CODEWITHSUNDEEP
makefilewhitespacegnu-make
Teddy
Teddy

Reputation: 1022

GNU make test output with leading spaces

I want to output some text in the rule help of a makefile (GNU make).

help:
  $(info Help:)
  $(info )
  $(info make all   Build all targets)
  $(info make this  Build target this)
  $(info make long  Build target long that has)
  $(info            a very long description)
  $(info            that must be shown on)
  $(info            several lines)
  $(info make that  Build target that)

When calling make help I would expect:

Help:

make all   Build all targets
make this  Build target this
make long  Build target long that has
           a very long description
           that must be shown on
           several lines
make that  Build target that

But I get:

Help:

make all   Build all targets
make this  Build target this
make long  Build target long that has
a very long description
that must be shown on
several lines
make that  Build target that

How can the leading spaces be preserved?

Edit:

The solution has to work on Windows too.

Solution:

The trick is to add a variable containing a space. Then make does not strip the string.

SPACE := $(subst ,, )

help:
  $(info Help:)
  $(info )
  $(info make all   Build all targets)
  $(info make this  Build target this)
  $(info make long  Build target long that has)
  $(info $(SPACE)          a very long description)
  $(info $(SPACE)          that must be shown on)
  $(info $(SPACE)          several lines)
  $(info make that  Build target that)

Upvotes: 0

Views: 437

Answers (1)

MadScientist
MadScientist

Reputation: 100946

Do not use make's info function. There is typically very little reason to use make functions like this inside a recipe: a recipe has the full power of the shell available and that's MUCH more powerful than GNU make function capabilities. Use the shell's echo function instead:

help:
        echo "Help:"
        echo
        echo "make all   Build all targets"
        echo "make this  Build target this"
        echo "make long  Build target long that has"
        echo "           a very long description"
        echo "           that must be shown on"
        echo "           several lines"
        echo "make that  Build target that"

ETA

If you really want to use $(info ...) for portability then you'll have to play a trick:

E :=

help:
        $(info $E        indented text)

This makes an empty variable $E, then you can use that and it will mark the end of the whitespace separating the function name from its arguments.

Upvotes: 3

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