On 2013-10-08 14:08, Salter, Thomas A wrote:
Was there any thought given to using this GNU Make feature to get rid of
significant tab characters, or is it not even possible in all the supported
build environments? Some of the legacy systems I deal with don't handle tab
characters well.
From: http://www.gnu.org/software/make/manual/make.html#Special-Variables
.RECIPEPREFIX
The first character of the value of this variable is used as the character make
assumes is introducing a recipe line. If the variable is empty (as it is by
default) that character is the standard tab character. For example, this is a
valid makefile:
.RECIPEPREFIX = >
all:
> @echo Hello, world
The value of .RECIPEPREFIX can be changed multiple times; once set it stays in
effect for all rules parsed until it is modified.
I was not aware of this feature. It is ... interesting. But a bit scary.
:-)
It's definitely worth considering, although not in this patch.
My first impression is that, while the decision to use tab as a special
character in makefile syntax was a particularly bad one, it is still the
norm. And even though IDE/editor support is quite limited for Makefiles,
they usually can succeed in determining recipes by the tabs and the
preceding colon. Change that, and you'll lose editor support (unless the
editors are intelligent enough to parse .RECIPEPREFIX; which is of
course possible, but unlikely).
On the other hand, tab in rules are not a good idea, and a character
like ">" would certainly make rules stand out more visibly.
Have you used a non-tab .RECIPEPREFIX in the real world, with good results?
/Magnus
