--no-undefined-version

[Ian Lance Taylor <iant at google dot com>]

The GNU ld option --no-undefined-version is defined as follows:

    Normally when a symbol has an undefined version, the linker will
    ignore it.  This option disallows symbols with undefined version
    and a fatal error will be issued instead.

As far as I can tell, what the option actually does is this:

For each version defined in a version script:
  for each global symbol pattern in that version listed in the script:
    if the pattern is a literal string--not a wildcard pattern:
      if the pattern does not match any symbol defined in the link:
        give an error.

In other words, the option does not check for symbols with undefined
versions.  It checks for cases where a version script explicitly lists
a symbol, but the symbol is not defined.

The option was added here:

http://sourceware.org/ml/binutils/2002-08/msg00100.html

I'm about to add the option to gold, so I wanted to mention this in
case anybody thinks that the error is in the code rather than in the
documentation.

According to PR 10980 this option is used by the libdebian-installer
package, but I haven't looked at that.

Ian