blob: 204114c96a26648b2beaff632fbc692e752dbf1d [file] [log] [blame]
/* Functions for generic Darwin as target machine for GNU C compiler.
Copyright (C) 1989-2021 Free Software Foundation, Inc.
Contributed by Apple Computer Inc.
This file is part of GCC.
GCC 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, or (at your option)
any later version.
GCC 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 GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "backend.h"
#include "target.h"
#include "rtl.h"
#include "tree.h"
#include "gimple.h"
#include "cfghooks.h"
#include "df.h"
#include "memmodel.h"
#include "tm_p.h"
#include "stringpool.h"
#include "attribs.h"
#include "insn-config.h"
#include "emit-rtl.h"
#include "cgraph.h"
#include "lto-streamer.h"
#include "output.h"
#include "varasm.h"
#include "stor-layout.h"
#include "explow.h"
#include "expr.h"
#include "langhooks.h"
#include "targhooks.h"
#include "toplev.h"
#include "lto-section-names.h"
#include "intl.h"
#include "optabs.h"
#include "flags.h"
#include "opts.h"
/* Fix and Continue.
NOTES:
1) this facility requires suitable support from a modified version
of GDB, which is not provided on any system after MacOS 10.7/Darwin11.
2) There is no support for this in any X86 version of the FSF compiler.
Fix and continue was used on some earlier MacOS systems for rapid turn
around debugging. When code is compiled with the -mfix-and-continue
flag, two changes are made to the generated code that allow the system
to do things that it would normally not be able to do easily. These
changes allow gdb to load in recompilation of a translation unit that
has been changed into a running program and replace existing functions
and methods of that translation unit with versions of those functions
and methods from the newly compiled translation unit. The new functions
access the existing static symbols from the old translation unit, if the
symbol existed in the unit to be replaced, and from the new translation
unit, otherwise.
The changes are to insert 5 nops at the beginning of all functions
and to use indirection to get at static symbols. The 5 nops
are required by consumers of the generated code. Currently, gdb
uses this to patch in a jump to the overriding function, this
allows all uses of the old name to forward to the replacement,
including existing function pointers and virtual methods. See
rs6000_emit_prologue for the code that handles the nop insertions.
The added indirection allows gdb to redirect accesses to static
symbols from the newly loaded translation unit to the existing
symbol, if any. @code{static} symbols are special and are handled by
setting the second word in the .non_lazy_symbol_pointer data
structure to symbol. See indirect_data for the code that handles
the extra indirection, and machopic_output_indirection and its use
of MACHO_SYMBOL_FLAG_STATIC for the code that handles @code{static}
symbol indirection. */
typedef struct GTY(()) cdtor_record {
rtx symbol;
int priority; /* [con/de]structor priority */
int position; /* original position */
} cdtor_record;
static GTY(()) vec<cdtor_record, va_gc> *ctors = NULL;
static GTY(()) vec<cdtor_record, va_gc> *dtors = NULL;
/* A flag to determine whether we are running c++ or obj-c++. This has to be
settable from non-c-family contexts too (i.e. we can't use the c_dialect_
functions). */
int darwin_running_cxx;
/* Some code-gen now depends on OS major version numbers (at least). */
int generating_for_darwin_version ;
/* For older linkers we need to emit special sections (marked 'coalesced') for
for weak or single-definition items. */
static bool ld_uses_coal_sects = false;
/* Very old (ld_classic) linkers need a symbol to mark the start of
each FDE. */
static bool ld_needs_eh_markers = false;
/* Emit a section-start symbol for mod init and term sections. */
static bool ld_init_term_start_labels = false;
/* Section names. */
section * darwin_sections[NUM_DARWIN_SECTIONS];
/* While we transition to using in-tests instead of ifdef'd code. */
#if !HAVE_lo_sum
#define gen_macho_high(m,a,b) (a)
#define gen_macho_low(m,a,b,c) (a)
#endif
/* True if we're setting __attribute__ ((ms_struct)). */
int darwin_ms_struct = false;
/* Earlier versions of Darwin as do not recognize an alignment field in
.comm directives, this should be set for versions that allow it. */
int emit_aligned_common = false;
/* A get_unnamed_section callback used to switch to an ObjC section.
DIRECTIVE is as for output_section_asm_op. */
static void
output_objc_section_asm_op (const void *directive)
{
static bool been_here = false;
/* The NeXT ObjC Runtime requires these sections to be present and in
order in the object. The code below implements this by emitting
a section header for each ObjC section the first time that an ObjC
section is requested. */
if (darwin_symbol_stubs && ! been_here)
{
section *saved_in_section = in_section;
static const enum darwin_section_enum tomark[] =
{
/* written, cold -> hot */
objc_cat_cls_meth_section,
objc_cat_inst_meth_section,
objc_string_object_section,
objc_constant_string_object_section,
objc_selector_refs_section,
objc_selector_fixup_section,
objc_cls_refs_section,
objc_class_section,
objc_meta_class_section,
/* shared, hot -> cold */
objc_cls_meth_section,
objc_inst_meth_section,
objc_protocol_section,
objc_class_names_section,
objc_meth_var_types_section,
objc_meth_var_names_section,
objc_category_section,
objc_class_vars_section,
objc_instance_vars_section,
objc_module_info_section,
objc_symbols_section,
};
/* ABI=1 */
static const enum darwin_section_enum tomarkv1[] =
{
objc1_protocol_ext_section,
objc1_class_ext_section,
objc1_prop_list_section
} ;
/* ABI=2 */
static const enum darwin_section_enum tomarkv2[] =
{
objc2_method_names_section,
objc2_message_refs_section,
objc2_selector_refs_section,
objc2_ivar_section,
objc2_classdefs_section,
objc2_metadata_section,
objc2_classrefs_section,
objc2_class_names_section,
objc2_classlist_section,
objc2_categorylist_section,
objc2_nonlazy_class_section,
objc2_nonlazy_category_section,
objc2_protocollist_section,
objc2_protocolrefs_section,
objc2_super_classrefs_section,
objc2_constant_string_object_section,
objc2_image_info_section,
} ;
size_t i;
been_here = true;
if (flag_objc_abi < 2)
{
for (i = 0; i < ARRAY_SIZE (tomark); i++)
switch_to_section (darwin_sections[tomark[i]]);
if (flag_objc_abi == 1)
for (i = 0; i < ARRAY_SIZE (tomarkv1); i++)
switch_to_section (darwin_sections[tomarkv1[i]]);
}
else
for (i = 0; i < ARRAY_SIZE (tomarkv2); i++)
switch_to_section (darwin_sections[tomarkv2[i]]);
/* Make sure we don't get varasm.c out of sync with us. */
switch_to_section (saved_in_section);
}
output_section_asm_op (directive);
}
/* Private flag applied to disable section-anchors in a particular section. */
#define SECTION_NO_ANCHOR SECTION_MACH_DEP
/* Implement TARGET_ASM_INIT_SECTIONS. */
void
darwin_init_sections (void)
{
#define DEF_SECTION(NAME, FLAGS, DIRECTIVE, OBJC) \
darwin_sections[NAME] = \
get_unnamed_section (FLAGS, (OBJC \
? output_objc_section_asm_op \
: output_section_asm_op), \
"\t" DIRECTIVE);
#include "config/darwin-sections.def"
#undef DEF_SECTION
readonly_data_section = darwin_sections[const_section];
exception_section = darwin_sections[darwin_exception_section];
eh_frame_section = darwin_sections[darwin_eh_frame_section];
/* If our linker is new enough to coalesce weak symbols, then we
can just put picbase_thunks into the text section. */
if (! ld_uses_coal_sects )
darwin_sections[picbase_thunk_section] = text_section;
}
int
name_needs_quotes (const char *name)
{
int c;
while ((c = *name++) != '\0')
if (! ISIDNUM (c)
&& c != '.' && c != '$' && c != '_' )
return 1;
return 0;
}
/* Return true if SYM_REF can be used without an indirection. */
int
machopic_symbol_defined_p (rtx sym_ref)
{
if (MACHO_SYMBOL_DEFINED_P (sym_ref))
return true;
/* If a symbol references local and is not an extern to this
file, then the symbol might be able to declared as defined. */
if (SYMBOL_REF_LOCAL_P (sym_ref) && ! SYMBOL_REF_EXTERNAL_P (sym_ref))
{
/* If the symbol references a variable and the variable is a
common symbol, then this symbol is not defined. */
if (MACHO_SYMBOL_VARIABLE_P (sym_ref))
{
tree decl = SYMBOL_REF_DECL (sym_ref);
if (!decl)
return true;
if (DECL_COMMON (decl))
return false;
}
return true;
}
return false;
}
/* This module assumes that (const (symbol_ref "foo")) is a legal pic
reference, which will not be changed. */
enum machopic_addr_class
machopic_classify_symbol (rtx sym_ref)
{
bool function_p;
function_p = SYMBOL_REF_FUNCTION_P (sym_ref);
if (machopic_symbol_defined_p (sym_ref))
return (function_p
? MACHOPIC_DEFINED_FUNCTION : MACHOPIC_DEFINED_DATA);
else
return (function_p
? MACHOPIC_UNDEFINED_FUNCTION : MACHOPIC_UNDEFINED_DATA);
}
#ifndef TARGET_FIX_AND_CONTINUE
#define TARGET_FIX_AND_CONTINUE 0
#endif
/* Indicate when fix-and-continue style code generation is being used
and when a reference to data should be indirected so that it can be
rebound in a new translation unit to reference the original instance
of that data. Symbol names that are for code generation local to
the translation unit are bound to the new translation unit;
currently this means symbols that begin with L or _OBJC_;
otherwise, we indicate that an indirect reference should be made to
permit the runtime to rebind new instances of the translation unit
to the original instance of the data. */
static int
indirect_data (rtx sym_ref)
{
int lprefix;
const char *name;
/* If we aren't generating fix-and-continue code, don't do anything
special. */
if (TARGET_FIX_AND_CONTINUE == 0)
return 0;
/* Otherwise, all symbol except symbols that begin with L or _OBJC_
are indirected. Symbols that begin with L and _OBJC_ are always
bound to the current translation unit as they are used for
generated local data of the translation unit. */
name = XSTR (sym_ref, 0);
lprefix = (((name[0] == '*' || name[0] == '&')
&& (name[1] == 'L' || (name[1] == '"' && name[2] == 'L')))
|| (startswith (name, "_OBJC_")));
return ! lprefix;
}
static int
machopic_data_defined_p (rtx sym_ref)
{
if (indirect_data (sym_ref))
return 0;
switch (machopic_classify_symbol (sym_ref))
{
case MACHOPIC_DEFINED_DATA:
case MACHOPIC_DEFINED_FUNCTION:
return 1;
default:
return 0;
}
}
void
machopic_define_symbol (rtx mem)
{
rtx sym_ref;
gcc_assert (GET_CODE (mem) == MEM);
sym_ref = XEXP (mem, 0);
SYMBOL_REF_FLAGS (sym_ref) |= MACHO_SYMBOL_FLAG_DEFINED;
}
/* Return either ORIG or:
(const:P (unspec:P [ORIG] UNSPEC_MACHOPIC_OFFSET))
depending on MACHO_DYNAMIC_NO_PIC_P. */
rtx
machopic_gen_offset (rtx orig)
{
if (MACHO_DYNAMIC_NO_PIC_P)
return orig;
else
{
/* Play games to avoid marking the function as needing pic if we
are being called as part of the cost-estimation process. */
if (current_ir_type () != IR_GIMPLE || currently_expanding_to_rtl)
crtl->uses_pic_offset_table = 1;
orig = gen_rtx_UNSPEC (Pmode, gen_rtvec (1, orig),
UNSPEC_MACHOPIC_OFFSET);
return gen_rtx_CONST (Pmode, orig);
}
}
static GTY(()) const char * function_base_func_name = NULL;
static GTY(()) unsigned current_pic_label_num = 0;
static GTY(()) unsigned emitted_pic_label_num = 0;
/* We need to keep one picbase label per function, but (when we emit code
to reload the picbase for setjump receiver) we might need to check for
a second use. So, only update the picbase label counter when we see a
new function. When there's no function decl, we assume that the call is
from the x86 stub generation code. */
static void
update_pic_label_number_if_needed (void)
{
if (current_function_decl)
{
const char *current_name =
IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (current_function_decl));
if (function_base_func_name != current_name)
{
++current_pic_label_num;
function_base_func_name = current_name;
}
}
else
{
++current_pic_label_num;
function_base_func_name = "L_machopic_stub_dummy";
}
}
void
machopic_output_function_base_name (FILE *file)
{
/* We should only get here for -fPIC. */
gcc_checking_assert (MACHOPIC_PURE);
update_pic_label_number_if_needed ();
fprintf (file, "L%u$pb", current_pic_label_num);
}
char curr_picbasename[32];
const char *
machopic_get_function_picbase (void)
{
/* We should only get here for -fPIC. */
gcc_checking_assert (MACHOPIC_PURE);
update_pic_label_number_if_needed ();
snprintf (curr_picbasename, 32, "L%u$pb", current_pic_label_num);
return (const char *) curr_picbasename;
}
bool
machopic_should_output_picbase_label (void)
{
update_pic_label_number_if_needed ();
if (current_pic_label_num == emitted_pic_label_num)
return false;
emitted_pic_label_num = current_pic_label_num;
return true;
}
/* The suffix attached to non-lazy pointer symbols. */
#define NON_LAZY_POINTER_SUFFIX "$non_lazy_ptr"
/* The suffix attached to stub symbols. */
#define STUB_SUFFIX "$stub"
typedef struct GTY ((for_user)) machopic_indirection
{
/* The SYMBOL_REF for the entity referenced. */
rtx symbol;
/* The name of the stub or non-lazy pointer. */
const char * ptr_name;
/* True iff this entry is for a stub (as opposed to a non-lazy
pointer). */
bool stub_p;
/* True iff this stub or pointer has been referenced. */
bool used;
/* True iff a non-lazy symbol pointer should be emitted into the .data
section, rather than the non-lazy symbol pointers section. The cases
for which this occurred seem to have been unintentional, and later
toolchains emit all of the indirections to the 'usual' section. We
are keeping this in case it is necessary to preserve compatibility with
older toolchains. */
bool nlsp_in_data_section;
} machopic_indirection;
struct indirection_hasher : ggc_ptr_hash<machopic_indirection>
{
typedef const char *compare_type;
static hashval_t hash (machopic_indirection *);
static bool equal (machopic_indirection *, const char *);
};
/* A table mapping stub names and non-lazy pointer names to
SYMBOL_REFs for the stubbed-to and pointed-to entities. */
static GTY (()) hash_table<indirection_hasher> *machopic_indirections;
/* Return a hash value for a SLOT in the indirections hash table. */
hashval_t
indirection_hasher::hash (machopic_indirection *p)
{
return htab_hash_string (p->ptr_name);
}
/* Returns true if the KEY is the same as that associated with
SLOT. */
bool
indirection_hasher::equal (machopic_indirection *s, const char *k)
{
return strcmp (s->ptr_name, k) == 0;
}
/* Return the name of the non-lazy pointer (if STUB_P is false) or
stub (if STUB_B is true) corresponding to the given name.
PR71767 - If we have a situation like:
global_weak_symbol:
....
Lnon_weak_local:
....
ld64 will be unable to split this into two atoms (because the "L" makes
the second symbol 'invisible'). This means that legitimate direct accesses
to the second symbol will appear to be direct accesses to an atom of type
weak, global which are not allowed.
To avoid this, we make any data-section indirections have a leading 'l'
(lower-case L) which has a special meaning: linker can see this and use
it to determine atoms, but it is not placed into the final symbol table.
Symbols in the non-lazy symbol pointers section (or stubs) do not have this
problem because ld64 already knows the size of each entry.
*/
const char *
machopic_indirection_name (rtx sym_ref, bool stub_p)
{
const char *name = XSTR (sym_ref, 0);
tree id = maybe_get_identifier (name);
if (id)
{
tree id_orig = id;
while (IDENTIFIER_TRANSPARENT_ALIAS (id))
id = TREE_CHAIN (id);
if (id != id_orig)
name = IDENTIFIER_POINTER (id);
}
const char *prefix = user_label_prefix;
/* If we are emitting the label 'verbatim' then omit the U_L_P and count
the name without the leading '*'. */
if (name[0] == '*')
{
prefix = "";
++name;
}
/* Here we are undoing a number of causes that placed some indirections
(apparently erroneously) into the .data section. Specifically, some
symbols that are ABI mandated indirections and some hidden symbols
were being placed there - which cause difficulties with later
versions of ld64. Iff (after these checks) some symbol still gets an
indirection in the data section, we want to adjust the indirection
name to be linker visible to deal with PR71767 (notes above). */
bool nlsp_in_data_section =
! MACHO_SYMBOL_MUST_INDIRECT_P (sym_ref)
&& ! MACHO_SYMBOL_HIDDEN_VIS_P (sym_ref)
&& (machopic_symbol_defined_p (sym_ref) || SYMBOL_REF_LOCAL_P (sym_ref))
&& ! indirect_data (sym_ref);
const char *suffix = stub_p ? STUB_SUFFIX : NON_LAZY_POINTER_SUFFIX;
/* If the indirection is in the data section, let the linker see it. */
char L_or_l = (!stub_p && nlsp_in_data_section) ? 'l' : 'L';
/* We have mangled symbols with spaces and punctuation which typically
need surrounding in quotes for the assembler to consume them. */
const char *quote = name_needs_quotes (name) ? "\"" : "";
char *buffer = XALLOCAVEC (char, 2 /* strlen ("&L") or ("&l") */
+ strlen (prefix)
+ strlen (name)
+ strlen (suffix)
+ 2 * strlen (quote)
+ 1 /* '\0' */);
/* Construct the name of the non-lazy pointer or stub. */
sprintf (buffer, "&%s%c%s%s%s%s", quote, L_or_l, prefix, name,
suffix, quote);
if (!machopic_indirections)
machopic_indirections = hash_table<indirection_hasher>::create_ggc (37);
machopic_indirection **slot
= machopic_indirections->find_slot_with_hash (buffer,
htab_hash_string (buffer),
INSERT);
machopic_indirection *p;
if (*slot)
p = *slot;
else
{
p = ggc_alloc<machopic_indirection> ();
p->symbol = sym_ref;
p->ptr_name = xstrdup (buffer);
p->stub_p = stub_p;
p->used = false;
p->nlsp_in_data_section = nlsp_in_data_section;
*slot = p;
}
return p->ptr_name;
}
/* If NAME is the name of a stub or a non-lazy pointer , mark the stub
or non-lazy pointer as used -- and mark the object to which the
pointer/stub refers as used as well, since the pointer/stub will
emit a reference to it. */
void
machopic_validate_stub_or_non_lazy_ptr (const char *name)
{
machopic_indirection *p
= machopic_indirections->find_with_hash (name, htab_hash_string (name));
if (p && ! p->used)
{
const char *real_name;
tree id;
p->used = true;
/* Do what output_addr_const will do when we actually call it. */
if (SYMBOL_REF_DECL (p->symbol))
mark_decl_referenced (SYMBOL_REF_DECL (p->symbol));
real_name = targetm.strip_name_encoding (XSTR (p->symbol, 0));
id = maybe_get_identifier (real_name);
if (id)
mark_referenced (id);
}
}
/* Transform ORIG, which may be any data source, to the corresponding
source using indirections. */
rtx
machopic_indirect_data_reference (rtx orig, rtx reg)
{
rtx ptr_ref = orig;
if (! MACHOPIC_INDIRECT)
return orig;
if (GET_CODE (orig) == SYMBOL_REF)
{
int defined = machopic_data_defined_p (orig);
if (defined && MACHO_DYNAMIC_NO_PIC_P)
{
if (DARWIN_PPC)
{
/* Create a new register for CSE opportunities. */
rtx hi_reg = (!can_create_pseudo_p () ? reg : gen_reg_rtx (Pmode));
emit_insn (gen_macho_high (Pmode, hi_reg, orig));
emit_insn (gen_macho_low (Pmode, reg, hi_reg, orig));
return reg;
}
else if (DARWIN_X86)
return orig;
else
/* some other cpu -- writeme! */
gcc_unreachable ();
}
else if (defined && ! MACHO_SYMBOL_MUST_INDIRECT_P (orig))
{
rtx offset = NULL;
if (DARWIN_PPC || HAVE_lo_sum)
offset = machopic_gen_offset (orig);
if (DARWIN_PPC)
{
rtx hi_sum_reg = (!can_create_pseudo_p ()
? reg
: gen_reg_rtx (Pmode));
gcc_assert (reg);
emit_insn (gen_rtx_SET (hi_sum_reg,
gen_rtx_PLUS (Pmode, pic_offset_table_rtx,
gen_rtx_HIGH (Pmode, offset))));
emit_insn (gen_rtx_SET (reg,
gen_rtx_LO_SUM (Pmode, hi_sum_reg,
copy_rtx (offset))));
orig = reg;
}
else if (HAVE_lo_sum)
{
gcc_assert (reg);
emit_insn (gen_rtx_SET (reg, gen_rtx_HIGH (Pmode, offset)));
emit_insn (gen_rtx_SET (reg, gen_rtx_LO_SUM (Pmode, reg,
copy_rtx (offset))));
emit_use (pic_offset_table_rtx);
orig = gen_rtx_PLUS (Pmode, pic_offset_table_rtx, reg);
}
return orig;
}
ptr_ref = (gen_rtx_SYMBOL_REF
(Pmode,
machopic_indirection_name (orig, /*stub_p=*/false)));
SYMBOL_REF_DATA (ptr_ref) = SYMBOL_REF_DATA (orig);
SYMBOL_REF_FLAGS (ptr_ref) |= MACHO_SYMBOL_FLAG_INDIRECTION;
ptr_ref = gen_const_mem (Pmode, ptr_ref);
machopic_define_symbol (ptr_ref);
if (DARWIN_X86
&& reg
&& MACHO_DYNAMIC_NO_PIC_P)
{
emit_insn (gen_rtx_SET (reg, ptr_ref));
ptr_ref = reg;
}
return ptr_ref;
}
else if (GET_CODE (orig) == CONST)
{
/* If "(const (plus ...", walk the PLUS and return that result.
PLUS processing (below) will restore the "(const ..." if
appropriate. */
if (GET_CODE (XEXP (orig, 0)) == PLUS)
return machopic_indirect_data_reference (XEXP (orig, 0), reg);
else
return orig;
}
else if (GET_CODE (orig) == MEM)
{
XEXP (ptr_ref, 0) =
machopic_indirect_data_reference (XEXP (orig, 0), reg);
return ptr_ref;
}
else if (GET_CODE (orig) == PLUS)
{
rtx base, result;
/* Legitimize both operands of the PLUS. */
base = machopic_indirect_data_reference (XEXP (orig, 0), reg);
orig = machopic_indirect_data_reference (XEXP (orig, 1),
(base == reg ? 0 : reg));
if (MACHOPIC_INDIRECT && (GET_CODE (orig) == CONST_INT))
result = plus_constant (Pmode, base, INTVAL (orig));
else
result = gen_rtx_PLUS (Pmode, base, orig);
if (MACHOPIC_JUST_INDIRECT && GET_CODE (base) == MEM)
{
if (reg)
{
emit_move_insn (reg, result);
result = reg;
}
else
{
result = force_reg (GET_MODE (result), result);
}
}
return result;
}
return ptr_ref;
}
/* Transform TARGET (a MEM), which is a function call target, to the
corresponding symbol_stub if necessary. Return a new MEM. */
rtx
machopic_indirect_call_target (rtx target)
{
if (! darwin_symbol_stubs)
return target;
if (GET_CODE (target) != MEM)
return target;
if (MACHOPIC_INDIRECT
&& GET_CODE (XEXP (target, 0)) == SYMBOL_REF
&& ! MACHO_SYMBOL_DEFINED_P (XEXP (target, 0)))
{
rtx sym_ref = XEXP (target, 0);
const char *stub_name = machopic_indirection_name (sym_ref,
/*stub_p=*/true);
machine_mode mode = GET_MODE (sym_ref);
XEXP (target, 0) = gen_rtx_SYMBOL_REF (mode, stub_name);
SYMBOL_REF_DATA (XEXP (target, 0)) = SYMBOL_REF_DATA (sym_ref);
SYMBOL_REF_FLAGS (XEXP (target, 0)) |= MACHO_SYMBOL_FLAG_INDIRECTION;
MEM_READONLY_P (target) = 1;
MEM_NOTRAP_P (target) = 1;
}
return target;
}
rtx
machopic_legitimize_pic_address (rtx orig, machine_mode mode, rtx reg)
{
rtx pic_ref = orig;
if (! MACHOPIC_INDIRECT)
return orig;
/* First handle a simple SYMBOL_REF or LABEL_REF */
if (GET_CODE (orig) == LABEL_REF
|| GET_CODE (orig) == SYMBOL_REF)
{
/* addr(foo) = &func+(foo-func) */
orig = machopic_indirect_data_reference (orig, reg);
if (GET_CODE (orig) == PLUS
&& GET_CODE (XEXP (orig, 0)) == REG)
{
if (reg == 0)
return force_reg (mode, orig);
emit_move_insn (reg, orig);
return reg;
}
if (GET_CODE (orig) == MEM)
{
if (reg == 0)
{
gcc_assert (!lra_in_progress);
reg = gen_reg_rtx (Pmode);
}
#if HAVE_lo_sum
if (MACHO_DYNAMIC_NO_PIC_P
&& (GET_CODE (XEXP (orig, 0)) == SYMBOL_REF
|| GET_CODE (XEXP (orig, 0)) == LABEL_REF))
{
#if defined (TARGET_TOC) /* ppc */
rtx temp_reg = (!can_create_pseudo_p ()
? reg :
gen_reg_rtx (Pmode));
rtx asym = XEXP (orig, 0);
rtx mem;
emit_insn (gen_macho_high (Pmode, temp_reg, asym));
mem = gen_const_mem (GET_MODE (orig),
gen_rtx_LO_SUM (Pmode, temp_reg,
copy_rtx (asym)));
emit_insn (gen_rtx_SET (reg, mem));
#else
/* Some other CPU -- WriteMe! but right now there are no other
platforms that can use dynamic-no-pic */
gcc_unreachable ();
#endif
pic_ref = reg;
}
else
if (GET_CODE (XEXP (orig, 0)) == SYMBOL_REF
|| GET_CODE (XEXP (orig, 0)) == LABEL_REF)
{
rtx offset = machopic_gen_offset (XEXP (orig, 0));
#if defined (TARGET_TOC) /* i.e., PowerPC */
/* Generating a new reg may expose opportunities for
common subexpression elimination. */
rtx hi_sum_reg = (!can_create_pseudo_p ()
? reg
: gen_reg_rtx (Pmode));
rtx mem;
rtx sum;
sum = gen_rtx_HIGH (Pmode, offset);
if (! MACHO_DYNAMIC_NO_PIC_P)
sum = gen_rtx_PLUS (Pmode, pic_offset_table_rtx, sum);
emit_insn (gen_rtx_SET (hi_sum_reg, sum));
mem = gen_const_mem (GET_MODE (orig),
gen_rtx_LO_SUM (Pmode,
hi_sum_reg,
copy_rtx (offset)));
rtx_insn *insn = emit_insn (gen_rtx_SET (reg, mem));
set_unique_reg_note (insn, REG_EQUAL, pic_ref);
pic_ref = reg;
#else
emit_use (gen_rtx_REG (Pmode, PIC_OFFSET_TABLE_REGNUM));
emit_insn (gen_rtx_SET (reg,
gen_rtx_HIGH (Pmode,
gen_rtx_CONST (Pmode,
offset))));
emit_insn (gen_rtx_SET (reg,
gen_rtx_LO_SUM (Pmode, reg,
gen_rtx_CONST (Pmode,
copy_rtx (offset)))));
pic_ref = gen_rtx_PLUS (Pmode,
pic_offset_table_rtx, reg);
#endif
}
else
#endif /* HAVE_lo_sum */
{
rtx pic = pic_offset_table_rtx;
if (GET_CODE (pic) != REG)
{
emit_move_insn (reg, pic);
pic = reg;
}
if (lra_in_progress && HARD_REGISTER_P (pic))
df_set_regs_ever_live (REGNO (pic), true);
pic_ref = gen_rtx_PLUS (Pmode, pic,
machopic_gen_offset (XEXP (orig, 0)));
}
#if !defined (TARGET_TOC)
emit_move_insn (reg, pic_ref);
pic_ref = gen_const_mem (GET_MODE (orig), reg);
#endif
}
else
{
#if HAVE_lo_sum
if (GET_CODE (orig) == SYMBOL_REF
|| GET_CODE (orig) == LABEL_REF)
{
rtx offset = machopic_gen_offset (orig);
#if defined (TARGET_TOC) /* i.e., PowerPC */
rtx hi_sum_reg;
if (reg == 0)
{
gcc_assert (!lra_in_progress);
reg = gen_reg_rtx (Pmode);
}
hi_sum_reg = reg;
emit_insn (gen_rtx_SET (hi_sum_reg,
(MACHO_DYNAMIC_NO_PIC_P)
? gen_rtx_HIGH (Pmode, offset)
: gen_rtx_PLUS (Pmode,
pic_offset_table_rtx,
gen_rtx_HIGH (Pmode,
offset))));
emit_insn (gen_rtx_SET (reg,
gen_rtx_LO_SUM (Pmode,
hi_sum_reg,
copy_rtx (offset))));
pic_ref = reg;
#else
emit_insn (gen_rtx_SET (reg, gen_rtx_HIGH (Pmode, offset)));
emit_insn (gen_rtx_SET (reg,
gen_rtx_LO_SUM (Pmode, reg,
copy_rtx (offset))));
pic_ref = gen_rtx_PLUS (Pmode,
pic_offset_table_rtx, reg);
#endif
}
else
#endif /* HAVE_lo_sum */
{
if (REG_P (orig)
|| GET_CODE (orig) == SUBREG)
{
return orig;
}
else
{
rtx pic = pic_offset_table_rtx;
if (GET_CODE (pic) != REG)
{
emit_move_insn (reg, pic);
pic = reg;
}
if (lra_in_progress && HARD_REGISTER_P (pic))
df_set_regs_ever_live (REGNO (pic), true);
pic_ref = gen_rtx_PLUS (Pmode,
pic,
machopic_gen_offset (orig));
}
}
}
if (GET_CODE (pic_ref) != REG)
{
if (reg != 0)
{
emit_move_insn (reg, pic_ref);
return reg;
}
else
{
return force_reg (mode, pic_ref);
}
}
else
{
return pic_ref;
}
}
else if (GET_CODE (orig) == PLUS
&& (GET_CODE (XEXP (orig, 0)) == MEM
|| GET_CODE (XEXP (orig, 0)) == SYMBOL_REF
|| GET_CODE (XEXP (orig, 0)) == LABEL_REF)
&& XEXP (orig, 0) != pic_offset_table_rtx
&& GET_CODE (XEXP (orig, 1)) != REG)
{
rtx base;
int is_complex = (GET_CODE (XEXP (orig, 0)) == MEM);
base = machopic_legitimize_pic_address (XEXP (orig, 0), Pmode, reg);
orig = machopic_legitimize_pic_address (XEXP (orig, 1),
Pmode, (base == reg ? 0 : reg));
if (GET_CODE (orig) == CONST_INT)
{
pic_ref = plus_constant (Pmode, base, INTVAL (orig));
is_complex = 1;
}
else
pic_ref = gen_rtx_PLUS (Pmode, base, orig);
if (reg && is_complex)
{
emit_move_insn (reg, pic_ref);
pic_ref = reg;
}
/* Likewise, should we set special REG_NOTEs here? */
}
else if (GET_CODE (orig) == CONST)
{
return machopic_legitimize_pic_address (XEXP (orig, 0), Pmode, reg);
}
else if (GET_CODE (orig) == MEM
&& GET_CODE (XEXP (orig, 0)) == SYMBOL_REF)
{
rtx addr = machopic_legitimize_pic_address (XEXP (orig, 0), Pmode, reg);
addr = replace_equiv_address (orig, addr);
emit_move_insn (reg, addr);
pic_ref = reg;
}
return pic_ref;
}
/* Callbacks to output the stub or non-lazy pointers.
Each works on the item in *SLOT,if it has been used.
DATA is the FILE* for assembly output.
Called from htab_traverses, invoked from machopic_finish(). */
int
machopic_output_data_section_indirection (machopic_indirection **slot,
FILE *out_file)
{
machopic_indirection *p = *slot;
if (!p->used || !p->nlsp_in_data_section)
return 1;
rtx symbol = p->symbol;
/* The original symbol name. */
const char *sym_name = XSTR (symbol, 0);
/* The name of the indirection symbol. */
const char *ptr_name = p->ptr_name;
switch_to_section (data_section);
assemble_align (GET_MODE_ALIGNMENT (Pmode));
assemble_label (out_file, ptr_name);
assemble_integer (gen_rtx_SYMBOL_REF (Pmode, sym_name),
GET_MODE_SIZE (Pmode),
GET_MODE_ALIGNMENT (Pmode), 1);
return 1;
}
int
machopic_output_stub_indirection (machopic_indirection **slot,
FILE *out_file)
{
machopic_indirection *p = *slot;
if (!p->used || !p->stub_p)
return 1;
rtx symbol = p->symbol;
/* The original symbol name. */
const char *sym_name = XSTR (symbol, 0);
/* The name of the stub symbol. */
const char *ptr_name = p->ptr_name;
tree id = maybe_get_identifier (sym_name);
if (id)
{
tree id_orig = id;
while (IDENTIFIER_TRANSPARENT_ALIAS (id))
id = TREE_CHAIN (id);
if (id != id_orig)
sym_name = IDENTIFIER_POINTER (id);
}
char *sym = XALLOCAVEC (char, strlen (sym_name) + 2);
if (sym_name[0] == '*' || sym_name[0] == '&')
strcpy (sym, sym_name + 1);
else if (sym_name[0] == '-' || sym_name[0] == '+')
strcpy (sym, sym_name);
else
sprintf (sym, "%s%s", user_label_prefix, sym_name);
char *stub = XALLOCAVEC (char, strlen (ptr_name) + 2);
if (ptr_name[0] == '*' || ptr_name[0] == '&')
strcpy (stub, ptr_name + 1);
else
sprintf (stub, "%s%s", user_label_prefix, ptr_name);
machopic_output_stub (out_file, sym, stub);
return 1;
}
int
machopic_output_indirection (machopic_indirection **slot, FILE *out_file)
{
machopic_indirection *p = *slot;
if (!p->used || p->stub_p || p->nlsp_in_data_section)
return 1;
rtx symbol = p->symbol;
/* The original symbol name. */
const char *sym_name = XSTR (symbol, 0);
/* The nonlazy-stub symbol name. */
const char *ptr_name = p->ptr_name;
switch_to_section (darwin_sections[machopic_nl_symbol_ptr_section]);
/* Mach-O symbols are passed around in code through indirect references and
the original symbol_ref hasn't passed through the generic handling and
reference-catching in output_operand, so we need to manually mark weak
references as such. */
if (SYMBOL_REF_WEAK (symbol))
{
tree decl = SYMBOL_REF_DECL (symbol);
gcc_checking_assert (DECL_P (decl));
if (decl != NULL_TREE
&& DECL_EXTERNAL (decl) && TREE_PUBLIC (decl)
/* Handle only actual external-only definitions, not
e.g. extern inline code or variables for which
storage has been allocated. */
&& !TREE_STATIC (decl))
{
fputs ("\t.weak_reference ", out_file);
assemble_name (out_file, sym_name);
fputc ('\n', out_file);
}
}
assemble_name (out_file, ptr_name);
fprintf (out_file, ":\n");
fprintf (out_file, "\t.indirect_symbol ");
assemble_name (out_file, sym_name);
fprintf (out_file, "\n");
/* Variables that are marked with MACHO_SYMBOL_FLAG_STATIC need to
have their symbol name instead of 0 in the second entry of
the non-lazy symbol pointer data structure when they are
defined. This allows the runtime to rebind newer instances
of the translation unit with the original instance of the
symbol. */
rtx init = const0_rtx;
if (MACHO_SYMBOL_STATIC_P (symbol) && machopic_symbol_defined_p (symbol))
init = gen_rtx_SYMBOL_REF (Pmode, sym_name);
assemble_integer (init, GET_MODE_SIZE (Pmode),
GET_MODE_ALIGNMENT (Pmode), 1);
return 1;
}
static void
machopic_finish (FILE *out_file)
{
if (!machopic_indirections)
return;
/* First output an symbol indirections that have been placed into .data
(we don't expect these now). */
machopic_indirections->traverse_noresize
<FILE *, machopic_output_data_section_indirection> (out_file);
machopic_indirections->traverse_noresize
<FILE *, machopic_output_stub_indirection> (out_file);
machopic_indirections->traverse_noresize
<FILE *, machopic_output_indirection> (out_file);
}
int
machopic_operand_p (rtx op)
{
if (MACHOPIC_JUST_INDIRECT)
return (GET_CODE (op) == SYMBOL_REF
&& machopic_symbol_defined_p (op));
else
return (GET_CODE (op) == CONST
&& GET_CODE (XEXP (op, 0)) == UNSPEC
&& XINT (XEXP (op, 0), 1) == UNSPEC_MACHOPIC_OFFSET);
}
/* This function:
computes and caches a series of flags that characterise the symbol's
properties that affect Mach-O code gen (including accidental cases
from older toolchains).
TODO:
Here we also need to do enough analysis to determine if a symbol's
name needs to be made linker-visible. This is more tricky - since
it depends on whether we've previously seen a global weak definition
in the same section.
*/
void
darwin_encode_section_info (tree decl, rtx rtl, int first)
{
/* Careful not to prod global register variables. */
if (!MEM_P (rtl))
return;
/* Do the standard encoding things first; this sets:
SYMBOL_FLAG_FUNCTION,
SYMBOL_FLAG_LOCAL, (binds_local_p)
TLS_MODEL, SYMBOL_FLAG_SMALL
SYMBOL_FLAG_EXTERNAL. */
default_encode_section_info (decl, rtl, first);
if (! VAR_OR_FUNCTION_DECL_P (decl))
return;
rtx sym_ref = XEXP (rtl, 0);
if (VAR_P (decl))
SYMBOL_REF_FLAGS (sym_ref) |= MACHO_SYMBOL_FLAG_VARIABLE;
/* Only really common if there's no initialiser. */
bool really_common_p = (DECL_COMMON (decl)
&& (DECL_INITIAL (decl) == NULL
|| (!in_lto_p
&& DECL_INITIAL (decl) == error_mark_node)));
/* For Darwin, if we have specified visibility and it's not the default
that's counted 'hidden'. */
if (DECL_VISIBILITY_SPECIFIED (decl)
&& DECL_VISIBILITY (decl) != VISIBILITY_DEFAULT)
SYMBOL_REF_FLAGS (sym_ref) |= MACHO_SYMBOL_FLAG_HIDDEN_VIS;
if (!DECL_EXTERNAL (decl)
&& (!TREE_PUBLIC (decl) || !DECL_WEAK (decl))
&& ! lookup_attribute ("weakref", DECL_ATTRIBUTES (decl))
&& ((TREE_STATIC (decl)
&& (!DECL_COMMON (decl) || !TREE_PUBLIC (decl)))
|| (!DECL_COMMON (decl) && DECL_INITIAL (decl)
&& DECL_INITIAL (decl) != error_mark_node)))
SYMBOL_REF_FLAGS (sym_ref) |= MACHO_SYMBOL_FLAG_DEFINED;
if (! TREE_PUBLIC (decl))
SYMBOL_REF_FLAGS (sym_ref) |= MACHO_SYMBOL_FLAG_STATIC;
/* Short cut check for Darwin 'must indirect' rules. */
if (really_common_p
|| (DECL_WEAK (decl) && ! MACHO_SYMBOL_HIDDEN_VIS_P (sym_ref))
|| lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
SYMBOL_REF_FLAGS (sym_ref) |= MACHO_SYMBOL_FLAG_MUST_INDIRECT;
#if DARWIN_PPC
/* Objective C V2 (m64) IVAR offset refs from Apple GCC-4.x have an
indirection for m64 code on PPC. Historically, these indirections
also appear in the .data section. */
tree o2meta = lookup_attribute ("OBJC2META", DECL_ATTRIBUTES (decl));
o2meta = o2meta ? TREE_VALUE (o2meta) : NULL_TREE;
if (o2meta && startswith (IDENTIFIER_POINTER (o2meta), "V2_IVRF"))
SYMBOL_REF_FLAGS (sym_ref) |= MACHO_SYMBOL_FLAG_MUST_INDIRECT;
#endif
}
void
darwin_mark_decl_preserved (const char *name)
{
/* Actually we shouldn't mark any local symbol this way, but for now
this only happens with ObjC meta-data. */
if (darwin_label_is_anonymous_local_objc_name (name))
return;
fprintf (asm_out_file, "\t.no_dead_strip ");
assemble_name (asm_out_file, name);
fputc ('\n', asm_out_file);
}
static section *
darwin_rodata_section (int use_coal, bool zsize, int reloc)
{
return (use_coal
? darwin_sections[const_coal_section]
: (zsize ? darwin_sections[zobj_const_section]
: reloc ? darwin_sections[const_data_section]
: darwin_sections[const_section]));
}
static section *
darwin_mergeable_string_section (tree exp,
unsigned HOST_WIDE_INT align)
{
/* Darwin's ld expects to see non-writable string literals in the .cstring
section. Later versions of ld check and complain when CFStrings are
enabled. Therefore we shall force the strings into .cstring since we
don't support writable ones anyway. */
if ((darwin_constant_cfstrings || flag_merge_constants)
&& TREE_CODE (exp) == STRING_CST
&& TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE
&& align <= 256
&& (int_size_in_bytes (TREE_TYPE (exp))
== TREE_STRING_LENGTH (exp))
&& ((size_t) TREE_STRING_LENGTH (exp)
== strlen (TREE_STRING_POINTER (exp)) + 1))
return darwin_sections[cstring_section];
if (DARWIN_SECTION_ANCHORS && flag_section_anchors
&& TREE_CODE (exp) == STRING_CST
&& TREE_STRING_LENGTH (exp) == 0)
return darwin_sections[zobj_const_section];
return readonly_data_section;
}
#ifndef HAVE_GAS_LITERAL16
#define HAVE_GAS_LITERAL16 0
#endif
static section *
darwin_mergeable_constant_section (tree exp,
unsigned HOST_WIDE_INT align,
bool zsize)
{
if (zsize)
return darwin_sections[zobj_const_section];
machine_mode mode = DECL_MODE (exp);
if (!flag_merge_constants
|| mode == VOIDmode
|| mode == BLKmode
|| align < 8
|| align > 256
|| (align & (align -1)) != 0)
return readonly_data_section;
/* This will ICE if the mode is not a constant size, but that is reasonable,
since one cannot put a variable-sized thing into a constant section, we
shouldn't be trying. */
const unsigned int modesize = GET_MODE_BITSIZE (mode).to_constant ();
if (modesize > align)
return readonly_data_section;
tree size = TYPE_SIZE_UNIT (TREE_TYPE (exp));
if (TREE_CODE (size) != INTEGER_CST)
return readonly_data_section;
unsigned isize = TREE_INT_CST_LOW (size);
if (isize == 4)
return darwin_sections[literal4_section];
else if (isize == 8)
return darwin_sections[literal8_section];
else if (HAVE_GAS_LITERAL16
&& TARGET_64BIT
&& isize == 16)
return darwin_sections[literal16_section];
return readonly_data_section;
}
section *
darwin_tm_clone_table_section (void)
{
return get_named_section (NULL,
"__DATA,__tm_clone_table,regular,no_dead_strip",
3);
}
int
machopic_reloc_rw_mask (void)
{
return MACHOPIC_INDIRECT ? 3 : 0;
}
/* We have to deal with ObjC/C++ metadata section placement in the common
code, since it will also be called from LTO.
Return metadata attributes, if present (searching for ABI=2 first)
Return NULL_TREE if no such attributes are found. */
static tree
is_objc_metadata (tree decl)
{
if (DECL_P (decl)
&& (TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == CONST_DECL)
&& DECL_ATTRIBUTES (decl))
{
tree meta = lookup_attribute ("OBJC2META", DECL_ATTRIBUTES (decl));
if (meta)
return meta;
meta = lookup_attribute ("OBJC1META", DECL_ATTRIBUTES (decl));
if (meta)
return meta;
}
return NULL_TREE;
}
static int classes_seen;
static int objc_metadata_seen;
/* Return the section required for Objective C ABI 2 metadata. */
static section *
darwin_objc2_section (tree decl ATTRIBUTE_UNUSED, tree meta, section * base)
{
const char *p;
tree ident = TREE_VALUE (meta);
gcc_assert (TREE_CODE (ident) == IDENTIFIER_NODE);
p = IDENTIFIER_POINTER (ident);
gcc_checking_assert (flag_next_runtime >= 1 && flag_objc_abi == 2);
objc_metadata_seen = 1;
if (base == data_section)
base = darwin_sections[objc2_metadata_section];
/* Most of the OBJC2 META-data end up in the base section, so check it
first. */
if (startswith (p, "V2_BASE"))
return base;
else if (startswith (p, "V2_CNAM"))
return darwin_sections[objc2_class_names_section];
else if (startswith (p, "V2_MNAM"))
return darwin_sections[objc2_method_names_section];
else if (startswith (p, "V2_MTYP"))
return darwin_sections[objc2_method_types_section];
else if (startswith (p, "V2_STRG"))
return darwin_sections[cstring_section];
else if (startswith (p, "G2_META") || startswith (p, "G2_CLAS"))
return darwin_sections[objc2_classdefs_section];
else if (startswith (p, "V2_PCOL"))
return ld_uses_coal_sects ? darwin_sections[data_coal_section]
: darwin_sections[objc2_data_section];
else if (startswith (p, "V2_MREF"))
return darwin_sections[objc2_message_refs_section];
else if (startswith (p, "V2_CLRF"))
return darwin_sections[objc2_classrefs_section];
else if (startswith (p, "V2_SURF"))
return darwin_sections[objc2_super_classrefs_section];
else if (startswith (p, "V2_NLCL"))
return darwin_sections[objc2_nonlazy_class_section];
else if (startswith (p, "V2_CLAB"))
{
classes_seen = 1;
return darwin_sections[objc2_classlist_section];
}
else if (startswith (p, "V2_SRFS"))
return darwin_sections[objc2_selector_refs_section];
else if (startswith (p, "V2_NLCA"))
return darwin_sections[objc2_nonlazy_category_section];
else if (startswith (p, "V2_CALA"))
return darwin_sections[objc2_categorylist_section];
else if (startswith (p, "V2_PLST"))
return darwin_sections[objc2_protocollist_section];
else if (startswith (p, "V2_PRFS"))
return darwin_sections[objc2_protocolrefs_section];
else if (startswith (p, "V2_INFO"))
return darwin_sections[objc2_image_info_section];
else if (startswith (p, "V2_EHTY"))
return ld_uses_coal_sects ? darwin_sections[data_coal_section]
: data_section;
else if (startswith (p, "V2_CSTR"))
return darwin_sections[objc2_constant_string_object_section];
else if (startswith (p, "V2_IVRF"))
return darwin_sections[objc2_ivar_section];
/* Not recognized, default. */
return base;
}
/* Return the section required for Objective C ABI 0/1 metadata. */
static section *
darwin_objc1_section (tree decl ATTRIBUTE_UNUSED, tree meta, section * base)
{
const char *p;
tree ident = TREE_VALUE (meta);
gcc_assert (TREE_CODE (ident) == IDENTIFIER_NODE);
p = IDENTIFIER_POINTER (ident);
gcc_checking_assert (flag_next_runtime >= 1 && flag_objc_abi < 2);
objc_metadata_seen = 1;
/* String sections first, cos there are lots of strings. */
if (startswith (p, "V1_STRG"))
return darwin_sections[cstring_section];
else if (startswith (p, "V1_CLSN"))
return darwin_sections[objc_class_names_section];
else if (startswith (p, "V1_METN"))
return darwin_sections[objc_meth_var_names_section];
else if (startswith (p, "V1_METT"))
return darwin_sections[objc_meth_var_types_section];
else if (startswith (p, "V1_CLAS"))
{
classes_seen = 1;
return darwin_sections[objc_class_section];
}
else if (startswith (p, "V1_META"))
return darwin_sections[objc_meta_class_section];
else if (startswith (p, "V1_CATG"))
return darwin_sections[objc_category_section];
else if (startswith (p, "V1_PROT"))
return darwin_sections[objc_protocol_section];
else if (startswith (p, "V1_CLCV"))
return darwin_sections[objc_class_vars_section];
else if (startswith (p, "V1_CLIV"))
return darwin_sections[objc_instance_vars_section];
else if (startswith (p, "V1_CLCM"))
return darwin_sections[objc_cls_meth_section];
else if (startswith (p, "V1_CLIM"))
return darwin_sections[objc_inst_meth_section];
else if (startswith (p, "V1_CACM"))
return darwin_sections[objc_cat_cls_meth_section];
else if (startswith (p, "V1_CAIM"))
return darwin_sections[objc_cat_inst_meth_section];
else if (startswith (p, "V1_PNSM"))
return darwin_sections[objc_cat_inst_meth_section];
else if (startswith (p, "V1_PCLM"))
return darwin_sections[objc_cat_cls_meth_section];
else if (startswith (p, "V1_CLPR"))
return darwin_sections[objc_cat_cls_meth_section];
else if (startswith (p, "V1_CAPR"))
return darwin_sections[objc_category_section]; /* ??? CHECK me. */
else if (startswith (p, "V1_PRFS"))
return darwin_sections[objc_cat_cls_meth_section];
else if (startswith (p, "V1_CLRF"))
return darwin_sections[objc_cls_refs_section];
else if (startswith (p, "V1_SRFS"))
return darwin_sections[objc_selector_refs_section];
else if (startswith (p, "V1_MODU"))
return darwin_sections[objc_module_info_section];
else if (startswith (p, "V1_SYMT"))
return darwin_sections[objc_symbols_section];
else if (startswith (p, "V1_INFO"))
return darwin_sections[objc_image_info_section];
else if (startswith (p, "V1_PLST"))
return darwin_sections[objc1_prop_list_section];
else if (startswith (p, "V1_PEXT"))
return darwin_sections[objc1_protocol_ext_section];
else if (startswith (p, "V1_CEXT"))
return darwin_sections[objc1_class_ext_section];
else if (startswith (p, "V2_CSTR"))
return darwin_sections[objc_constant_string_object_section];
return base;
}
section *
machopic_select_section (tree decl,
int reloc,
unsigned HOST_WIDE_INT align)
{
bool zsize, one, weak, use_coal, ro;
section *base_section = NULL;
weak = (DECL_P (decl)
&& DECL_WEAK (decl)
&& !lookup_attribute ("weak_import", DECL_ATTRIBUTES (decl)));
/* Darwin pads zero-sized objects with at least one byte, so that the ld64
atom model is preserved (objects must have distinct regions starting with
a unique linker-visible symbol).
In order to support section anchors, we need to move objects with zero
size into sections which are marked as "no section anchors"; the padded
objects, obviously, have real sizes that differ from their DECL sizes. */
zsize = DARWIN_SECTION_ANCHORS && flag_section_anchors;
/* In the streaming of LTO symbol data, we might have a situation where the
var is incomplete or layout not finished (DECL_SIZE_UNIT is NULL_TREE).
We cannot tell if it is zero-sized then, but we can get the section
category correct so that nm reports the right kind of section
(e.g. BSS c.f. data). */
zsize = (zsize
&& DECL_P (decl)
&& (TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == CONST_DECL)
&& DECL_SIZE_UNIT (decl)
&& tree_to_uhwi (DECL_SIZE_UNIT (decl)) == 0);
one = DECL_P (decl)
&& TREE_CODE (decl) == VAR_DECL
&& DECL_COMDAT_GROUP (decl);
use_coal = (weak || one) && ld_uses_coal_sects;
ro = TREE_READONLY (decl) || TREE_CONSTANT (decl) ;
switch (categorize_decl_for_section (decl, reloc))
{
case SECCAT_TEXT:
gcc_unreachable ();
break;
case SECCAT_RODATA:
case SECCAT_SRODATA:
base_section = darwin_rodata_section (use_coal, zsize, reloc);
break;
case SECCAT_RODATA_MERGE_STR:
base_section = darwin_mergeable_string_section (decl, align);
break;
case SECCAT_RODATA_MERGE_STR_INIT:
base_section = darwin_mergeable_string_section (DECL_INITIAL (decl), align);
break;
case SECCAT_RODATA_MERGE_CONST:
base_section = darwin_mergeable_constant_section (decl, align, zsize);
break;
case SECCAT_DATA:
case SECCAT_DATA_REL:
case SECCAT_DATA_REL_LOCAL:
case SECCAT_DATA_REL_RO:
case SECCAT_DATA_REL_RO_LOCAL:
case SECCAT_SDATA:
case SECCAT_TDATA:
if (use_coal)
{
if (ro)
base_section = darwin_sections[const_data_coal_section];
else
base_section = darwin_sections[data_coal_section];
}
else if (zsize)
{
/* If we're doing section anchors, then punt zero-sized objects into
their own sections so that they don't interfere with offset
computation for the remaining vars. */
if (ro)
base_section = darwin_sections[zobj_const_data_section];
else
base_section = darwin_sections[zobj_data_section];
}
else if (ro)
base_section = darwin_sections[const_data_section];
else
base_section = data_section;
break;
case SECCAT_BSS:
case SECCAT_SBSS:
case SECCAT_TBSS:
if (use_coal)
base_section = darwin_sections[data_coal_section];
else
{
if (!TREE_PUBLIC (decl))
base_section = lcomm_section;
else if (bss_noswitch_section)
base_section = bss_noswitch_section;
else
base_section = data_section;
}
break;
default:
gcc_unreachable ();
}
/* Darwin weird special cases.
a) OBJC Meta-data. */
if (DECL_P (decl)
&& (TREE_CODE (decl) == VAR_DECL
|| TREE_CODE (decl) == CONST_DECL)
&& DECL_ATTRIBUTES (decl))
{
tree meta = lookup_attribute ("OBJC2META", DECL_ATTRIBUTES (decl));
if (meta)
return darwin_objc2_section (decl, meta, base_section);
meta = lookup_attribute ("OBJC1META", DECL_ATTRIBUTES (decl));
if (meta)
return darwin_objc1_section (decl, meta, base_section);
meta = lookup_attribute ("OBJC1METG", DECL_ATTRIBUTES (decl));
if (meta)
return base_section; /* GNU runtime is happy with it all in one pot. */
}
/* b) Constant string objects. */
if (TREE_CODE (decl) == CONSTRUCTOR
&& TREE_TYPE (decl)
&& TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE
&& TYPE_NAME (TREE_TYPE (decl)))
{
tree name = TYPE_NAME (TREE_TYPE (decl));
if (TREE_CODE (name) == TYPE_DECL)
name = DECL_NAME (name);
if (!strcmp (IDENTIFIER_POINTER (name), "__builtin_ObjCString"))
{
if (flag_next_runtime)
{
if (flag_objc_abi == 2)
return darwin_sections[objc2_constant_string_object_section];
else
return darwin_sections[objc_constant_string_object_section];
}
else
return darwin_sections[objc_string_object_section];
}
else if (!strcmp (IDENTIFIER_POINTER (name), "__builtin_CFString"))
return darwin_sections[cfstring_constant_object_section];
else
return base_section;
}
else if (flag_next_runtime
&& VAR_P (decl)
&& DECL_NAME (decl)
&& TREE_CODE (DECL_NAME (decl)) == IDENTIFIER_NODE
&& IDENTIFIER_POINTER (DECL_NAME (decl))
&& startswith (IDENTIFIER_POINTER (DECL_NAME (decl)), "_OBJC_"))
/* c) legacy meta-data selection was deprecated at 4.6, removed now. */
gcc_unreachable ();
return base_section;
}
/* This can be called with address expressions as "rtx".
They must go in "const". */
section *
machopic_select_rtx_section (machine_mode mode, rtx x,
unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
{
if (known_eq (GET_MODE_SIZE (mode), 8)
&& (GET_CODE (x) == CONST_INT
|| GET_CODE (x) == CONST_WIDE_INT
|| GET_CODE (x) == CONST_DOUBLE))
return darwin_sections[literal8_section];
else if (known_eq (GET_MODE_SIZE (mode), 4)
&& (GET_CODE (x) == CONST_INT
|| GET_CODE (x) == CONST_WIDE_INT
|| GET_CODE (x) == CONST_DOUBLE))
return darwin_sections[literal4_section];
else if (HAVE_GAS_LITERAL16
&& TARGET_64BIT
&& known_eq (GET_MODE_SIZE (mode), 16)
&& (GET_CODE (x) == CONST_INT
|| GET_CODE (x) == CONST_WIDE_INT
|| GET_CODE (x) == CONST_DOUBLE
|| GET_CODE (x) == CONST_VECTOR))
return darwin_sections[literal16_section];
else if (MACHOPIC_INDIRECT
&& (GET_CODE (x) == SYMBOL_REF
|| GET_CODE (x) == CONST
|| GET_CODE (x) == LABEL_REF))
return darwin_sections[const_data_section];
else
return darwin_sections[const_section];
}
void
machopic_asm_out_constructor (rtx symbol, int priority ATTRIBUTE_UNUSED)
{
cdtor_record new_elt = {symbol, priority, vec_safe_length (ctors)};
vec_safe_push (ctors, new_elt);
if (! MACHOPIC_INDIRECT)
fprintf (asm_out_file, ".reference .constructors_used\n");
}
void
machopic_asm_out_destructor (rtx symbol, int priority ATTRIBUTE_UNUSED)
{
cdtor_record new_elt = {symbol, priority, vec_safe_length (dtors)};
vec_safe_push (dtors, new_elt);
if (! MACHOPIC_INDIRECT)
fprintf (asm_out_file, ".reference .destructors_used\n");
}
static int
sort_cdtor_records (const void * a, const void * b)
{
const cdtor_record *cda = (const cdtor_record *)a;
const cdtor_record *cdb = (const cdtor_record *)b;
if (cda->priority > cdb->priority)
return 1;
if (cda->priority < cdb->priority)
return -1;
if (cda->position > cdb->position)
return 1;
if (cda->position < cdb->position)
return -1;
return 0;
}
static void
finalize_ctors ()
{
unsigned int i;
cdtor_record *elt;
if (MACHOPIC_INDIRECT)
switch_to_section (darwin_sections[mod_init_section]);
else
switch_to_section (darwin_sections[constructor_section]);
/* Where needed, provide a linker-visible section-start symbol so that we
have stable output between debug and non-debug. */
if (ld_init_term_start_labels)
fputs (MACHOPIC_INDIRECT ? "_Mod.init:\n" : "_CTOR.sect:\n", asm_out_file);
if (vec_safe_length (ctors) > 1)
ctors->qsort (sort_cdtor_records);
FOR_EACH_VEC_SAFE_ELT (ctors, i, elt)
{
assemble_align (POINTER_SIZE);
assemble_integer (elt->symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
}
}
static void
finalize_dtors ()
{
unsigned int i;
cdtor_record *elt;
if (MACHOPIC_INDIRECT)
switch_to_section (darwin_sections[mod_term_section]);
else
switch_to_section (darwin_sections[destructor_section]);
/* Where needed, provide a linker-visible section-start symbol so that we
have stable output between debug and non-debug. */
if (ld_init_term_start_labels)
fputs (MACHOPIC_INDIRECT ? "_Mod.term:\n" : "_DTOR.sect:\n", asm_out_file);
if (vec_safe_length (dtors) > 1)
dtors->qsort (sort_cdtor_records);
FOR_EACH_VEC_SAFE_ELT (dtors, i, elt)
{
assemble_align (POINTER_SIZE);
assemble_integer (elt->symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
}
}
void
darwin_globalize_label (FILE *stream, const char *name)
{
if (!startswith (name, "_OBJC_"))
default_globalize_label (stream, name);
/* We have some Objective C cases that need to be global, but only on newer
OS versions. */
if (flag_objc_abi < 2 || flag_next_runtime < 100700)
return;
if (startswith (name+6, "LabelPro"))
default_globalize_label (stream, name);
if (startswith (name+6, "Protocol_"))
default_globalize_label (stream, name);
}
/* This routine returns non-zero if 'name' starts with the special objective-c
anonymous file-scope static name. It accommodates c++'s mangling of such
symbols (in this case the symbols will have form _ZL{d}*_OBJC_* d=digit). */
int
darwin_label_is_anonymous_local_objc_name (const char *name)
{
const unsigned char *p = (const unsigned char *) name;
if (*p != '_')
return 0;
if (p[1] == 'Z' && p[2] == 'L')
{
p += 3;
while (*p >= '0' && *p <= '9')
p++;
}
if (!startswith ((const char *)p, "_OBJC_"))
return false;
/* We need some of the objective c meta-data symbols to be visible to the
linker (when the target OS version is newer). FIXME: this is horrible,
we need a better mechanism. */
if (flag_objc_abi < 2 || flag_next_runtime < 100700)
return true;
p += 6;
if (startswith ((const char *)p, "ClassRef"))
return false;
else if (startswith ((const char *)p, "SelRef"))
return false;
else if (startswith ((const char *)p, "Category"))
{
if (p[8] == '_' || p[8] == 'I' || p[8] == 'P' || p[8] == 'C' )
return false;
return true;
}
else if (startswith ((const char *)p, "ClassMethods"))
return false;
else if (startswith ((const char *)p, "Instance"))
{
if (p[8] == 'I' || p[8] == 'M')
return false;
return true;
}
else if (startswith ((const char *)p, "CLASS_RO"))
return false;
else if (startswith ((const char *)p, "METACLASS_RO"))
return false;
else if (startswith ((const char *)p, "Protocol"))
{
if (p[8] == '_' || p[8] == 'I' || p[8] == 'P'
|| p[8] == 'M' || p[8] == 'C' || p[8] == 'O')
return false;
return true;
}
else if (startswith ((const char *)p, "LabelPro"))
return false;
return true;
}
/* LTO support for Mach-O.
This version uses three mach-o sections to encapsulate the (unlimited
number of) lto sections.
__GNU_LTO, __lto_sections contains the concatented GNU LTO section data.
__GNU_LTO, __section_names contains the GNU LTO section names.
__GNU_LTO, __section_index contains an array of values that index these.
Indexed thus:
<section offset from the start of __GNU_LTO, __lto_sections>,
<section length>
<name offset from the start of __GNU_LTO, __section_names,
<name length>.
At present, for both m32 and m64 mach-o files each of these fields is
represented by a uint32_t. This is because, AFAICT, a mach-o object
cannot exceed 4Gb because the section_64 offset field (see below) is 32bits.
uint32_t offset;
"offset An integer specifying the offset to this section in the file." */
/* Count lto section numbers. */
static unsigned int lto_section_num = 0;
/* A vector of information about LTO sections, at present, we only have
the name. TODO: see if we can get the data length somehow. */
typedef struct GTY (()) darwin_lto_section_e {
const char *sectname;
} darwin_lto_section_e ;
static GTY (()) vec<darwin_lto_section_e, va_gc> *lto_section_names;
/* Section wrapper scheme (used here to wrap the unlimited number of LTO
sections into three Mach-O ones).
NOTE: These names MUST be kept in sync with those in
libiberty/simple-object-mach-o. */
#define LTO_SECTS_SECTION "__wrapper_sects"
#define LTO_NAMES_SECTION "__wrapper_names"
#define LTO_INDEX_SECTION "__wrapper_index"
/* File to temporarily store LTO data. This is appended to asm_out_file
in darwin_end_file. */
static FILE *lto_asm_out_file, *saved_asm_out_file;
static char *lto_asm_out_name;
static enum debug_info_levels saved_debug_info_level;
/* Prepare asm_out_file for LTO output. For darwin, this means hiding
asm_out_file and switching to an alternative output file. */
void
darwin_asm_lto_start (void)
{
gcc_assert (! saved_asm_out_file);
saved_asm_out_file = asm_out_file;
saved_debug_info_level = debug_info_level;
debug_info_level = DINFO_LEVEL_NONE;
if (! lto_asm_out_name)
lto_asm_out_name = make_temp_file (".lto.s");
lto_asm_out_file = fopen (lto_asm_out_name, "a");
if (lto_asm_out_file == NULL)
fatal_error (input_location,
"failed to open temporary file %s for LTO output",
lto_asm_out_name);
asm_out_file = lto_asm_out_file;
}
/* Restore asm_out_file. */
void
darwin_asm_lto_end (void)
{
gcc_assert (saved_asm_out_file);
fclose (lto_asm_out_file);
asm_out_file = saved_asm_out_file;
saved_asm_out_file = NULL;
debug_info_level = saved_debug_info_level;
}
static void
darwin_asm_dwarf_section (const char *name, unsigned int flags,
tree decl, bool is_for_lto);
/* Called for the TARGET_ASM_NAMED_SECTION hook. */
void
darwin_asm_named_section (const char *name,
unsigned int flags,
tree decl ATTRIBUTE_UNUSED)
{
/* LTO sections go in a special section that encapsulates the (unlimited)
number of GNU LTO sections within a single mach-o one. */
if (startswith (name, LTO_SECTION_NAME_PREFIX))
{
darwin_lto_section_e e;
/* We expect certain flags to be set... */
gcc_assert ((flags & (SECTION_DEBUG | SECTION_NAMED))
== (SECTION_DEBUG | SECTION_NAMED));
/* Switch to our combined section. */
fprintf (asm_out_file, "\t.section %s,%s,regular,debug\n",
LTO_SEGMENT_NAME, LTO_SECTS_SECTION);
/* Output a label for the start of this sub-section. */
fprintf (asm_out_file, "L_GNU_LTO%d:\t;# %s\n",
lto_section_num, name);
/* We have to jump through hoops to get the values of the intra-section
offsets... */
fprintf (asm_out_file, "\t.set L$gnu$lto$offs%d,L_GNU_LTO%d-L_GNU_LTO0\n",
lto_section_num, lto_section_num);
fprintf (asm_out_file,
"\t.set L$gnu$lto$size%d,L_GNU_LTO%d-L_GNU_LTO%d\n",
lto_section_num, lto_section_num+1, lto_section_num);
lto_section_num++;
e.sectname = xstrdup (name);
/* Keep the names, we'll need to make a table later.
TODO: check that we do not revisit sections, that would break
the assumption of how this is done. */
if (lto_section_names == NULL)
vec_alloc (lto_section_names, 16);
vec_safe_push (lto_section_names, e);
}
else if (startswith (name, "__DWARF,"))
darwin_asm_dwarf_section (name, flags, decl, false);
else if (startswith (name, "__GNU_DWARF_LTO,"))
darwin_asm_dwarf_section (name, flags, decl, true);
else
fprintf (asm_out_file, "\t.section %s\n", name);
}
void
darwin_unique_section (tree decl ATTRIBUTE_UNUSED, int reloc ATTRIBUTE_UNUSED)
{
/* Darwin does not use unique sections. */
}
/* Handle __attribute__ ((apple_kext_compatibility)).
This only applies to darwin kexts for 2.95 compatibility -- it shrinks the
vtable for classes with this attribute (and their descendants) by not
outputting the new 3.0 nondeleting destructor. This means that such
objects CANNOT be allocated on the stack or as globals UNLESS they have
a completely empty `operator delete'.
Luckily, this fits in with the Darwin kext model.
This attribute also disables gcc3's potential overlaying of derived
class data members on the padding at the end of the base class. */
tree
darwin_handle_kext_attribute (tree *node, tree name,
tree args ATTRIBUTE_UNUSED,
int flags ATTRIBUTE_UNUSED,
bool *no_add_attrs)
{
/* APPLE KEXT stuff -- only applies with pure static C++ code. */
if (! TARGET_KEXTABI)
{
warning (0, "%qE 2.95 vtable-compatibility attribute applies "
"only when compiling a kext", name);
*no_add_attrs = true;
}
else if (TREE_CODE (*node) != RECORD_TYPE)
{
warning (0, "%qE 2.95 vtable-compatibility attribute applies "
"only to C++ classes", name);
*no_add_attrs = true;
}
return NULL_TREE;
}
/* Handle a "weak_import" attribute; arguments as in
struct attribute_spec.handler. */
tree
darwin_handle_weak_import_attribute (tree *node, tree name,
tree ARG_UNUSED (args),
int ARG_UNUSED (flags),
bool * no_add_attrs)
{
if (TREE_CODE (*node) != FUNCTION_DECL && TREE_CODE (*node) != VAR_DECL)
{
warning (OPT_Wattributes, "%qE attribute ignored",
name);
*no_add_attrs = true;
}
else
declare_weak (*node);
return NULL_TREE;
}
/* Emit a label for an FDE, making it global and/or weak if appropriate.
The third parameter is nonzero if this is for exception handling.
The fourth parameter is nonzero if this is just a placeholder for an
FDE that we are omitting. */
void
darwin_emit_unwind_label (FILE *file, tree decl, int for_eh, int empty)
{
char *lab ;
char buf[32];
static int invok_count = 0;
static tree last_fun_decl = NULL_TREE;
/* Modern linkers can produce distinct FDEs without compiler support. */
if (! for_eh || ! ld_needs_eh_markers)
return;
/* FIXME: This only works when the eh for all sections of a function are
emitted at the same time. If that changes, we would need to use a lookup
table of some form to determine what to do. Also, we should emit the
unadorned label for the partition containing the public label for a
function. This is of limited use, probably, since we do not currently
enable partitioning. */
strcpy (buf, ".eh");
if (decl && TREE_CODE (decl) == FUNCTION_DECL)
{
if (decl == last_fun_decl)
{
invok_count++;
snprintf (buf, 31, "$$part$$%d.eh", invok_count);
}
else
{
last_fun_decl = decl;
invok_count = 0;
}
}
lab = concat (IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)), buf, NULL);
if (TREE_PUBLIC (decl))
{
targetm.asm_out.globalize_label (file, lab);
if (DECL_VISIBILITY (decl) == VISIBILITY_HIDDEN)
{
fputs ("\t.private_extern ", file);
assemble_name (file, lab);
fputc ('\n', file);
}
}
if (DECL_WEAK (decl))
{
fputs ("\t.weak_definition ", file);
assemble_name (file, lab);
fputc ('\n', file);
}
assemble_name (file, lab);
if (empty)
{
fputs (" = 0\n", file);
/* Mark the absolute .eh and .eh1 style labels as needed to
ensure that we don't dead code strip them and keep such
labels from another instantiation point until we can fix this
properly with group comdat support. */
darwin_mark_decl_preserved (lab);
}
else
fputs (":\n", file);
free (lab);
}
static GTY(()) unsigned long except_table_label_num;
void
darwin_emit_except_table_label (FILE *file)
{
char section_start_label[30];
ASM_GENERATE_INTERNAL_LABEL (section_start_label, "GCC_except_table",
except_table_label_num++);
ASM_OUTPUT_LABEL (file, section_start_label);
}
rtx
darwin_make_eh_symbol_indirect (rtx orig, bool ARG_UNUSED (pubvis))
{
if (DARWIN_PPC == 0 && TARGET_64BIT)
return orig;
return gen_rtx_SYMBOL_REF (Pmode,
machopic_indirection_name (orig,
/*stub_p=*/false));
}
/* The unwinders in earlier Darwin versions are based on an old version
of libgcc_s and need current frame address stateto be reset after a
DW_CFA_restore_state recovers the register values. */
bool
darwin_should_restore_cfa_state (void)
{
return generating_for_darwin_version <= 10;
}
/* Return, and mark as used, the name of the stub for the mcount function.
Currently, this is only called by X86 code in the expansion of the
FUNCTION_PROFILER macro, when stubs are enabled. */
const char*
machopic_mcount_stub_name (void)
{
rtx symbol = gen_rtx_SYMBOL_REF (Pmode, "*mcount");
const char *name = machopic_indirection_name (symbol, /*stub_p=*/true);
machopic_validate_stub_or_non_lazy_ptr (name);
return name;
}
/* Generate a PC-relative reference to a Mach-O non-lazy-symbol. */
void
darwin_non_lazy_pcrel (FILE *file, rtx addr)
{
const char *nlp_name;
gcc_assert (GET_CODE (addr) == SYMBOL_REF);
nlp_name = machopic_indirection_name (addr, /*stub_p=*/false);
fputs ("\t.long\t", file);
ASM_OUTPUT_LABELREF (file, nlp_name);
fputs ("-.", file);
}
/* If this is uncommented, details of each allocation will be printed
in the asm right before the actual code. WARNING - this will cause some
test-suite fails (since the printout will contain items that some tests
are not expecting) -- so don't leave it on by default (it bloats the
asm too). */
/*#define DEBUG_DARWIN_MEM_ALLOCATORS*/
/* The first two of these routines are ostensibly just intended to put
names into the asm. However, they are both hijacked in order to ensure
that zero-sized items do not make their way into the output. Consequently,
we also need to make these participate in provisions for dealing with
such items in section anchors. */
/* The implementation of ASM_DECLARE_OBJECT_NAME. */
/* The RTTI data (e.g., __ti4name) is common and public (and static),
but it does need to be referenced via indirect PIC data pointers.
The machopic_define_symbol calls are telling the machopic subsystem
that the name *is* defined in this module, so it doesn't need to
make them indirect. */
void
darwin_asm_declare_object_name (FILE *file,
const char *nam, tree decl)
{
const char *xname = nam;
unsigned HOST_WIDE_INT size;
bool local_def, weak;
weak = (DECL_P (decl)
&& DECL_WEAK (decl)
&& !lookup_attribute ("weak_import",
DECL_ATTRIBUTES (decl)));
local_def = DECL_INITIAL (decl) || (TREE_STATIC (decl)
&& (!DECL_COMMON (decl)
|| !TREE_PUBLIC (decl)));
if (GET_CODE (XEXP (DECL_RTL (decl), 0)) != SYMBOL_REF)
xname = IDENTIFIER_POINTER (DECL_NAME (decl));
if (local_def)
{
(* targetm.encode_section_info) (decl, DECL_RTL (decl), false);
if (!weak)
machopic_define_symbol (DECL_RTL (decl));
}
size = tree_to_uhwi (DECL_SIZE_UNIT (decl));
#ifdef DEBUG_DARWIN_MEM_ALLOCATORS
fprintf (file, "# dadon: %s %s (%llu, %u) local %d weak %d"
" stat %d com %d pub %d t-const %d t-ro %d init %lx\n",
xname, (TREE_CODE (decl) == VAR_DECL?"var":"const"),
(unsigned long long)size, DECL_ALIGN (decl), local_def,
DECL_WEAK (decl), TREE_STATIC (decl), DECL_COMMON (decl),
TREE_PUBLIC (decl), TREE_CONSTANT (decl), TREE_READONLY (decl),
(unsigned long)DECL_INITIAL (decl));
#endif
/* Darwin needs help to support local zero-sized objects.
They must be made at least one byte, and the section containing must be
marked as unsuitable for section-anchors (see storage allocators below).
For non-zero objects this output is handled by varasm.c.
*/
if (!size)
{
unsigned int l2align = 0;
/* The align must be honored, even for zero-sized. */
if (DECL_ALIGN (decl))
{
l2align = floor_log2 (DECL_ALIGN (decl) / BITS_PER_UNIT);
fprintf (file, "\t.align\t%u\n", l2align);
}
ASM_OUTPUT_LABEL (file, xname);
size = 1;
fprintf (file, "\t.space\t" HOST_WIDE_INT_PRINT_UNSIGNED"\n", size);
/* Check that we've correctly picked up the zero-sized item and placed it
properly. */
gcc_assert ((!DARWIN_SECTION_ANCHORS || !flag_section_anchors)
|| (in_section
&& (in_section->common.flags & SECTION_NO_ANCHOR)));
}
else
ASM_OUTPUT_LABEL (file, xname);
}
/* The implementation of ASM_DECLARE_CONSTANT_NAME. */
void
darwin_asm_declare_constant_name (FILE *file, const char *name,
const_tree exp ATTRIBUTE_UNUSED,
HOST_WIDE_INT size)
{
assemble_label (file, name);
/* As for other items, we need at least one byte. */
if (!size)
{
fputs ("\t.space\t1\n", file);
/* Check that we've correctly picked up the zero-sized item and placed it
properly. */
gcc_assert ((!DARWIN_SECTION_ANCHORS || !flag_section_anchors)
|| (in_section
&& (in_section->common.flags & SECTION_NO_ANCHOR)));
}
}
/* Darwin storage allocators.
Zerofill sections are desirable for large blank data since, otherwise, these
data bloat objects (PR33210).
However, section anchors don't work in .zerofill sections (one cannot switch
to a zerofill section). Ergo, for Darwin targets using section anchors we need
to put (at least some) data into 'normal' switchable sections.
Here we set a relatively arbitrary value for the size of an object to trigger
zerofill when section anchors are enabled (anything bigger than a page for
current Darwin implementations). FIXME: there ought to be some objective way
to make this choice.
When section anchor are off this is ignored anyway. */
#define BYTES_ZFILL 4096
/* Emit a chunk of data for items coalesced by the linker. */
static void
darwin_emit_weak_or_comdat (FILE *fp, tree decl, const char *name,
unsigned HOST_WIDE_INT size,
bool use_coal,
unsigned int align)
{
/* Since the sections used here are coalesced, they will not be eligible
for section anchors, and therefore we don't need to break that out.
CHECKME: for modern linker on PowerPC. */
if (TREE_READONLY (decl) || TREE_CONSTANT (decl))
switch_to_section (use_coal ? darwin_sections[const_data_coal_section]
: darwin_sections[const_data_section]);
else
switch_to_section (use_coal ? darwin_sections[data_coal_section]
: data_section);
/* To be consistent, we'll allow darwin_asm_declare_object_name to assemble
the align info for zero-sized items... but do it here otherwise. */
if (size && align)
fprintf (fp, "\t.align\t%d\n", floor_log2 (align / BITS_PER_UNIT));
if (TREE_PUBLIC (decl))
darwin_globalize_label (fp, name);
/* ... and we let it deal with outputting one byte of zero for them too. */
darwin_asm_declare_object_name (fp, name, decl);
if (size)
assemble_zeros (size);
}
/* Emit a chunk of data for ObjC meta-data that got placed in BSS erroneously. */
static void
darwin_emit_objc_zeroed (FILE *fp, tree decl, const char *name,
unsigned HOST_WIDE_INT size,
unsigned int align, tree meta)
{
section *ocs = data_section;
if (TREE_PURPOSE (meta) == get_identifier("OBJC2META"))
ocs = darwin_objc2_section (decl, meta, ocs);
else
ocs = darwin_objc1_section (decl, meta, ocs);
switch_to_section (ocs);
/* We shall declare that zero-sized meta-data are not valid (yet). */
gcc_assert (size);
fprintf (fp, "\t.align\t%d\n", floor_log2 (align / BITS_PER_UNIT));
/* ... and we let it deal with outputting one byte of zero for them too. */
darwin_asm_declare_object_name (fp, name, decl);
assemble_zeros (size);
}
/* This routine emits 'local' storage:
When Section Anchors are off this routine emits .zerofill commands in
sections named for their alignment.
When Section Anchors are on, smaller (non-zero-sized) items are placed in
the .static_data section so that the section anchoring system can see them.
Larger items are still placed in .zerofill sections, addressing PR33210.
The routine has no checking - it is all assumed to be done by the caller.
*/
static void
darwin_emit_local_bss (FILE *fp, tree decl, const char *name,
unsigned HOST_WIDE_INT size,
unsigned int l2align)
{
if (DARWIN_SECTION_ANCHORS && flag_section_anchors && size < BYTES_ZFILL)
{
/* Put smaller objects in _static_data, where the section anchors system
can get them.
However, if they are zero-sized punt them to yet a different section
(that is not allowed to participate in anchoring). */
if (!size)
{
fputs ("\t.section\t__DATA,__zobj_bss\n", fp);
in_section = darwin_sections[zobj_bss_section];
size = 1;
}
else
{
fputs ("\t.static_data\n", fp);
in_section = darwin_sections[static_data_section];
}
if (l2align)
fprintf (fp, "\t.align\t%u\n", l2align);
assemble_name (fp, name);
fprintf (fp, ":\n\t.space\t" HOST_WIDE_INT_PRINT_UNSIGNED"\n", size);
}
else
{
/* When we are on a non-section anchor target (or not using section
anchors, we can get zero-sized items here. However, all we need to
do is to bump them to one byte and the section alignment will take
care of the rest. */
char secnam[64];
snprintf (secnam, 64, "__DATA,__bss");
unsigned int flags = SECTION_BSS|SECTION_WRITE|SECTION_NO_ANCHOR;
in_section = get_section (secnam, flags, NULL);
fprintf (fp, "\t.zerofill %s,", secnam);
assemble_name (fp, name);
if (!size)
size = 1;
if (l2align)
fprintf (fp, "," HOST_WIDE_INT_PRINT_UNSIGNED",%u\n",
size, (unsigned) l2align);
else
fprintf (fp, "," HOST_WIDE_INT_PRINT_UNSIGNED",0\n", size);
}
(*targetm.encode_section_info) (decl, DECL_RTL (decl), false);
/* This is defined as a file-scope var, so we know to notify machopic. */
machopic_define_symbol (DECL_RTL (decl));
}
/* Emit a chunk of common. */
static void
darwin_emit_common (FILE *fp, const char *name,
unsigned HOST_WIDE_INT size, unsigned int align)
{
unsigned HOST_WIDE_INT rounded;
unsigned int l2align;
/* Earlier systems complain if the alignment exceeds the page size.
The magic number is 4096 * 8 - hard-coded for legacy systems. */
if (!emit_aligned_common && (align > 32768UL))
align = 4096UL; /* In units. */
else
align /= BITS_PER_UNIT;
/* Make sure we have a meaningful align. */
if (!align)
align = 1;
/* For earlier toolchains, we need to emit the var as a rounded size to
tell ld the alignment. */
if (size < align)
rounded = align;
else
rounded = (size + (align-1)) & ~(align-1);
l2align = floor_log2 (align);
gcc_assert (l2align <= L2_MAX_OFILE_ALIGNMENT);
in_section = comm_section;
/* We mustn't allow multiple public symbols to share an address when using
the normal OSX toolchain. */
if (!size)
{
/* Put at least one byte. */
size = 1;
/* This section can no longer participate in section anchoring. */
comm_section->common.flags |= SECTION_NO_ANCHOR;
}
fputs ("\t.comm\t", fp);
assemble_name (fp, name);
fprintf (fp, "," HOST_WIDE_INT_PRINT_UNSIGNED,
emit_aligned_common?size:rounded);
if (l2align && emit_aligned_common)
fprintf (fp, ",%u", l2align);
fputs ("\n", fp);
}
/* Output a var which is all zero - into aligned BSS sections, common, lcomm
or coalescable data sections (for weak or comdat) as appropriate. */
void
darwin_output_aligned_bss (FILE *fp, tree decl, const char *name,
unsigned HOST_WIDE_INT size, unsigned int align)
{
unsigned int l2align;
bool one, pub, weak;
tree meta;
pub = TREE_PUBLIC (decl);
one = DECL_ONE_ONLY (decl);
weak = (DECL_P (decl)
&& DECL_WEAK (decl)
&& !lookup_attribute ("weak_import",
DECL_ATTRIBUTES (decl)));
#ifdef DEBUG_DARWIN_MEM_ALLOCATORS
fprintf (fp, "# albss: %s (%lld,%d) ro %d cst %d stat %d com %d"
" pub %d weak %d one %d init %lx\n",
name, (long long)size, (int)align, TREE_READONLY (decl),
TREE_CONSTANT (decl), TREE_STATIC (decl), DECL_COMMON (decl),
pub, weak, one, (unsigned long)DECL_INITIAL (decl));
#endif
/* ObjC metadata can get put in BSS because varasm.c decides it's BSS
before the target has a chance to comment. */
if ((meta = is_objc_metadata (decl)))
{
darwin_emit_objc_zeroed (fp, decl, name, size, DECL_ALIGN (decl), meta);
return;
}
/* Check that any initializer is valid. */
gcc_assert ((DECL_INITIAL (decl) == NULL)
|| (DECL_INITIAL (decl) == error_mark_node)
|| initializer_zerop (DECL_INITIAL (decl)));
gcc_assert (DECL_SECTION_NAME (decl) == NULL);
gcc_assert (!DECL_COMMON (decl));
/* Pick up the correct alignment. */
if (!size || !align)
align = DECL_ALIGN (decl);
l2align = floor_log2 (align / BITS_PER_UNIT);
gcc_assert (l2align <= L2_MAX_OFILE_ALIGNMENT);
last_assemble_variable_decl = decl;
/* We would rather not have to check this here - but it seems that we might
be passed a decl that should be in coalesced space. */
if (one || weak)
{
/* Weak or COMDAT objects are put in mergeable sections. */
darwin_emit_weak_or_comdat (fp, decl, name, size,
ld_uses_coal_sects, DECL_ALIGN (decl));
return;
}
/* If this is not public, then emit according to local rules. */
if (!pub)
{
darwin_emit_local_bss (fp, decl, name, size, l2align);
return;
}
/* So we have a public symbol. */
if (DARWIN_SECTION_ANCHORS && flag_section_anchors && size < BYTES_ZFILL)
{
/* Put smaller objects in data, where the section anchors system can get
them. However, if they are zero-sized punt them to yet a different
section (that is not allowed to participate in anchoring). */
if (!size)
{
fputs ("\t.section\t__DATA,__zobj_data\n", fp);
in_section = darwin_sections[zobj_data_section];
size = 1;
}
else
{
fputs ("\t.data\n", fp);
in_section = data_section;
}
if (l2align)
fprintf (fp, "\t.align\t%u\n", l2align);
assemble_name (fp, name);
fprintf (fp, ":\n\t.space\t" HOST_WIDE_INT_PRINT_UNSIGNED"\n", size);
}
else
{
/* Section anchors not in use. */
unsigned int flags = SECTION_BSS|SECTION_WRITE|SECTION_NO_ANCHOR;
char secnam[64];
snprintf (secnam, 64, "__DATA,__common");
in_section = get_section (secnam, flags, NULL);
fprintf (fp, "\t.zerofill %s,", secnam);
assemble_name (fp, name);
if (!size)
size = 1;
if (l2align)
fprintf (fp, "," HOST_WIDE_INT_PRINT_UNSIGNED",%u\n", size, l2align);
else
fprintf (fp, "," HOST_WIDE_INT_PRINT_UNSIGNED",0\n", size);
}
(* targetm.encode_section_info) (decl, DECL_RTL (decl), false);
}
/* Output a chunk of common, with alignment specified (where the target
supports this). */
void
darwin_asm_output_aligned_decl_common (FILE *fp, tree decl, const char *name,
unsigned HOST_WIDE_INT size,
unsigned int align)
{
unsigned int l2align;
bool one, weak;
tree meta;
/* No corresponding var. */
if (decl==NULL)
{
#ifdef DEBUG_DARWIN_MEM_ALLOCATORS
fprintf (fp, "# adcom: %s (%d,%d) decl=0x0\n", name, (int)size, (int)align);
#endif
darwin_emit_common (fp, name, size, align);
return;
}
one = DECL_ONE_ONLY (decl);
weak = (DECL_P (decl)
&& DECL_WEAK (decl)
&& !lookup_attribute ("weak_import",
DECL_ATTRIBUTES (decl)));
#ifdef DEBUG_DARWIN_MEM_ALLOCATORS
fprintf (fp, "# adcom: %s (%lld,%d) ro %d cst %d stat %d com %d pub %d"
" weak %d one %d init %lx\n",
name, (long long)size, (int)align, TREE_READONLY (decl),
TREE_CONSTANT (decl), TREE_STATIC (decl), DECL_COMMON (decl),
TREE_PUBLIC (decl), weak, one, (unsigned long)DECL_INITIAL (decl));
#endif
/* ObjC metadata can get put in BSS because varasm.c decides it's BSS
before the target has a chance to comment. */
if ((meta = is_objc_metadata (decl)))
{
darwin_emit_objc_zeroed (fp, decl, name, size, DECL_ALIGN (decl), meta);
return;
}
/* We shouldn't be messing with this if the decl has a section name. */
gcc_assert (DECL_SECTION_NAME (decl) == NULL);
/* We would rather not have to check this here - but it seems that we might
be passed a decl that should be in coalesced space. */
if (one || weak)
{
/* Weak or COMDAT objects are put in mergable sections. */
darwin_emit_weak_or_comdat (fp, decl, name, size,
ld_uses_coal_sects, DECL_ALIGN (decl));
return;
}
/* We should only get here for DECL_COMMON, with a zero init (and, in
principle, only for public symbols too - although we deal with local
ones below). */
/* Check the initializer is OK. */
gcc_assert (DECL_COMMON (decl)
&& ((DECL_INITIAL (decl) == NULL)
|| (DECL_INITIAL (decl) == error_mark_node)
|| initializer_zerop (DECL_INITIAL (decl))));
last_assemble_variable_decl = decl;
if (!size || !align)
align = DECL_ALIGN (decl);
l2align = floor_log2 (align / BITS_PER_UNIT);
/* Check we aren't asking for more aligment than the platform allows. */
gcc_assert (l2align <= L2_MAX_OFILE_ALIGNMENT);
if (TREE_PUBLIC (decl) != 0)
darwin_emit_common (fp, name, size, align);
else
darwin_emit_local_bss (fp, decl, name, size, l2align);
}
/* Output a chunk of BSS with alignment specfied. */
void
darwin_asm_output_aligned_decl_local (FILE *fp, tree decl, const char *name,
unsigned HOST_WIDE_INT size,
unsigned int align)
{
unsigned long l2align;
bool one, weak;
tree meta;
one = DECL_ONE_ONLY (decl);
weak = (DECL_P (decl)
&& DECL_WEAK (decl)
&& !lookup_attribute ("weak_import",
DECL_ATTRIBUTES (decl)));
#ifdef DEBUG_DARWIN_MEM_ALLOCATORS
fprintf (fp, "# adloc: %s (%lld,%d) ro %d cst %d stat %d one %d pub %d"
" weak %d init %lx\n",
name, (long long)size, (int)align, TREE_READONLY (decl),
TREE_CONSTANT (decl), TREE_STATIC (decl), one, TREE_PUBLIC (decl),
weak , (unsigned long)DECL_INITIAL (decl));
#endif
/* ObjC metadata can get put in BSS because varasm.c decides it's BSS
before the target has a chance to comment. */
if ((meta = is_objc_metadata (decl)))
{
darwin_emit_objc_zeroed (fp, decl, name, size, DECL_ALIGN (decl), meta);
return;
}
/* We shouldn't be messing with this if the decl has a section name. */
gcc_assert (DECL_SECTION_NAME (decl) == NULL);
/* We would rather not have to check this here - but it seems that we might
be passed a decl that should be in coalesced space. */
if (one || weak)
{
/* Weak or COMDAT objects are put in mergable sections. */
darwin_emit_weak_or_comdat (fp, decl, name, size,
ld_uses_coal_sects, DECL_ALIGN (decl));
return;
}
/* .. and it should be suitable for placement in local mem. */
gcc_assert(!TREE_PUBLIC (decl) && !DECL_COMMON (decl));
/* .. and any initializer must be all-zero. */
gcc_assert ((DECL_INITIAL (decl) == NULL)
|| (DECL_INITIAL (decl) == error_mark_node)
|| initializer_zerop (DECL_INITIAL (decl)));
last_assemble_variable_decl = decl;
if (!size || !align)
align = DECL_ALIGN (decl);
l2align = floor_log2 (align / BITS_PER_UNIT);
gcc_assert (l2align <=</