binutils-gdb/gold/errors.cc
Cary Coutant 648c5cbbf3 Fix problem where gold fails to issue an undefined symbol error during LTO.
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.
2016-03-21 21:42:15 -07:00

429 lines
9.9 KiB
C++

// errors.cc -- handle errors for gold
// Copyright (C) 2006-2016 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
// MA 02110-1301, USA.
#include "gold.h"
#include <cstdarg>
#include <cstdio>
#include "gold-threads.h"
#include "parameters.h"
#include "object.h"
#include "symtab.h"
#include "errors.h"
namespace gold
{
// Class Errors.
const int Errors::max_undefined_error_report;
Errors::Errors(const char* program_name)
: program_name_(program_name), lock_(NULL), initialize_lock_(&this->lock_),
error_count_(0), warning_count_(0), undefined_symbols_()
{
}
// Initialize the lock_ field. If we have not yet processed the
// parameters, then we can't initialize, since we don't yet know
// whether we are using threads. That is OK, since if we haven't
// processed the parameters, we haven't created any threads, and we
// don't need a lock. Return true if the lock is now initialized.
bool
Errors::initialize_lock()
{
return this->initialize_lock_.initialize();
}
// Increment a counter, holding the lock if available.
void
Errors::increment_counter(int *counter)
{
if (!this->initialize_lock())
{
// The lock does not exist, which means that we don't need it.
++*counter;
}
else
{
Hold_lock h(*this->lock_);
++*counter;
}
}
// Report a fatal error.
void
Errors::fatal(const char* format, va_list args)
{
fprintf(stderr, _("%s: fatal error: "), this->program_name_);
vfprintf(stderr, format, args);
fputc('\n', stderr);
gold_exit(GOLD_ERR);
}
// Report a fallback error.
void
Errors::fallback(const char* format, va_list args)
{
fprintf(stderr, _("%s: fatal error: "), this->program_name_);
vfprintf(stderr, format, args);
fputc('\n', stderr);
gold_exit(GOLD_FALLBACK);
}
// Report an error.
void
Errors::error(const char* format, va_list args)
{
fprintf(stderr, _("%s: error: "), this->program_name_);
vfprintf(stderr, format, args);
fputc('\n', stderr);
this->increment_counter(&this->error_count_);
}
// Report a warning.
void
Errors::warning(const char* format, va_list args)
{
fprintf(stderr, _("%s: warning: "), this->program_name_);
vfprintf(stderr, format, args);
fputc('\n', stderr);
this->increment_counter(&this->warning_count_);
}
// Print an informational message.
void
Errors::info(const char* format, va_list args)
{
vfprintf(stderr, format, args);
fputc('\n', stderr);
}
// Report an error at a reloc location.
template<int size, bool big_endian>
void
Errors::error_at_location(const Relocate_info<size, big_endian>* relinfo,
size_t relnum, off_t reloffset,
const char* format, va_list args)
{
fprintf(stderr, _("%s: error: "),
relinfo->location(relnum, reloffset).c_str());
vfprintf(stderr, format, args);
fputc('\n', stderr);
this->increment_counter(&this->error_count_);
}
// Report a warning at a reloc location.
template<int size, bool big_endian>
void
Errors::warning_at_location(const Relocate_info<size, big_endian>* relinfo,
size_t relnum, off_t reloffset,
const char* format, va_list args)
{
fprintf(stderr, _("%s: warning: "),
relinfo->location(relnum, reloffset).c_str());
vfprintf(stderr, format, args);
fputc('\n', stderr);
this->increment_counter(&this->warning_count_);
}
// Issue an undefined symbol error with a caller-supplied location string.
void
Errors::undefined_symbol(const Symbol* sym, const std::string& location)
{
bool initialized = this->initialize_lock();
gold_assert(initialized);
const char* zmsg;
{
Hold_lock h(*this->lock_);
if (++this->undefined_symbols_[sym] >= max_undefined_error_report)
return;
if (parameters->options().warn_unresolved_symbols())
{
++this->warning_count_;
zmsg = _("warning");
}
else
{
++this->error_count_;
zmsg = _("error");
}
}
const char* const version = sym->version();
if (version == NULL)
fprintf(stderr, _("%s: %s: undefined reference to '%s'\n"),
location.c_str(), zmsg, sym->demangled_name().c_str());
else
fprintf(stderr,
_("%s: %s: undefined reference to '%s', version '%s'\n"),
location.c_str(), zmsg, sym->demangled_name().c_str(), version);
if (sym->is_cxx_vtable())
gold_info(_("%s: the vtable symbol may be undefined because "
"the class is missing its key function"),
program_name);
if (sym->is_placeholder())
gold_info(_("%s: the symbol should have been defined by a plugin"),
program_name);
}
// Issue a debugging message.
void
Errors::debug(const char* format, ...)
{
fprintf(stderr, _("%s: "), this->program_name_);
va_list args;
va_start(args, format);
vfprintf(stderr, format, args);
va_end(args);
fputc('\n', stderr);
}
// The functions which the rest of the code actually calls.
// Report a fatal error.
void
gold_fatal(const char* format, ...)
{
va_list args;
va_start(args, format);
parameters->errors()->fatal(format, args);
va_end(args);
}
// Report a fallback error.
void
gold_fallback(const char* format, ...)
{
va_list args;
va_start(args, format);
parameters->errors()->fallback(format, args);
va_end(args);
}
// Report an error.
void
gold_error(const char* format, ...)
{
va_list args;
va_start(args, format);
parameters->errors()->error(format, args);
va_end(args);
}
// Report a warning.
void
gold_warning(const char* format, ...)
{
va_list args;
va_start(args, format);
parameters->errors()->warning(format, args);
va_end(args);
}
// Print an informational message.
void
gold_info(const char* format, ...)
{
va_list args;
va_start(args, format);
parameters->errors()->info(format, args);
va_end(args);
}
// Report an error at a location.
template<int size, bool big_endian>
void
gold_error_at_location(const Relocate_info<size, big_endian>* relinfo,
size_t relnum, off_t reloffset,
const char* format, ...)
{
va_list args;
va_start(args, format);
parameters->errors()->error_at_location(relinfo, relnum, reloffset,
format, args);
va_end(args);
}
// Report a warning at a location.
template<int size, bool big_endian>
void
gold_warning_at_location(const Relocate_info<size, big_endian>* relinfo,
size_t relnum, off_t reloffset,
const char* format, ...)
{
va_list args;
va_start(args, format);
parameters->errors()->warning_at_location(relinfo, relnum, reloffset,
format, args);
va_end(args);
}
// Report an undefined symbol.
void
gold_undefined_symbol(const Symbol* sym)
{
parameters->errors()->undefined_symbol(sym, sym->object()->name().c_str());
}
// Report an undefined symbol at a reloc location
template<int size, bool big_endian>
void
gold_undefined_symbol_at_location(const Symbol* sym,
const Relocate_info<size, big_endian>* relinfo,
size_t relnum, off_t reloffset)
{
parameters->errors()->undefined_symbol(sym,
relinfo->location(relnum, reloffset));
}
#ifdef HAVE_TARGET_32_LITTLE
template
void
gold_error_at_location<32, false>(const Relocate_info<32, false>* relinfo,
size_t relnum, off_t reloffset,
const char* format, ...);
#endif
#ifdef HAVE_TARGET_32_BIG
template
void
gold_error_at_location<32, true>(const Relocate_info<32, true>* relinfo,
size_t relnum, off_t reloffset,
const char* format, ...);
#endif
#ifdef HAVE_TARGET_64_LITTLE
template
void
gold_error_at_location<64, false>(const Relocate_info<64, false>* relinfo,
size_t relnum, off_t reloffset,
const char* format, ...);
#endif
#ifdef HAVE_TARGET_64_BIG
template
void
gold_error_at_location<64, true>(const Relocate_info<64, true>* relinfo,
size_t relnum, off_t reloffset,
const char* format, ...);
#endif
#ifdef HAVE_TARGET_32_LITTLE
template
void
gold_warning_at_location<32, false>(const Relocate_info<32, false>* relinfo,
size_t relnum, off_t reloffset,
const char* format, ...);
#endif
#ifdef HAVE_TARGET_32_BIG
template
void
gold_warning_at_location<32, true>(const Relocate_info<32, true>* relinfo,
size_t relnum, off_t reloffset,
const char* format, ...);
#endif
#ifdef HAVE_TARGET_64_LITTLE
template
void
gold_warning_at_location<64, false>(const Relocate_info<64, false>* relinfo,
size_t relnum, off_t reloffset,
const char* format, ...);
#endif
#ifdef HAVE_TARGET_64_BIG
template
void
gold_warning_at_location<64, true>(const Relocate_info<64, true>* relinfo,
size_t relnum, off_t reloffset,
const char* format, ...);
#endif
#ifdef HAVE_TARGET_32_LITTLE
template
void
gold_undefined_symbol_at_location<32, false>(
const Symbol* sym,
const Relocate_info<32, false>* relinfo,
size_t relnum, off_t reloffset);
#endif
#ifdef HAVE_TARGET_32_BIG
template
void
gold_undefined_symbol_at_location<32, true>(
const Symbol* sym,
const Relocate_info<32, true>* relinfo,
size_t relnum, off_t reloffset);
#endif
#ifdef HAVE_TARGET_64_LITTLE
template
void
gold_undefined_symbol_at_location<64, false>(
const Symbol* sym,
const Relocate_info<64, false>* relinfo,
size_t relnum, off_t reloffset);
#endif
#ifdef HAVE_TARGET_64_BIG
template
void
gold_undefined_symbol_at_location<64, true>(
const Symbol* sym,
const Relocate_info<64, true>* relinfo,
size_t relnum, off_t reloffset);
#endif
} // End namespace gold.