帮我写一个makefile文件。我有一个程序叫parser，遍历test文件夹下所有xxx.cmm都运行./parser xxx.cmm

Sure, here's a sample makefile that should work for you:

CC=gcc
CFLAGS=-Wall -Wextra -pedantic -std=c99

SRCDIR=./test
OBJDIR=./obj
BINDIR=./bin

SRCS=$(wildcard $(SRCDIR)/*.cmm)
OBJS=$(patsubst $(SRCDIR)/%.cmm,$(OBJDIR)/%.o,$(SRCS))
BINS=$(patsubst $(SRCDIR)/%.cmm,$(BINDIR)/%,$(SRCS))

.PHONY: all clean

all: $(BINS)

$(BINDIR)/%: $(OBJDIR)/%.o
	$(CC) $(CFLAGS) $< -o $@

$(OBJDIR)/%.o: $(SRCDIR)/%.cmm
	$(CC) $(CFLAGS) -c $< -o $@

clean:
	rm -f $(OBJS) $(BINS)

You can save this as a file named `Makefile` in the same directory as your `parser` program and the `test` folder. Then, simply run `make` in the terminal to compile all the `xxx.cmm` files in the `test` folder and generate corresponding executables in the `bin` folder.