make.bash,bat,rc: use Go 1.20.6 instead of Go 1.17.13

This was missed in the update of the bootstrap toolchain
and should help people who don't set GOROOT_BOOTSTRAP
and instead assume these scripts will find the right one.

For #54265.

Change-Id: I37a0d0976006d13b73df00013780be5abf202e91
Reviewed-on: https://go-review.googlesource.com/c/go/+/512275
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Auto-Submit: Russ Cox <rsc@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>

Author: rsc

src/cmd/dist/README

@@ -4,24 +4,18 @@ As of Go 1.5, dist and other parts of the compiler toolchain are written
 in Go, making bootstrapping a little more involved than in the past.
 The approach is to build the current release of Go with an earlier one.
 
-The process to install Go 1.x, for x ≥ 20, is:
+The process to install Go 1.x, for x ≥ 22, is:
 
-1. Build cmd/dist with Go 1.17.13.
-2. Using dist, build Go 1.x compiler toolchain with Go 1.17.13.
+1. Build cmd/dist with Go 1.20.6.
+2. Using dist, build Go 1.x compiler toolchain with Go 1.20.6.
 3. Using dist, rebuild Go 1.x compiler toolchain with itself.
 4. Using dist, build Go 1.x cmd/go (as go_bootstrap) with Go 1.x compiler toolchain.
 5. Using go_bootstrap, build the remaining Go 1.x standard library and commands.
 
-NOTE: During the transition from the old C-based toolchain to the Go-based one,
-step 2 also builds the parts of the toolchain written in C, and step 3 does not
-recompile those.
+Because of backward compatibility, although the steps above say Go 1.20.6,
+in practice any release ≥ Go 1.20.6 but < Go 1.x will work as the bootstrap base.
+Releases ≥ Go 1.x are very likely to work as well.
 
-Because of backward compatibility, although the steps above say Go 1.17.13,
-in practice any release ≥ Go 1.17.13 but < Go 1.x will work as the bootstrap base.
+See golang.org/s/go15bootstrap for more details about the original bootstrap
+and https://go.dev/cl/54265 for details about later bootstrap version bumps.
 
-See golang.org/s/go15bootstrap for more details.
-
-Compared to Go 1.4 and earlier, dist will also take over much of what used to
-be done by make.bash/make.bat/make.rc and all of what used to be done by
-run.bash/run.bat/run.rc, because it is nicer to implement that logic in Go
-than in three different scripting languages simultaneously.

src/make.bash

@@ -67,14 +67,14 @@
 # timing information to this file. Useful for profiling where the
 # time goes when these scripts run.
 #
-# GOROOT_BOOTSTRAP: A working Go tree >= Go 1.17.13 for bootstrap.
+# GOROOT_BOOTSTRAP: A working Go tree >= Go 1.20.6 for bootstrap.
 # If $GOROOT_BOOTSTRAP/bin/go is missing, $(go env GOROOT) is
-# tried for all "go" in $PATH. By default, one of $HOME/go1.17.13,
-# $HOME/sdk/go1.17.13, or $HOME/go1.4, whichever exists, in that order.
+# tried for all "go" in $PATH. By default, one of $HOME/go1.20.6,
+# $HOME/sdk/go1.20.6, or $HOME/go1.4, whichever exists, in that order.
 # We still check $HOME/go1.4 to allow for build scripts that still hard-code
 # that name even though they put newer Go toolchains there.
 
-bootgo=1.17.13
+bootgo=1.20.6
 
 set -e
 

src/make.bat

@@ -85,7 +85,7 @@ for /f "tokens=*" %%g in ('where go 2^>nul') do (
 	)
 )
 
-set bootgo=1.17.13
+set bootgo=1.20.6
 if "x%GOROOT_BOOTSTRAP%"=="x" if exist "%HOMEDRIVE%%HOMEPATH%\go%bootgo%" set GOROOT_BOOTSTRAP=%HOMEDRIVE%%HOMEPATH%\go%bootgo%
 if "x%GOROOT_BOOTSTRAP%"=="x" if exist "%HOMEDRIVE%%HOMEPATH%\sdk\go%bootgo%" set GOROOT_BOOTSTRAP=%HOMEDRIVE%%HOMEPATH%\sdk\go%bootgo%
 if "x%GOROOT_BOOTSTRAP%"=="x" set GOROOT_BOOTSTRAP=%HOMEDRIVE%%HOMEPATH%\Go1.4

src/make.rc

@@ -51,7 +51,7 @@ fn nogoenv {
 	GO111MODULE=off GOENV=off GOOS=() GOARCH=() GOEXPERIMENT=() GOFLAGS=() $*
 }
 
-bootgo = 1.17.13
+bootgo = 1.20.6
 GOROOT = `{cd .. && pwd}
 goroot_bootstrap_set = 'true'
 if(! ~ $#GOROOT_BOOTSTRAP 1){