/* Load module for 'compile' command.
Copyright (C) 2014-2022 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 "compile-object-load.h"
#include "compile-internal.h"
#include "command.h"
#include "objfiles.h"
#include "gdbcore.h"
#include "readline/tilde.h"
#include "bfdlink.h"
#include "gdbcmd.h"
#include "regcache.h"
#include "inferior.h"
#include "gdbthread.h"
#include "compile.h"
#include "block.h"
#include "arch-utils.h"
#include <algorithm>
/* Add inferior mmap memory range ADDR..ADDR+SIZE (exclusive) to the
list. */
void
munmap_list::add (CORE_ADDR addr, CORE_ADDR size)
{
struct munmap_item item = { addr, size };
items.push_back (item);
}
/* Destroy an munmap_list. */
munmap_list::~munmap_list ()
{
for (auto &item : items)
{
try
{
gdbarch_infcall_munmap (target_gdbarch (), item.addr, item.size);
}
catch (const gdb_exception_error &ex)
{
/* There's not much the user can do, so just ignore
this. */
}
}
}
/* A data structure that is used to lay out sections of our objfile in
inferior memory. */
struct setup_sections_data
{
explicit setup_sections_data (bfd *abfd)
: m_bfd (abfd),
m_last_section_first (abfd->sections)
{
}
/* Place all ABFD sections next to each other obeying all
constraints. */
void setup_one_section (asection *sect);
/* List of inferior mmap ranges where setup_sections should add its
next range. */
struct munmap_list munmap_list;
private:
/* The BFD. */
bfd *m_bfd;
/* Size of all recent sections with matching LAST_PROT. */
CORE_ADDR m_last_size = 0;
/* First section matching LAST_PROT. */
asection *m_last_section_first;
/* Memory protection like the prot parameter of gdbarch_infcall_mmap. */
unsigned m_last_prot = -1;
/* Maximum of alignments of all sections matching LAST_PROT.
This value is always at least 1. This value is always a power of 2. */
CORE_ADDR m_last_max_alignment = -1;
};
/* See setup_sections_data. */
void
setup_sections_data::setup_one_section (asection *sect)
{
CORE_ADDR alignment;
unsigned prot;
if (sect != NULL)
{
/* It is required by later bfd_get_relocated_section_contents. */
if (sect->output_section == NULL)
sect->output_section = sect;
if ((bfd_section_flags (sect) & SEC_ALLOC) == 0)
return;
/* Make the memory always readable. */
prot = GDB_MMAP_PROT_READ;
if ((bfd_section_flags (sect) & SEC_READONLY) == 0)
prot |= GDB_MMAP_PROT_WRITE;
if ((bfd_section_flags (sect) & SEC_CODE) != 0)
prot |= GDB_MMAP_PROT_EXEC;
if (compile_debug)
gdb_printf (gdb_stdlog,
"module \"%s\" section \"%s\" size %s prot %u\n",
bfd_get_filename (m_bfd),
bfd_section_name (sect),
paddress (target_gdbarch (),
bfd_section_size (sect)),
prot);
}
else
prot = -1;
if (sect == NULL
|| (m_last_prot != prot && bfd_section_size (sect) != 0))
{
CORE_ADDR addr;
asection *sect_iter;
if (m_last_size != 0)
{
addr = gdbarch_infcall_mmap (target_gdbarch (), m_last_size,
m_last_prot);
munmap_list.add (addr, m_last_size);
if (compile_debug)
gdb_printf (gdb_stdlog,
"allocated %s bytes at %s prot %u\n",
paddress (target_gdbarch (), m_last_size),
paddress (target_gdbarch (), addr),
m_last_prot);
}
else
addr = 0;
if ((addr & (m_last_max_alignment - 1)) != 0)
error (_("Inferior compiled module address %s "
"is not aligned to BFD required %s."),
paddress (target_gdbarch (), addr),
paddress (target_gdbarch (), m_last_max_alignment));
for (sect_iter = m_last_section_first; sect_iter != sect;
sect_iter = sect_iter->next)
if ((bfd_section_flags (sect_iter) & SEC_ALLOC) != 0)
bfd_set_section_vma (sect_iter, addr + bfd_section_vma (sect_iter));
m_last_size = 0;
m_last_section_first = sect;
m_last_prot = prot;
m_last_max_alignment = 1;
}
if (sect == NULL)
return;
alignment = ((CORE_ADDR) 1) << bfd_section_alignment (sect);
m_last_max_alignment = std::max (m_last_max_alignment, alignment);
m_last_size = (m_last_size + alignment - 1) & -alignment;
bfd_set_section_vma (sect, m_last_size);
m_last_size += bfd_section_size (sect);
m_last_size = (m_last_size + alignment - 1) & -alignment;
}
/* Helper for link_callbacks callbacks vector. */
static void
link_callbacks_multiple_definition (struct bfd_link_info *link_info,
struct bfd_link_hash_entry *h, bfd *nbfd,
asection *nsec, bfd_vma nval)
{
bfd *abfd = link_info->input_bfds;
if (link_info->allow_multiple_definition)
return;
warning (_("Compiled module \"%s\": multiple symbol definitions: %s"),
bfd_get_filename (abfd), h->root.string);
}
/* Helper for link_callbacks callbacks vector. */
static void
link_callbacks_warning (struct bfd_link_info *link_info, const char *xwarning,
const char *symbol, bfd *abfd, asection *section,
bfd_vma address)
{
warning (_("Compiled module \"%s\" section \"%s\": warning: %s"),
bfd_get_filename (abfd), bfd_section_name (section),
xwarning);
}
/* Helper for link_callbacks callbacks vector. */
static void
link_callbacks_undefined_symbol (struct bfd_link_info *link_info,
const char *name, bfd *abfd, asection *section,
bfd_vma address, bfd_boolean is_fatal)
{
warning (_("Cannot resolve relocation to \"%s\" "
"from compiled module \"%s\" section \"%s\"."),
name, bfd_get_filename (abfd), bfd_section_name (section));
}
/* Helper for link_callbacks callbacks vector. */
static void
link_callbacks_reloc_overflow (struct bfd_link_info *link_info,
struct bfd_link_hash_entry *entry,
const char *name, const char *reloc_name,
bfd_vma addend, bfd *abfd, asection *section,
bfd_vma address)
{
}
/* Helper for link_callbacks callbacks vector. */
static void
link_callbacks_reloc_dangerous (struct bfd_link_info *link_info,
const char *message, bfd *abfd,
asection *section, bfd_vma address)
{
warning (_("Compiled module \"%s\" section \"%s\": dangerous "
"relocation: %s\n"),
bfd_get_filename (abfd), bfd_section_name (section),
message);
}
/* Helper for link_callbacks callbacks vector. */
static void
link_callbacks_unattached_reloc (struct bfd_link_info *link_info,
const char *name, bfd *abfd, asection *section,
bfd_vma address)
{
warning (_("Compiled module \"%s\" section \"%s\": unattached "
"relocation: %s\n"),
bfd_get_filename (abfd), bfd_section_name (section),
name);
}
/* Helper for link_callbacks callbacks vector. */
static void link_callbacks_einfo (const char *fmt, ...)
ATTRIBUTE_PRINTF (1, 2);
static void
link_callbacks_einfo (const char *fmt, ...)
{
va_list ap;
va_start (ap, fmt);
std::string str = string_vprintf (fmt, ap);
va_end (ap);
warning (_("Compile module: warning: %s"), str.c_str ());
}
/* Helper for bfd_get_relocated_section_contents.
Only these symbols are set by bfd_simple_get_relocated_section_contents
but bfd/ seems to use even the NULL ones without checking them first. */
static const struct bfd_link_callbacks link_callbacks =
{
NULL, /* add_archive_element */
link_callbacks_multiple_definition, /* multiple_definition */
NULL, /* multiple_common */
NULL, /* add_to_set */
NULL, /* constructor */
link_callbacks_warning, /* warning */
link_callbacks_undefined_symbol, /* undefined_symbol */
link_callbacks_reloc_overflow, /* reloc_overflow */
link_callbacks_reloc_dangerous, /* reloc_dangerous */
link_callbacks_unattached_reloc, /* unattached_reloc */
NULL, /* notice */
link_callbacks_einfo, /* einfo */
NULL, /* info */
NULL, /* minfo */
NULL, /* override_segment_assignment */
};
struct link_hash_table_cleanup_data
{
explicit link_hash_table_cleanup_data (bfd *abfd_)
: abfd (abfd_),
link_next (abfd->link.next)
{
}
~link_hash_table_cleanup_data ()
{
if (abfd->is_linker_output)
(*abfd->link.hash->hash_table_free) (abfd);
abfd->link.next = link_next;
}
DISABLE_COPY_AND_ASSIGN (link_hash_table_cleanup_data);
private:
bfd *abfd;
bfd *link_next;
};
/* Relocate and store into inferior memory each section SECT of ABFD. */
static void
copy_sections (bfd *abfd, asection *sect, void *data)
{
asymbol **symbol_table = (asymbol **) data;
bfd_byte *sect_data_got;
struct bfd_link_info link_info;
struct bfd_link_order link_order;
CORE_ADDR inferior_addr;
if ((bfd_section_flags (sect) & (SEC_ALLOC | SEC_LOAD))
!= (SEC_ALLOC | SEC_LOAD))
return;
if (bfd_section_size (sect) == 0)
return;
/* Mostly a copy of bfd_simple_get_relocated_section_contents which GDB
cannot use as it does not report relocations to undefined symbols. */
memset (&link_info, 0, sizeof (link_info));
link_info.output_bfd = abfd;
link_info.input_bfds = abfd;
link_info.input_bfds_tail = &abfd->link.next;
struct link_hash_table_cleanup_data cleanup_data (abfd);
abfd->link.next = NULL;
link_info.hash = bfd_link_hash_table_create (abfd);
link_info.callbacks = &link_callbacks;
memset (&link_order, 0, sizeof (link_order));
link_order.next = NULL;
link_order.type = bfd_indirect_link_order;
link_order.offset = 0;
link_order.size = bfd_section_size (sect);
link_order.u.indirect.section = sect;
gdb::unique_xmalloc_ptr<gdb_byte> sect_data
((bfd_byte *) xmalloc (bfd_section_size (sect)));
sect_data_got = bfd_get_relocated_section_contents (abfd, &link_info,
&link_order,
sect_data.get (),
FALSE, symbol_table);
if (sect_data_got == NULL)
error (_("Cannot map compiled module \"%s\" section \"%s\": %s"),
bfd_get_filename (abfd), bfd_section_name (sect),
bfd_errmsg (bfd_get_error ()));
gdb_assert (sect_data_got == sect_data.get ());
inferior_addr = bfd_section_vma (sect);
if (0 != target_write_memory (inferior_addr, sect_data.get (),
bfd_section_size (sect)))
error (_("Cannot write compiled module \"%s\" section \"%s\" "
"to inferior memory range %s-%s."),
bfd_get_filename (abfd), bfd_section_name (sect),
paddress (target_gdbarch (), inferior_addr),
paddress (target_gdbarch (),
inferior_addr + bfd_section_size (sect)));
}
/* Fetch the type of COMPILE_I_EXPR_PTR_TYPE and COMPILE_I_EXPR_VAL
symbols in OBJFILE so we can calculate how much memory to allocate
for the out parameter. This avoids needing a malloc in the generated
code. Throw an error if anything fails.
GDB first tries to compile the code with COMPILE_I_PRINT_ADDRESS_SCOPE.
If it finds user tries to print an array type this function returns
NULL. Caller will then regenerate the code with
COMPILE_I_PRINT_VALUE_SCOPE, recompiles it again and finally runs it.
This is because __auto_type array-to-pointer type conversion of
COMPILE_I_EXPR_VAL which gets detected by COMPILE_I_EXPR_PTR_TYPE
preserving the array type. */
static struct type *
get_out_value_type (struct symbol *func_sym, struct objfile *objfile,
enum compile_i_scope_types scope)
{
struct symbol *gdb_ptr_type_sym;
/* Initialize it just to avoid a GCC false warning. */
struct symbol *gdb_val_sym = NULL;
struct type *gdb_ptr_type, *gdb_type_from_ptr, *gdb_type, *retval;
/* Initialize it just to avoid a GCC false warning. */
const struct block *block = NULL;
const struct blockvector *bv;
int nblocks = 0;
int block_loop = 0;
lookup_name_info func_matcher (GCC_FE_WRAPPER_FUNCTION,
symbol_name_match_type::SEARCH_NAME);
bv = func_sym->symtab ()->compunit ()->blockvector ();
nblocks = bv->num_blocks ();
gdb_ptr_type_sym = NULL;
for (block_loop = 0; block_loop < nblocks; block_loop++)
{
struct symbol *function = NULL;
const struct block *function_block;
block = bv->block (block_loop);
if (block->function () != NULL)
continue;
gdb_val_sym = block_lookup_symbol (block,
COMPILE_I_EXPR_VAL,
symbol_name_match_type::SEARCH_NAME,
VAR_DOMAIN);
if (gdb_val_sym == NULL)
continue;
function_block = block;
while (function_block != bv->static_block ()
&& function_block != bv->global_block ())
{
function_block = function_block->superblock ();
function = function_block->function ();
if (function != NULL)
break;
}
if (function != NULL
&& function_block->superblock () == bv->static_block ()
&& symbol_matches_search_name (function, func_matcher))
break;
}
if (block_loop == nblocks)
error (_("No \"%s\" symbol found"), COMPILE_I_EXPR_VAL);
gdb_type = gdb_val_sym->type ();
gdb_type = check_typedef (gdb_type);
gdb_ptr_type_sym = block_lookup_symbol (block, COMPILE_I_EXPR_PTR_TYPE,
symbol_name_match_type::SEARCH_NAME,
VAR_DOMAIN);
if (gdb_ptr_type_sym == NULL)
error (_("No \"%s\" symbol found"), COMPILE_I_EXPR_PTR_TYPE);
gdb_ptr_type = gdb_ptr_type_sym->type ();
gdb_ptr_type = check_typedef (gdb_ptr_type);
if (gdb_ptr_type->code () != TYPE_CODE_PTR)
error (_("Type of \"%s\" is not a pointer"), COMPILE_I_EXPR_PTR_TYPE);
gdb_type_from_ptr = check_typedef (TYPE_TARGET_TYPE (gdb_ptr_type));
if (types_deeply_equal (gdb_type, gdb_type_from_ptr))
{
if (scope != COMPILE_I_PRINT_ADDRESS_SCOPE)
error (_("Expected address scope in compiled module \"%s\"."),
objfile_name (objfile));
return gdb_type;
}
if (gdb_type->code () != TYPE_CODE_PTR)
error (_("Invalid type code %d of symbol \"%s\" "
"in compiled module \"%s\"."),
gdb_type_from_ptr->code (), COMPILE_I_EXPR_VAL,
objfile_name (objfile));
retval = gdb_type_from_ptr;
switch (gdb_type_from_ptr->code ())
{
case TYPE_CODE_ARRAY:
gdb_type_from_ptr = TYPE_TARGET_TYPE (gdb_type_from_ptr);
break;
case TYPE_CODE_FUNC:
break;
default:
error (_("Invalid type code %d of symbol \"%s\" "
"in compiled module \"%s\"."),
gdb_type_from_ptr->code (), COMPILE_I_EXPR_PTR_TYPE,
objfile_name (objfile));
}
if (!types_deeply_equal (gdb_type_from_ptr,
TYPE_TARGET_TYPE (gdb_type)))
error (_("Referenced types do not match for symbols \"%s\" and \"%s\" "
"in compiled module \"%s\"."),
COMPILE_I_EXPR_PTR_TYPE, COMPILE_I_EXPR_VAL,
objfile_name (objfile));
if (scope == COMPILE_I_PRINT_ADDRESS_SCOPE)
return NULL;
return retval;
}
/* Fetch the type of first parameter of FUNC_SYM.
Return NULL if FUNC_SYM has no parameters. Throw an error otherwise. */
static struct type *
get_regs_type (struct symbol *func_sym, struct objfile *objfile)
{
struct type *func_type = func_sym->type ();
struct type *regsp_type, *regs_type;
/* No register parameter present. */
if (func_type->num_fields () == 0)
return NULL;
regsp_type = check_typedef (func_type->field (0).type ());
if (regsp_type->code () != TYPE_CODE_PTR)
error (_("Invalid type code %d of first parameter of function \"%s\" "
"in compiled module \"%s\"."),
regsp_type->code (), GCC_FE_WRAPPER_FUNCTION,
objfile_name (objfile));
regs_type = check_typedef (TYPE_TARGET_TYPE (regsp_type));
if (regs_type->code () != TYPE_CODE_STRUCT)
error (_("Invalid type code %d of dereferenced first parameter "
"of function \"%s\" in compiled module \"%s\"."),
regs_type->code (), GCC_FE_WRAPPER_FUNCTION,
objfile_name (objfile));
return regs_type;
}
/* Store all inferior registers required by REGS_TYPE to inferior memory
starting at inferior address REGS_BASE. */
static void
store_regs (struct type *regs_type, CORE_ADDR regs_base)
{
struct gdbarch *gdbarch = target_gdbarch ();
int fieldno;
for (fieldno = 0; fieldno < regs_type->num_fields (); fieldno++)
{
const char *reg_name = regs_type->field (fieldno).name ();
ULONGEST reg_bitpos = regs_type->field (fieldno).loc_bitpos ();
ULONGEST reg_bitsize = TYPE_FIELD_BITSIZE (regs_type, fieldno);
ULONGEST reg_offset;
struct type *reg_type
= check_typedef (regs_type->field (fieldno).type ());
ULONGEST reg_size = TYPE_LENGTH (reg_type);
int regnum;
struct value *regval;
CORE_ADDR inferior_addr;
if (strcmp (reg_name, COMPILE_I_SIMPLE_REGISTER_DUMMY) == 0)
continue;
if ((reg_bitpos % 8) != 0 || reg_bitsize != 0)
error (_("Invalid register \"%s\" position %s bits or size %s bits"),
reg_name, pulongest (reg_bitpos), pulongest (reg_bitsize));
reg_offset = reg_bitpos / 8;
if (reg_type->code () != TYPE_CODE_INT
&& reg_type->code () != TYPE_CODE_PTR)
error (_("Invalid register \"%s\" type code %d"), reg_name,
reg_type->code ());
regnum = compile_register_name_demangle (gdbarch, reg_name);
regval = value_from_register (reg_type, regnum, get_current_frame ());
if (value_optimized_out (regval))
error (_("Register \"%s\" is optimized out."), reg_name);
if (!value_entirely_available (regval))
error (_("Register \"%s\" is not available."), reg_name);
inferior_addr = regs_base + reg_offset;
if (0 != target_write_memory (inferior_addr,
value_contents (regval).data (),
reg_size))
error (_("Cannot write register \"%s\" to inferior memory at %s."),
reg_name, paddress (gdbarch, inferior_addr));
}
}
/* Load the object file specified in FILE_NAMES into inferior memory.
Throw an error otherwise. Caller must fully dispose the return
value by calling compile_object_run. Returns NULL only for
COMPILE_I_PRINT_ADDRESS_SCOPE when COMPILE_I_PRINT_VALUE_SCOPE
should have been used instead. */
compile_module_up
compile_object_load (const compile_file_names &file_names,
enum compile_i_scope_types scope, void *scope_data)
{
CORE_ADDR regs_addr, out_value_addr = 0;
struct symbol *func_sym;
struct type *func_type;
struct bound_minimal_symbol bmsym;
long storage_needed;
asymbol **symbol_table, **symp;
long number_of_symbols, missing_symbols;
struct type *regs_type, *out_value_type = NULL;
char **matching;
struct objfile *objfile;
int expect_parameters;
struct type *expect_return_type;
gdb::unique_xmalloc_ptr<char> filename
(tilde_expand (file_names.object_file ()));
gdb_bfd_ref_ptr abfd (gdb_bfd_open (filename.get (), gnutarget));
if (abfd == NULL)
error (_("\"%s\": could not open as compiled module: %s"),
filename.get (), bfd_errmsg (bfd_get_error ()));
if (!bfd_check_format_matches (abfd.get (), bfd_object, &matching))
error (_("\"%s\": not in loadable format: %s"),
filename.get (),
gdb_bfd_errmsg (bfd_get_error (), matching).c_str ());
if ((bfd_get_file_flags (abfd.get ()) & (EXEC_P | DYNAMIC)) != 0)
error (_("\"%s\": not in object format."), filename.get ());
struct setup_sections_data setup_sections_data (abfd.get ());
for (asection *sect = abfd->sections; sect != nullptr; sect = sect->next)
setup_sections_data.setup_one_section (sect);
setup_sections_data.setup_one_section (nullptr);
storage_needed = bfd_get_symtab_upper_bound (abfd.get ());
if (storage_needed < 0)
error (_("Cannot read symbols of compiled module \"%s\": %s"),
filename.get (), bfd_errmsg (bfd_get_error ()));
/* SYMFILE_VERBOSE is not passed even if FROM_TTY, user is not interested in
"Reading symbols from ..." message for automatically generated file. */
objfile_up objfile_holder (symbol_file_add_from_bfd (abfd.get (),
filename.get (),
0, NULL, 0, NULL));
objfile = objfile_holder.get ();
func_sym = lookup_global_symbol_from_objfile (objfile,
GLOBAL_BLOCK,
GCC_FE_WRAPPER_FUNCTION,
VAR_DOMAIN).symbol;
if (func_sym == NULL)
error (_("Cannot find function \"%s\" in compiled module \"%s\"."),
GCC_FE_WRAPPER_FUNCTION, objfile_name (objfile));
func_type = func_sym->type ();
if (func_type->code () != TYPE_CODE_FUNC)
error (_("Invalid type code %d of function \"%s\" in compiled "
"module \"%s\"."),
func_type->code (), GCC_FE_WRAPPER_FUNCTION,
objfile_name (objfile));
switch (scope)
{
case COMPILE_I_SIMPLE_SCOPE:
expect_parameters = 1;
expect_return_type = builtin_type (target_gdbarch ())->builtin_void;
break;
case COMPILE_I_RAW_SCOPE:
expect_parameters = 0;
expect_return_type = builtin_type (target_gdbarch ())->builtin_void;
break;
case COMPILE_I_PRINT_ADDRESS_SCOPE:
case COMPILE_I_PRINT_VALUE_SCOPE:
expect_parameters = 2;
expect_return_type = builtin_type (target_gdbarch ())->builtin_void;
break;
default:
internal_error (__FILE__, __LINE__, _("invalid scope %d"), scope);
}
if (func_type->num_fields () != expect_parameters)
error (_("Invalid %d parameters of function \"%s\" in compiled "
"module \"%s\"."),
func_type->num_fields (), GCC_FE_WRAPPER_FUNCTION,
objfile_name (objfile));
if (!types_deeply_equal (expect_return_type, TYPE_TARGET_TYPE (func_type)))
error (_("Invalid return type of function \"%s\" in compiled "
"module \"%s\"."),
GCC_FE_WRAPPER_FUNCTION, objfile_name (objfile));
/* The memory may be later needed
by bfd_generic_get_relocated_section_contents
called from default_symfile_relocate. */
symbol_table = (asymbol **) obstack_alloc (&objfile->objfile_obstack,
storage_needed);
number_of_symbols = bfd_canonicalize_symtab (abfd.get (), symbol_table);
if (number_of_symbols < 0)
error (_("Cannot parse symbols of compiled module \"%s\": %s"),
filename.get (), bfd_errmsg (bfd_get_error ()));
missing_symbols = 0;
for (symp = symbol_table; symp < symbol_table + number_of_symbols; symp++)
{
asymbol *sym = *symp;
if (sym->flags != 0)
continue;
sym->flags = BSF_GLOBAL;
sym->section = bfd_abs_section_ptr;
if (strcmp (sym->name, "_GLOBAL_OFFSET_TABLE_") == 0)
{
if (compile_debug)
gdb_printf (gdb_stdlog,
"ELF symbol \"%s\" relocated to zero\n",
sym->name);
/* It seems to be a GCC bug, with -mcmodel=large there should be no
need for _GLOBAL_OFFSET_TABLE_. Together with -fPIE the data
remain PC-relative even with _GLOBAL_OFFSET_TABLE_ as zero. */
sym->value = 0;
continue;
}
if (strcmp (sym->name, ".TOC.") == 0)
{
/* Handle the .TOC. symbol as the linker would do. Set the .TOC.
sections value to 0x8000 (see bfd/elf64-ppc.c TOC_BASE_OFF);
point the symbol section at the ".toc" section;
and pass the toc->vma value into bfd_set_gp_value().
If the .toc section is not found, use the first section
with the SEC_ALLOC flag set. In the unlikely case that
we still do not have a section identified, fall back to using
the "*ABS*" section. */
asection *toc_fallback = bfd_get_section_by_name(abfd.get(), ".toc");
if (toc_fallback == NULL)
{
for (asection *tsect = abfd->sections; tsect != nullptr;
tsect = tsect->next)
{
if (bfd_section_flags (tsect) & SEC_ALLOC)
{
toc_fallback = tsect;
break;
}
}
}
if (toc_fallback == NULL)
/* If we've gotten here, we have not found a section usable
as a backup for the .toc section. In this case, use the
absolute (*ABS*) section. */
toc_fallback = bfd_abs_section_ptr;
sym->section = toc_fallback;
sym->value = 0x8000;
bfd_set_gp_value(abfd.get(), toc_fallback->vma);
if (compile_debug)
gdb_printf (gdb_stdlog,
"Connectiong ELF symbol \"%s\" to the .toc section (%s)\n",
sym->name,
paddress (target_gdbarch (), sym->value));
continue;
}
bmsym = lookup_minimal_symbol (sym->name, NULL, NULL);
switch (bmsym.minsym == NULL
? mst_unknown : bmsym.minsym->type ())
{
case mst_text:
case mst_bss:
case mst_data:
sym->value = bmsym.value_address ();
if (compile_debug)
gdb_printf (gdb_stdlog,
"ELF mst_text symbol \"%s\" relocated to %s\n",
sym->name,
paddress (target_gdbarch (), sym->value));
break;
case mst_text_gnu_ifunc:
sym->value = gnu_ifunc_resolve_addr (target_gdbarch (),
bmsym.value_address ());
if (compile_debug)
gdb_printf (gdb_stdlog,
"ELF mst_text_gnu_ifunc symbol \"%s\" "
"relocated to %s\n",
sym->name,
paddress (target_gdbarch (), sym->value));
break;
default:
warning (_("Could not find symbol \"%s\" "
"for compiled module \"%s\"."),
sym->name, filename.get ());
missing_symbols++;
}
}
if (missing_symbols)
error (_("%ld symbols were missing, cannot continue."), missing_symbols);
bfd_map_over_sections (abfd.get (), copy_sections, symbol_table);
regs_type = get_regs_type (func_sym, objfile);
if (regs_type == NULL)
regs_addr = 0;
else
{
/* Use read-only non-executable memory protection. */
regs_addr = gdbarch_infcall_mmap (target_gdbarch (),
TYPE_LENGTH (regs_type),
GDB_MMAP_PROT_READ);
gdb_assert (regs_addr != 0);
setup_sections_data.munmap_list.add (regs_addr, TYPE_LENGTH (regs_type));
if (compile_debug)
gdb_printf (gdb_stdlog,
"allocated %s bytes at %s for registers\n",
paddress (target_gdbarch (),
TYPE_LENGTH (regs_type)),
paddress (target_gdbarch (), regs_addr));
store_regs (regs_type, regs_addr);
}
if (scope == COMPILE_I_PRINT_ADDRESS_SCOPE
|| scope == COMPILE_I_PRINT_VALUE_SCOPE)
{
out_value_type = get_out_value_type (func_sym, objfile, scope);
if (out_value_type == NULL)
return NULL;
check_typedef (out_value_type);
out_value_addr = gdbarch_infcall_mmap (target_gdbarch (),
TYPE_LENGTH (out_value_type),
(GDB_MMAP_PROT_READ
| GDB_MMAP_PROT_WRITE));
gdb_assert (out_value_addr != 0);
setup_sections_data.munmap_list.add (out_value_addr,
TYPE_LENGTH (out_value_type));
if (compile_debug)
gdb_printf (gdb_stdlog,
"allocated %s bytes at %s for printed value\n",
paddress (target_gdbarch (),
TYPE_LENGTH (out_value_type)),
paddress (target_gdbarch (), out_value_addr));
}
compile_module_up retval (new struct compile_module);
retval->objfile = objfile_holder.release ();
retval->source_file = file_names.source_file ();
retval->func_sym = func_sym;
retval->regs_addr = regs_addr;
retval->scope = scope;
retval->scope_data = scope_data;
retval->out_value_type = out_value_type;
retval->out_value_addr = out_value_addr;
retval->munmap_list = std::move (setup_sections_data.munmap_list);
return retval;
}