20050314: compiling udunits requires -lm on mandrake

Patrice,

> To: address@hidden
> From: Patrice Dumas <address@hidden>
> Subject: compiling udunits requires -lm on mandrake
> Organization: ?
> Keywords: 200503111801.j2BI1uv2007313 UDUNITS Mandrake Linux

The above message contained the following:

> I  tried to rebuild udunits 1.12.4 on mandrake 10.1. First I had to add 
> CPPFLAGS='-Df2cFortran'. No trouble so far.

That C macro is necessary for Linux systems that use the gcc(1) and
f77(1) compilers.  The file INSTALL contains an example of this.

> I had the following error when building with the default:
> [dumas@patoune src]$ ./configure CPPFLAGS='-Df2cFortran'
> ...
> make[1]: Entering directory `/home/dumas/src/udunits-1.12.4/src/udunits'
> make[2]: Entering directory `/home/dumas/src/udunits-1.12.4/src/udunits'
> c89 -c -g -O2 -I../lib -I../port/misc -Df2cFortran udunits.c

Your c89(1) compiler accepts the "-O2" option.  Interesting.  It
shouldn't.

> udunits.c: In function `main':
> udunits.c:95: error: `_POSIX_MAX_INPUT' undeclared (first use in this
> function)
> udunits.c:95: error: (Each undeclared identifier is reported only once
> udunits.c:95: error: for each function it appears in.)
> make[2]: *** [udunits.o] Erreur 1

It's likely that a C macro must be defined in order for the c89(1)
compiler to see the Standard UNIX definitions.  I wonder if

    CPPFLAGS='-Df2cFortran -D_XOPEN_SOURCE=500'

would work?

> With CC='gcc' it passes that point, and I get an error during linking:

> gcc -o udunits -g -O2 udunits.o -L/home/dumas/src/udunits-1.12.4/src/lib 
> -ludunits -L/home/dumas/src/udunits-1.12.4/src/port/misc -ludport
> /home/dumas/src/udunits-1.12.4/src/lib/libudunits.a(utlib.o)(.text+0x45a): In 
> function `dectime':
> /home/dumas/src/udunits-1.12.4/src/lib/utlib.c:366: undefined reference to 
> `fmod'
> /home/dumas/src/udunits-1.12.4/src/lib/libudunits.a(utlib.o)(.text+0xc36): In 
> function `utRaise':
> /home/dumas/src/udunits-1.12.4/src/lib/utlib.c:807: undefined reference to 
> `pow'
> /home/dumas/src/udunits-1.12.4/src/lib/libudunits.a(utlib.o)(.text+0x1096): 
> In function `utPrint':
> /usr/include/bits/mathinline.h:541: undefined reference to `log10'
> collect2: ld returned 1 exit status
> 
> It doesn't find libm. There wasn't a way to give arguments to the link
> command for udunits. Therefore I added to udunits/Makefile.in the line
> 
> LDFLAGS         = @LDFLAGS@
> 
> and called
> ./configure CPPFLAGS='-Df2cFortran' LDFLAGS='-lm' CC='gcc'

You could have also set the environment variable LIBS before executing
the configure(1) script.  For example

    LIBS=-lm ./configure ...

The file INSTALL has examples of this.

> Everything seems right now.

Great!

Thanks for the feedback.

> Pat

Regards,
Steve Emmerson

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