GH Actions: Use pre-installed clang packages

Also fix the run by setting up the environment in non-deprecated way.

Always run with --debug to understand better what sort of stuff is happening in
the background. Also split out the bmake bootstrap stage (takes about 31s on
ubuntu, but 1m14 on macOS?)

Drops the dependency on coreutils (realpath, nproc) and thus (?) fixes macOS to
be just as fast (4 logical cores vs 2 physical cores before, go figure.)

Reviewed by:		arichardson

.github/workflows/cross-bootstrap-tools.yml

@@ -1,4 +1,4 @@
-name: Cross-build CI
+name: Cross-build Kernel
 
 on:
   push:
@@ -8,28 +8,51 @@ on:
 
 jobs:
   build:
-    name: ${{ matrix.os }}
+    name: ${{ matrix.os }} (${{ matrix.compiler }})
     runs-on: ${{ matrix.os }}
     strategy:
+      fail-fast: false
       matrix:
-        os: [ubuntu-18.04, ubuntu-20.04, macOS-latest]
+        include:
+          # TODO: both Ubuntu and macOS have bmake packages, we should try them instead of bootstrapping our own copy.
+          - os: ubuntu-20.04
+            compiler: clang-9
+            cross-bindir: /usr/lib/llvm-9/bin
+            pkgs: bmake libarchive-dev
+          - os: ubuntu-20.04
+            compiler: clang-10
+            cross-bindir: /usr/lib/llvm-10/bin
+            pkgs: bmake libarchive-dev
+          - os: macOS-latest
+            compiler: clang-11
+            #cross-bindir: /usr/local/Cellar/llvm/11.0.0/bin  # script figures this out automatically
+            pkgs: bmake libarchive llvm@11
 
     steps:
       - uses: actions/checkout@v2
-      - name: install LLVM+libarchive (Ubuntu)
+      - name: install packages (Ubuntu)
+        if: runner.os == 'Linux'
         run: |
-          wget -O /tmp/llvm.sh https://apt.llvm.org/llvm.sh
-          chmod +x /tmp/llvm.sh
-          sudo /tmp/llvm.sh 11
-          sudo apt install -y libarchive-dev
-          echo "::set-env name=EXTRA_MAKE_ARGS::--cross-bindir=/usr/lib/llvm-11/bin"
-        if: ${{ startsWith(matrix.os, 'ubuntu') }}
-      - name: install LLVM+libarchive (macOS)
-        run: brew install llvm coreutils libarchive xz
-        if: ${{ startsWith(matrix.os, 'macOS') }}
-      - name: create build dir
-        run: rm -rf ../build && mkdir -p ../build
+          sudo apt-get update --quiet || true
+          sudo apt-get -yq --no-install-suggests --no-install-recommends install ${{ matrix.pkgs }}
+      - name: install packages (macOS)
+        if: runner.os == 'macOS'
+        run: |
+          brew update --quiet || true
+          brew install ${{ matrix.pkgs }}
+      - name: create environment
+        run: |
+          echo "GITHUB_WORKSPACE = $GITHUB_WORKSPACE"
+          if [ -n "${{ matrix.cross-bindir }}" ]; then
+            echo "EXTRA_BUILD_ARGS=--cross-bindir=${{ matrix.cross-bindir }}" >> $GITHUB_ENV
+          fi
+          mkdir -p ../build
+          echo "MAKEOBJDIRPREFIX=${PWD%/*}/build" >> $GITHUB_ENV
+          # heh, works on Linux/BSD/macOS ...
+          echo "NPROC=`getconf _NPROCESSORS_ONLN 2>/dev/null || getconf NPROCESSORS_ONLN 2>/dev/null || echo 1`" >> $GITHUB_ENV
+      - name: bootstrap bmake
+        run: ./tools/build/make.py --debug $EXTRA_BUILD_ARGS TARGET=amd64 TARGET_ARCH=amd64 -n
       - name: make kernel-toolchain
-        run: env MAKEOBJDIRPREFIX=`realpath ../build` ./tools/build/make.py $EXTRA_MAKE_ARGS TARGET=amd64 TARGET_ARCH=amd64 kernel-toolchain -s -j$(nproc)
+        run: ./tools/build/make.py --debug $EXTRA_BUILD_ARGS TARGET=amd64 TARGET_ARCH=amd64 kernel-toolchain -s -j$NPROC
       - name: make buildkernel
-        run: env MAKEOBJDIRPREFIX=`realpath ../build` ./tools/build/make.py $EXTRA_MAKE_ARGS TARGET=amd64 TARGET_ARCH=amd64 KERNCONF=GENERIC NO_MODULES=yes buildkernel -s -j$(nproc)
+        run: ./tools/build/make.py --debug $EXTRA_BUILD_ARGS TARGET=amd64 TARGET_ARCH=amd64 KERNCONF=GENERIC NO_MODULES=yes buildkernel -s -j$NPROC $EXTRA_MAKE_ARGS

tools/build/make.py

@@ -115,6 +115,9 @@ def check_required_make_env_var(varname, binary_name, bindir):
                  " does not exist")
     new_env_vars[varname] = guess
     debug("Inferred", varname, "as", guess)
+    global parsed_args
+    if parsed_args.debug:
+        run([guess, "--version"])
 
 
 def default_cross_toolchain():
@@ -188,6 +191,9 @@ def default_cross_toolchain():
 
         if parsed_args.host_compiler_type == "gcc":
             default_cc, default_cxx, default_cpp = ("gcc", "g++", "cpp")
+        # FIXME: this should take values like `clang-9` and then look for
+        # clang-cpp-9, etc. Would alleviate the need to set the bindir on
+        # ubuntu/debian at least.
         elif parsed_args.host_compiler_type == "clang":
             default_cc, default_cxx, default_cpp = (
                 "clang", "clang++", "clang-cpp")
@@ -235,7 +241,5 @@ def default_cross_toolchain():
         shlex.quote(s) for s in [str(bmake_binary)] + bmake_args)
     debug("Running `env ", env_cmd_str, " ", make_cmd_str, "`", sep="")
     os.environ.update(new_env_vars)
-    if parsed_args.debug:
-        input("Press enter to continue...")
     os.chdir(str(source_root))
     os.execv(str(bmake_binary), [str(bmake_binary)] + bmake_args)