Re: [Discuss-gnuradio] how to get dqpsk2 block?

[Mark J. Blair]

On Aug 21, 2010, at 1:46 AM, Thunder87 wrote:
> log repeatedly says:
> failed program was /* confdefs.h */
> 
> So I guess it's confdefs.h )) You have any idea what is it?

That "/* confdefs.h */" is just the first line of a temporary C program 
generated by the configure script to check whether some header file or function 
can be found. It's not the thing that configure is complaining that it can't 
find. For example, here's a snippet of my config.log file where it looks for 
the header file minix/config.h, and doesn't find it:

configure:5554: checking minix/config.h presence
configure:5554: /usr/bin/gcc -E -I/opt/local/include -I/opt/local/include/qwt 
-I/opt/local/include/qwtplot3d conftest.c
conftest.c:21:26: error: minix/config.h: No such file or directory
configure:5554: $? = 1
configure: failed program was:
| /* confdefs.h */
| #define PACKAGE_NAME ""
| #define PACKAGE_TARNAME ""
| #define PACKAGE_VERSION ""
| #define PACKAGE_STRING ""
| #define PACKAGE_BUGREPORT ""
| #define PACKAGE_URL ""
| #define PACKAGE "gnuradio"
| #define VERSION "v3.3.1git-47-gf6337c62"
| #define STDC_HEADERS 1
| #define HAVE_SYS_TYPES_H 1
| #define HAVE_SYS_STAT_H 1
| #define HAVE_STDLIB_H 1
| #define HAVE_STRING_H 1
| #define HAVE_MEMORY_H 1
| #define HAVE_STRINGS_H 1
| #define HAVE_INTTYPES_H 1
| #define HAVE_STDINT_H 1
| #define HAVE_UNISTD_H 1
| /* end confdefs.h.  */
| #include <minix/config.h>
configure:5554: result: no


See, first it says that it's checking for the presence of minix/config.h. Next, 
it prints the command it used to check for that file (the /usr/bin/gcc line). 
Next, it prints the output of that command, where the C compiler said that it 
couldn't find minix/config.h. After that attempted little compilation fails, 
the configure script prints out the contents of the temporary little program it 
created for the failed test compilation (all of the lines beginning with "|"). 
Finally, is prints that the result of its test was "no".

In this case, it's not a problem for me that minix/config.h wasn't found. It's 
just a system-specific variation that the configure script is testing for. But 
when a gnuradio component isn't built, there will usually be come output that 
looks like this:


configure:25705: result: no
configure:25707: result: gr-audio-alsa requires package alsa, not found.
configure:25742: result: Not building component gr-audio-alsa.


There was a whole bunch of output right before this from configure's tests to 
see if it could find the "alsa" package, but the part that I would care about 
if I wanted to build gr-audio-alsa is just the line where configure tells me 
that it's not building gr-audio-alsa because it couldn't find the alsa 
package... so then I'd go looking for the alsa package and install it on my 
system to fix the missing dependency.

At this point, you're not so much having a gnuradio problem yet... you're still 
learning how to understand the output of the "configure" script, which is 
created by the Gnu Autoconf tools. It's kind of complicated, but once you get 
over the learning curve this knowledge will apply towards working with lots of 
other open-source stuff, too.

Keep plugging along, and you'll get there!



-- 
Mark J. Blair, NF6X <address@hidden>
Web page: http://www.nf6x.net/
GnuPG public key available from my web page.