From e109400748a62f142d0b1ca6957dab69ca411de1 Mon Sep 17 00:00:00 2001
From: Nobuyoshi Nakada <nobu@ruby-lang.org>
Date: Fri, 27 Dec 2024 16:26:14 +0900
Subject: [PATCH] Win32: Fix sub make commands

`cmd.exe` built-in `cd` does not recognize slashes as path separators,
replace to backslashes.
---
 ext/extmk.rb          | 6 +++---
 template/exts.mk.tmpl | 8 +++++---
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/ext/extmk.rb b/ext/extmk.rb
index 8b6b365a99..30ae56e095 100755
--- a/ext/extmk.rb
+++ b/ext/extmk.rb
@@ -817,9 +817,9 @@ begin
     if $gnumake == "yes"
       submake = "$(MAKE) -C $(@D)"
     else
-      submake = "cd $(@D) && "
-      config_string("exec") {|str| submake << str << " "}
-      submake << "$(MAKE)"
+      submake = ["cd", (sep ? "$(@D:/=#{sep})" : "$(@D)"), "&&"]
+      config_string("exec") {|str| submake << str}
+      submake = (submake << "$(MAKE)").join(" ")
     end
     targets.each do |tgt|
       exts.each do |d|
diff --git a/template/exts.mk.tmpl b/template/exts.mk.tmpl
index 0abbca1f06..e482808f54 100644
--- a/template/exts.mk.tmpl
+++ b/template/exts.mk.tmpl
@@ -110,12 +110,14 @@ def self.column
   w
 end
 objext = RbConfig::CONFIG["OBJEXT"]
+sep = RbConfig::CONFIG['BUILD_FILE_SEPARATOR']
+sep = nil if sep and sep.empty?
 if gnumake
   submake = "$(MAKE) -C $(@D)"
 else
-  submake = "cd $(@D) && "
-  exec = RbConfig::CONFIG["exec"] and !exec.empty? and submake << exec << " "
-  submake << "$(MAKE)"
+  submake = ["cd", (sep ? "$(@D:/=#{sep})" : "$(@D)"), "&&"]
+  exec = RbConfig::CONFIG["exec"] and !exec.empty? and submake << exec
+  submake = (submake << "$(MAKE)").join(" ")
   mflags = " $(MFLAGS)"
 end
 -%>