Avoid the need to set MINGW32 or MINGW64 environment variables when using a standard MSYS environment on Windows.

Author: cuavas

.github/workflows/ci-windows.yml

@@ -31,7 +31,6 @@ jobs:
             os: windows-latest
             msys: MINGW64
             slug: mingw-w64-x86_64
-            root: "/mingw64"
             cc: gcc
             cxx: g++
             subtarget: mame
@@ -40,7 +39,6 @@ jobs:
             os: windows-latest
             msys: MINGW64
             slug: mingw-w64-x86_64
-            root: "/mingw64"
             cc: clang
             cxx: clang++
             subtarget: tiny
@@ -50,7 +48,6 @@ jobs:
             msys: CLANGARM64
             slug: mingw-w64-clang-aarch64
             extrapkg: mingw-w64-clang-aarch64-gcc-compat
-            root: "/clangarm64"
             cc: clang
             cxx: clang++
             subtarget: mame
@@ -69,7 +66,6 @@ jobs:
         fetch-depth: 0
     - name: Build
       env:
-        MINGW64: ${{ matrix.root }}
         OVERRIDE_AR: "llvm-ar"
         OVERRIDE_CC: ${{ matrix.cc }}
         OVERRIDE_CXX: ${{ matrix.cxx }}

docs/source/initialsetup/compilingmame.rst

@@ -150,14 +150,8 @@ with MSYS2 and the **pacman** package manager.
 * To generate API documentation from source, you’ll need ``doxygen``.
 * If you plan to rebuild bgfx shaders and you want to rebuild the GLSL parser,
   you’ll need ``bison``.
-* For 64-bit builds, open **MSYS2 MinGW 64-bit** from the start menu, and set
-  up the environment variables ``MINGW64`` to ``/mingw64`` and ``MINGW32`` to an
-  empty string (e.g. using the command **export MINGW64=/mingw64 MINGW32=** in
-  the Bash shell).
-* For 32-bit builds, open **MSYS2 MinGW 32-bit** from the start menu, and set
-  up the environment variables ``MINGW32`` to ``/mingw32`` and ``MINGW64`` to an
-  empty string (e.g. using the command **export MINGW32=/mingw32 MINGW64=** in
-  the Bash shell).
+* For 64-bit builds, open **MSYS2 MinGW 64-bit** from the start menu.
+* For 32-bit builds, open **MSYS2 MinGW 32-bit** from the start menu.
 
 For example you could use these commands to ensure you have the packages you
 need to compile MAME, omitting the ones for configurations you don’t plan to

makefile

@@ -234,12 +234,28 @@ $(error Unable to detect OS from uname -a: $(UNAME))
 endif
 endif
 
-MINGW:=
+ifdef MSYSTEM
+MINGW := $(MINGW_PREFIX)
+ifeq ($(MSYSTEM),MINGW32)
+	MINGW32 := $(MINGW_PREFIX)
+endif
+ifeq ($(MSYSTEM),MINGW64)
+	MINGW64 := $(MINGW_PREFIX)
+endif
+ifeq ($(MSYSTEM),CLANGARM64)
+	MINGW64 := $(MINGW_PREFIX)
+endif
+ifndef TOOLCHAIN
+	TOOLCHAIN := $(MINGW_PREFIX)/bin/
+endif
+else # MSYSTEM
+MINGW :=
 ifdef MINGW64
 	MINGW := $(MINGW64)
-else
+else # MINGW64
 	MINGW := $(MINGW32)
-endif
+endif # MINGW64
+endif # MSYSTEM
 
 #-------------------------------------------------
 # specify core target: mame, ldplayer

scripts/toolchain.lua

@@ -163,10 +163,10 @@ function toolchain(_buildDir, _subDir)
 		end
 
 		if "mingw32-gcc" == _OPTIONS["gcc"] then
-			if not os.getenv("MINGW32") then
-				print("Set MINGW32 envrionment variable.")
-			end
 			if toolchainPrefix == nil or toolchainPrefix == "" then
+				if not os.getenv("MINGW32") then
+					print("Set MINGW32 envrionment variable.")
+				end
 				toolchainPrefix = "$(MINGW32)/bin/i686-w64-mingw32-"
 			end
 			premake.gcc.cc  = toolchainPrefix .. "gcc"
@@ -176,10 +176,10 @@ function toolchain(_buildDir, _subDir)
 		end
 
 		if "mingw64-gcc" == _OPTIONS["gcc"] then
-			if not os.getenv("MINGW64") then
-				print("Set MINGW64 envrionment variable.")
-			end
 			if toolchainPrefix == nil or toolchainPrefix == "" then
+				if not os.getenv("MINGW64") then
+					print("Set MINGW64 envrionment variable.")
+				end
 				toolchainPrefix = "$(MINGW64)/bin/x86_64-w64-mingw32-"
 			end
 			premake.gcc.cc  = toolchainPrefix .. "gcc"