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authorNick Clifton <nickc@redhat.com>2013-05-29 14:58:35 +0000
committerNick Clifton <nickc@redhat.com>2013-05-29 14:58:35 +0000
commit95e34fb4f43f5cc57c48d4799c5c59d7dcf6c2a2 (patch)
treee7b5e06c3d8cdef52646bda770679b629d6aac5d /bfd/dwarf2.c
parent28439a30acd9aaafe5d7dc75573b3629533cb873 (diff)
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* dwarf2.c (struct dwarf2_debug): Add fields for handling
alternate debug info source. (dwarf_debug_sections): Add entries for alternate .debug_str and .debug_info sections. (dwarf_debug_section_enum): Likewise. (read_alt_indirect_string): New function. Handles a DW_FORM_GNU_strp_alt attribute. (read_alt_indirect_ref): New function. Handles a DW_FORM_GNU_ref_alt attribute. (read_attribute_value): Process DW_FORM_GNU_ref_alt and DW_FORM_GNU_strp_alt. (find_abstract_instance_name): Handle DW_FORM_GNU_ref_alt attributes. (_bfd_dwarf2_cleanup_debug_info): Free alternate debug info sources. * opncls.c (GNU_DEBUGALTLINK): Define. (bfd_get_alt_debug_link_info): New function. (separate_alt_debug_file_exists): New function. (find_separate_debug_file): Add parameters for fetch and check functions. (bfd_follow_gnu_debugaltlink): New function. * bfd-in2.h: Regenerate.
Diffstat (limited to 'bfd/dwarf2.c')
-rw-r--r--bfd/dwarf2.c148
1 files changed, 142 insertions, 6 deletions
diff --git a/bfd/dwarf2.c b/bfd/dwarf2.c
index 7a1a4ae..c9349da 100644
--- a/bfd/dwarf2.c
+++ b/bfd/dwarf2.c
@@ -1,6 +1,5 @@
/* DWARF 2 support.
- Copyright 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
- 2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
+ Copyright 1994-2013 Free Software Foundation, Inc.
Adapted from gdb/dwarf2read.c by Gavin Koch of Cygnus Solutions
(gavin@cygnus.com).
@@ -108,6 +107,16 @@ struct dwarf2_debug
asection *sec;
bfd_byte *sec_info_ptr;
+ /* Support for alternate debug info sections created by the DWZ utility:
+ This includes a pointer to an alternate bfd which contains *extra*,
+ possibly duplicate debug sections, and pointers to the loaded
+ .debug_str and .debug_info sections from this bfd. */
+ bfd * alt_bfd_ptr;
+ bfd_byte * alt_dwarf_str_buffer;
+ bfd_size_type alt_dwarf_str_size;
+ bfd_byte * alt_dwarf_info_buffer;
+ bfd_size_type alt_dwarf_info_size;
+
/* A pointer to the memory block allocated for info_ptr. Neither
info_ptr nor sec_info_ptr are guaranteed to stay pointing to the
beginning of the malloc block. This is used only to free the
@@ -290,6 +299,7 @@ const struct dwarf_debug_section dwarf_debug_sections[] =
{ ".debug_aranges", ".zdebug_aranges" },
{ ".debug_frame", ".zdebug_frame" },
{ ".debug_info", ".zdebug_info" },
+ { ".debug_info", ".zdebug_info" },
{ ".debug_line", ".zdebug_line" },
{ ".debug_loc", ".zdebug_loc" },
{ ".debug_macinfo", ".zdebug_macinfo" },
@@ -300,6 +310,7 @@ const struct dwarf_debug_section dwarf_debug_sections[] =
{ ".debug_static_func", ".zdebug_static_func" },
{ ".debug_static_vars", ".zdebug_static_vars" },
{ ".debug_str", ".zdebug_str", },
+ { ".debug_str", ".zdebug_str", },
{ ".debug_types", ".zdebug_types" },
/* GNU DWARF 1 extensions */
{ ".debug_sfnames", ".zdebug_sfnames" },
@@ -312,12 +323,15 @@ const struct dwarf_debug_section dwarf_debug_sections[] =
{ NULL, NULL },
};
+/* NB/ Numbers in this enum must match up with indicies
+ into the dwarf_debug_sections[] array above. */
enum dwarf_debug_section_enum
{
debug_abbrev = 0,
debug_aranges,
debug_frame,
debug_info,
+ debug_info_alt,
debug_line,
debug_loc,
debug_macinfo,
@@ -328,6 +342,7 @@ enum dwarf_debug_section_enum
debug_static_func,
debug_static_vars,
debug_str,
+ debug_str_alt,
debug_types,
debug_sfnames,
debug_srcinfo,
@@ -484,8 +499,8 @@ read_section (bfd * abfd,
asection *msec;
const char *section_name = sec->uncompressed_name;
- /* read_section is a noop if the section has already been read. */
- if (!*section_buffer)
+ /* The section may have already been read. */
+ if (*section_buffer == NULL)
{
msec = bfd_get_section_by_name (abfd, section_name);
if (! msec)
@@ -626,6 +641,104 @@ read_indirect_string (struct comp_unit * unit,
return str;
}
+/* Like read_indirect_string but uses a .debug_str located in
+ an alternate filepointed to by the .gnu_debuglink section.
+ Used to impement DW_FORM_GNU_strp_alt. */
+
+static char *
+read_alt_indirect_string (struct comp_unit * unit,
+ bfd_byte * buf,
+ unsigned int * bytes_read_ptr)
+{
+ bfd_uint64_t offset;
+ struct dwarf2_debug *stash = unit->stash;
+ char *str;
+
+ if (unit->offset_size == 4)
+ offset = read_4_bytes (unit->abfd, buf);
+ else
+ offset = read_8_bytes (unit->abfd, buf);
+
+ *bytes_read_ptr = unit->offset_size;
+
+ if (stash->alt_bfd_ptr == NULL)
+ {
+ bfd * debug_bfd;
+ char * debug_filename = bfd_follow_gnu_debugaltlink (unit->abfd, DEBUGDIR);
+
+ if (debug_filename == NULL)
+ return NULL;
+
+ if ((debug_bfd = bfd_openr (debug_filename, NULL)) == NULL
+ || ! bfd_check_format (debug_bfd, bfd_object))
+ {
+ if (debug_bfd)
+ bfd_close (debug_bfd);
+
+ /* FIXME: Should we report our failure to follow the debuglink ? */
+ free (debug_filename);
+ return NULL;
+ }
+ stash->alt_bfd_ptr = debug_bfd;
+ }
+
+ if (! read_section (unit->stash->alt_bfd_ptr,
+ stash->debug_sections + debug_str_alt,
+ NULL, /* FIXME: Do we need to load alternate symbols ? */
+ offset,
+ &stash->alt_dwarf_str_buffer,
+ &stash->alt_dwarf_str_size))
+ return NULL;
+
+ str = (char *) stash->alt_dwarf_str_buffer + offset;
+ if (*str == '\0')
+ return NULL;
+
+ return str;
+}
+
+/* Resolve an alternate reference from UNIT at OFFSET.
+ Returns a pointer into the loaded alternate CU upon success
+ or NULL upon failure. */
+
+static bfd_byte *
+read_alt_indirect_ref (struct comp_unit * unit,
+ bfd_uint64_t offset)
+{
+ struct dwarf2_debug *stash = unit->stash;
+
+ if (stash->alt_bfd_ptr == NULL)
+ {
+ bfd * debug_bfd;
+ char * debug_filename = bfd_follow_gnu_debugaltlink (unit->abfd, DEBUGDIR);
+
+ if (debug_filename == NULL)
+ return FALSE;
+
+ if ((debug_bfd = bfd_openr (debug_filename, NULL)) == NULL
+ || ! bfd_check_format (debug_bfd, bfd_object))
+ {
+ if (debug_bfd)
+ bfd_close (debug_bfd);
+
+ /* FIXME: Should we report our failure to follow the debuglink ? */
+ free (debug_filename);
+ return NULL;
+ }
+ stash->alt_bfd_ptr = debug_bfd;
+ }
+
+ if (! read_section (unit->stash->alt_bfd_ptr,
+ stash->debug_sections + debug_info_alt,
+ NULL, /* FIXME: Do we need to load alternate symbols ? */
+ offset,
+ &stash->alt_dwarf_info_buffer,
+ &stash->alt_dwarf_info_size))
+ return NULL;
+
+ return stash->alt_dwarf_info_buffer + offset;
+}
+
static bfd_uint64_t
read_address (struct comp_unit *unit, bfd_byte *buf)
{
@@ -829,6 +942,7 @@ read_attribute_value (struct attribute *attr,
attr->u.val = read_address (unit, info_ptr);
info_ptr += unit->addr_size;
break;
+ case DW_FORM_GNU_ref_alt:
case DW_FORM_sec_offset:
if (unit->offset_size == 4)
attr->u.val = read_4_bytes (unit->abfd, info_ptr);
@@ -878,6 +992,10 @@ read_attribute_value (struct attribute *attr,
attr->u.str = read_indirect_string (unit, info_ptr, &bytes_read);
info_ptr += bytes_read;
break;
+ case DW_FORM_GNU_strp_alt:
+ attr->u.str = read_alt_indirect_string (unit, info_ptr, &bytes_read);
+ info_ptr += bytes_read;
+ break;
case DW_FORM_exprloc:
case DW_FORM_block:
amt = sizeof (struct dwarf_block);
@@ -950,7 +1068,7 @@ read_attribute_value (struct attribute *attr,
info_ptr = read_attribute_value (attr, form, unit, info_ptr);
break;
default:
- (*_bfd_error_handler) (_("Dwarf Error: Invalid or unhandled FORM value: %u."),
+ (*_bfd_error_handler) (_("Dwarf Error: Invalid or unhandled FORM value: %#x."),
form);
bfd_set_error (bfd_error_bad_value);
return NULL;
@@ -1996,7 +2114,7 @@ find_abstract_instance_name (struct comp_unit *unit,
struct abbrev_info *abbrev;
bfd_uint64_t die_ref = attr_ptr->u.val;
struct attribute attr;
- char *name = 0;
+ char *name = NULL;
/* DW_FORM_ref_addr can reference an entry in a different CU. It
is an offset from the .debug_info section, not the current CU. */
@@ -2009,8 +2127,20 @@ find_abstract_instance_name (struct comp_unit *unit,
info_ptr = unit->sec_info_ptr + die_ref;
}
+ else if (attr_ptr->form == DW_FORM_GNU_ref_alt)
+ {
+ info_ptr = read_alt_indirect_ref (unit, die_ref);
+ if (info_ptr == NULL)
+ {
+ (*_bfd_error_handler)
+ (_("Dwarf Error: Unable to read alt ref %u."), die_ref);
+ bfd_set_error (bfd_error_bad_value);
+ return name;
+ }
+ }
else
info_ptr = unit->info_ptr_unit + die_ref;
+
abbrev_number = read_unsigned_leb128 (abfd, info_ptr, &bytes_read);
info_ptr += bytes_read;
@@ -3694,4 +3824,10 @@ _bfd_dwarf2_cleanup_debug_info (bfd *abfd, void **pinfo)
free (stash->info_ptr_memory);
if (stash->close_on_cleanup)
bfd_close (stash->bfd_ptr);
+ if (stash->alt_dwarf_str_buffer)
+ free (stash->alt_dwarf_str_buffer);
+ if (stash->alt_dwarf_info_buffer)
+ free (stash->alt_dwarf_info_buffer);
+ if (stash->alt_bfd_ptr)
+ bfd_close (stash->alt_bfd_ptr);
}