ruby extconf.rb example

Question

I am following instructions to http://people.apache.org/~rooneg/talks/ruby-extensions/ruby-extensions.html (page 6) and my make command is only returning make: Nothing to be done for 'all'.

Does anyone have any ideas?

I am using ruby 1.9.2 and I'm on OSX 10.6.8

SHELL = /bin/sh

#### Start of system configuration section. ####

srcdir = .
topdir = /Users/pcoder/.rvm/rubies/ruby-1.9.2-p290/include/ruby-1.9.1
hdrdir = /Users/pcoder/.rvm/rubies/ruby-1.9.2-p290/include/ruby-1.9.1
arch_hdrdir = /Users/pcoder/.rvm/rubies/ruby-1.9.2-p290/include/ruby-1.9.1/$(arch)
VPATH = $(srcdir):$(arch_hdrdir)/ruby:$(hdrdir)/ruby
prefix = $(DESTDIR)/Users/pcoder/.rvm/rubies/ruby-1.9.2-p290
rubylibprefix = $(libdir)/$(RUBY_BASE_NAME)
exec_prefix = $(prefix)
vendorhdrdir = $(rubyhdrdir)/vendor_ruby
sitehdrdir = $(rubyhdrdir)/site_ruby
rubyhdrdir = $(includedir)/$(RUBY_BASE_NAME)-$(ruby_version)
vendordir = $(rubylibprefix)/vendor_ruby
sitedir = $(rubylibprefix)/site_ruby
ridir = $(datarootdir)/$(RI_BASE_NAME)
mandir = $(datarootdir)/man
localedir = $(datarootdir)/locale
libdir = $(exec_prefix)/lib
psdir = $(docdir)
pdfdir = $(docdir)
dvidir = $(docdir)
htmldir = $(docdir)
infodir = $(datarootdir)/info
docdir = $(datarootdir)/doc/$(PACKAGE)
oldincludedir = $(DESTDIR)/usr/include
includedir = $(prefix)/include
localstatedir = $(prefix)/var
sharedstatedir = $(prefix)/com
sysconfdir = $(prefix)/etc
datadir = $(datarootdir)
datarootdir = $(prefix)/share
libexecdir = $(exec_prefix)/libexec
sbindir = $(exec_prefix)/sbin
bindir = $(exec_prefix)/bin
rubylibdir = $(rubylibprefix)/$(ruby_version)
archdir = $(rubylibdir)/$(arch)
sitelibdir = $(sitedir)/$(ruby_version)
sitearchdir = $(sitelibdir)/$(sitearch)
vendorlibdir = $(vendordir)/$(ruby_version)
vendorarchdir = $(vendorlibdir)/$(sitearch)

CC = gcc
CXX = g++
LIBRUBY = $(LIBRUBY_SO)
LIBRUBY_A = lib$(RUBY_SO_NAME)-static.a
LIBRUBYARG_SHARED = -l$(RUBY_SO_NAME)
LIBRUBYARG_STATIC = -l$(RUBY_SO_NAME)-static
OUTFLAG = -o 
COUTFLAG = -o 

RUBY_EXTCONF_H = 
cflags   =  $(optflags) $(debugflags) $(warnflags)
optflags = -O3
debugflags = -ggdb
warnflags = -Wextra -Wno-unused-parameter -Wno-parentheses -Wpointer-arith -Wwrite-strings -Wno-missing-field-initializers -Wshorten-64-to-32 -Wno-long-long
CFLAGS   = -fno-common -isysroot /Developer/SDKs/MacOSX10.6.sdk -arch x86_64 -fno-common -pipe 
INCFLAGS = -I. -I$(arch_hdrdir) -I$(hdrdir)/ruby/backward -I$(hdrdir) -I$(srcdir)
DEFS     = 
CPPFLAGS =  -D_XOPEN_SOURCE -D_DARWIN_C_SOURCE $(DEFS) $(cppflags)
CXXFLAGS = $(CFLAGS) $(cxxflags)
ldflags  = -L. -Wl,-syslibroot /Developer/SDKs/MacOSX10.6.sdk -arch x86_64
dldflags = -Wl,-undefined,dynamic_lookup -Wl,-multiply_defined,suppress -Wl,-flat_namespace
ARCH_FLAG = 
DLDFLAGS = $(ldflags) $(dldflags)
LDSHARED = $(CC) -dynamic -bundle
LDSHAREDXX = $(CXX) -dynamic -bundle
AR = ar
EXEEXT = 

RUBY_BASE_NAME = ruby
RUBY_INSTALL_NAME = ruby
RUBY_SO_NAME = ruby.1.9.1
arch = x86_64-darwin10.7.0
sitearch = $(arch)
ruby_version = 1.9.1
ruby = /Users/pcoder/.rvm/rubies/ruby-1.9.2-p290/bin/ruby
RUBY = $(ruby)
RM = rm -f
RM_RF = $(RUBY) -run -e rm -- -rf
RMDIRS = $(RUBY) -run -e rmdir -- -p
MAKEDIRS = mkdir -p
INSTALL = /usr/bin/install -c
INSTALL_PROG = $(INSTALL) -m 0755
INSTALL_DATA = $(INSTALL) -m 644
COPY = cp

#### End of system configuration section. ####

preload = 

libpath = . $(libdir)
LIBPATH =  -L. -L$(libdir)
DEFFILE = 

CLEANFILES = mkmf.log
DISTCLEANFILES = 
DISTCLEANDIRS = 

extout = 
extout_prefix = 
target_prefix = 
LOCAL_LIBS = 
LIBS = $(LIBRUBYARG_SHARED)  -lpthread -ldl -lobjc 
SRCS = 
OBJS = 
TARGET = 
DLLIB = 
EXTSTATIC = 
STATIC_LIB = 

BINDIR        = $(bindir)
RUBYCOMMONDIR = $(sitedir)$(target_prefix)
RUBYLIBDIR    = $(sitelibdir)$(target_prefix)
RUBYARCHDIR   = $(sitearchdir)$(target_prefix)
HDRDIR        = $(rubyhdrdir)/ruby$(target_prefix)
ARCHHDRDIR    = $(rubyhdrdir)/$(arch)/ruby$(target_prefix)

TARGET_SO     = $(DLLIB)
CLEANLIBS     = $(TARGET).bundle 
CLEANOBJS     = *.o  *.bak

all:    Makefile
static: $(STATIC_LIB)
.PHONY: all install static install-so install-rb
.PHONY: clean clean-so clean-rb

clean-rb-default::
clean-rb::
clean-so::
clean: clean-so clean-rb-default clean-rb
        @-$(RM) $(CLEANLIBS) $(CLEANOBJS) $(CLEANFILES)

distclean-rb-default::
distclean-rb::
distclean-so::
distclean: clean distclean-so distclean-rb-default distclean-rb
        @-$(RM) Makefile $(RUBY_EXTCONF_H) conftest.* mkmf.log
        @-$(RM) core ruby$(EXEEXT) *~ $(DISTCLEANFILES)
        @-$(RMDIRS) $(DISTCLEANDIRS)

realclean: distclean
install: install-so install-rb

install-so: Makefile
install-rb: pre-install-rb install-rb-default
install-rb-default: pre-install-rb-default
pre-install-rb: Makefile
pre-install-rb-default: Makefile

site-install: site-install-so site-install-rb
site-install-so: install-so
site-install-rb: install-rb

Answer 1

all:    Makefile

this string is wrong, all target should make your extension, and not a Makefile itself. here is a part of Makefile generated from a random extconf.rb on my system:

all:    $(DLLIB)

yours should be the same. a possible error is in extconf.rb.

my extconf.rb:

require 'mkmf'

have_header('ruby.h') or missing('ruby.h')
create_makefile('ext')

files ext.c & ext.h are presend and contain actual extension C code