Re: GSL_CFLAGS, GSL_LIBS, gsl.m4

[Brian Gough <bjg at network-theory dot co dot uk>]

Your second problem can be fixed, I think, by using "#include
<gsl/gsl_foo.h>" (this is now the recommended way to do it, a change
from earlier versions of gsl).

Regarding the flags that come out of gsl.m4 and gsl-config, I believe
they follow GNOME's conventions. I'm not sure exactly how that
evolved, as I don't follow GNOME myself. I'd be glad of an
explanation/introduction to this type of package configuration scheme
from anyone on the list who knows about it.

William Brower writes:
 > In gsl.m4, it appears that instead of just
 > making GSL_LIBS and GSL_CFLAGS, there is the
 > attempt to append these results to the more
 > general CFLAGS and LIBS variables.
 > 
 > Is this what you want to do? My package builds
 > multiple libraries and multiple binaries. Some
 > of these require the GSL, some do not. When the
 > more global CFLAGS and LIBS variables are messed
 > with, my non-GSL apps have all that extra baggage.
 >
 > Also, my GSL_CFLAGS gets set to '-g -O2 -I/usr/local/include'
 > but the headers are in '/usr/local/include/gsl' so
 > my Makefile.am's have to look like '$(GSL_CFLAGS)/gsl'
 > Should the flags used to build the GSL be inherited
 > by *my* package? Should there also be defined a GSL_INCS
 > that shows only the (correct) path to the headers?
 >
 >
 > One more. My GSL_LIBS gets set to '-L/usr/local/lib -lgsl -lm'
 > Forget about the fact that -lgslblasnative is not present
 > (I suspect that is to allow someone to link against their
 > own BLAS lib but that's not my concern right now).
 > I notice that when X_LIBS (or somthing) is set, it usually
 > only contains the *path* to the library (the -L part),
 > not the libraries themselves. I supppose one could argue
 > that in light of there being only ONE library (-lgsl),
 > it is OK to add it (and its -lm dependency).
 > It appears inconsistent; then again, I don't have enough
 > experience to know the "right" way to do this.
 > 
 > --
 > William Brower  MIT Lincoln Laboratory
 > 805.355.1310    KMR Field Site, Kwajalein
 > 
 >