During LTO, if (1) an IR file contains a COMDAT group that is kept,
(2) a later non-claimed file contains the same group, which we discard,
and (3) the plugin fails to provide a definition of the symbols in that
COMDAT group, gold silently resolves any references to those symbols
to 0.
This patch adds a check for a placeholder symbol when deciding
whether to issue an undefined symbol error. It also adds an extra
note after any undefined placeholder symbol error that explains
that a definition was expected from the plugin.
gold/
PR gold/19842
* errors.cc (Errors::undefined_symbol): Add info message when
symbol should have been provided by a plugin.
* target-reloc.h (issue_undefined_symbol_error): Check for
placeholder symbols defined in discarded sections.
* testsuite/Makefile.am (plugin_test_9b): New test case.
* testsuite/Makefile.in: Regenerate.
* testsuite/plugin_test_9b_elf.cc: New test source file.
* testsuite/plugin_test_9b_ir.cc: New test source file.
PR binutils/15435 complains that gold issues a visibility error for an
weak undefined symbol with hidden visibility. The message should be
suppressed if the symbol is a weak undef.
An earlier patch to add an extra note about key functions when a class's
vtable symbol is undefined missed a case where the reference to the
vtable came from a shared library. This patch moves the check to a
lower-level routine that catches both cases.
gold/
2014-02-05 Cary Coutant <ccoutant@google.com>
* errors.cc (Errors::undefined_symbol): Move undef vtable symbol
check to here.
* target-reloc.h (is_strong_undefined): New function.
(relocate_section): Move undef vtable symbol check from here.
Check for is_strong_undefined.
* gold.h (gold_undefined_symbol): Change to take only a Symbol
pointer and to report location as the file name associated with
the symbol.
(gold_undefined_symbol_at_location): New function to replace the
old gold_undefined_symbol functionality.
* target-reloc.h (relocate_section): Update to use
gold_undefined_symbol_at_location.
* symtab.cc (Symbol_table::warn_about_undefined_dynobj_symbol):
Call gold_undefined_symbol function rather than gold_error.
* errors.h (Errors::undefined_symbol): Take location as a
string, rather than calculating it from a relocation.
* errors.cc (Errors::fatal): Print "fatal error:" before the
formatted message.
(Errors::error, Errors::error_at_location): Print "error: "
before the formatted message.
(Errors::undefined_symbol): Take location as a string, rather
than calculating it from a relocation.
(gold_undefined_symbol_at_location): New function akin to
old gold_undefined_symbol, calculates location from relocation.
(gold_undefined_symbol): Change to take only a Symbol pointer
and to report location as the file name associated with the symbol.
* testsuite/debug_msg.sh: Update for changed error messages.
* testsuite/undef_symbol.sh: Likewise.
