CODEWITHSUNDEEP
c++cgccmakefile
jamie_y
jamie_y

Reputation: 1919

Makefile: error running 'make all'

When I run the same gcc command specified in my make all rule, I get no error. But when I run make all, I get a bunch of errors. Why is this happening?

Makefile:

all: program.c
      gcc -I$HOME/ffmpeg/include program.c -L$HOME/ffmpeg/lib -lswscale -lavdevice -lavfilter -lswscale -lswresample -lavformat -lavcodec -lavutil -lz -lm -lpthread -o program

Running the gcc command:

 (No error)

Running make all:

gcc -IOME/ffmpeg/include program.c -LOME/ffmpeg/lib -lswscale -lavdevice -lavfilter -lswscale -lswresample -lavformat -lavcodec -lavutil -lz -lm -lpthread -o program
program.c:15:32: error: libavcodec/avcodec.h: No such file or directory
program.c:16:32: error: libswscale/swscale.h: No such file or directory
program.c:17:34: error: libavformat/avformat.h: No such file or directory
program.c:19: error: expected '=', ',', ';', 'asm' or '__attribute__' before '*' token
program.c:24: error: expected '=', ',', ';', 'asm' or '__attribute__' before '*' token
program.c:95: error: expected ')' before '*' token
program.c:128: error: expected ')' before '*' token
program.c:201: error: expected '=', ',', ';', 'asm' or '__attribute__' before '*' token
program.c: In function 'main':
program.c:253: error: 'AVFrame' undeclared (first use in this function)
program.c:253: error: (Each undeclared identifier is reported only once
program.c:253: error: for each function it appears in.)
program.c:253: error: 'loaded_image' undeclared (first use in this function)
program.c:255: error: 'img_copy' undeclared (first use in this function)
program.c:255: error: 'AV_PIX_FMT_RGB24' undeclared (first use in this function)
program.c:256: error: 'current_frame' undeclared (first use in this function)
make: *** [all] Error 1

Upvotes: 1

Views: 682

Answers (2)

Olaf Dietsche
Olaf Dietsche

Reputation: 74008

There is a difference in using $HOME on the command line (shell) and using $HOME in a Makefile.

In a Makefile, you must surround the variable name with parenthesis, like 

all: program.c
      gcc -I$(HOME)/ffmpeg/include program.c -L$HOME/ffmpeg/lib -lswscale -lavdevice -lavfilter -lswscale -lswresample -lavformat -lavcodec -lavutil -lz -lm -lpthread -o program

See Basics of Variable References and Variables from the Environment for more.

Upvotes: 3

Carl Norum
Carl Norum

Reputation: 224834

$HOME expands as OME in your make environment. If you want the shell to expand it, you need to escape it:

  gcc -I$$HOME/ffmpeg/include ...

What's happening to you now is that make is expanding $H to nothing, then using the rest of the line as-is.

Upvotes: 5

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