如何使用makefile将编译后的文件保存在单独的目录中？

Question

我正在 macos Ventura 13.2.1 上的 vscode 中使用以下 makefile 编译 FORTRAN90 代码。现在我想将编译期间生成的所有类型的文件（例如，MODS XML 或 *.mod、Unix 可执行文件或 *.exe、*.o）放在名为 Build 的单独文件夹中。有没有一种简单的方法可以编辑我的 makefile 以获得预期的结果？我尝试了 StackOverflow 中提供的一些相关答案，但没有一个对我有用。

# Compiler settings - Can be customized.
CC = gfortran
CPP = gfortran -cpp
CXXFLAGS = -g -O0 -Wall -Wextra -Wshadow -pedantic
LDFLAGS =

# Makefile settings - Can be customized.
APPNAME = myapp
EXT = .f90
SRCDIR = src
OBJDIR = obj

############## Do not change anything from here downwards! #############
SRC = $(wildcard $(SRCDIR)/*$(EXT))
OBJ = $(SRC:$(SRCDIR)/%$(EXT)=$(OBJDIR)/%.o)
DEP = $(OBJ:$(OBJDIR)/%.o=%.d)
# UNIX-based OS variables & settings
RM = rm
DELOBJ = $(OBJ)
# Windows OS variables & settings
DEL = del
EXE = .exe
WDELOBJ = $(SRC:$(SRCDIR)/%$(EXT)=$(OBJDIR)\\%.o)

########################################################################
####################### Targets beginning here #########################
########################################################################

all: $(APPNAME)

# Builds the app
$(APPNAME): $(OBJ)
$(CC) $(CXXFLAGS) -o $@ $^ $(LDFLAGS)

# Creates the dependecy rules
%.d: $(SRCDIR)/%$(EXT)
@$(CPP) $(CFLAGS) $< -MM -MT $(@:%.d=$(OBJDIR)/%.o) >$@

# Includes all .h files
-include $(DEP)

# Building rule for .o files and its .c/.cpp in combination with all .h
$(OBJDIR)/%.o: $(SRCDIR)/%$(EXT)
$(CC) $(CXXFLAGS) -o $@ -c $<

################### Cleaning rules for Unix-based OS ###################
# Cleans complete project
.PHONY: clean
clean:
   $(RM) $(DELOBJ) $(DEP) $(APPNAME)

# Cleans only all files with the extension .d
.PHONY: cleandep
cleandep:
  $(RM) $(DEP)

#################### Cleaning rules for Windows OS #####################
# Cleans complete project
.PHONY: clean
clean:
   $(DEL) $(WDELOBJ) $(DEP) $(APPNAME)$(EXE)

# Cleans only all files with the extension .d
.PHONY: cleandepw
cleandepw:
 $(DEL) $(DEP)