Experimental Physics and
Industrial Control System

Michael Davidsaver via Tech-talk <[email protected]> · Thu, 29 Nov 2018 07:58:49 -0800

On 11/29/18 1:44 AM, Giacomo S. via Tech-talk wrote:
> Hello everyone.
> 
> In epics 3.16 I see a couple of .pc files are generated and installed:
> 
> ./lib/pkgconfig/epics-base-linux-x86_64.pc
> ./lib/pkgconfig/epics-base.pc
> 
> Nonetheless, when using pkgconfig to build/link against Epics, needed  -lca -ldbCore -lCom  are missing from the command line.
> 
> Looking at the "Libs:" line at the bottom of epics-base-linux-x86_64.pc, I see they are actually missing. I added them manually and the build works.
> 
> Am I missing something or is it a bug?

This is an intentional omission as the Base libraries are used in different combinations.
The names 'ca' and 'Com' are meant to be included explicitly in user builds.
The others are listed in the EPICS_BASE_IOC_LIBS variable.

> $ pkg-config --variable=EPICS_BASE_IOC_LIBS epics-base-linux-x86_64
> dbRecStd dbCore ca Com

The basic recipe in a user makefile being something like:

EPICS_HOST_ARCH ?= $(shell pkg-config --variable=ARCH epics-base)
CFLAGS += $(shell pkg-config epics-base-$(EPICS_HOST_ARCH) --cflags)
LDFLAGS += $(shell pkg-config epics-base-$(EPICS_HOST_ARCH) --libs)
EPICS_BASE_IOC_LIBS = $(shell pkg-config epics-base-$(EPICS_HOST_ARCH) --variable=EPICS_BASE_IOC_LIBS)

%.o: %.c
	$(CC) -o $@ -c $< $(CFLAGS)

myexe: some.o
	$(CC) -o $@ $* $(LDFLAGS) $(EPICS_BASE_IOC_LIBS:%=-l%) $(LDADD)

As an aside, thank you for bringing this up.  I've noticed that EPICS_BASE_IOC_LIBS
isn't being populated in the forthcoming 7.0.2 release.

> Thanks.
> 
> Giacomo, Elettra Synchrotron Radiation Facility, Trieste, Italy.
> 
> 
> ======================================
> 
> A portion of the .pc file follows:
> 
> ======================================
> 
> 
> EPICS_BASE_IOC_LIBS=dbRecStd dbCore ca Com
> 
> # Directories
> 
> includedir_osi=${prefix}/include
> includedir_osd=${prefix}/include/os/Linux
> includedir_comp=${prefix}/include/compiler/gcc
> 
> includedirs=${includedir_osi} ${includedir_osd} ${includedir_comp}
> 
> dbddir=${prefix}/dbd
> dbdir=${prefix}/db
> 
> # Tool chain
> 
> CC=/usr/bin/gcc
> CXX=/usr/bin/g++
> CPP=/usr/bin/gcc -x c -E
> AR=/usr/bin/ar -rc
> LD=/usr/bin/ld -r
> 
> Name: epics-base-linux-x86_64
> Version: 3.16.2.0
> Description: EPICS Base for linux-x86_64
> Cflags: -I${includedir_osi} -I${includedir_osd} -I${includedir_comp} -D_GNU_SOURCE -D_DEFAULT_SOURCE -DUSE_TYPED_RSET -D_X86_64_ -DUNIX -Dlinux -mtune=generic -m64
> Libs: -L${libdir} -rdynamic -m64
> Libs.private: -lpthread -lreadline -lm -lrt -ldl -lgcc
> 

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System