/* Support for the generic parts of most COFF variants, for BFD.
Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
- 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
+ 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
Free Software Foundation, Inc.
Written by Cygnus Support.
@file{coffcode.h} because it would not be used by any other
target.
+SUBSUBSECTION
+ Coff long section names
+
+ In the standard Coff object format, section names are limited to
+ the eight bytes available in the @code{s_name} field of the
+ @code{SCNHDR} section header structure. The format requires the
+ field to be NUL-padded, but not necessarily NUL-terminated, so
+ the longest section names permitted are a full eight characters.
+
+ The Microsoft PE variants of the Coff object file format add
+ an extension to support the use of long section names. This
+ extension is defined in section 4 of the Microsoft PE/COFF
+ specification (rev 8.1). If a section name is too long to fit
+ into the section header's @code{s_name} field, it is instead
+ placed into the string table, and the @code{s_name} field is
+ filled with a slash ("/") followed by the ASCII decimal
+ representation of the offset of the full name relative to the
+ string table base.
+
+ Note that this implies that the extension can only be used in object
+ files, as executables do not contain a string table. The standard
+ specifies that long section names from objects emitted into executable
+ images are to be truncated.
+
+ However, as a GNU extension, BFD can generate executable images
+ that contain a string table and long section names. This
+ would appear to be technically valid, as the standard only says
+ that Coff debugging information is deprecated, not forbidden,
+ and in practice it works, although some tools that parse PE files
+ expecting the MS standard format may become confused; @file{PEview} is
+ one known example.
+
+ The functionality is supported in BFD by code implemented under
+ the control of the macro @code{COFF_LONG_SECTION_NAMES}. If not
+ defined, the format does not support long section names in any way.
+ If defined, it is used to initialise a flag,
+ @code{_bfd_coff_long_section_names}, and a hook function pointer,
+ @code{_bfd_coff_set_long_section_names}, in the Coff backend data
+ structure. The flag controls the generation of long section names
+ in output BFDs at runtime; if it is false, as it will be by default
+ when generating an executable image, long section names are truncated;
+ if true, the long section names extension is employed. The hook
+ points to a function that allows the value of the flag to be altered
+ at runtime, on formats that support long section names at all; on
+ other formats it points to a stub that returns an error indication.
+
+ If @code{COFF_LONG_SECTION_NAMES} is simply defined (blank), or is
+ defined to the value "1", then long section names are enabled by
+ default; if it is defined to the value zero, they are disabled by
+ default (but still accepted in input BFDs). The header @file{coffcode.h}
+ defines a macro, @code{COFF_DEFAULT_LONG_SECTION_NAMES}, which is
+ used in the backends to initialise the backend data structure fields
+ appropriately; see the comments for further detail.
+
SUBSUBSECTION
Bit twiddling
#define DOT_DEBUG ".debug"
#define GNU_LINKONCE_WI ".gnu.linkonce.wi."
+#if defined (COFF_LONG_SECTION_NAMES)
+/* Needed to expand the inputs to BLANKOR1TOODD. */
+#define COFFLONGSECTIONCATHELPER(x,y) x ## y
+/* If the input macro Y is blank or '1', return an odd number; if it is
+ '0', return an even number. Result undefined in all other cases. */
+#define BLANKOR1TOODD(y) COFFLONGSECTIONCATHELPER(1,y)
+/* Defined to numerical 0 or 1 according to whether generation of long
+ section names is disabled or enabled by default. */
+#define COFF_ENABLE_LONG_SECTION_NAMES (BLANKOR1TOODD(COFF_LONG_SECTION_NAMES) & 1)
+/* Where long section names are supported, we allow them to be enabled
+ and disabled at runtime, so select an appropriate hook function for
+ _bfd_coff_set_long_section_names. */
+#define COFF_LONG_SECTION_NAMES_SETTER bfd_coff_set_long_section_names_allowed
+#else /* !defined (COFF_LONG_SECTION_NAMES) */
+/* If long section names are not supported, this stub disallows any
+ attempt to enable them at run-time. */
+#define COFF_LONG_SECTION_NAMES_SETTER bfd_coff_set_long_section_names_disallowed
+#endif /* defined (COFF_LONG_SECTION_NAMES) */
+
+/* Define a macro that can be used to initialise both the fields relating
+ to long section names in the backend data struct simultaneously. */
+#if COFF_ENABLE_LONG_SECTION_NAMES
+#define COFF_DEFAULT_LONG_SECTION_NAMES (TRUE), COFF_LONG_SECTION_NAMES_SETTER
+#else /* !COFF_ENABLE_LONG_SECTION_NAMES */
+#define COFF_DEFAULT_LONG_SECTION_NAMES (FALSE), COFF_LONG_SECTION_NAMES_SETTER
+#endif /* COFF_ENABLE_LONG_SECTION_NAMES */
+
+#if defined (COFF_LONG_SECTION_NAMES)
+static bfd_boolean bfd_coff_set_long_section_names_allowed
+ (bfd *, int);
+#else /* !defined (COFF_LONG_SECTION_NAMES) */
+static bfd_boolean bfd_coff_set_long_section_names_disallowed
+ (bfd *, int);
+#endif /* defined (COFF_LONG_SECTION_NAMES) */
static long sec_to_styp_flags
(const char *, flagword);
static bfd_boolean styp_to_sec_flags
\f
/* void warning(); */
+#if defined (COFF_LONG_SECTION_NAMES)
+static bfd_boolean
+bfd_coff_set_long_section_names_allowed (bfd *abfd, int enable)
+{
+ coff_backend_info (abfd)->_bfd_coff_long_section_names = enable;
+ return TRUE;
+}
+#else /* !defined (COFF_LONG_SECTION_NAMES) */
+static bfd_boolean
+bfd_coff_set_long_section_names_disallowed (bfd *abfd, int enable)
+{
+ (void) abfd;
+ (void) enable;
+ return FALSE;
+}
+#endif /* defined (COFF_LONG_SECTION_NAMES) */
+
/* Return a word with STYP_* (scnhdr.s_flags) flags set to represent
the incoming SEC_* flags. The inverse of this function is
styp_to_sec_flags(). NOTE: If you add to/change this routine, you
. unsigned int _bfd_linesz;
. unsigned int _bfd_filnmlen;
. bfd_boolean _bfd_coff_long_filenames;
+.
. bfd_boolean _bfd_coff_long_section_names;
+. bfd_boolean (*_bfd_coff_set_long_section_names)
+. (bfd *, int);
+.
. unsigned int _bfd_coff_default_section_alignment_power;
. bfd_boolean _bfd_coff_force_symnames_in_strings;
. unsigned int _bfd_coff_debug_string_prefix_length;
. (coff_backend_info (abfd)->_bfd_coff_long_filenames)
.#define bfd_coff_long_section_names(abfd) \
. (coff_backend_info (abfd)->_bfd_coff_long_section_names)
+.#define bfd_coff_set_long_section_names(abfd, enable) \
+. ((coff_backend_info (abfd)->_bfd_coff_set_long_section_names) (abfd, enable))
.#define bfd_coff_default_section_alignment_power(abfd) \
. (coff_backend_info (abfd)->_bfd_coff_default_section_alignment_power)
.#define bfd_coff_swap_filehdr_in(abfd, i,o) \
#ifdef COFF_LONG_SECTION_NAMES
/* Handle long section names as in PE. This must be compatible
with the code in coff_write_symbols and _bfd_coff_final_link. */
- {
- size_t len;
+ if (bfd_coff_long_section_names (abfd))
+ {
+ size_t len;
- len = strlen (current->name);
- if (len > SCNNMLEN)
- {
- memset (section.s_name, 0, SCNNMLEN);
- sprintf (section.s_name, "/%lu", (unsigned long) string_size);
- string_size += len + 1;
- long_section_names = TRUE;
- }
- }
+ len = strlen (current->name);
+ if (len > SCNNMLEN)
+ {
+ memset (section.s_name, 0, SCNNMLEN);
+ sprintf (section.s_name, "/%lu", (unsigned long) string_size);
+ string_size += len + 1;
+ long_section_names = TRUE;
+ }
+ }
#endif
#ifdef _LIB
#define coff_SWAP_scnhdr_in coff_swap_scnhdr_in
#endif
-static const bfd_coff_backend_data bfd_coff_std_swap_table ATTRIBUTE_UNUSED =
+static bfd_coff_backend_data bfd_coff_std_swap_table ATTRIBUTE_UNUSED =
{
coff_SWAP_aux_in, coff_SWAP_sym_in, coff_SWAP_lineno_in,
coff_SWAP_aux_out, coff_SWAP_sym_out,
#else
FALSE,
#endif
-#ifdef COFF_LONG_SECTION_NAMES
- TRUE,
-#else
- FALSE,
-#endif
+ COFF_DEFAULT_LONG_SECTION_NAMES,
COFF_DEFAULT_SECTION_ALIGNMENT_POWER,
#ifdef COFF_FORCE_SYMBOLS_IN_STRINGS
TRUE,
#ifdef TICOFF
/* COFF0 differs in file/section header size and relocation entry size. */
-static const bfd_coff_backend_data ticoff0_swap_table =
+static bfd_coff_backend_data ticoff0_swap_table =
{
coff_SWAP_aux_in, coff_SWAP_sym_in, coff_SWAP_lineno_in,
coff_SWAP_aux_out, coff_SWAP_sym_out,
#else
FALSE,
#endif
-#ifdef COFF_LONG_SECTION_NAMES
- TRUE,
-#else
- FALSE,
-#endif
+ COFF_DEFAULT_LONG_SECTION_NAMES,
COFF_DEFAULT_SECTION_ALIGNMENT_POWER,
#ifdef COFF_FORCE_SYMBOLS_IN_STRINGS
TRUE,
#ifdef TICOFF
/* COFF1 differs in section header size. */
-static const bfd_coff_backend_data ticoff1_swap_table =
+static bfd_coff_backend_data ticoff1_swap_table =
{
coff_SWAP_aux_in, coff_SWAP_sym_in, coff_SWAP_lineno_in,
coff_SWAP_aux_out, coff_SWAP_sym_out,
#else
FALSE,
#endif
-#ifdef COFF_LONG_SECTION_NAMES
- TRUE,
-#else
- FALSE,
-#endif
+ COFF_DEFAULT_LONG_SECTION_NAMES,
COFF_DEFAULT_SECTION_ALIGNMENT_POWER,
#ifdef COFF_FORCE_SYMBOLS_IN_STRINGS
TRUE,
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