patsubst: Whitespaces are not replaced by spaces | Possible issue in make or the documentation

Marek Küthe <[email protected]> Wed, 30 Apr 2025 12:15:18 +0000

Newsgroups	gmane.comp.gnu.make.bugs,gmane.comp.gnu.make.general
Message-ID	<20250430121518.7b90f398@ciel>

Hello,

I am currently taking a closer look at the `patsubst` function in
`make`. The documentation [1] says
> Whitespace between words is folded into single space characters; leading and trailing whitespace is discarded. 

I have now created a example file (see attachment):
```
code := $(patsubst ,,  int index  =  10;	// Hier wird x auf 10
gesetzt  )

beispiel_zeigen:
	echo "$(code)"

.PHONY: beispiel_zeigen
```
However, the result contains the original whitespaces:
```
echo "  char index  =  10;	// Hier wird x auf 10 gesetzt  "
  char index  =  10;	// Hier wird x auf 10 gesetzt  
```

My make version:
```
$ make --version
GNU Make 4.4.1
Built for x86_64-pc-linux-gnu
Copyright (C) 1988-2023 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later
<https://gnu.org/licenses/gpl.html> This is free software: you are free
to change and redistribute it. There is NO WARRANTY, to the extent
permitted by law. ```

Is this a bug, an issue in the documentation or am I doing something
wrong?

I would appreciate an answer!

Regards
Marek Küthe

[1]
https://www.gnu.org/software/make/manual/html_node/Text-Functions.html

-- 
Marek Küthe
[email protected]
er/ihm he/him

Makefile (text/x-makefile, 133 B)

code := $(patsubst ,,  int index  =  10;	// Hier wird x auf 10 gesetzt  )

beispiel_zeigen:
	echo "$(code)"

.PHONY: beispiel_zeigen

signature.asc (application/pgp-signature, 833 B)