Re: make(1): is this a bug or PEBKAC?

[Mouse <mouse%Rodents-Montreal.ORG@localhost>]

Thank you for the quick and very helpful response!

>>     121	$(x:C;^.*\.([0-9].*)$$;$(INSTMANDIR)/cat\1;):

>> So, I'm wondering, is this a bug in 9.1's make, or am I doing
>> something wrong here?

> TL;DR: There are several cases in which make silently ignores parse
> errors, such as '$$' in variable modifiers.  In other cases, it has
> become stricter over time, or the accepted syntax just changed.

:-(

> The crucial part in your example is the '$$'.

Actually, they were initially single $s.  I changed them in an attempt
to fix it after seeing the 9.1 manpage note that the pattern and
replacement were subject to variable expansion; I wasn't sure what a
trailing single $ would do, so I doubled it.

> In normal strings, '$$' is used to escape a '$'.  But in variable
> modifiers such as ':C', '\$' is used instead to escape a '$'.

Hm, is that documented somewhere?  The only place I see \$ in the 9.1
manpage is in an example in the description of :q.

> In netbsd-9:usr.bin/make/var.c, the parser looks at
> '$(x:...(...)$$)', trying to figure out which parentheses match, see
> the comment "Attempt to avoid ';' inside substitution patterns" in
> parse.c.  In this case, the parser fails.  It counts the '$(' as
> starting a subexpression, then ignores the following '(', and when it
> sees the first ')', it considers the expression completed, leaving
> the '$$)' for a syntax error.

I don't see $$) anywhere in my lie above - nor anywhere else in
local-prog, for that matter.  I'd have to go read the code, because
your description doesn't seem to match the results I see.

> To avoid all these edge cases, you should rewrite your makefile:

> * In the ':C' modifier, replace '$$' with '$', as there is no need to
> double it.

Okay.

> * In dependency lines, avoid modifiers containing ';'.

So my use of ; as the delimiter character is confusing things?  Okay, I
can change that.

> To make the makefile easier readable and at the same time avoiding
> line noise, you can use a multi-variable .for loop, which are
> available since 2000:

Maybe.  I'd have to see if that's present in all the make versions I
care about.  I use <local-prog> on more than just work machines....

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