CODEWITHSUNDEEP
c++makefileraspberry-pi
WillzSawyer
WillzSawyer

Reputation: 133

{Makefile Error} "commands commence before first target. Stop."

I'm trying to produce a makefile for use with my Raspberry Pi, the intention is to use the Pi's camera board to detect faces with opencv. However I keep facing myself with the following error:

Makefile:12: *** commands commence before first target.  Stop.

I use the following makefile:

FLAGS = 'pkg-config --cflags opencv --libs opencv'
CC = g++
HOME = /home/pi
LDFLAGS_CAMCV = -L$(HOME)/git/robidouille/raspicam_cv -lraspicamcv
LDFLAGS_USER =-L$(HOME)/git/raspberrypi/userland/build/lib -lmmal_core -lmmal -$
LDFLAGS_FACE = -l$(HOME)/git/emobot/libfacere0.04
LDFLAGS = $(LDFLAGS_CAMCV) $(LDFLAGS_USER)  $(LDFLAGS_FACE)
INCLUDE = -I$(HOME)/git/robidouille/raspicam_cv
        $(CC) -o emobot_test.exe:  main.cpp $(INCLUDE) $(LDFLAGS)

LDFLAGS_CAMCV and LDFLAGS_USER are required for the raspicamcv library and INCLUDE is the associated header file. LDFLAGS_FACE is needed to detect faces in opencv2.3 as 2.4 is currently unsupported by the Pi.

I'm certain this error is incredibly trivial however clear documentation about makefiles is few and far between if anyone can provide a solution I would be grateful.

Upvotes: 1

Views: 14972

Answers (2)

Tim Seed
Tim Seed

Reputation: 5289

I had the same issue ...

I already have rules for check, test and build... but wanted to string them together...

Easy I thought... 

.DEFAULT_GOAL := fullcheck
    $(MAKE) check
    $(MAKE) test
    $(MAKE) build

But no commands commence before first target. Stop.

What I had omitted was, the name of the rule. It should be like this. 

.DEFAULT_GOAL := fullcheck
fullcheck:
    $(MAKE) check
    $(MAKE) test
    $(MAKE) build

Upvotes: 0

user3159253
user3159253

Reputation: 17455

Smth like:

FLAGS = 'pkg-config --cflags opencv --libs opencv'
CC = g++
HOME = /home/pi
LDFLAGS_CAMCV = -L$(HOME)/git/robidouille/raspicam_cv -lraspicamcv
LDFLAGS_USER =-L$(HOME)/git/raspberrypi/userland/build/lib -lmmal_core -lmmal -$
LDFLAGS_FACE = -l$(HOME)/git/emobot/libfacere0.04
LDFLAGS = $(LDFLAGS_CAMCV) $(LDFLAGS_USER)  $(LDFLAGS_FACE)
INCLUDE = -I$(HOME)/git/robidouille/raspicam_cv

all: emobot_test

emobot_test:
tab$(CC) -o emobot_test.exe  main.cpp $(INCLUDE) $(LDFLAGS)

<tab> is a literal keypress, donna how to insert it in the answer field.

Explanation:
$(CC) -o emobot_test... is a command which should be executed upon a target invocation.

all is the default target which is executed when you simply run make without parameters.

all depends on emobot_test target emobot_test doesn't depend on any target but always runs $(CC) -o emobot_test... for completion

Upvotes: 3

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