mkmf.rb

- check_sizeof() crashes my extconf.rb script.
$ echo 'check_sizeof("short")' | ruby -r mkmf -
checking size of short... 2
/usr/local/lib/ruby/1.8/mkmf.rb:570:in `check_sizeof': undefined local
variable or method `r' for main:Object (NameError)
        from -:1
------
## Looking at the source, seems like size should be returned not r:
def check_sizeof(type, header = nil, &b)
  expr = "sizeof(#{type})"
  m = "checking size of #{type}... "
  message "%s", m
  Logging::message "check_sizeof: %s--------------------\n", m
  if size = try_constant(expr, header, &b)
    $defs.push(format("-DSIZEOF_%s", type.upcase))
  end
  message(a = size ? "#{size}\n" : "failed\n")
  Logging::message "-------------------- %s\n", a
  r
end
------
Other problems with check_sizeof():
the line:
    $defs.push(format("-DSIZEOF_%s", type.upcase))
should probably be:
    $defs.push(format("-DSIZEOF_%s=%i", type.upcase, size))
or (taken from latest source)
    $defs.push(format("-DSIZEOF_%s=%i", type.upcase.tr_s("^A-Z0-9_", "_"),
size))
-----
This leads to a problem with create_header()
Looks like the regexp on line 619
/^-D(.*)(?:=(.*))?/
used to parse $defs should be
/^-D([^=]+)(=(.*))?/
and line 620 changed to:
    hfile.print "#define #$1 #{$3 || 1}\n"
from
    hfile.print "#define #$1 #{$2 || 1}\n"
----
using irb:
> '-DSIZEOF_INT=4' =~  /^-D(.*)(?:=(.*))?/  # old regexp
=> 0
> puts $1, $2, $3
SIZEOF_INT=4
nil
nil
=> nil
> '-DSIZEOF_INT=4' =~  /^-D([^=]+)(=(.*))?/  # possible replacement
=> 0
> puts $1, $2, $3
SIZEOF_INT
=4
4
=> nil
> '-DHAVE_STRING_H' =~  /^-D([^=]+)(=(.*))?/  # possible replacement
=> 0
> puts $1, $2, $3
HAVE_STRING_H
nil
nil
=> nil
------------
Charlie