Makefile无法正常工作

[wurui1994]

在Manjaro上会报错：
[wurui@computer light2d]$ make
cc basic.c -o basic
/tmp/ccb1Fj9Q.o：在函数‘circleSDF’中：
basic.c:(.text+0x104e)：对‘sqrtf’未定义的引用
/tmp/ccb1Fj9Q.o：在函数‘sample’中：
basic.c:(.text+0x1189)：对‘sinf’未定义的引用
basic.c:(.text+0x119e)：对‘cosf’未定义的引用
/tmp/ccb1Fj9Q.o：在函数‘main’中：
basic.c:(.text+0x1264)：对‘fminf’未定义的引用
collect2: 错误：ld 返回 1
make: *** [<内置>：basic] 错误 1

必须要改成这样，才能正常工作：
TARGETS=basic csg
OUTPUTS=$(addsuffix .png, $(TARGETS))

all: $(TARGETS)
test: $(TARGETS) $(OUTPUTS)

%: %.c
gcc -lm -Wall -O3 -o $@ $&lt;

%.png: %
sh -c "time ./$<"

clean:
rm $(TARGETS) *.png

[leinlin]

用Unity 把算法 依葫芦画瓢的搞了一个下来，makefile文盲可以来试试看
https://github.com/ElPsyCongree/light2d_for_unity

[miloyip]

@wurui1994 感觉这是平台的问题。例子代码都只使用了 C99 标准库。

[kimci86]

I had a similar issue because of a small mistake in the makefile : %.: %.c should be %: %.c (notice the dot). Then I had to add the -lm flag for gcc.

[micfan]

gcc (GCC) 8.2.1 20181127 compile error, how to solve it?

gcc -Wall -O3 -o csg csg.c
/usr/bin/ld: /tmp/ccv6tJMs.o: in function `circleSDF':
csg.c:(.text+0xa1a): undefined reference to `sqrtf'
/usr/bin/ld: /tmp/ccv6tJMs.o: in function `scene':
csg.c:(.text+0xc03): undefined reference to `sqrtf'
/usr/bin/ld: csg.c:(.text+0xc30): undefined reference to `sqrtf'
/usr/bin/ld: /tmp/ccv6tJMs.o: in function `trace':
csg.c:(.text+0xd8b): undefined reference to `sqrtf'
/usr/bin/ld: csg.c:(.text+0xe2d): undefined reference to `sqrtf'
/usr/bin/ld: /tmp/ccv6tJMs.o: in function `sample':
csg.c:(.text+0xf0d): undefined reference to `sincosf'
/usr/bin/ld: csg.c:(.text+0x1053): undefined reference to `sqrtf'
/usr/bin/ld: csg.c:(.text+0x10a6): undefined reference to `sqrtf'
/usr/bin/ld: /tmp/ccv6tJMs.o: in function `main':
csg.c:(.text.startup+0x63): undefined reference to `fminf'
collect2: error: ld returned 1 exit status
make: *** [makefile:11: csg] Error 1