c - MakeFile - 当目标通过时避免某些文件

Question

我正在尝试创建一个避免某些 c 文件的目标。我这样做是因为某些文件不兼容并且希望在构建过程中避免它们。波纹管是我正在使用的方法，但这样做会引起争议warning: overriding commands for target ... 。我确实了解错误的原因，但不知道更好的方法。请指导我，我是 MakeFiles 新手。提前致谢

SRCDIR = ../src
BUILDDIR = build
INCDIR = ../inc

# Compiler to use
CC = gcc

# Include paths for header files
INCLUDES = -I $(INCDIR)

# Compiler flags
# WARNING: Optimization will remove critical code (Problems seen in delay function). Use with caution.
CFLAGS = -Wall -Wextra -g $(INCLUDES) --std=gnu99
CFLAGSNOWARN = -g $(INCLUDES) --std=gnu99

# extra gcc flags used to build dependency files
DEPFLAGS = -MMD -MP

# Paths to required libraries (-L flags)
LFLAGS =

# The specific libraries that project depends on (-l flags)
LIBS = -lreadline -lpthread

# All source files
SRCS = $(wildcard $(SRCDIR)/*.c)
SRCS_1 = $(filter-out $(SRCDIR)/FileToAvoid.c, $(wildcard $(SRCDIR)/*.c))

# All object files
OBJS := $(SRCS:$(SRCDIR)/%.c=%.o)
OBJS_1 := $(SRCS_1:$(SRCDIR)/%.c=%.o)

# name of executable
MAIN = test.exe

# make all
.PHONY: all

# this is the default target
## create temporary .o files and compile main executable
all: $(MAIN)

avoidfile: $(OBJS_1)
    @echo "Compiling executable: $(MAIN)"
    @$(CC) $(CFLAGS) -o $(MAIN) $(OBJS_1) $(LFLAGS) $(LIBS)
    @echo

$(MAIN): $(OBJS)
    @echo "Compiling executable: $(MAIN)"
    @$(CC) $(CFLAGS) -o $(MAIN) $(OBJS) $(LFLAGS) $(LIBS)
    @echo

# Automatically builds all object files from source files
# -c option compiles but does not link (create object files)
# -o is output filename
$(OBJS): %.o : $(SRCDIR)/%.c
    @echo "Compiling object file: $@"
    @$(CC) $(CFLAGS) $(DEPFLAGS) -c $< -o $@
    @echo

$(OBJS_1): %.o : $(SRCDIR)/%.c 
    @echo "Compiling object fileslean: $@"
    @$(CC) $(CFLAGS) $(DEPFLAGS) -c $< -o $@
    @echo

Answer 1

由于要编译的两个规则相同，因此您可以制定一个规则:

$(sort $(OBJS) $(OBJS_1)): %.o : $(SRCDIR)/%.c 
    echo "Compiling object file: $@"
    $(CC) $(CFLAGS) $(DEPFLAGS) -c $< -o $@

sort 函数可以删除重复项，即使您不关心排序，也建议用于此目的。

您可能认为双冒号规则可能有帮助，但要小心!这些配方全部都被执行，导致相同源的多次编译。