[B.A.T.M.A.N.] [PATCH] alfred-gpsd: add -lm to linker flags for libgps

[B.A.T.M.A.N.] [PATCH] alfred-gpsd: add -lm to linker flags for libgps

[Simon Wunderlich]

Appearently applications using libgps must link -lm themselves. A patch
was submitted [1] to change this unusual behaviour upstream, but was
never applied. Therefore link to -lm to alfred-gpsd too as this should
not hurt anyway.

[1] https://lists.berlios.de/pipermail/gpsd-dev/2011-August/009451.html

Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
---
 gpsd/Makefile |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gpsd/Makefile b/gpsd/Makefile
index 9b21652..92e690f 100644
--- a/gpsd/Makefile
+++ b/gpsd/Makefile
@@ -49,7 +49,7 @@ ifeq ($(origin LIBGPS_CFLAGS) $(origin LIBGPS_LDLIBS), undefined undefined)
     $(error No $(LIBGPS_NAME) development libraries found!)
   endif
   LIBGPS_CFLAGS += $(shell $(PKG_CONFIG) --cflags $(LIBGPS_NAME))
-  LIBGPS_LDLIBS +=  $(shell $(PKG_CONFIG) --libs $(LIBGPS_NAME))
+  LIBGPS_LDLIBS +=  $(shell $(PKG_CONFIG) --libs $(LIBGPS_NAME)) -lm
 endif
 CFLAGS += $(LIBGPS_CFLAGS)
 LDLIBS += $(LIBGPS_LDLIBS)
-- 
1.7.10.4

Re: [B.A.T.M.A.N.] [PATCH] alfred-gpsd: add -lm to linker flags for libgps

[Andrew Lunn]

On Wed, Oct 23, 2013 at 01:27:43AM +0200, Simon Wunderlich wrote:
> Appearently applications using libgps must link -lm themselves. A patch
> was submitted [1] to change this unusual behaviour upstream, but was
> never applied. Therefore link to -lm to alfred-gpsd too as this should
> not hurt anyway.

Hi Simon

What the gpsd sources i have says is:

     On some systems (those which do not support implicit linking in
     libraries) you may need to add -lm to your link line when you
     link libgps.  It is always safe to do this.

So i guess my Debian system does have implicit linking, and ldd on the
library does include libm. Hence it worked for me.

However, as you said, it does not harm, so:

Acked-by: Andrew Lunn <andrew@lunn.ch>

	  Andrew

> 
> [1] https://lists.berlios.de/pipermail/gpsd-dev/2011-August/009451.html
> 
> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
> ---
>  gpsd/Makefile |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/gpsd/Makefile b/gpsd/Makefile
> index 9b21652..92e690f 100644
> --- a/gpsd/Makefile
> +++ b/gpsd/Makefile
> @@ -49,7 +49,7 @@ ifeq ($(origin LIBGPS_CFLAGS) $(origin LIBGPS_LDLIBS), undefined undefined)
>      $(error No $(LIBGPS_NAME) development libraries found!)
>    endif
>    LIBGPS_CFLAGS += $(shell $(PKG_CONFIG) --cflags $(LIBGPS_NAME))
> -  LIBGPS_LDLIBS +=  $(shell $(PKG_CONFIG) --libs $(LIBGPS_NAME))
> +  LIBGPS_LDLIBS +=  $(shell $(PKG_CONFIG) --libs $(LIBGPS_NAME)) -lm
>  endif
>  CFLAGS += $(LIBGPS_CFLAGS)
>  LDLIBS += $(LIBGPS_LDLIBS)
> -- 
> 1.7.10.4
>