Update postgresql-libpq.cabal

[AlexanderAA]

Fix issue #12 Credit goes to the maintainer of the OpenBSD package, David Coppa. Tested on OpenBSD 5.4-release

[lpsmith]

Thanks, but this breaks the build on my linux box. You are going to have to hide those additional Extra-libraries behind an appropriate .cabal file conditional. Let me investigate the right syntax, which I can't quite remember off the top of my head.

[lpsmith]

Ok, this should almost work:

Extra-Libraries: pq
if os(openbsd)
    Extra-Libraries:  crypto ssl com_err asn1 krb5 wind roken heimbase

Try this out on your platform, and amend your pull request. I'm not sure if the name of the os is quite right; you should check the value of System.Info.os per the cabal package developer's guide.

[AlexanderAA]

Thanks Leon, I can confirm that the conditional works fine on OpenBSD 5.4-release and Debian "wheezy".

[lpsmith]

Thanks!

[lpsmith]

Looking at this email thread a bit more carefully, I would certainly like to use the output of pg_config to set Extra-Libraries appropriately, and I can certainly help with that as I've done a bit of Setup.hs hacking. However I guess I don't really understand the issue brought up that the order of the libraries emitted by pg_config not being quite right, and whether or not it's possible to fix that in Setup.hs in any sane way.

[AlexanderAA]

Thanks Leon.

I can't agree more; "os(openbsd)" conditional should certainly be replaced with something else, which tests for features, not platform. Unfortunately, I do not know how to implement that yet.

In the meantime, here is the output from pg_config on OpenBSD 5.4. It seems, that the missing libraries are listed in LDFLAGS:

$ pg_config
BINDIR = /usr/local/bin
DOCDIR = /usr/local/share/doc/postgresql
HTMLDIR = /usr/local/share/doc/postgresql
INCLUDEDIR = /usr/local/include/postgresql
PKGINCLUDEDIR = /usr/local/include/postgresql
INCLUDEDIR-SERVER = /usr/local/include/postgresql/server
LIBDIR = /usr/local/lib
PKGLIBDIR = /usr/local/lib/postgresql
LOCALEDIR = /usr/local/share/locale
MANDIR = /usr/local/man
SHAREDIR = /usr/local/share/postgresql
SYSCONFDIR = /etc/postgresql
PGXS = /usr/local/lib/postgresql/pgxs/src/makefiles/pgxs.mk
CONFIGURE = '--disable-rpath' '--with-openssl=/usr' '--with-perl' '--with-pam=no' '--enable-integer-datetimes' '--includedir=/usr/local/include/postgresql' '--datadir=/usr/local/share/postgresql' '--docdir=/usr/local/share/doc/postgresql' '--with-includes=' '--with-libraries=/usr/local/lib' '--with-system-tzdata=/usr/share/zoneinfo' '--with-openssl' '--with-ossp-uuid' '--with-libxml' '--with-krb5' '--disable-thread-safety' '--prefix=/usr/local' '--sysconfdir=/etc' '--mandir=/usr/local/man' '--infodir=/usr/local/info' '--localstatedir=/var' '--disable-silent-rules' 'CC=cc' 'CFLAGS=-O2 -pipe' 'LDFLAGS=-L/usr/local/lib -L/usr/lib -lkrb5 -lasn1 -lcrypto -lwind -lroken -lcom_err -lheimbase' 'CPPFLAGS=-I/usr/local/include -I/usr/include/kerberosV '
CC = cc
CPPFLAGS = -I/usr/local/include -I/usr/include/kerberosV -I/usr/local/include/libxml2 -I/usr/local/include
CFLAGS = -O2 -pipe -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv
CFLAGS_SL = -fpic -DPIC
LDFLAGS = -L/usr/local/lib -L/usr/lib -lkrb5 -lasn1 -lcrypto -lwind -lroken -lcom_err -lheimbase -L/usr/local/lib -L/usr/local/lib -L/usr/local/lib -Wl,-Bdynamic
LDFLAGS_EX = 
LDFLAGS_SL = 
LIBS = -lpgport -lxml2 -lssl -lcrypto -lz -lreadline -ltermcap -lm 
VERSION = PostgreSQL 9.2.4

$ pg_config --configure
'--disable-rpath' '--with-openssl=/usr' '--with-perl' '--with-pam=no' '--enable-integer-datetimes' '--includedir=/usr/local/include/postgresql' '--datadir=/usr/local/share/postgresql' '--docdir=/usr/local/share/doc/postgresql' '--with-includes=' '--with-libraries=/usr/local/lib' '--with-system-tzdata=/usr/share/zoneinfo' '--with-openssl' '--with-ossp-uuid' '--with-libxml' '--with-krb5' '--disable-thread-safety' '--prefix=/usr/local' '--sysconfdir=/etc' '--mandir=/usr/local/man' '--infodir=/usr/local/info' '--localstatedir=/var' '--disable-silent-rules' 'CC=cc' 'CFLAGS=-O2 -pipe' 'LDFLAGS=-L/usr/local/lib -L/usr/lib -lkrb5 -lasn1 -lcrypto -lwind -lroken -lcom_err -lheimbase' 'CPPFLAGS=-I/usr/local/include -I/usr/include/kerberosV '

[AlexanderAA]

pg_config output, Debian "wheezy" (for comparison):

$ pg_config             
BINDIR = /usr/lib/postgresql/9.1/bin
DOCDIR = /usr/share/doc/postgresql-doc-9.1
HTMLDIR = /usr/share/doc/postgresql-doc-9.1
INCLUDEDIR = /usr/include/postgresql
PKGINCLUDEDIR = /usr/include/postgresql
INCLUDEDIR-SERVER = /usr/include/postgresql/9.1/server
LIBDIR = /usr/lib
PKGLIBDIR = /usr/lib/postgresql/9.1/lib
LOCALEDIR = /usr/share/locale
MANDIR = /usr/share/postgresql/9.1/man
SHAREDIR = /usr/share/postgresql/9.1
SYSCONFDIR = /etc/postgresql-common
PGXS = /usr/lib/postgresql/9.1/lib/pgxs/src/makefiles/pgxs.mk
CONFIGURE = '--with-tcl' '--with-perl' '--with-python' '--with-pam' '--with-krb5' '--with-gssapi' '--with-openssl' '--with-libxml' '--with-libxslt' '--with-ldap' '--with-tclconfig=/usr/lib/tcl8.5' '--with-tkconfig=/usr/lib/tk8.5' '--with-includes=/usr/include/tcl8.5' 'PYTHON=/usr/bin/python' '--mandir=/usr/share/postgresql/9.1/man' '--docdir=/usr/share/doc/postgresql-doc-9.1' '--sysconfdir=/etc/postgresql-common' '--datarootdir=/usr/share/' '--datadir=/usr/share/postgresql/9.1' '--bindir=/usr/lib/postgresql/9.1/bin' '--libdir=/usr/lib/' '--libexecdir=/usr/lib/postgresql/' '--includedir=/usr/include/postgresql/' '--enable-nls' '--enable-integer-datetimes' '--enable-thread-safety' '--enable-debug' '--disable-rpath' '--with-ossp-uuid' '--with-gnu-ld' '--with-pgport=5432' '--with-system-tzdata=/usr/share/zoneinfo' 'CFLAGS=-g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security -fPIC -pie' 'CPPFLAGS=-D_FORTIFY_SOURCE=2 -DLINUX_OOM_ADJ=0' 'LDFLAGS=-Wl,-z,relro -Wl,-z,now -Wl,--as-needed'
CC = gcc
CPPFLAGS = -D_FORTIFY_SOURCE=2 -DLINUX_OOM_ADJ=0 -D_GNU_SOURCE -I/usr/include/libxml2 -I/usr/include/tcl8.5
CFLAGS = -g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security -fPIC -pie -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wformat-security -fno-strict-aliasing -fwrapv -fexcess-precision=standard -g
CFLAGS_SL = -fpic
LDFLAGS = -Wl,-z,relro -Wl,-z,now -Wl,--as-needed -L/usr/lib -Wl,--as-needed
LDFLAGS_EX = 
LDFLAGS_SL = 
LIBS = -lpgport -lxslt -lxml2 -lpam -lssl -lcrypto -lkrb5 -lcom_err -lgssapi_krb5 -lz -ledit -lcrypt -ldl -lm 
VERSION = PostgreSQL 9.1.9

$ pg_config --configure 
'--with-tcl' '--with-perl' '--with-python' '--with-pam' '--with-krb5' '--with-gssapi' '--with-openssl' '--with-libxml' '--with-libxslt' '--with-ldap' '--with-tclconfig=/usr/lib/tcl8.5' '--with-tkconfig=/usr/lib/tk8.5' '--with-includes=/usr/include/tcl8.5' 'PYTHON=/usr/bin/python' '--mandir=/usr/share/postgresql/9.1/man' '--docdir=/usr/share/doc/postgresql-doc-9.1' '--sysconfdir=/etc/postgresql-common' '--datarootdir=/usr/share/' '--datadir=/usr/share/postgresql/9.1' '--bindir=/usr/lib/postgresql/9.1/bin' '--libdir=/usr/lib/' '--libexecdir=/usr/lib/postgresql/' '--includedir=/usr/include/postgresql/' '--enable-nls' '--enable-integer-datetimes' '--enable-thread-safety' '--enable-debug' '--disable-rpath' '--with-ossp-uuid' '--with-gnu-ld' '--with-pgport=5432' '--with-system-tzdata=/usr/share/zoneinfo' 'CFLAGS=-g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security -fPIC -pie' 'CPPFLAGS=-D_FORTIFY_SOURCE=2 -DLINUX_OOM_ADJ=0' 'LDFLAGS=-Wl,-z,relro -Wl,-z,now -Wl,--as-needed'

[lpsmith]

Well, my recommendation for Setup.hs hacking is first to be patient, it's going to take quite a bit of effort for small but very tangible improvements in functionality. Second, install groom, and then use that to pretty-print various cabal data structures until you see the data you are looking for. Populating a field with some useless information can help you locate your goal too. From there you can deduce where to look in the cabal haddocks for further information. A few times I've had to resort to reading the cabal source as well.

It's also worth pointing out that you need Build-type: Custom in the .cabal file; Build-type: Simple tends to ignore the Setup.hs file altogether, unless you specifically run it (and don't use the cabal executable provided by the cabal-install package)

So for example, here's a simple Setup.hs that prints out the main data structures associated with a confHook:

import Distribution.Simple
import Text.Groom

main = defaultMainWithHooks simpleUserHooks {
    confHook = \pkg flags -> do
        putStr "pkg:\n\n"
        putStr (groom pkg) 
        putStr "\n\n\n\n"
        putStr "flags:\n\n"
        putStr (groom flags)
        putStr "\n\n\n\n"
        putStr "running default confHook:\n\n"
        lbi <- confHook simpleUserHooks pkg flags
        putStr "\n\n\n\n"
        putStr "lbi:\n\n"
        putStr (groom lbi)
        putStr "\n\n\n\n"
        return lbi
  }

Then just cabal configure and inspect the output; this generates a lot of output so you almost certainly want to pipe this to less -S or a file or whatever you prefer, not least so you can search for strings in the output. I suspect what you are looking for is probably in the ConfigFlags structure.

[lpsmith]

You might also want to figure out exactly how Cabal generates it's flags for gcc and ld, I don't know if that's particularly well documented or not (documentation is often a little sparse, sadly) or if you'll need to resort to reading the source. You might also find it helpful to ask questions on the #hackage irc channel on FreeNode.