[PD] Problem compiling hello world external
martinrp at vax2.concordia.ca
Thu Sep 30 17:53:34 CEST 2004
Jamie Bullock wrote:
> Dear list,
> I am thinking of writing a few PD externals, and so decided to try the
> HOW-TO tutorial at http://iem.kug.ac.at/pd/externals-HOWTO/node1.html.
> I am using gcc 3.3.3. m_pd.h is version 0.37 and is in /usr/include.
> The problem is that if I simply copy and paste the helloworld code
> into a text editor and try to compile with something like:
> gcc helloworld_pd.c -o helloworld.pd_linux -l/usr/include
> It fails with the wollowing output:
> In function `_start':
> : undefined reference to `main'
Here gcc is looking to compile a regular executable, when you really
want it to build a shared library.
> /tmp/ccWU3J7M.o(.text+0xf): In function `helloworld_bang':
> : undefined reference to `post'
This and the following errors all relate to gcc not being able to find
the pd header files, the first of which is m_pd.h.
> /tmp/ccWU3J7M.o(.text+0x28): In function `helloworld_new':
> : undefined reference to `pd_new'
> /tmp/ccWU3J7M.o(.text+0x53): In function `helloworld_setup':
> : undefined reference to `gensym'
> /tmp/ccWU3J7M.o(.text+0x5c): In function `helloworld_setup':
> : undefined reference to `class_new'
> /tmp/ccWU3J7M.o(.text+0x77): In function `helloworld_setup':
> : undefined reference to `class_addbang'
> collect2: ld returned 1 exit status
> I apologise in advance if this question has already been answered - I
> couldn't find anything in the mail archives...
Previous posts have alluded to the absence of this vital information
from the HOW-TO...
> Any help would be appreciated.
Assuming you have the source for pd, check out the makefile in
pd/extra/pique for an example of how to do it properly on all platforms.
In particular note the need for -export_dynamic and -shared to indicate
that you want to build a shared library, as well as -I../../src to give
the path to m_pd.h. The easiest thing is usually to copy such a makefile
and modify the file names and paths to suit your setup, then type 'make'
to build your external.
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