reuse config/build_config.txt for all bootstrap scripts (posix + windows + ci); use build_all.bat in 1 CI, fix bug in build_all.bat (#17899)

* reuse config/build_config.txt for all bootstrap scripts (posix + windows + ci)
* ci_docs: use build_all.bat in CI (just in that pipeline) to ensure it keeps working
* fixup
* fix pre-existing bug in build_all.bat
* fixup
* cp => copy /y
* auto-generate build_all.bat, build_all.sh
* fixup

tools/ci_generate.nim

@@ -12,9 +12,10 @@ nim r tools/ci_generate.nim
 
 import std/[strformat, os]
 
+const doNotEdit = "DO NO EDIT DIRECTLY! auto-generated by `nim r tools/ci_generate.nim`"
 proc genCiBsd(header: string, batch: int, num: int): string =
   result = fmt"""
-## DO NO EDIT DIRECTLY! auto-generated by `nim r tools/ci_generate.nim`
+## {doNotEdit}
 
 {header}
 
@@ -43,6 +44,64 @@ triggers:
   to: Andreas Rumpf <rumpf_a@web.de>
 """
 
+proc genBuildExtras(echoRun, koch, nim: string): string =
+  result = fmt"""
+{echoRun} {nim} c --skipUserCfg --skipParentCfg --hints:off koch
+{echoRun} {koch} boot -d:release --skipUserCfg --skipParentCfg --hints:off
+{echoRun} {koch} tools --skipUserCfg --skipParentCfg --hints:off
+"""
+
+proc genWindowsScript(buildAll: bool): string =
+  result = fmt"""
+@echo off
+rem {doNotEdit}
+rem Build development version of the compiler; can be rerun safely
+rem bare bones version of ci/funs.sh adapted for windows.
+
+rem Read in some common shared variables (shared with other tools),
+rem see https://stackoverflow.com/questions/3068929/how-to-read-file-contents-into-a-variable-in-a-batch-file
+for /f "delims== tokens=1,2" %%G in (config/build_config.txt) do set %%G=%%H
+SET nim_csources=bin\nim_csources_%nim_csourcesHash%.exe
+echo "building from csources: %nim_csources%"
+
+if not exist %nim_csourcesDir% (
+  git clone -q --depth 1 %nim_csourcesUrl% %nim_csourcesDir%
+)
+
+if not exist %nim_csources% (
+  cd %nim_csourcesDir%
+  git checkout %nim_csourcesHash%
+  echo "%PROCESSOR_ARCHITECTURE%"
+  if "%PROCESSOR_ARCHITECTURE%"=="AMD64" (
+    SET ARCH=64
+  )
+  CALL build.bat
+  cd ..
+  copy /y bin\nim.exe  %nim_csources%
+)
+"""
+
+  if buildAll:
+    result.add genBuildExtras("", "koch", r"bin\nim.exe")
+
+proc genPosixScript(): string =
+  result = fmt"""
+#! /bin/sh
+rem {doNotEdit}
+
+# build development version of the compiler; can be rerun safely.
+# arguments can be passed, e.g.:
+# CC=gcc ucpu=amd64 uos=darwin
+
+set -u # error on undefined variables
+set -e # exit on first error
+
+. ci/funs.sh
+nimBuildCsourcesIfNeeded "$@"
+
+{genBuildExtras("echo_run", "./koch", "bin/nim")}
+"""
+
 proc main()=
   let dir = ".builds"
   # not too large to be resource friendly, refs bug #17107
@@ -74,9 +133,13 @@ packages:
 - sdl2
 - libffi
 """
+
   for i in 0..<num:
     writeFile(dir / fmt"openbsd_{i}.yml", genCiBsd(headerOpenbsd, i, num))
   writeFile(dir / "freebsd.yml", genCiBsd(headerFreebsd, 0, 1))
+  writeFile("build_all.sh", genPosixScript())
+  writeFile("build_all.bat", genWindowsScript(buildAll = true))
+  writeFile("ci/build_autogen.bat", genWindowsScript(buildAll = false))
 
 when isMainModule:
   main()