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Fix symbol versioning problems in PR 18703.

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If a symbol is defined with ".symver foo,foo@VER", the assembler
creates two symbols in the object: one unversioned, and one with
the (non-default) version "VER". If foo is listed in a version
script, gold would then make the first of those symbols the
default version, and would ignore the second symbol as a
duplicate, without making it a non-default version. While this is
arguably reasonable behavior, it doesn't match Gnu ld behavior,
so this patch fixes that by allowing the second definition to
override the first by resetting the "default version" indication.

Several test cases from the Gnu ld testsuite also exposed another
related problem, where a symbol defined with ".symver foo,foo@",
placed into a shared library, is not handled properly by gold.
This patch also fixes that case, binding the symbol to the base
version.

gold/
	PR gold/18703
	* dynobj.cc (Versions::record_version): Handle symbol defined with
	base version.
	(Versions::symbol_section_contents): Likewise.
	* symtab.h (Symbol::set_is_not_default): New class method.
	(Symbol_table::resolve): Add is_default_version parameter.
	(Symbol_table::should_override): Likewise.
	* resolve.cc (Symbol_table::resolve): Add is_default_version parameter,
	and pass to should_override. Adjust all callers and explicit
	instantiations.
	(Symbol_table::should_override): Add is_default_value parameter;
	allow default version in a dynamic object to override existing
	definition from same object.
	* symtab.cc (Symbol_table::add_from_object): Handle case where same
	symbol is defined as unversioned and non-default version in the same
	object.
	* testsuite/Makefile.am (ver_test_13): New test case.
	* testsuite/Makefile.in: Regenerate.
	* testsuite/ver_test_4.cc: Add test for symbol with base version.
	* testsuite/ver_test_4.sh: Likewise.
	* testsuite/ver_test_13.c: New source file.
	* testsuite/ver_test_13.script: New version script.
	* testsuite/ver_test_13.sh: New test case.
This commit is contained in:
Cary Coutant
2015-07-27 15:09:08 -07:00
parent e49433d22d
commit b45e00b3ed
11 changed files with 171 additions and 21 deletions
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12
gold/dynobj.cc
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@@ -1499,6 +1499,10 @@ Versions::record_version(const Symbol_table* symtab,
gold_assert(!this->is_finalized_);
gold_assert(sym->version() != NULL);
// A symbol defined as "sym@" is bound to an unspecified base version.
if (sym->version()[0] == '\0')
return;
Stringpool::Key version_key;
const char* version = dynpool->add(sym->version(), false, &version_key);
@@ -1731,15 +1735,17 @@ Versions::symbol_section_contents(const Symbol_table* symtab,
{
unsigned int version_index;
const char* version = (*p)->version();
if (version != NULL)
version_index = this->version_index(symtab, dynpool, *p);
else
if (version == NULL)
{
if ((*p)->is_defined() && !(*p)->is_from_dynobj())
version_index = elfcpp::VER_NDX_GLOBAL;
else
version_index = elfcpp::VER_NDX_LOCAL;
}
else if (version[0] == '\0')
version_index = elfcpp::VER_NDX_GLOBAL;
else
version_index = this->version_index(symtab, dynpool, *p);
// If the symbol was defined as foo@V1 instead of foo@@V1, add
// the hidden bit.
if ((*p)->version() != NULL && !(*p)->is_default())