Adjust build for Linux

Makefile

@@ -1,20 +1,17 @@
 
 VERBOSE_BUILD := false
 
-IsMinGW := $(findstring MINGW,$(shell uname -s)) $(findstring MSYS,$(shell uname -s))
-IsDarwin := $(findstring Darwin,$(shell uname -s))
-ifneq (,$(IsMinGW))
+HOST_ARCH   := 
+HOST_OS     := $(shell uname -o )
+HOST_KERNEL := $(shell uname -s )
+ifeq ($(HOST_OS),Msys)
 	HOST_ARCH := mingw
-else
-ifneq (,$(IsDarwin))
-	HOST_ARCH := macosx
-else
+endif
+ifeq ($(HOST_KERNEL),Linux)
 	HOST_ARCH := linux
 endif
-endif
-
-ifeq ($(arch),emscripten)
-	HOST_ARCH := emscripten
+ifeq ($(HOST_KERNEL),Darwin)
+	HOST_ARCH := macosx
 endif
 
 
@@ -31,7 +28,7 @@ ifeq ($(HOST_ARCH),mingw)
 	LDFLAGS := -g -mwindows -D_GNU_SOURCE=1
 
 	RES_GAMELIB := libgame.a
-	BUILDDIR    := build-$(shell gcc -v 2>&1 | grep "Target:" | cut --delimiter=' ' --fields=2)
+	BUILDDIR    := build-$(shell gcc -dumpmachine )
 endif
 ifeq ($(HOST_ARCH),linux)
 	CC       := gcc
@@ -47,7 +44,7 @@ ifeq ($(HOST_ARCH),linux)
 
 	RES_GAMELIB := libgame.a
 	RES_GAME    := game
-	BUILDDIR    := build-$(shell gcc -v 2>&1 | grep "Target:" | cut --delimiter=' ' --fields=2)
+	BUILDDIR    := build-$(shell gcc -dumpmachine )
 endif
 ifeq ($(HOST_ARCH),macosx)
 	CC       := gcc
@@ -62,18 +59,15 @@ ifeq ($(HOST_ARCH),macosx)
 	LDFLAGS :=
 
 	RES_GAMELIB := libgame.a
-	BUILDDIR    := build-$(shell gcc -v 2>&1 | grep "Target:" | cut -d ' ' -f 2)
+	BUILDDIR    := build-$(shell gcc -dumpmachine )
 endif
-ifeq ($(HOST_ARCH),emscripten)
+ifeq ($(arch),emscripten)
 	CC       := emcc
 	AR       := emar
 	LAUNCHER := emrun --port 8080
-	RM       := rm -rf
-	MKDIR    := mkdir
-	ECHO     := echo
 
 	LIBS    := 
-	CFLAGS  := -s FULL_ES2=1 -s ASM_JS=1 -s USE_SDL=2 -O2 -Wno-implicit-function-declaration -DEMSCRIPTEN
+	CFLAGS  := -s USE_SDL=2 -O2 -Wno-implicit-function-declaration -DEMSCRIPTEN
 	LDFLAGS := --preload-file data -s TOTAL_MEMORY=134217728 -lidbfs.js
 
 	RES_GAMELIB := libgame.a