isGNU then tools.libstdcxxClang else tools.libcxxClang;
+    # pick clang appropriate for package set we are targeting
+    clang =
+      /**/ if stdenv.targetPlatform.useLLVM or false then tools.clangUseLLVM
+      else if (pkgs.targetPackages.stdenv or stdenv).cc.isGNU then tools.libstdcxxClang
+      else tools.libcxxClang;
 
     libstdcxxClang = wrapCCWith rec {
       cc = tools.clang-unwrapped;

pkgs/development/compilers/llvm/12/default.nix

@@ -92,7 +92,11 @@ let
     #   python3 = pkgs.python3;  # don't use python-boot
     # });
 
-    clang = if stdenv.cc.isGNU then tools.libstdcxxClang else tools.libcxxClang;
+    # pick clang appropriate for package set we are targeting
+    clang =
+      /**/ if stdenv.targetPlatform.useLLVM or false then tools.clangUseLLVM
+      else if (pkgs.targetPackages.stdenv or stdenv).cc.isGNU then tools.libstdcxxClang
+      else tools.libcxxClang;
 
     libstdcxxClang = wrapCCWith rec {
       cc = tools.clang-unwrapped;

pkgs/development/compilers/llvm/13/default.nix

@@ -93,7 +93,11 @@ let
     #   python3 = pkgs.python3;  # don't use python-boot
     # });
 
-    clang = if stdenv.cc.isGNU then tools.libstdcxxClang else tools.libcxxClang;
+    # pick clang appropriate for package set we are targeting
+    clang =
+      /**/ if stdenv.targetPlatform.useLLVM or false then tools.clangUseLLVM
+      else if (pkgs.targetPackages.stdenv or stdenv).cc.isGNU then tools.libstdcxxClang
+      else tools.libcxxClang;
 
     libstdcxxClang = wrapCCWith rec {
       cc = tools.clang-unwrapped;

pkgs/development/compilers/llvm/5/default.nix

@@ -65,7 +65,11 @@ let
       python3 = pkgs.python3;  # don't use python-boot
     });
 
-    clang = if stdenv.cc.isGNU then tools.libstdcxxClang else tools.libcxxClang;
+    # pick clang appropriate for package set we are targeting
+    clang =
+      /**/ if stdenv.targetPlatform.useLLVM or false then tools.clangUseLLVM
+      else if (pkgs.targetPackages.stdenv or stdenv).cc.isGNU then tools.libstdcxxClang
+      else tools.libcxxClang;
 
     libstdcxxClang = wrapCCWith rec {
       cc = tools.clang-unwrapped;

pkgs/development/compilers/llvm/6/default.nix

@@ -66,7 +66,11 @@ let
       python3 = pkgs.python3;  # don't use python-boot
     });
 
-    clang = if stdenv.cc.isGNU then tools.libstdcxxClang else tools.libcxxClang;
+    # pick clang appropriate for package set we are targeting
+    clang =
+      /**/ if stdenv.targetPlatform.useLLVM or false then tools.clangUseLLVM
+      else if (pkgs.targetPackages.stdenv or stdenv).cc.isGNU then tools.libstdcxxClang
+      else tools.libcxxClang;
 
     libstdcxxClang = wrapCCWith rec {
       cc = tools.clang-unwrapped;

pkgs/development/compilers/llvm/7/default.nix

@@ -96,7 +96,11 @@ let
       python3 = pkgs.python3;  # don't use python-boot
     });
 
-    clang = if stdenv.cc.isGNU then tools.libstdcxxClang else tools.libcxxClang;
+    # pick clang appropriate for package set we are targeting
+    clang =
+      /**/ if stdenv.targetPlatform.useLLVM or false then tools.clangUseLLVM
+      else if (pkgs.targetPackages.stdenv or stdenv).cc.isGNU then tools.libstdcxxClang
+      else tools.libcxxClang;
 
     libstdcxxClang = wrapCCWith rec {
       cc = tools.clang-unwrapped;

pkgs/development/compilers/llvm/8/default.nix

@@ -97,7 +97,11 @@ let
       python3 = pkgs.python3;  # don't use python-boot
     });
 
-    clang = if stdenv.cc.isGNU then tools.libstdcxxClang else tools.libcxxClang;
+    # pick clang appropriate for package set we are targeting
+    clang =
+      /**/ if stdenv.targetPlatform.useLLVM or false then tools.clangUseLLVM
+      else if (pkgs.targetPackages.stdenv or stdenv).cc.isGNU then tools.libstdcxxClang
+      else tools.libcxxClang;
 
     libstdcxxClang = wrapCCWith rec {
       cc = tools.clang-unwrapped;

pkgs/development/compilers/llvm/9/default.nix

@@ -97,7 +97,11 @@ let
       python3 = pkgs.python3;  # don't use python-boot
     });
 
-    clang = if stdenv.cc.isGNU then tools.libstdcxxClang else tools.libcxxClang;
+    # pick clang appropriate for package set we are targeting
+    clang =
+      /**/ if stdenv.targetPlatform.useLLVM or false then tools.clangUseLLVM
+      else if (pkgs.targetPackages.stdenv or stdenv).cc.isGNU then tools.libstdcxxClang
+      else tools.libcxxClang;
 
     libstdcxxClang = wrapCCWith rec {
       cc = tools.clang-unwrapped;

pkgs/development/compilers/llvm/git/default.nix

@@ -93,7 +93,11 @@ let
     #   python3 = pkgs.python3;  # don't use python-boot
     # });
 
-    clang = if stdenv.cc.isGNU then tools.libstdcxxClang else tools.libcxxClang;
+    # pick clang appropriate for package set we are targeting
+    clang =
+      /**/ if stdenv.targetPlatform.useLLVM or false then tools.clangUseLLVM
+      else if (pkgs.targetPackages.stdenv or stdenv).cc.isGNU then tools.libstdcxxClang
+      else tools.libcxxClang;
 
     libstdcxxClang = wrapCCWith rec {
       cc = tools.clang-unwrapped;

pkgs/stdenv/booter.nix

@@ -124,7 +124,13 @@ stageFuns: let
       if buildPackages.stdenv.hasCC
       then
         if buildPackages.stdenv.cc.isClang or false
-        then buildPackages.clang
+        # buildPackages.clang checks targetPackages.stdenv.cc (i. e. this
+        # attribute) to get a sense of the its set's default compiler and
+        # chooses between libc++ and libstdc++ based on that. If we hit this
+        # code here, we'll cause an infinite recursion. Since a set with
+        # clang as its default compiler always means libc++, we can infer this
+        # decision statically.
+        then buildPackages.llvmPackages.libcxxClang
         else buildPackages.gcc
       else
         # This will blow up if anything uses it, but that's OK. The `if

pkgs/stdenv/cross/default.nix

@@ -70,7 +70,7 @@ in lib.init bootStages ++ [
              # when there is a C compiler and everything should be fine.
              then throw "no C compiler provided for this platform"
            else if crossSystem.isDarwin
-             then buildPackages.llvmPackages.clang
+             then buildPackages.llvmPackages.libcxxClang
            else if crossSystem.useLLVM or false
              then buildPackages.llvmPackages.clangUseLLVM
            else buildPackages.gcc;

pkgs/top-level/all-packages.nix

@@ -13268,7 +13268,11 @@ with pkgs;
       # Others should instead delegate to the next stage's choice with
       # `targetPackages.stdenv.cc.bintools`. This one is different just to
       # provide the default choice, avoiding infinite recursion.
-      bintools ? if stdenv.targetPlatform.isDarwin then darwin.binutils else binutils
+      # See the bintools attribute for the logic and reasoning. We need to provide
+      # a default here, since eval will hit this function when bootstrapping
+      # stdenv where the bintools attribute doesn't exist, but will never actually
+      # be evaluated -- callPackage ends up being too eager.
+      bintools ? pkgs.bintools
     , libc ? bintools.libc
     , # libc++ from the default LLVM version is bound at the top level, but we
       # want the C++ library to be explicitly chosen by the caller, and null by