Question

• Utility: NMake
• Platform : Windows 7

I have the following Makefile

FILE = $(shell) *.c
FILE += $(shell) *.cpp

exec:
    @echo $(FILE)

This works perfectly fine with make. This throws up the following error with nmake

makefile(2) : fatal error U1036: syntax error : too many names to left of '='
Stop.

What could be the reason?

Without the line

FILE += $(shell) *.cpp

nmake works perfectly fine.

Answer 1

The += syntax is a GNU Make extension that was pioneered in Sun’s make in the late 80s. It is not part of the syntax for POSIX standard make, or the original AT&T make.

If you use extensions, you get caught when you switch to a system that doesn’t support them. You either have to rework things (hard) or stick with the original system.

---

One way to modify the file to work with nmake is probably:

FILE1 = $(shell) *.c
FILE2 = $(shell) *.cpp
FILE  = $(FILE1) $(FILE2)

exec:
    @echo $(FILE)

Or, given that the macro shell is not defined, even:

FILE1 = *.c
FILE2 = *.cpp
FILE  = $(FILE1) $(FILE2)

exec:
    @echo $(FILE)