code review 5608059: build: dist-based build for Plan 9

src/make.rc

 #!/bin/rc -e
 # Copyright 2012 The Go Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style
 # license that can be found in the LICENSE file.
 
-rfork en
+# Environment variables that control make.rc:
+#
+# GOROOT_FINAL: The expected final Go root, baked into binaries.
+# The default is the location of the Go tree during the build.
+#
+# GOHOSTARCH: The architecture for host tools (compilers and
+# binaries).  Binaries of this type must be executable on the current
+# system, so the only common reason to set this is to set
+# GOHOSTARCH=386 on an amd64 machine.
+#
+# GOARCH: The target architecture for installed packages and tools.
+#
+# GOOS: The target operating system for installed packages and tools.
+#
+# GO_GCFLAGS: Additional 5g/6g/8g arguments to use when
+# building the packages and commands.
+#
+# GO_LDFLAGS: Additional 5l/6l/8l arguments to use when
+# building the commands.
+#
+# CGO_ENABLED: Setting this to 0 disables the use of cgo
+# in the built and installed packages and tools.
 
+rfork e
 if(! test -f run.bash){
         echo 'make.rc must be run from $GOROOT/src' >[1=2]
         exit wrongdir
 }
 
-switch($objtype){
-case arm
-        O = 5
-case amd64
-        O = 6
-case 386
-        O = 8
-case *
-        echo 'unknown $objtype:' $objtype >[1=2]
-        exit objtype
+# Clean old generated file that will cause problems in the build.
+rm -rf ./pkg/runtime/runtime_defs.go
+
+# Determine the host compiler toolchain.
+eval `{grep '^(CC|LD|O)=' /$objtype/mkfile}
+
+echo '# Building C bootstrap tool.'
+echo cmd/dist
+GOROOT = `{cd .. && pwd}
+if(! ~ $#GOROOT_FINAL 1)
+        GOROOT_FINAL = $GOROOT
+DEFGOROOT='-DGOROOT_FINAL="'$GOROOT_FINAL'"'
+
+for(i in cmd/dist/*.c)
+        $CC -FTVwp+ -DPLAN9 $DEFGOROOT $i
+$LD -o cmd/dist/dist *.$O
+rm *.$O
+
+eval `{./cmd/dist/dist env -9}
+echo
+
+if(~ $1 --dist-tool){
+        # Stop after building dist tool.
+        mkdir -p $GOTOOLDIR
+        if(! ~ $2 '')
+                cp cmd/dist/dist $2
+        mv cmd/dist/dist $GOTOOLDIR/dist
+        exit
 }
 
-# The go tool will be installed here.
-if(! ~ $#GOBIN 1)
-        GOBIN = /$objtype/bin
-
-echo '# Building C bootstrap tool.'
-mkdir -p ../bin/tool
-@{
-        cd ../bin/tool
-        for(i in ../../src/cmd/dist/*.c)
-                $O^c -FTVwp+ -DPLAN9 -DDEFAULT_GOROOT'="'$GOROOT'"' $i
-        $O^l -o dist *.$O
-        rm -f *.$O
-}
-echo
-
-echo '# Building compilers and Go bootstrap tool.'
-../bin/tool/dist bootstrap -v # builds go_bootstrap
+echo '# Building compilers and Go bootstrap tool for host,' $GOHOSTOS/$GOHOSTARCH^.
+buildall = -a
+if(~ $1 --no-clean)
+        buildall = ()
+./cmd/dist/dist bootstrap $buildall -v # builds go_bootstrap
+# Delay move of dist tool to now, because bootstrap may clear tool directory.
+mv cmd/dist/dist $GOTOOLDIR/dist
+$GOTOOLDIR/go_bootstrap clean -i std
 echo
 
 # TODO(ality): remove the -p flag once the exec/await/RFNOTEG race is fixed.
 
-echo '# Building packages and commands.'
-../bin/tool/go_bootstrap clean std
-../bin/tool/go_bootstrap install -a -v -p 1 std
-rm -f ../bin/tool/go_bootstrap
+if(! ~ $GOHOSTARCH $GOARCH || ! ~ $GOHOSTOS $GOOS){
+        echo '# Building packages and commands for host,' $GOHOSTOS/$GOHOSTARCH^.
+        GOOS=$GOHOSTOS GOARCH=$GOHOSTARCH \
+                $GOTOOLDIR/go_bootstrap install -gcflags $"GO_GCFLAGS -ldflags $"GO_LDFLAGS -v -p 1 std
+        echo
+}
+
+echo '# Building packages and commands for' $GOOS/$GOARCH^.
+$GOTOOLDIR/go_bootstrap install -gcflags $"GO_GCFLAGS -ldflags $"GO_LDFLAGS -v -p 1 std
 echo
 
-if(~ $1 --no-banner)
-        shift
-if not
-        ../bin/tool/dist banner
+rm -f $GOTOOLDIR/go_bootstrap
+
+if(! ~ $1 --no-banner)
+        $GOTOOLDIR/dist banner