[PATCH] D21745: [ELF] - Implemented --no-undefined-version flag

[George Rimar via llvm-commits]

grimar created this revision.
grimar added reviewers: ruiu, rafael.
grimar added subscribers: llvm-commits, grimar.

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.

Description in not very clear in my opinion about what it should do.
Fortunately, Ian Lance Tailor leaved a message in binutils maillist
(https://sourceware.org/ml/binutils/2010-01/msg00092.html)

From there:
"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."

Patch implements that behavior. This fixes PR27448.


http://reviews.llvm.org/D21745

Files:
  ELF/Config.h
  ELF/Driver.cpp
  ELF/Options.td
  ELF/SymbolTable.cpp
  test/ELF/version-script-noundef.s

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