make yields “commands commence before first target” error

Question

I'm new to linux driver dev.

I'm writing helloworld driver.

here is the code:

#define MODULE
#define __KERNEL__
#include <module.h>
int init_module() 
{
 return 0;
}

void cleanup_module()
{
 return;
}

and here is makefile:

    CC=gcc
    MODFLAGS:= -O3 -Wall -DLINUX
    module.o: module.c
    $(CC) $(MODFLAGS) -c module.c

But when I run make command I have the following: makefile:3: * “commands commence before first target” error

whats wrong?

Are those spaces on the left margin in the makefile? Or tabs? — Beta, May 14 '12 at 18:18

score 8 · Accepted Answer · answered May 14 '12 at 18:27

8

Remove the leading tabs in the makefile, from every line that isn't a command:

CC=gcc
MODFLAGS:= -O3 -Wall -DLINUX
module.o: module.c
    $(CC) $(MODFLAGS) -c module.c

answered May 14 '12 at 18:27

Beta

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score 2 · Answer 2 · answered Mar 05 '13 at 04:46

Although this wasn't the case for you, I encountered the same error message with a different reason. So I am answering here as well so that it may aid people in the future when they encounter the error message but the reason isn't as obvious as in your case.

Here's a minimal example to provoke the error condition by merely having a file with an equal sign in its name match the $(wildcard) (obviously here for demonstration purposes I am matching only file names with a =). Strictly speaking it doesn't matter what method you use to retrieve the names for the $(FILES) variable.

FILES := $(wildcard ./*=*)

.PHONY: all

define foo
all: something-$(1)
something-$(1): $(1)
    cat $$^ > $$@
endef

$(foreach goal,$(sort $(FILES)),$(eval $(call foo,$(goal))))

The problem appears to be in the way the expansion happens - in this case and it will only happen due to the macro.

Anyway, I was stumped when I ended up with this error message while the make file itself - also according to version control - hadn't changed. Until it dawned on me that there must be some circumstantial reason for the problem then. May it help the future person in search for an answer.

make yields “commands commence before first target” error

2 Answers2