/* Mach-O object file format
- Copyright 2009, 2011 Free Software Foundation, Inc.
+ Copyright 2009, 2011, 2012 Free Software Foundation, Inc.
This file is part of GAS, the GNU Assembler.
#include "mach-o/loader.h"
#include "obj-macho.h"
+#include <string.h>
+
+/* Forward decls. */
+static segT obj_mach_o_segT_from_bfd_name (const char *, int);
+
/* TODO: Implement "-dynamic"/"-static" command line options. */
static int obj_mach_o_is_static;
-/* Allow for special re-ordering on output. */
+/* TODO: Implement the "-n" command line option to suppress the initial
+ switch to the text segment. */
+static int obj_mach_o_start_with_text_section = 1;
-static int seen_objc_section;
+/* Allow for special re-ordering on output. */
-/* Remember the subsections_by_symbols state in case we need to reset
- the file flags. */
-static int obj_mach_o_subsections_by_symbols;
+static int obj_mach_o_seen_objc_section;
-static void
-obj_mach_o_weak (int ignore ATTRIBUTE_UNUSED)
+/* Start-up: At present, just create the sections we want. */
+void
+mach_o_begin (void)
{
- char *name;
- int c;
- symbolS *symbolP;
-
- do
+ /* Mach-O only defines the .text section by default, and even this can
+ be suppressed by a flag. In the latter event, the first code MUST
+ be a section definition. */
+ if (obj_mach_o_start_with_text_section)
{
- /* Get symbol name. */
- name = input_line_pointer;
- c = get_symbol_end ();
- symbolP = symbol_find_or_make (name);
- S_SET_WEAK (symbolP);
- *input_line_pointer = c;
- SKIP_WHITESPACE ();
-
- if (c != ',')
- break;
- input_line_pointer++;
- SKIP_WHITESPACE ();
+ text_section = obj_mach_o_segT_from_bfd_name (TEXT_SECTION_NAME, 1);
+ subseg_set (text_section, 0);
+ if (obj_mach_o_is_static)
+ {
+ bfd_mach_o_section *mo_sec
+ = bfd_mach_o_get_mach_o_section (text_section);
+ mo_sec->flags &= ~BFD_MACH_O_S_ATTR_PURE_INSTRUCTIONS;
+ }
}
- while (*input_line_pointer != '\n');
- demand_empty_rest_of_line ();
}
+/* Remember the subsections_by_symbols state in case we need to reset
+ the file flags. */
+
+static int obj_mach_o_subsections_by_symbols;
+
/* This will put at most 16 characters (terminated by a ',' or newline) from
the input stream into dest. If there are more than 16 chars before the
delimiter, a warning is given and the string is truncated. On completion of
return 0;
}
+static int
+obj_mach_o_get_section_names (char *seg, char *sec,
+ unsigned segl, unsigned secl)
+{
+ /* Zero-length segment and section names are allowed. */
+ /* Parse segment name. */
+ memset (seg, 0, segl);
+ if (collect_16char_name (seg, "segment", 1))
+ {
+ ignore_rest_of_line ();
+ return 0;
+ }
+ input_line_pointer++; /* Skip the terminating ',' */
+
+ /* Parse section name, which can be empty. */
+ memset (sec, 0, secl);
+ collect_16char_name (sec, "section", 0);
+ return 1;
+}
+
+/* Build (or get) a section from the mach-o description - which includes
+ optional definitions for type, attributes, alignment and stub size.
+
+ BFD supplies default values for sections which have a canonical name. */
+
+#define SECT_TYPE_SPECIFIED 0x0001
+#define SECT_ATTR_SPECIFIED 0x0002
+#define SECT_ALGN_SPECIFIED 0x0004
+
+static segT
+obj_mach_o_make_or_get_sect (char * segname, char * sectname,
+ unsigned int specified_mask,
+ unsigned int usectype, unsigned int usecattr,
+ unsigned int ualign, offsetT stub_size)
+{
+ unsigned int sectype, secattr, secalign;
+ flagword oldflags, flags;
+ const char *name;
+ segT sec;
+ bfd_mach_o_section *msect;
+ const mach_o_section_name_xlat *xlat;
+
+ /* This provides default bfd flags and default mach-o section type and
+ attributes along with the canonical name. */
+ xlat = bfd_mach_o_section_data_for_mach_sect (stdoutput, segname, sectname);
+
+ /* TODO: more checking of whether overides are acually allowed. */
+
+ if (xlat != NULL)
+ {
+ name = xstrdup (xlat->bfd_name);
+ sectype = xlat->macho_sectype;
+ if (specified_mask & SECT_TYPE_SPECIFIED)
+ {
+ if ((sectype == BFD_MACH_O_S_ZEROFILL
+ || sectype == BFD_MACH_O_S_GB_ZEROFILL)
+ && sectype != usectype)
+ as_bad (_("cannot overide zerofill section type for `%s,%s'"),
+ segname, sectname);
+ else
+ sectype = usectype;
+ }
+ secattr = xlat->macho_secattr;
+ secalign = xlat->sectalign;
+ flags = xlat->bfd_flags;
+ }
+ else
+ {
+ /* There is no normal BFD section name for this section. Create one.
+ The name created doesn't really matter as it will never be written
+ on disk. */
+ size_t seglen = strlen (segname);
+ size_t sectlen = strlen (sectname);
+ char *n;
+
+ n = xmalloc (seglen + 1 + sectlen + 1);
+ memcpy (n, segname, seglen);
+ n[seglen] = '.';
+ memcpy (n + seglen + 1, sectname, sectlen);
+ n[seglen + 1 + sectlen] = 0;
+ name = n;
+ if (specified_mask & SECT_TYPE_SPECIFIED)
+ sectype = usectype;
+ else
+ sectype = BFD_MACH_O_S_REGULAR;
+ secattr = BFD_MACH_O_S_ATTR_NONE;
+ secalign = 0;
+ flags = SEC_NO_FLAGS;
+ }
+
+ /* For now, just use what the user provided. */
+
+ if (specified_mask & SECT_ATTR_SPECIFIED)
+ secattr = usecattr;
+
+ if (specified_mask & SECT_ALGN_SPECIFIED)
+ secalign = ualign;
+
+ /* Sub-segments don't exists as is on Mach-O. */
+ sec = subseg_new (name, 0);
+
+ oldflags = bfd_get_section_flags (stdoutput, sec);
+ msect = bfd_mach_o_get_mach_o_section (sec);
+
+ if (oldflags == SEC_NO_FLAGS)
+ {
+ /* New, so just use the defaults or what's specified. */
+ if (! bfd_set_section_flags (stdoutput, sec, flags))
+ as_warn (_("failed to set flags for \"%s\": %s"),
+ bfd_section_name (stdoutput, sec),
+ bfd_errmsg (bfd_get_error ()));
+
+ strncpy (msect->segname, segname, sizeof (msect->segname));
+ strncpy (msect->sectname, sectname, sizeof (msect->sectname));
+
+ msect->align = secalign;
+ msect->flags = sectype | secattr;
+ msect->reserved2 = stub_size;
+
+ if (sectype == BFD_MACH_O_S_ZEROFILL
+ || sectype == BFD_MACH_O_S_GB_ZEROFILL)
+ seg_info (sec)->bss = 1;
+ }
+ else if (flags != SEC_NO_FLAGS)
+ {
+ if (flags != oldflags
+ || msect->flags != (secattr | sectype))
+ as_warn (_("Ignoring changed section attributes for %s"), name);
+ }
+
+ return sec;
+}
+
/* .section
The '.section' specification syntax looks like:
static void
obj_mach_o_section (int ignore ATTRIBUTE_UNUSED)
{
- char *p;
- char c;
unsigned int sectype = BFD_MACH_O_S_REGULAR;
- unsigned int defsectype = BFD_MACH_O_S_REGULAR;
- unsigned int sectype_given = 0;
+ unsigned int specified_mask = 0;
unsigned int secattr = 0;
- unsigned int defsecattr = 0;
- int secattr_given = 0;
- unsigned int secalign = 0;
offsetT sizeof_stub = 0;
- const mach_o_section_name_xlat * xlat;
- const char *name;
- flagword oldflags, flags;
- asection *sec;
- bfd_mach_o_section *msect;
+ segT new_seg;
char segname[17];
char sectname[17];
md_flush_pending_output ();
#endif
- /* Zero-length segment and section names are allowed. */
- /* Parse segment name. */
- memset (segname, 0, sizeof(segname));
- if (collect_16char_name (segname, "segment", 1))
- {
- ignore_rest_of_line ();
- return;
- }
- input_line_pointer++; /* Skip the terminating ',' */
+ /* Get the User's segment annd section names. */
+ if (! obj_mach_o_get_section_names (segname, sectname, 17, 17))
+ return;
- /* Parse section name. */
- memset (sectname, 0, sizeof(sectname));
- collect_16char_name (sectname, "section", 0);
-
- /* Parse type. */
+ /* Parse section type, if present. */
if (*input_line_pointer == ',')
{
+ char *p;
+ char c;
char tmpc;
int len;
input_line_pointer++;
return;
}
else
- sectype_given = 1;
+ specified_mask |= SECT_TYPE_SPECIFIED;
/* Restore. */
p[len] = tmpc;
/* Parse attributes.
TODO: check validity of attributes for section type. */
- if (sectype_given && c == ',')
+ if ((specified_mask & SECT_TYPE_SPECIFIED)
+ && c == ',')
{
do
{
}
else
{
- secattr_given = 1;
+ specified_mask |= SECT_ATTR_SPECIFIED;
secattr |= attr;
}
/* Restore. */
while (*input_line_pointer == '+');
/* Parse sizeof_stub. */
- if (secattr_given && *input_line_pointer == ',')
+ if ((specified_mask & SECT_ATTR_SPECIFIED)
+ && *input_line_pointer == ',')
{
if (sectype != BFD_MACH_O_S_SYMBOL_STUBS)
{
input_line_pointer++;
sizeof_stub = get_absolute_expression ();
}
- else if (secattr_given && sectype == BFD_MACH_O_S_SYMBOL_STUBS)
+ else if ((specified_mask & SECT_ATTR_SPECIFIED)
+ && sectype == BFD_MACH_O_S_SYMBOL_STUBS)
{
as_bad (_("missing sizeof_stub expression"));
ignore_rest_of_line ();
}
}
- flags = SEC_NO_FLAGS;
- /* This provides default bfd flags and default mach-o section type and
- attributes along with the canonical name. */
- xlat = bfd_mach_o_section_data_for_mach_sect (stdoutput, segname, sectname);
- if (xlat != NULL)
+ new_seg = obj_mach_o_make_or_get_sect (segname, sectname, specified_mask,
+ sectype, secattr, 0 /*align */,
+ sizeof_stub);
+ if (new_seg != NULL)
{
- name = xstrdup (xlat->bfd_name);
- flags = xlat->bfd_flags;
- defsectype = xlat->macho_sectype;
- defsecattr = xlat->macho_secattr;
- secalign = xlat->sectalign;
+ subseg_set (new_seg, 0);
+ demand_empty_rest_of_line ();
}
- else
- {
- /* There is no normal BFD section name for this section. Create one.
- The name created doesn't really matter as it will never be written
- on disk. */
- size_t seglen = strlen (segname);
- size_t sectlen = strlen (sectname);
- char *n;
+}
- n = xmalloc (seglen + 1 + sectlen + 1);
- memcpy (n, segname, seglen);
- n[seglen] = '.';
- memcpy (n + seglen + 1, sectname, sectlen);
- n[seglen + 1 + sectlen] = 0;
- name = n;
- }
+/* .zerofill segname, sectname [, symbolname, size [, align]]
- /* Sub-segments don't exists as is on Mach-O. */
- sec = subseg_new (name, 0);
+ Zerofill switches, temporarily, to a sect of type 'zerofill'.
- oldflags = bfd_get_section_flags (stdoutput, sec);
- msect = bfd_mach_o_get_mach_o_section (sec);
- if (oldflags == SEC_NO_FLAGS)
+ If a variable name is given, it defines that in the section.
+ Otherwise it just creates the section if it doesn't exist. */
+
+static void
+obj_mach_o_zerofill (int ignore ATTRIBUTE_UNUSED)
+{
+ char segname[17];
+ char sectname[17];
+ segT old_seg = now_seg;
+ segT new_seg;
+ symbolS *sym = NULL;
+ unsigned int align = 0;
+ unsigned int specified_mask = 0;
+ offsetT size = 0;
+
+#ifdef md_flush_pending_output
+ md_flush_pending_output ();
+#endif
+
+ /* Get the User's segment annd section names. */
+ if (! obj_mach_o_get_section_names (segname, sectname, 17, 17))
+ return;
+
+ /* Parse variable definition, if present. */
+ if (*input_line_pointer == ',')
{
- if (! bfd_set_section_flags (stdoutput, sec, flags))
- as_warn (_("error setting flags for \"%s\": %s"),
- bfd_section_name (stdoutput, sec),
- bfd_errmsg (bfd_get_error ()));
- strncpy (msect->segname, segname, sizeof (msect->segname));
- msect->segname[16] = 0;
- strncpy (msect->sectname, sectname, sizeof (msect->sectname));
- msect->sectname[16] = 0;
- msect->align = secalign;
- if (sectype_given)
+ /* Parse symbol, size [.align]
+ We follow the method of s_common_internal, with the difference
+ that the symbol cannot be a duplicate-common. */
+ char *name;
+ char c;
+ char *p;
+ expressionS exp;
+
+ input_line_pointer++; /* Skip ',' */
+ SKIP_WHITESPACE ();
+ name = input_line_pointer;
+ c = get_symbol_end ();
+ /* Just after name is now '\0'. */
+ p = input_line_pointer;
+ *p = c;
+
+ if (name == p)
{
- msect->flags = sectype;
- if (secattr_given)
- msect->flags |= secattr;
- else
- msect->flags |= defsecattr;
+ as_bad (_("expected symbol name"));
+ ignore_rest_of_line ();
+ goto done;
+ }
+
+ SKIP_WHITESPACE ();
+ if (*input_line_pointer == ',')
+ input_line_pointer++;
+
+ expression_and_evaluate (&exp);
+ if (exp.X_op != O_constant
+ && exp.X_op != O_absent)
+ {
+ as_bad (_("bad or irreducible absolute expression"));
+ ignore_rest_of_line ();
+ goto done;
+ }
+ else if (exp.X_op == O_absent)
+ {
+ as_bad (_("missing size expression"));
+ ignore_rest_of_line ();
+ goto done;
+ }
+
+ size = exp.X_add_number;
+ size &= ((offsetT) 2 << (stdoutput->arch_info->bits_per_address - 1)) - 1;
+ if (exp.X_add_number != size || !exp.X_unsigned)
+ {
+ as_warn (_("size (%ld) out of range, ignored"),
+ (long) exp.X_add_number);
+ ignore_rest_of_line ();
+ goto done;
+ }
+
+ *p = 0; /* Make the name into a c string for err messages. */
+ sym = symbol_find_or_make (name);
+ if (S_IS_DEFINED (sym) || symbol_equated_p (sym))
+ {
+ as_bad (_("symbol `%s' is already defined"), name);
+ *p = c;
+ ignore_rest_of_line ();
+ goto done;
+ }
+
+ size = S_GET_VALUE (sym);
+ if (size == 0)
+ size = exp.X_add_number;
+ else if (size != exp.X_add_number)
+ as_warn (_("size of \"%s\" is already %ld; not changing to %ld"),
+ name, (long) size, (long) exp.X_add_number);
+
+ *p = c; /* Restore the termination char. */
+
+ SKIP_WHITESPACE ();
+ if (*input_line_pointer == ',')
+ {
+ align = (unsigned int) parse_align (0);
+ if (align == (unsigned int) -1)
+ {
+ as_warn (_("align value not recognized, using size"));
+ align = size;
+ }
+ if (align > 15)
+ {
+ as_warn (_("Alignment (%lu) too large: 15 assumed."),
+ (unsigned long)align);
+ align = 15;
+ }
+ specified_mask |= SECT_ALGN_SPECIFIED;
}
- else
- msect->flags = defsectype | defsecattr;
- msect->reserved2 = sizeof_stub;
}
- else if (flags != SEC_NO_FLAGS)
+ /* else just a section definition. */
+
+ specified_mask |= SECT_TYPE_SPECIFIED;
+ new_seg = obj_mach_o_make_or_get_sect (segname, sectname, specified_mask,
+ BFD_MACH_O_S_ZEROFILL,
+ BFD_MACH_O_S_ATTR_NONE,
+ align, (offsetT) 0 /*stub size*/);
+ if (new_seg == NULL)
+ return;
+
+ /* In case the user specifies the bss section by mach-o name.
+ Create it on demand */
+ if (strcmp (new_seg->name, BSS_SECTION_NAME) == 0
+ && bss_section == NULL)
+ bss_section = new_seg;
+
+ subseg_set (new_seg, 0);
+
+ if (sym != NULL)
{
- if (flags != oldflags
- || msect->flags != (secattr | sectype))
- as_warn (_("Ignoring changed section attributes for %s"), name);
+ char *pfrag;
+
+ if (align)
+ {
+ record_alignment (new_seg, align);
+ frag_align (align, 0, 0);
+ }
+
+ /* Detach from old frag. */
+ if (S_GET_SEGMENT (sym) == new_seg)
+ symbol_get_frag (sym)->fr_symbol = NULL;
+
+ symbol_set_frag (sym, frag_now);
+ pfrag = frag_var (rs_org, 1, 1, 0, sym, size, NULL);
+ *pfrag = 0;
+
+ S_SET_SEGMENT (sym, new_seg);
+ if (new_seg == bss_section)
+ S_CLEAR_EXTERNAL (sym);
}
- demand_empty_rest_of_line ();
+
+done:
+ /* switch back to the section that was current before the .zerofill. */
+ subseg_set (old_seg, 0);
}
static segT
section = obj_mach_o_segT_from_bfd_name (objc_sections[sect_index], 1);
if (section != NULL)
{
- seen_objc_section = 1; /* We need to ensure that certain sections are
- present and in the right order. */
+ obj_mach_o_seen_objc_section = 1; /* We need to ensure that certain
+ sections are present and in the
+ right order. */
subseg_set (section, 0);
}
addressT size)
{
addressT align = 0;
+ bfd_mach_o_asymbol *s;
+
+ SKIP_WHITESPACE ();
/* Both comm and lcomm take an optional alignment, as a power
of two between 1 and 15. */
}
}
+ s = (bfd_mach_o_asymbol *) symbol_get_bfdsym (symbolP);
if (is_local)
{
/* Create the BSS section on demand. */
seg_info (bss_section)->bss = 1;
}
bss_alloc (symbolP, size, align);
+ s->n_type = BFD_MACH_O_N_SECT;
S_CLEAR_EXTERNAL (symbolP);
}
else
S_SET_ALIGN (symbolP, align);
S_SET_EXTERNAL (symbolP);
S_SET_SEGMENT (symbolP, bfd_com_section_ptr);
+ s->n_type = BFD_MACH_O_N_UNDF | BFD_MACH_O_N_EXT;
}
- symbol_get_bfdsym (symbolP)->flags |= BSF_OBJECT;
+ /* This is a data object (whatever we choose that to mean). */
+ s->symbol.flags |= BSF_OBJECT;
+
+ /* We've set symbol qualifiers, so validate if you can. */
+ s->symbol.udata.i = SYM_MACHO_FIELDS_NOT_VALIDATED;
return symbolP;
}
}
}
-/* Dummy function to allow test-code to work while we are working
- on things. */
+/* Temporary markers for symbol reference data.
+ Lazy will remain in place. */
+#define LAZY 0x01
+#define REFE 0x02
+
+/* We have a bunch of qualifiers that may be applied to symbols.
+ .globl is handled here so that we might make sure that conflicting qualifiers
+ are caught where possible. */
+
+typedef enum obj_mach_o_symbol_type {
+ OBJ_MACH_O_SYM_UNK = 0,
+ OBJ_MACH_O_SYM_LOCAL = 1,
+ OBJ_MACH_O_SYM_GLOBL = 2,
+ OBJ_MACH_O_SYM_REFERENCE = 3,
+ OBJ_MACH_O_SYM_WEAK_REF = 4,
+ OBJ_MACH_O_SYM_LAZY_REF = 5,
+ OBJ_MACH_O_SYM_WEAK_DEF = 6,
+ OBJ_MACH_O_SYM_PRIV_EXT = 7,
+ OBJ_MACH_O_SYM_NO_DEAD_STRIP = 8,
+ OBJ_MACH_O_SYM_WEAK = 9
+} obj_mach_o_symbol_type;
+
+/* Set Mach-O-specific symbol qualifiers. */
+
+static int
+obj_mach_o_set_symbol_qualifier (symbolS *sym, int type)
+{
+ int is_defined;
+ bfd_mach_o_asymbol *s = (bfd_mach_o_asymbol *) symbol_get_bfdsym (sym);
+ bfd_mach_o_section *sec;
+ int sectype = -1;
+ int err = 0;
+
+ /* If the symbol is defined, then we can do more rigorous checking on
+ the validity of the qualifiers. Otherwise, we are stuck with waiting
+ until it's defined - or until write the file.
+
+ In certain cases (e.g. when a symbol qualifier is intended to introduce
+ an undefined symbol in a stubs section) we should check that the current
+ section is appropriate to the qualifier. */
+
+ is_defined = s->symbol.section != bfd_und_section_ptr;
+ if (is_defined)
+ sec = bfd_mach_o_get_mach_o_section (s->symbol.section) ;
+ else
+ sec = bfd_mach_o_get_mach_o_section (now_seg) ;
+
+ if (sec != NULL)
+ sectype = sec->flags & BFD_MACH_O_SECTION_TYPE_MASK;
+
+ switch ((obj_mach_o_symbol_type) type)
+ {
+ case OBJ_MACH_O_SYM_LOCAL:
+ /* This is an extension over the system tools. */
+ if (s->n_type & (BFD_MACH_O_N_PEXT | BFD_MACH_O_N_EXT))
+ {
+ as_bad (_("'%s' previously declared as '%s'."), s->symbol.name,
+ (s->n_type & BFD_MACH_O_N_PEXT) ? "private extern"
+ : "global" );
+ err = 1;
+ }
+ else
+ {
+ s->n_type &= ~BFD_MACH_O_N_EXT;
+ S_CLEAR_EXTERNAL (sym);
+ }
+ break;
+
+ case OBJ_MACH_O_SYM_PRIV_EXT:
+ s->n_type |= BFD_MACH_O_N_PEXT ;
+ s->n_desc &= ~LAZY; /* The native tool switches this off too. */
+ /* We follow the system tools in marking PEXT as also global. */
+ /* Fall through. */
+
+ case OBJ_MACH_O_SYM_GLOBL:
+ /* It's not an error to define a symbol and then make it global. */
+ s->n_type |= BFD_MACH_O_N_EXT;
+ S_SET_EXTERNAL (sym);
+ break;
+
+ case OBJ_MACH_O_SYM_REFERENCE:
+ if (is_defined)
+ s->n_desc |= BFD_MACH_O_N_NO_DEAD_STRIP;
+ else
+ s->n_desc |= (REFE | BFD_MACH_O_N_NO_DEAD_STRIP);
+ break;
+
+ case OBJ_MACH_O_SYM_LAZY_REF:
+ if (is_defined)
+ s->n_desc |= BFD_MACH_O_N_NO_DEAD_STRIP;
+ else
+ s->n_desc |= (REFE | LAZY | BFD_MACH_O_N_NO_DEAD_STRIP);
+ break;
+
+ /* Force ld to retain the symbol - even if it appears unused. */
+ case OBJ_MACH_O_SYM_NO_DEAD_STRIP:
+ s->n_desc |= BFD_MACH_O_N_NO_DEAD_STRIP ;
+ break;
+
+ /* Mach-O's idea of weak ... */
+ case OBJ_MACH_O_SYM_WEAK_REF:
+ s->n_desc |= BFD_MACH_O_N_WEAK_REF ;
+ break;
+
+ case OBJ_MACH_O_SYM_WEAK_DEF:
+ if (is_defined && sectype != BFD_MACH_O_S_COALESCED)
+ {
+ as_bad (_("'%s' can't be a weak_definition (currently only"
+ " supported in sections of type coalesced)"),
+ s->symbol.name);
+ err = 1;
+ }
+ else
+ s->n_desc |= BFD_MACH_O_N_WEAK_DEF;
+ break;
+
+ case OBJ_MACH_O_SYM_WEAK:
+ /* A generic 'weak' - we try to figure out what it means at
+ symbol frob time. */
+ S_SET_WEAK (sym);
+ break;
+
+ default:
+ break;
+ }
+
+ /* We've seen some kind of qualifier - check validity if or when the entity
+ is defined. */
+ s->symbol.udata.i = SYM_MACHO_FIELDS_NOT_VALIDATED;
+ return err;
+}
+
+/* Respond to symbol qualifiers.
+ All of the form:
+ .<qualifier> symbol [, symbol]*
+ a list of symbols is an extension over the Darwin system as. */
+
+static void
+obj_mach_o_sym_qual (int ntype)
+{
+ char *name;
+ char c;
+ symbolS *symbolP;
+
+#ifdef md_flush_pending_output
+ md_flush_pending_output ();
+#endif
+
+ do
+ {
+ name = input_line_pointer;
+ c = get_symbol_end ();
+ symbolP = symbol_find_or_make (name);
+ obj_mach_o_set_symbol_qualifier (symbolP, ntype);
+ *input_line_pointer = c;
+ SKIP_WHITESPACE ();
+ c = *input_line_pointer;
+ if (c == ',')
+ {
+ input_line_pointer++;
+ SKIP_WHITESPACE ();
+ if (is_end_of_line[(unsigned char) *input_line_pointer])
+ c = '\n';
+ }
+ }
+ while (c == ',');
+
+ demand_empty_rest_of_line ();
+}
+
+typedef struct obj_mach_o_indirect_sym
+{
+ symbolS *sym;
+ segT sect;
+ struct obj_mach_o_indirect_sym *next;
+} obj_mach_o_indirect_sym;
+
+/* We store in order an maintain a pointer to the last one - to save reversing
+ later. */
+obj_mach_o_indirect_sym *indirect_syms;
+obj_mach_o_indirect_sym *indirect_syms_tail;
static void
-obj_mach_o_placeholder (int arg ATTRIBUTE_UNUSED)
+obj_mach_o_indirect_symbol (int arg ATTRIBUTE_UNUSED)
{
- ignore_rest_of_line ();
+ bfd_mach_o_section *sec = bfd_mach_o_get_mach_o_section (now_seg);
+
+#ifdef md_flush_pending_output
+ md_flush_pending_output ();
+#endif
+
+ if (obj_mach_o_is_static)
+ as_bad (_("use of .indirect_symbols requires `-dynamic'"));
+
+ switch (sec->flags & BFD_MACH_O_SECTION_TYPE_MASK)
+ {
+ case BFD_MACH_O_S_SYMBOL_STUBS:
+ case BFD_MACH_O_S_LAZY_SYMBOL_POINTERS:
+ case BFD_MACH_O_S_NON_LAZY_SYMBOL_POINTERS:
+ {
+ obj_mach_o_indirect_sym *isym;
+ char *name = input_line_pointer;
+ char c = get_symbol_end ();
+ symbolS *sym = symbol_find_or_make (name);
+ unsigned int elsize =
+ bfd_mach_o_section_get_entry_size (stdoutput, sec);
+
+ if (elsize == 0)
+ {
+ as_bad (_("attempt to add an indirect_symbol to a stub or"
+ " reference section with a zero-sized element at %s"),
+ name);
+ *input_line_pointer = c;
+ ignore_rest_of_line ();
+ return;
+ }
+ *input_line_pointer = c;
+
+ isym = (obj_mach_o_indirect_sym *)
+ xmalloc (sizeof (obj_mach_o_indirect_sym));
+
+ /* Just record the data for now, we will validate it when we
+ compute the output in obj_mach_o_set_indirect_symbols. */
+ isym->sym = sym;
+ isym->sect = now_seg;
+ isym->next = NULL;
+ if (indirect_syms == NULL)
+ indirect_syms = isym;
+ else
+ indirect_syms_tail->next = isym;
+ indirect_syms_tail = isym;
+ }
+ break;
+
+ default:
+ as_bad (_("an .indirect_symbol must be in a symbol pointer"
+ " or stub section."));
+ ignore_rest_of_line ();
+ return;
+ }
+ demand_empty_rest_of_line ();
}
const pseudo_typeS mach_o_pseudo_table[] =
{ "picsymbol_stub3", obj_mach_o_opt_tgt_section, 4}, /* extension. */
{ "section", obj_mach_o_section, 0},
+ { "zerofill", obj_mach_o_zerofill, 0},
+
+ /* Symbol qualifiers. */
+ {"local", obj_mach_o_sym_qual, OBJ_MACH_O_SYM_LOCAL},
+ {"globl", obj_mach_o_sym_qual, OBJ_MACH_O_SYM_GLOBL},
+ {"reference", obj_mach_o_sym_qual, OBJ_MACH_O_SYM_REFERENCE},
+ {"weak_reference", obj_mach_o_sym_qual, OBJ_MACH_O_SYM_WEAK_REF},
+ {"lazy_reference", obj_mach_o_sym_qual, OBJ_MACH_O_SYM_LAZY_REF},
+ {"weak_definition", obj_mach_o_sym_qual, OBJ_MACH_O_SYM_WEAK_DEF},
+ {"private_extern", obj_mach_o_sym_qual, OBJ_MACH_O_SYM_PRIV_EXT},
+ {"no_dead_strip", obj_mach_o_sym_qual, OBJ_MACH_O_SYM_NO_DEAD_STRIP},
+ {"weak", obj_mach_o_sym_qual, OBJ_MACH_O_SYM_WEAK}, /* ext */
- /* Symbol-related. */
- { "indirect_symbol", obj_mach_o_placeholder, 0},
- { "weak_definition", obj_mach_o_placeholder, 0},
- { "private_extern", obj_mach_o_placeholder, 0},
- { "weak", obj_mach_o_weak, 0}, /* extension */
+ { "indirect_symbol", obj_mach_o_indirect_symbol, 0},
/* File flags. */
{ "subsections_via_symbols", obj_mach_o_fileprop,
{NULL, NULL, 0}
};
+
+/* Determine the default n_type value for a symbol from its section. */
+
+static unsigned
+obj_mach_o_type_for_symbol (bfd_mach_o_asymbol *s)
+{
+ if (s->symbol.section == bfd_abs_section_ptr)
+ return BFD_MACH_O_N_ABS;
+ else if (s->symbol.section == bfd_com_section_ptr
+ || s->symbol.section == bfd_und_section_ptr)
+ return BFD_MACH_O_N_UNDF;
+ else
+ return BFD_MACH_O_N_SECT;
+}
+
+/* We need to check the correspondence between some kinds of symbols and their
+ sections. Common and BSS vars will seen via the obj_macho_comm() function.
+
+ The earlier we can pick up a problem, the better the diagnostics will be.
+
+ However, when symbol type information is attached, the symbol section will
+ quite possibly be unknown. So we are stuck with checking (most of the)
+ validity at the time the file is written (unfortunately, then one doesn't
+ get line number information in the diagnostic). */
+
+/* Here we pick up the case where symbol qualifiers have been applied that
+ are possibly incompatible with the section etc. that the symbol is defined
+ in. */
+
+void obj_macho_frob_label (struct symbol *sp)
+{
+ bfd_mach_o_asymbol *s;
+ unsigned base_type;
+ bfd_mach_o_section *sec;
+ int sectype = -1;
+
+ /* Leave local symbols alone. */
+
+ if (S_IS_LOCAL (sp))
+ return;
+
+ s = (bfd_mach_o_asymbol *) symbol_get_bfdsym (sp);
+ /* Leave debug symbols alone. */
+ if ((s->n_type & BFD_MACH_O_N_STAB) != 0)
+ return;
+
+ /* This is the base symbol type, that we mask in. */
+ base_type = obj_mach_o_type_for_symbol (s);
+
+ sec = bfd_mach_o_get_mach_o_section (s->symbol.section);
+ if (sec != NULL)
+ sectype = sec->flags & BFD_MACH_O_SECTION_TYPE_MASK;
+
+ /* If there is a pre-existing qualifier, we can make some checks about
+ validity now. */
+
+ if(s->symbol.udata.i == SYM_MACHO_FIELDS_NOT_VALIDATED)
+ {
+ if ((s->n_desc & BFD_MACH_O_N_WEAK_DEF)
+ && sectype != BFD_MACH_O_S_COALESCED)
+ as_bad (_("'%s' can't be a weak_definition (currently only supported"
+ " in sections of type coalesced)"), s->symbol.name);
+
+ /* Have we changed from an undefined to defined ref? */
+ s->n_desc &= ~(REFE | LAZY);
+ }
+
+ s->n_type &= ~BFD_MACH_O_N_TYPE;
+ s->n_type |= base_type;
+}
+
+/* This is the fall-back, we come here when we get to the end of the file and
+ the symbol is not defined - or there are combinations of qualifiers required
+ (e.g. global + weak_def). */
+
+int
+obj_macho_frob_symbol (struct symbol *sp)
+{
+ bfd_mach_o_asymbol *s;
+ unsigned base_type;
+ bfd_mach_o_section *sec;
+ int sectype = -1;
+
+ /* Leave local symbols alone. */
+ if (S_IS_LOCAL (sp))
+ return 0;
+
+ s = (bfd_mach_o_asymbol *) symbol_get_bfdsym (sp);
+ /* Leave debug symbols alone. */
+ if ((s->n_type & BFD_MACH_O_N_STAB) != 0)
+ return 0;
+
+ base_type = obj_mach_o_type_for_symbol (s);
+ sec = bfd_mach_o_get_mach_o_section (s->symbol.section);
+ if (sec != NULL)
+ sectype = sec->flags & BFD_MACH_O_SECTION_TYPE_MASK;
+
+ if (s->symbol.section == bfd_und_section_ptr)
+ {
+ /* ??? Do we really gain much from implementing this as well as the
+ mach-o specific ones? */
+ if (s->symbol.flags & BSF_WEAK)
+ s->n_desc |= BFD_MACH_O_N_WEAK_REF;
+
+ /* Undefined syms, become extern. */
+ s->n_type |= BFD_MACH_O_N_EXT;
+ S_SET_EXTERNAL (sp);
+ }
+ else if (s->symbol.section == bfd_com_section_ptr)
+ {
+ /* ... so do comm. */
+ s->n_type |= BFD_MACH_O_N_EXT;
+ S_SET_EXTERNAL (sp);
+ }
+ else
+ {
+ if ((s->symbol.flags & BSF_WEAK)
+ && (sectype == BFD_MACH_O_S_COALESCED)
+ && (s->n_type & (BFD_MACH_O_N_PEXT | BFD_MACH_O_N_EXT)))
+ s->n_desc |= BFD_MACH_O_N_WEAK_DEF;
+/* ??? we should do this - but then that reveals that the semantics of weak
+ are different from what's supported in mach-o object files.
+ else
+ as_bad (_("'%s' can't be a weak_definition."),
+ s->symbol.name); */
+ }
+
+ if (s->symbol.udata.i == SYM_MACHO_FIELDS_UNSET)
+ {
+ /* Anything here that should be added that is non-standard. */
+ s->n_desc &= ~BFD_MACH_O_REFERENCE_MASK;
+ s->symbol.udata.i = SYM_MACHO_FIELDS_NOT_VALIDATED;
+ }
+ else if (s->symbol.udata.i == SYM_MACHO_FIELDS_NOT_VALIDATED)
+ {
+ /* Try to validate any combinations. */
+ if (s->n_desc & BFD_MACH_O_N_WEAK_DEF)
+ {
+ if (s->symbol.section == bfd_und_section_ptr)
+ as_bad (_("'%s' can't be a weak_definition (since it is"
+ " undefined)"), s->symbol.name);
+ else if (sectype != BFD_MACH_O_S_COALESCED)
+ as_bad (_("'%s' can't be a weak_definition (currently only supported"
+ " in sections of type coalesced)"), s->symbol.name);
+ else if (! (s->n_type & (BFD_MACH_O_N_PEXT | BFD_MACH_O_N_EXT)))
+ as_bad (_("Non-global symbol: '%s' can't be a weak_definition."),
+ s->symbol.name);
+ }
+
+ }
+ else
+ as_bad (_("internal error: [%s] unexpected code [%lx] in frob symbol"),
+ s->symbol.name, (unsigned long)s->symbol.udata.i);
+
+ s->n_type &= ~BFD_MACH_O_N_TYPE;
+ s->n_type |= base_type;
+
+ if (s->symbol.flags & BSF_GLOBAL)
+ s->n_type |= BFD_MACH_O_N_EXT;
+
+ /* This cuts both ways - we promote some things to external above. */
+ if (s->n_type & (BFD_MACH_O_N_PEXT | BFD_MACH_O_N_EXT))
+ S_SET_EXTERNAL (sp);
+
+ return 0;
+}
+
+/* Zerofill and GB Zerofill sections must be sorted to follow all other
+ sections in their segments.
+
+ The native 'as' leaves the sections physically in the order they appear in
+ the source, and adjusts the section VMAs to meet the constraint.
+
+ We follow this for now - if nothing else, it makes comparison easier.
+
+ An alternative implementation would be to sort the sections as ld requires.
+ It might be advantageous to implement such a scheme in the future (or even
+ to make the style of section ordering user-selectable). */
+
+typedef struct obj_mach_o_set_vma_data
+{
+ bfd_vma vma;
+ unsigned vma_pass;
+ unsigned zerofill_seen;
+ unsigned gb_zerofill_seen;
+} obj_mach_o_set_vma_data;
+
+/* We do (possibly) three passes through to set the vma, so that:
+
+ zerofill sections get VMAs after all others in their segment
+ GB zerofill get VMAs last.
+
+ As we go, we notice if we see any Zerofill or GB Zerofill sections, so that
+ we can skip the additional passes if there's nothing to do. */
+
+static void
+obj_mach_o_set_section_vma (bfd *abfd ATTRIBUTE_UNUSED, asection *sec, void *v_p)
+{
+ bfd_mach_o_section *ms = bfd_mach_o_get_mach_o_section (sec);
+ unsigned bfd_align = bfd_get_section_alignment (abfd, sec);
+ obj_mach_o_set_vma_data *p = (struct obj_mach_o_set_vma_data *)v_p;
+ unsigned sectype = (ms->flags & BFD_MACH_O_SECTION_TYPE_MASK);
+ unsigned zf;
+
+ zf = 0;
+ if (sectype == BFD_MACH_O_S_ZEROFILL)
+ {
+ zf = 1;
+ p->zerofill_seen = zf;
+ }
+ else if (sectype == BFD_MACH_O_S_GB_ZEROFILL)
+ {
+ zf = 2;
+ p->gb_zerofill_seen = zf;
+ }
+
+ if (p->vma_pass != zf)
+ return;
+
+ /* We know the section size now - so make a vma for the section just
+ based on order. */
+ ms->size = bfd_get_section_size (sec);
+
+ /* Make sure that the align agrees, and set to the largest value chosen. */
+ ms->align = ms->align > bfd_align ? ms->align : bfd_align;
+ bfd_set_section_alignment (abfd, sec, ms->align);
+
+ p->vma += (1 << ms->align) - 1;
+ p->vma &= ~((1 << ms->align) - 1);
+ ms->addr = p->vma;
+ bfd_set_section_vma (abfd, sec, p->vma);
+ p->vma += ms->size;
+}
+
+/* (potentially) three passes over the sections, setting VMA. We skip the
+ {gb}zerofill passes if we didn't see any of the relevant sections. */
+
+void obj_mach_o_post_relax_hook (void)
+{
+ obj_mach_o_set_vma_data d;
+
+ memset (&d, 0, sizeof (d));
+
+ bfd_map_over_sections (stdoutput, obj_mach_o_set_section_vma, (char *) &d);
+ if ((d.vma_pass = d.zerofill_seen) != 0)
+ bfd_map_over_sections (stdoutput, obj_mach_o_set_section_vma, (char *) &d);
+ if ((d.vma_pass = d.gb_zerofill_seen) != 0)
+ bfd_map_over_sections (stdoutput, obj_mach_o_set_section_vma, (char *) &d);
+}
+
+static void
+obj_mach_o_set_indirect_symbols (bfd *abfd, asection *sec,
+ void *xxx ATTRIBUTE_UNUSED)
+{
+ bfd_vma sect_size = bfd_section_size (abfd, sec);
+ bfd_mach_o_section *ms = bfd_mach_o_get_mach_o_section (sec);
+ unsigned lazy = 0;
+
+ /* See if we have any indirect syms to consider. */
+ if (indirect_syms == NULL)
+ return;
+
+ /* Process indirect symbols.
+ Check for errors, if OK attach them as a flat array to the section
+ for which they are defined. */
+
+ switch (ms->flags & BFD_MACH_O_SECTION_TYPE_MASK)
+ {
+ case BFD_MACH_O_S_SYMBOL_STUBS:
+ case BFD_MACH_O_S_LAZY_SYMBOL_POINTERS:
+ lazy = LAZY;
+ /* Fall through. */
+ case BFD_MACH_O_S_NON_LAZY_SYMBOL_POINTERS:
+ {
+ unsigned int nactual = 0;
+ unsigned int ncalc;
+ obj_mach_o_indirect_sym *isym;
+ obj_mach_o_indirect_sym *list = NULL;
+ obj_mach_o_indirect_sym *list_tail = NULL;
+ unsigned long eltsiz =
+ bfd_mach_o_section_get_entry_size (abfd, ms);
+
+ for (isym = indirect_syms; isym != NULL; isym = isym->next)
+ {
+ if (isym->sect == sec)
+ {
+ nactual++;
+ if (list == NULL)
+ list = isym;
+ else
+ list_tail->next = isym;
+ list_tail = isym;
+ }
+ }
+
+ /* If none are in this section, stop here. */
+ if (nactual == 0)
+ break;
+
+ /* If we somehow added indirect symbols to a section with a zero
+ entry size, we're dead ... */
+ gas_assert (eltsiz != 0);
+
+ ncalc = (unsigned int) (sect_size / eltsiz);
+ if (nactual != ncalc)
+ as_bad (_("the number of .indirect_symbols defined in section %s"
+ " does not match the number expected (%d defined, %d"
+ " expected)"), sec->name, nactual, ncalc);
+ else
+ {
+ unsigned n;
+ bfd_mach_o_asymbol *sym;
+ ms->indirect_syms =
+ bfd_zalloc (abfd,
+ nactual * sizeof (bfd_mach_o_asymbol *));
+
+ if (ms->indirect_syms == NULL)
+ {
+ as_fatal (_("internal error: failed to allocate %d indirect"
+ "symbol pointers"), nactual);
+ }
+
+ for (isym = list, n = 0; isym != NULL; isym = isym->next, n++)
+ {
+ sym = (bfd_mach_o_asymbol *)symbol_get_bfdsym (isym->sym);
+ /* Array is init to NULL & NULL signals a local symbol
+ If the section is lazy-bound, we need to keep the
+ reference to the symbol, since dyld can override.
+
+ Absolute symbols are handled specially. */
+ if (sym->symbol.section == bfd_abs_section_ptr)
+ ms->indirect_syms[n] = sym;
+ else if (S_IS_LOCAL (isym->sym) && ! lazy)
+ ;
+ else
+ {
+ if (sym == NULL)
+ ;
+ /* If the symbols is external ... */
+ else if (S_IS_EXTERNAL (isym->sym)
+ || (sym->n_type & BFD_MACH_O_N_EXT)
+ || ! S_IS_DEFINED (isym->sym)
+ || lazy)
+ {
+ sym->n_desc &= ~LAZY;
+ /* ... it can be lazy, if not defined or hidden. */
+ if ((sym->n_type & BFD_MACH_O_N_TYPE)
+ == BFD_MACH_O_N_UNDF
+ && ! (sym->n_type & BFD_MACH_O_N_PEXT)
+ && (sym->n_type & BFD_MACH_O_N_EXT))
+ sym->n_desc |= lazy;
+ ms->indirect_syms[n] = sym;
+ }
+ }
+ }
+ }
+ }
+ break;
+
+ default:
+ break;
+ }
+}
+
+/* The process of relocation could alter what's externally visible, thus we
+ leave setting the indirect symbols until last. */
+
+void
+obj_mach_o_frob_file_after_relocs (void)
+{
+ bfd_map_over_sections (stdoutput, obj_mach_o_set_indirect_symbols, (char *) 0);
+}
+
+/* Reverse relocations order to make ld happy. */
+
+void
+obj_mach_o_reorder_section_relocs (asection *sec, arelent **rels, unsigned int n)
+{
+ unsigned int i;
+ unsigned int max = n / 2;
+
+ for (i = 0; i < max; i++)
+ {
+ arelent *r = rels[i];
+ rels[i] = rels[n - i - 1];
+ rels[n - i - 1] = r;
+ }
+ bfd_set_reloc (stdoutput, sec, rels, n);
+}
+
+/* Support stabs for mach-o. */
+
+void
+obj_mach_o_process_stab (int what, const char *string,
+ int type, int other, int desc)
+{
+ symbolS *symbolP;
+ bfd_mach_o_asymbol *s;
+
+ switch (what)
+ {
+ case 'd':
+ symbolP = symbol_new ("", now_seg, frag_now_fix (), frag_now);
+ /* Special stabd NULL name indicator. */
+ S_SET_NAME (symbolP, NULL);
+ break;
+
+ case 'n':
+ case 's':
+ symbolP = symbol_new (string, undefined_section, (valueT) 0,
+ &zero_address_frag);
+ pseudo_set (symbolP);
+ break;
+
+ default:
+ as_bad(_("unrecognized stab type '%c'"), (char)what);
+ abort ();
+ break;
+ }
+
+ s = (bfd_mach_o_asymbol *) symbol_get_bfdsym (symbolP);
+ s->n_type = type;
+ s->n_desc = desc;
+ /* For stabd, this will eventually get overwritten by the section number. */
+ s->n_sect = other;
+
+ /* It's a debug symbol. */
+ s->symbol.flags |= BSF_DEBUGGING;
+}
projects / external / binutils.git / blobdiff