build: implement platform-agnostic build system

- Split Makefile into gmake.mk (Linux/Windows) and bmake.mk (BSD/macOS)
- Added config.mk for shared variables.
- Added build.sh and build.bat dispatchers.
- Retains old build behavior with dependency tracking.

Makefile

@@ -1,74 +0,0 @@
-SRC_DIR = src
-INC_DIR = include
-OBJ_DIR = obj
-BIN_DIR = bin
-
-CC = cc
-CFLAGS_DEBUG = -g -O0 -Wall -Wpedantic -I$(INC_DIR) -std=c89 -fPIC
-CFLAGS_RELEASE = -O2 -Wall -Wpedantic -I$(INC_DIR) -std=c89 -fPIC
-LDFLAGS = -ldl
-
-LIB_NAME = libstk.so
-
-OBJS_DEBUG = \
-	$(OBJ_DIR)/debug/module.o \
-	$(OBJ_DIR)/debug/platform.o \
-	$(OBJ_DIR)/debug/stk.o \
-	$(OBJ_DIR)/debug/stk_log.o
-
-OBJS_RELEASE = \
-	$(OBJ_DIR)/release/module.o \
-	$(OBJ_DIR)/release/platform.o \
-	$(OBJ_DIR)/release/stk.o \
-	$(OBJ_DIR)/release/stk_log.o
-
-.PHONY: all debug release clean
-
-all: debug
-
-debug: $(BIN_DIR)/debug/$(LIB_NAME)
-
-release: $(BIN_DIR)/release/$(LIB_NAME)
-
-$(BIN_DIR)/debug/$(LIB_NAME): $(OBJS_DEBUG)
-	@mkdir -p $(BIN_DIR)/debug
-	$(CC) -shared -o $@ $(OBJS_DEBUG) $(LDFLAGS)
-
-$(BIN_DIR)/release/$(LIB_NAME): $(OBJS_RELEASE)
-	@mkdir -p $(BIN_DIR)/release
-	$(CC) -shared -o $@ $(OBJS_RELEASE) $(LDFLAGS)
-
-$(OBJ_DIR)/debug/module.o: $(SRC_DIR)/module.c
-	@mkdir -p $(OBJ_DIR)/debug
-	$(CC) $(CFLAGS_DEBUG) -c $(SRC_DIR)/module.c -o $@
-
-$(OBJ_DIR)/debug/platform.o: $(SRC_DIR)/platform.c
-	@mkdir -p $(OBJ_DIR)/debug
-	$(CC) $(CFLAGS_DEBUG) -c $(SRC_DIR)/platform.c -o $@
-
-$(OBJ_DIR)/debug/stk.o: $(SRC_DIR)/stk.c
-	@mkdir -p $(OBJ_DIR)/debug
-	$(CC) $(CFLAGS_DEBUG) -c $(SRC_DIR)/stk.c -o $@
-
-$(OBJ_DIR)/debug/stk_log.o: $(SRC_DIR)/stk_log.c
-	@mkdir -p $(OBJ_DIR)/debug
-	$(CC) $(CFLAGS_DEBUG) -c $(SRC_DIR)/stk_log.c -o $@
-
-$(OBJ_DIR)/release/module.o: $(SRC_DIR)/module.c
-	@mkdir -p $(OBJ_DIR)/release
-	$(CC) $(CFLAGS_RELEASE) -c $(SRC_DIR)/module.c -o $@
-
-$(OBJ_DIR)/release/platform.o: $(SRC_DIR)/platform.c
-	@mkdir -p $(OBJ_DIR)/release
-	$(CC) $(CFLAGS_RELEASE) -c $(SRC_DIR)/platform.c -o $@
-
-$(OBJ_DIR)/release/stk.o: $(SRC_DIR)/stk.c
-	@mkdir -p $(OBJ_DIR)/release
-	$(CC) $(CFLAGS_RELEASE) -c $(SRC_DIR)/stk.c -o $@
-
-$(OBJ_DIR)/release/stk_log.o: $(SRC_DIR)/stk_log.c
-	@mkdir -p $(OBJ_DIR)/release
-	$(CC) $(CFLAGS_RELEASE) -c $(SRC_DIR)/stk_log.c -o $@
-
-clean:
-	@rm -rf $(OBJ_DIR) $(BIN_DIR)

bmake.mk

@@ -0,0 +1,40 @@
+.include "config.mk"
+
+FULL_LIB     = lib${LIB_NAME}.so
+LDFLAGS_PLAT = -ldl
+CFLAGS_PLAT  = -fPIC
+CFLAGS_BASE  = -Wall -Wpedantic -I${INC_DIR} -std=c89 ${CFLAGS_PLAT}
+
+.PHONY: all debug release clean
+
+all: debug
+
+OBJS_DEBUG   = ${SRCS:S/^src\//obj\/debug\//:S/.c$/.o/}
+OBJS_RELEASE = ${SRCS:S/^src\//obj\/release\//:S/.c$/.o/}
+
+debug: ${BIN_DIR}/debug/${FULL_LIB}
+release: ${BIN_DIR}/release/${FULL_LIB}
+
+${BIN_DIR}/debug/${FULL_LIB}: ${OBJS_DEBUG}
+	@mkdir -p ${.TARGET:H}
+	${CC} -shared -o ${.TARGET} ${.ALLSRC} ${LDFLAGS_PLAT}
+
+${BIN_DIR}/release/${FULL_LIB}: ${OBJS_RELEASE}
+	@mkdir -p ${.TARGET:H}
+	${CC} -shared -o ${.TARGET} ${.ALLSRC} ${LDFLAGS_PLAT}
+
+.for _src in ${SRCS}
+obj/debug/${_src:T:R}.o: ${_src}
+	@mkdir -p ${.TARGET:H}
+	${CC} ${CFLAGS_BASE} -g -O0 -MMD -MP -c ${_src} -o ${.TARGET}
+
+obj/release/${_src:T:R}.o: ${_src}
+	@mkdir -p ${.TARGET:H}
+	${CC} ${CFLAGS_BASE} -O2 -MMD -MP -c ${_src} -o ${.TARGET}
+.endfor
+
+.dinclude "obj/debug/*.d"
+.dinclude "obj/release/*.d"
+
+clean:
+	rm -rf ${OBJ_DIR} ${BIN_DIR}

build.bat

@@ -0,0 +1,2 @@
+@echo off
+make -f gmake.mk %*

build.sh

@@ -0,0 +1,11 @@
+#!/bin/sh
+
+OS=$(uname -s | tr '[:upper:]' '[:lower:]')
+
+if [ "$OS" = "linux" ]; then
+	MK_FILE="gmake.mk"
+else
+	MK_FILE="bmake.mk"
+fi
+
+make -f "$MK_FILE" "$@"

config.mk

@@ -0,0 +1,11 @@
+SRC_DIR = src
+INC_DIR = include
+OBJ_DIR = obj
+BIN_DIR = bin
+
+LIB_NAME = stk
+
+SRCS = src/module.c \
+       src/platform.c \
+       src/stk.c \
+       src/stk_log.c

gmake.mk

@@ -0,0 +1,43 @@
+include config.mk
+
+ifeq ($(OS),Windows_NT)
+    FULL_LIB := $(LIB_NAME).dll
+    LDFLAGS_PLAT := -ldl
+else
+    FULL_LIB := lib$(LIB_NAME).so
+    LDFLAGS_PLAT := -ldl
+    CFLAGS_PLAT := -fPIC
+endif
+
+CFLAGS_BASE := -Wall -Wpedantic -I$(INC_DIR) -std=c89 $(CFLAGS_PLAT)
+
+.PHONY: all debug release clean
+
+all: debug
+
+debug: $(BIN_DIR)/debug/$(FULL_LIB)
+release: $(BIN_DIR)/release/$(FULL_LIB)
+
+# Debug Rules
+$(BIN_DIR)/debug/$(FULL_LIB): $(SRCS:src/%.c=obj/debug/%.o)
+	@mkdir -p $(@D)
+	$(CC) -shared -o $@ $^ $(LDFLAGS_PLAT)
+
+obj/debug/%.o: src/%.c
+	@mkdir -p $(@D)
+	$(CC) $(CFLAGS_BASE) -g -O0 -MMD -MP -c $< -o $@
+
+# Release Rules
+$(BIN_DIR)/release/$(FULL_LIB): $(SRCS:src/%.c=obj/release/%.o)
+	@mkdir -p $(@D)
+	$(CC) -shared -o $@ $^ $(LDFLAGS_PLAT)
+
+obj/release/%.o: src/%.c
+	@mkdir -p $(@D)
+	$(CC) $(CFLAGS_BASE) -O2 -MMD -MP -c $< -o $@
+
+-include $(wildcard obj/debug/*.d)
+-include $(wildcard obj/release/*.d)
+
+clean:
+	rm -rf $(OBJ_DIR) $(BIN_DIR)