binutils-gdb/gdb/buildsym-legacy.c
Tom Tromey 48e0f38c30 Fix line table regression
Simon pointed out a line table regression, and after a couple of false
starts, I was able to reproduce it by hand using his instructions.

The bug is that most of the code in do_mixed_source_and_assembly uses
unrelocated addresses, but one spot does:

  pc = low;

... after the text offset has been removed.

This patch fixes the problem by introducing a new type to represent
unrelocated addresses in the line table.  This prevents this sort of
bug to some degree (it's still possible to manipulate a CORE_ADDR in a
bad way, this is unavoidable).

However, this did let the compiler flag a few spots in that function,
and now it's not possible to compare an unrelocated address from a
line table with an ordinary CORE_ADDR.

Regression tested on x86-64 Fedora 36, though note this setup never
reproduced the bug in the first place.  I also tested it by hand on
the disasm-optim test program.
2023-03-17 16:17:43 -06:00

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/* Legacy support routines for building symbol tables in GDB's internal format.
Copyright (C) 1986-2023 Free Software Foundation, Inc.
This file is part of GDB.
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, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "buildsym-legacy.h"
#include "symtab.h"
/* The work-in-progress of the compunit we are building.
This is created first, before any subfiles by start_compunit_symtab. */
static struct buildsym_compunit *buildsym_compunit;
void
record_debugformat (const char *format)
{
buildsym_compunit->record_debugformat (format);
}
void
record_producer (const char *producer)
{
buildsym_compunit->record_producer (producer);
}
/* See buildsym.h. */
void
set_last_source_file (const char *name)
{
gdb_assert (buildsym_compunit != nullptr || name == nullptr);
if (buildsym_compunit != nullptr)
buildsym_compunit->set_last_source_file (name);
}
/* See buildsym.h. */
const char *
get_last_source_file ()
{
if (buildsym_compunit == nullptr)
return nullptr;
return buildsym_compunit->get_last_source_file ();
}
/* See buildsym.h. */
void
set_last_source_start_addr (CORE_ADDR addr)
{
gdb_assert (buildsym_compunit != nullptr);
buildsym_compunit->set_last_source_start_addr (addr);
}
/* See buildsym.h. */
CORE_ADDR
get_last_source_start_addr ()
{
gdb_assert (buildsym_compunit != nullptr);
return buildsym_compunit->get_last_source_start_addr ();
}
/* See buildsym.h. */
bool
outermost_context_p ()
{
gdb_assert (buildsym_compunit != nullptr);
return buildsym_compunit->outermost_context_p ();
}
/* See buildsym.h. */
int
get_context_stack_depth ()
{
gdb_assert (buildsym_compunit != nullptr);
return buildsym_compunit->get_context_stack_depth ();
}
/* See buildsym.h. */
struct subfile *
get_current_subfile ()
{
gdb_assert (buildsym_compunit != nullptr);
return buildsym_compunit->get_current_subfile ();
}
/* See buildsym.h. */
struct pending **
get_local_symbols ()
{
gdb_assert (buildsym_compunit != nullptr);
return buildsym_compunit->get_local_symbols ();
}
/* See buildsym.h. */
struct pending **
get_file_symbols ()
{
gdb_assert (buildsym_compunit != nullptr);
return buildsym_compunit->get_file_symbols ();
}
/* See buildsym.h. */
struct pending **
get_global_symbols ()
{
gdb_assert (buildsym_compunit != nullptr);
return buildsym_compunit->get_global_symbols ();
}
void
start_subfile (const char *name)
{
gdb_assert (buildsym_compunit != nullptr);
buildsym_compunit->start_subfile (name);
}
void
patch_subfile_names (struct subfile *subfile, const char *name)
{
gdb_assert (buildsym_compunit != nullptr);
buildsym_compunit->patch_subfile_names (subfile, name);
}
void
push_subfile ()
{
gdb_assert (buildsym_compunit != nullptr);
buildsym_compunit->push_subfile ();
}
const char *
pop_subfile ()
{
gdb_assert (buildsym_compunit != nullptr);
return buildsym_compunit->pop_subfile ();
}
/* Delete the buildsym compunit. */
static void
free_buildsym_compunit (void)
{
if (buildsym_compunit == NULL)
return;
delete buildsym_compunit;
buildsym_compunit = NULL;
}
struct compunit_symtab *
end_compunit_symtab (CORE_ADDR end_addr)
{
gdb_assert (buildsym_compunit != nullptr);
struct compunit_symtab *result
= buildsym_compunit->end_compunit_symtab (end_addr);
free_buildsym_compunit ();
return result;
}
struct context_stack *
push_context (int desc, CORE_ADDR valu)
{
gdb_assert (buildsym_compunit != nullptr);
return buildsym_compunit->push_context (desc, valu);
}
struct context_stack
pop_context ()
{
gdb_assert (buildsym_compunit != nullptr);
return buildsym_compunit->pop_context ();
}
struct block *
finish_block (struct symbol *symbol, struct pending_block *old_blocks,
const struct dynamic_prop *static_link,
CORE_ADDR start, CORE_ADDR end)
{
gdb_assert (buildsym_compunit != nullptr);
return buildsym_compunit->finish_block (symbol, old_blocks, static_link,
start, end);
}
void
record_line (struct subfile *subfile, int line, unrelocated_addr pc)
{
gdb_assert (buildsym_compunit != nullptr);
/* Assume every line entry is a statement start, that is a good place to
put a breakpoint for that line number. */
buildsym_compunit->record_line (subfile, line, pc, LEF_IS_STMT);
}
/* Start a new compunit_symtab for a new source file in OBJFILE. Called, for
example, when a stabs symbol of type N_SO is seen, or when a DWARF
DW_TAG_compile_unit DIE is seen. It indicates the start of data for one
original source file.
NAME is the name of the file (cannot be NULL). COMP_DIR is the
directory in which the file was compiled (or NULL if not known).
START_ADDR is the lowest address of objects in the file (or 0 if
not known). LANGUAGE is the language of the source file, or
language_unknown if not known, in which case it'll be deduced from
the filename. */
struct compunit_symtab *
start_compunit_symtab (struct objfile *objfile, const char *name,
const char *comp_dir, CORE_ADDR start_addr,
enum language language)
{
/* These should have been reset either by successful completion of building
a symtab, or by the scoped_free_pendings destructor. */
gdb_assert (buildsym_compunit == nullptr);
buildsym_compunit = new struct buildsym_compunit (objfile, name, comp_dir,
language, start_addr);
return buildsym_compunit->get_compunit_symtab ();
}
/* At end of reading syms, or in case of quit, ensure everything
associated with building symtabs is freed.
N.B. This is *not* intended to be used when building psymtabs. Some debug
info readers call this anyway, which is harmless if confusing. */
scoped_free_pendings::~scoped_free_pendings ()
{
free_buildsym_compunit ();
}
/* See buildsym-legacy.h. */
struct buildsym_compunit *
get_buildsym_compunit ()
{
gdb_assert (buildsym_compunit != nullptr);
return buildsym_compunit;
}