[RFC-v2] Fix .text section offset for windows DLL (was Calling __stdcall functions in the inferior)

Pierre Muller
2012-11-06T14:31:56Z

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I wrote a new version of the patch
that tries to implement most of the things we talked about.

It works quite nicely on my windows 7 64-bit using
cygwin, mingw32 or a cross-built mingw64 binary.

Interestingly, it seems that the mingw64 binary is
not really affected by this issue because the 64-bit system DLLs
do have a section offset of 0x1000 for .text section,
while the 32-bit DLLs have 0x10000.

Pierre Muller

2012-11-06 Pierre Muller <muller@sourceware.org>

* coff-pe-read.h (pe_text_section_offset): Declare new function.
* coff-pe-read.c (debug_coff_pe_read): New static variable.
(struct read_pe_section_data): Add section_name field.
(pe_as16): New function.
(IMAGE_SCN_CNT_CODE): New macro, if not already defined.
(IMAGE_SCN_CNT_INITIALIZED_DATA): Ditto.
(IMAGE_SCN_CNT_UNINITIALIZED_DATA): Ditto.
(add_pe_exported_sym): Handle unnamed exported function.
(add_pe_forwarded_sym): New function.
(read_pe_exported_syms): Use ordinal of function to
retrieve correct RVA address of function and handle
forwarded symbol.
(pe_text_section_offset): New function.
(show_debug_coff_pe_read): New function.
(_initialize_coff_pe_read): New function adding
'set/show debug coff_pe_read' commands.

* windows-tdep.c (windows_xfer_shared_library): Use
pe_text_section_offset function instead of possibly wrong
0x1000 constant for .text sextion offset.

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2012-11-06 Pierre Muller <muller@sourceware.org>

* coff-pe-read.h (pe_text_section_offset): Declare new function.
* coff-pe-read.c (debug_coff_pe_read): New static variable.
(struct read_pe_section_data): Add section_name field.
(pe_as16): New function.
(IMAGE_SCN_CNT_CODE): New macro, if not already defined.
(IMAGE_SCN_CNT_INITIALIZED_DATA): Ditto.
(IMAGE_SCN_CNT_UNINITIALIZED_DATA): Ditto.
(add_pe_exported_sym): Handle unnamed exported function.
(add_pe_forwarded_sym): New function.
(read_pe_exported_syms): Use ordinal of function to
retrieve correct RVA address of function and handle
forwarded symbol.
(pe_text_section_offset): New function.
(show_debug_coff_pe_read): New function.
(_initialize_coff_pe_read): New function adding
'set/show debug coff_pe_read' commands.

* windows-tdep.c (windows_xfer_shared_library): Use
pe_text_section_offset function instead of possibly wrong
0x1000 constant for .text sextion offset.

Index: coff-pe-read.h
===================================================================
RCS file: /cvs/src/src/gdb/coff-pe-read.h,v
retrieving revision 1.11
diff -u -p -r1.11 coff-pe-read.h
--- coff-pe-read.h 4 Jan 2012 08:17:00 -0000 1.11
+++ coff-pe-read.h 6 Nov 2012 13:37:01 -0000
@@ -21,11 +21,17 @@

#if !defined (COFF_PE_READ_H)
#define COFF_PE_READ_H
+#include "defs.h"

struct objfile;
+struct bfd;

/* Read the export table and convert it to minimal symbol table
entries */
extern void read_pe_exported_syms (struct objfile *objfile);

+/* Extract for ABFD the offset of the .text section.
+ Returns default value 0x1000 if information is not found. */
+extern CORE_ADDR pe_text_section_offset (struct bfd *abfd);
+
#endif /* !defined (COFF_PE_READ_H) */
Index: coff-pe-read.c
===================================================================
RCS file: /cvs/src/src/gdb/coff-pe-read.c,v
retrieving revision 1.17
diff -u -p -r1.17 coff-pe-read.c
--- coff-pe-read.c 4 Jan 2012 08:17:00 -0000 1.17
+++ coff-pe-read.c 6 Nov 2012 13:37:01 -0000
@@ -23,16 +23,26 @@

#include "coff-pe-read.h"

+#include <ctype.h>
#include "defs.h"
#include "bfd.h"
#include "gdbtypes.h"

+#include "command.h"
+#include "gdbcmd.h"
#include "symtab.h"
#include "symfile.h"
#include "objfiles.h"
+#include "common/common-utils.h"

/* Internal section information */

+/* Coff PE read debugging flag:
+ default value is 0,
+ value 1 outputs problems encountered while parsing PE file,
+ value above 1 also lists all generated minimal symbols. */
+static unsigned int debug_coff_pe_read;
+
struct read_pe_section_data
{
CORE_ADDR vma_offset; /* Offset to loaded address of section. */
@@ -40,8 +50,18 @@ struct read_pe_section_data
unsigned long rva_end; /* End offset within the pe. */
enum minimal_symbol_type ms_type; /* Type to assign symbols in
section. */
+ char *section_name; /* Recorded section name. */
};

+#ifndef IMAGE_SCN_CNT_CODE
+# define IMAGE_SCN_CNT_CODE 0x20
+#endif
+#ifndef IMAGE_SCN_CNT_INITIALIZED_DATA
+# define IMAGE_SCN_CNT_INITIALIZED_DATA 0x40
+#endif
+#ifndef IMAGE_SCN_CNT_UNINITIALIZED_DATA
+# define IMAGE_SCN_CNT_UNINITIALIZED_DATA 0x80
+#endif
#define PE_SECTION_INDEX_TEXT 0
#define PE_SECTION_INDEX_DATA 1
#define PE_SECTION_INDEX_BSS 2
@@ -99,9 +119,11 @@ get_section_vmas (bfd *abfd, asection *s
static void
add_pe_exported_sym (char *sym_name,
unsigned long func_rva,
+ int ordinal,
const struct read_pe_section_data *section_data,
const char *dll_name, struct objfile *objfile)
{
+ char ordinal_name[10];
/* Add the stored offset to get the loaded address of the symbol. */

CORE_ADDR vma = func_rva + section_data->vma_offset;
@@ -113,39 +135,130 @@ add_pe_exported_sym (char *sym_name,
of the dll name, e.g. KERNEL32!AddAtomA. This matches the style
used by windbg from the "Microsoft Debugging Tools for Windows". */

+ if (*sym_name == '\0')
+ {
+ xsnprintf (ordinal_name, sizeof (ordinal_name), "#%d", ordinal);
+ sym_name = ordinal_name;
+ }
+
qualified_name = xmalloc (dll_name_len + strlen (sym_name) + 2);

strncpy (qualified_name, dll_name, dll_name_len);
qualified_name[dll_name_len] = '!';
strcpy (qualified_name + dll_name_len + 1, sym_name);

+ if ((section_data->ms_type == mst_unknown) && debug_coff_pe_read)
+ printf_filtered (_("Unknown section type for \"%s\" for entry \"%s\" \
+in dll \"%s\"\n"),
+ section_data->section_name, sym_name, dll_name);
+
prim_record_minimal_symbol (qualified_name,
vma, section_data->ms_type, objfile);

xfree (qualified_name);

/* Enter the plain name as well, which might not be unique. */
- prim_record_minimal_symbol (sym_name, vma,
+ prim_record_minimal_symbol (sym_name, vma,
section_data->ms_type, objfile);
+ if (debug_coff_pe_read > 1)
+ printf_filtered (_("Adding exported symbol \"%s\" in dll \"%s\"\n"),
+ sym_name, dll_name);
}

-/* Truncate a dll_name at the first dot character. */
+/* Create a minimal symbol entry for an exported forward symbol.
+ Returns 1 if the forwarded function was found 0 otherwise. */

-static void
-read_pe_truncate_name (char *dll_name)
+static int
+add_pe_forwarded_sym (char *sym_name, char *forward_dll_name,
+ char *forward_func_name, int ordinal,
+ const char *dll_name, struct objfile *objfile)
{
- while (*dll_name)
+ char ordinal_name[10];
+ int forward_dll_name_len = strlen (forward_dll_name);
+ int forward_func_name_len = strlen (forward_func_name);
+ CORE_ADDR vma;
+ struct objfile *forward_objfile;
+ struct minimal_symbol *msymbol;
+ short section;
+ enum minimal_symbol_type msymtype;
+ char *qualified_name = 0;
+ int dll_name_len = strlen (dll_name);
+ char *forward_minimal_name = xmalloc (forward_dll_name_len +
+ forward_func_name_len + 2);
+
+ strncpy (forward_minimal_name, forward_dll_name, forward_dll_name_len);
+ forward_minimal_name[forward_dll_name_len] = '!';
+ strcpy (forward_minimal_name + forward_dll_name_len + 1, forward_func_name);
+
+
+ msymbol = lookup_minimal_symbol_and_objfile (forward_minimal_name,
+ &forward_objfile);
+
+ if (!msymbol)
{
- if ((*dll_name) == '.')
- {
- *dll_name = '\0'; /* truncates and causes loop exit. */
- }
+ int i;
+ for (i = 0; i < forward_dll_name_len; i++)
+ forward_minimal_name[i] = tolower (forward_minimal_name[i]);
+ msymbol = lookup_minimal_symbol_and_objfile (forward_minimal_name,
+ &forward_objfile);
+ }

- else
- {
- ++dll_name;
- }
+ if (debug_coff_pe_read > 1)
+ printf_filtered (_("Adding forwarded exported symbol \"%s\" "
+ "in dll \"%s\", pointing to \"%s\"\n"),
+ sym_name, dll_name, forward_minimal_name);
+
+ xfree (forward_minimal_name);
+
+ if (!msymbol)
+ {
+ if (debug_coff_pe_read)
+ printf_filtered (_("Unable to find function \"%s\" in dll \"%s\" "
+ ", forward of \"%s\" in dll \"%s\"\n"),
+ forward_func_name, forward_dll_name, sym_name,
+ dll_name);
+ return 0;
}
+
+ vma = SYMBOL_VALUE_ADDRESS (msymbol);
+ section = SYMBOL_SECTION (msymbol);
+ msymtype = MSYMBOL_TYPE (msymbol);
+
+ /* Generate a (hopefully unique) qualified name using the first part
+ of the dll name, e.g. KERNEL32!AddAtomA. This matches the style
+ used by windbg from the "Microsoft Debugging Tools for Windows". */
+
+ if (*sym_name == '\0')
+ {
+ xsnprintf (ordinal_name, sizeof (ordinal_name), "#%d", ordinal);
+ sym_name = ordinal_name;
+ }
+
+ qualified_name = xmalloc (dll_name_len + strlen (sym_name) + 2);
+
+ strncpy (qualified_name, dll_name, dll_name_len);
+ qualified_name[dll_name_len] = '!';
+ strcpy (qualified_name + dll_name_len + 1, sym_name);
+
+ prim_record_minimal_symbol (qualified_name,
+ vma, msymtype, objfile);
+
+ xfree (qualified_name);
+
+ /* Enter the plain name as well, which might not be unique. */
+ prim_record_minimal_symbol (sym_name, vma,
+ msymtype, objfile);
+ return 1;
+}
+
+/* Truncate a dll_name at the last dot character. */
+
+static void
+read_pe_truncate_name (char *dll_name)
+{
+ char * last_point = strrchr (dll_name, '.');
+ if (last_point != NULL)
+ *last_point = '\0';
}
\f
/* Low-level support functions, direct from the ld module pe-dll.c. */
@@ -170,6 +283,14 @@ pe_get32 (bfd *abfd, int where)
}

static unsigned int
+pe_as16 (void *ptr)
+{
+ unsigned char *b = ptr;
+
+ return b[0] + (b[1] << 8);
+}
+
+static unsigned int
pe_as32 (void *ptr)
{
unsigned char *b = ptr;
@@ -185,35 +306,50 @@ void
read_pe_exported_syms (struct objfile *objfile)
{
bfd *dll = objfile->obfd;
+ unsigned long nbnormal, nbforward;
unsigned long pe_header_offset, opthdr_ofs, num_entries, i;
+ unsigned long export_opthdrrva, export_opthdrsize;
unsigned long export_rva, export_size, nsections, secptr, expptr;
unsigned long exp_funcbase;
unsigned char *expdata, *erva;
unsigned long name_rvas, ordinals, nexp, ordbase;
- char *dll_name;
+ char *dll_name = (char *) dll->filename;
+ int otherix = PE_SECTION_TABLE_SIZE;
+ int exportix = -1;
int is_pe64 = 0;
int is_pe32 = 0;

/* Array elements are for text, data and bss in that order
- Initialization with start_rva > end_rva guarantees that
+ Initialization with RVA_START > RVA_END guarantees that
unused sections won't be matched. */
- struct read_pe_section_data section_data[PE_SECTION_TABLE_SIZE]
- = { {0, 1, 0, mst_text},
- {0, 1, 0, mst_data},
- {0, 1, 0, mst_bss}
- };
+ struct read_pe_section_data *section_data;

struct cleanup *back_to = 0;

char const *target = bfd_get_target (objfile->obfd);

+ section_data = xzalloc (PE_SECTION_TABLE_SIZE
+ * sizeof (struct read_pe_section_data));
+
+ for (i=0; i < PE_SECTION_TABLE_SIZE; i++)
+ {
+ section_data[i].vma_offset = 0;
+ section_data[i].rva_start = 1;
+ section_data[i].rva_end = 0;
+ };
+ section_data[PE_SECTION_INDEX_TEXT].ms_type = mst_text;
+ section_data[PE_SECTION_INDEX_TEXT].section_name = ".text";
+ section_data[PE_SECTION_INDEX_DATA].ms_type = mst_data;
+ section_data[PE_SECTION_INDEX_DATA].section_name = ".data";
+ section_data[PE_SECTION_INDEX_BSS].ms_type = mst_bss;
+ section_data[PE_SECTION_INDEX_BSS].section_name = ".bss";
+
is_pe64 = (strcmp (target, "pe-x86-64") == 0
|| strcmp (target, "pei-x86-64") == 0);
is_pe32 = (strcmp (target, "pe-i386") == 0
|| strcmp (target, "pei-i386") == 0
|| strcmp (target, "pe-arm-wince-little") == 0
|| strcmp (target, "pei-arm-wince-little") == 0);
-
if (!is_pe32 && !is_pe64)
{
/* This is not a recognized PE format file. Abort now, because
@@ -234,21 +370,21 @@ read_pe_exported_syms (struct objfile *o
{
return;
}
-
if (is_pe64)
{
- export_rva = pe_get32 (dll, opthdr_ofs + 112);
- export_size = pe_get32 (dll, opthdr_ofs + 116);
+ export_opthdrrva = pe_get32 (dll, opthdr_ofs + 112);
+ export_opthdrsize = pe_get32 (dll, opthdr_ofs + 116);
}
else
{
- export_rva = pe_get32 (dll, opthdr_ofs + 96);
- export_size = pe_get32 (dll, opthdr_ofs + 100);
+ export_opthdrrva = pe_get32 (dll, opthdr_ofs + 96);
+ export_opthdrsize = pe_get32 (dll, opthdr_ofs + 100);
}
nsections = pe_get16 (dll, pe_header_offset + 4 + 2);
secptr = (pe_header_offset + 4 + 20 +
pe_get16 (dll, pe_header_offset + 4 + 16));
expptr = 0;
+ export_size = 0;

/* Get the rva and size of the export section. */
for (i = 0; i < nsections; i++)
@@ -262,15 +398,30 @@ read_pe_exported_syms (struct objfile *o
bfd_seek (dll, (file_ptr) secptr1, SEEK_SET);
bfd_bread (sname, (bfd_size_type) 8, dll);

- if (vaddr <= export_rva && vaddr + vsize > export_rva)
+ if ((strcmp (sname, ".edata") == 0)
+ || ((vaddr <= export_opthdrrva)
+ && (export_opthdrrva < vaddr + vsize)))
{
- expptr = fptr + (export_rva - vaddr);
- if (export_rva + export_size > vaddr + vsize)
- export_size = vsize - (export_rva - vaddr);
+ if (strcmp (sname, ".edata") != 0)
+ {
+ if (debug_coff_pe_read)
+ printf_filtered (_("Export RVA for dll "
+ "\"%s\" is in section \"%s\"\n"),
+ dll_name, sname);
+ }
+ else if ((export_opthdrrva != vaddr) && debug_coff_pe_read)
+ printf_filtered (_("Wrong value of export RVA for dll \"%s\": "
+ "0x%lx instead of 0x%lx\n"),
+ dll_name, export_opthdrrva, vaddr);
+ expptr = fptr + (export_opthdrrva - vaddr);
+ exportix = i;
break;
}
}

+ export_rva = export_opthdrrva;
+ export_size = export_opthdrsize;
+
if (export_size == 0)
{
/* Empty export table. */
@@ -284,6 +435,7 @@ read_pe_exported_syms (struct objfile *o
unsigned long secptr1 = secptr + 40 * i;
unsigned long vsize = pe_get32 (dll, secptr1 + 8);
unsigned long vaddr = pe_get32 (dll, secptr1 + 12);
+ unsigned long characteristics = pe_get32 (dll, secptr1 + 36);
char sec_name[9];
int sectix;

@@ -298,6 +450,24 @@ read_pe_exported_syms (struct objfile *o
section_data[sectix].rva_start = vaddr;
section_data[sectix].rva_end = vaddr + vsize;
}
+ else
+ {
+ otherix++;
+ section_data = xrealloc (section_data, otherix
+ * sizeof (struct read_pe_section_data));
+ section_data[otherix - 1].section_name = xstrdup (sec_name);
+ section_data[otherix - 1].rva_start = vaddr;
+ section_data[otherix - 1].rva_end = vaddr + vsize;
+ section_data[otherix - 1].vma_offset = 0;
+ if (characteristics & IMAGE_SCN_CNT_CODE)
+ section_data[otherix - 1].ms_type = mst_text;
+ else if (characteristics & IMAGE_SCN_CNT_INITIALIZED_DATA)
+ section_data[otherix - 1].ms_type = mst_data;
+ else if (characteristics & IMAGE_SCN_CNT_UNINITIALIZED_DATA)
+ section_data[otherix - 1].ms_type = mst_bss;
+ else
+ section_data[otherix - 1].ms_type = mst_unknown;
+ }
}

expdata = (unsigned char *) xmalloc (export_size);
@@ -321,7 +491,7 @@ read_pe_exported_syms (struct objfile *o
/* Adjust the vma_offsets in case this PE got relocated. This
assumes that *all* sections share the same relocation offset
as the text section. */
- for (i = 0; i < PE_SECTION_TABLE_SIZE; i++)
+ for (i = 0; i < otherix; i++)
{
section_data[i].vma_offset
+= ANOFFSET (objfile->section_offsets, SECT_OFF_TEXT (objfile));
@@ -331,31 +501,183 @@ read_pe_exported_syms (struct objfile *o
lower case for convenience on Windows. */
read_pe_truncate_name (dll_name);

+ if (debug_coff_pe_read)
+ printf_filtered (_("DLL \"%s\" has %ld export entries, base=%ld\n"),
+ dll_name, nexp, ordbase);
+ nbforward = 0;
+ nbnormal = 0;
/* Iterate through the list of symbols. */
for (i = 0; i < nexp; i++)
{
/* Pointer to the names vector. */
unsigned long name_rva = pe_as32 (erva + name_rvas + i * 4);
+ /* Retrieve ordinal value */
+
+ unsigned long ordinal = pe_as16 (erva + ordinals + i * 2);
+

/* Pointer to the function address vector. */
- unsigned long func_rva = pe_as32 (erva + exp_funcbase + i * 4);
+ /* This is relatived to ordinal value. */
+ unsigned long func_rva = pe_as32 (erva + exp_funcbase +
+ ordinal * 4);

/* Find this symbol's section in our own array. */
int sectix = 0;
+ int section_found = 0;
+
+ /* First handle forward cases. */
+ if ((func_rva >= export_rva)
+ && (func_rva < export_rva + export_size))
+ {
+ char *forward_name = (char *) (erva + func_rva);
+ char *funcname = (char *) (erva + name_rva);
+ char *forward_dll_name = forward_name;
+ char *forward_func_name = forward_name;
+ char *sep = strchr (forward_name, '.');
+
+ if (sep)
+ {
+ int len = (int) (sep - forward_name);
+ forward_dll_name = xmalloc (len + 1);
+ strncpy (forward_dll_name, forward_name, len);
+ forward_dll_name[len] = '\0';
+ forward_func_name = ++sep;
+ }
+ if (add_pe_forwarded_sym (funcname, forward_dll_name,
+ forward_func_name, ordinal,
+ dll_name, objfile) != 0)
+ ++nbforward;
+ if (sep)
+ xfree (forward_dll_name);
+ continue;
+ }

- for (sectix = 0; sectix < PE_SECTION_TABLE_SIZE; ++sectix)
+ for (sectix = 0; sectix < otherix; ++sectix)
{
if ((func_rva >= section_data[sectix].rva_start)
&& (func_rva < section_data[sectix].rva_end))
{
+ section_found = 1;
add_pe_exported_sym (erva + name_rva,
- func_rva,
+ func_rva, ordinal,
section_data + sectix, dll_name, objfile);
+ ++nbnormal;
break;
}
}
+ if (!section_found)
+ {
+ char *funcname = (char *) (erva + name_rva);
+
+ if (name_rva == 0)
+ {
+ static char null_char = '\0';
+
+ add_pe_exported_sym (&null_char, func_rva, ordinal,
+ section_data, dll_name, objfile);
+ ++nbnormal;
+ }
+ else if (debug_coff_pe_read)
+ printf_filtered (_("Export name \"%s\" ord. %lu, RVA 0x%lx \
+in dll \"%s\" not handled\n"),
+ funcname, ordinal, func_rva, dll_name);
+ }
}

+ if (debug_coff_pe_read)
+ printf_filtered (_("Finished reading \"%s\", exports %ld, forwards \
+%ld, total %ld/%ld.\n"),
+ dll_name, nbnormal, nbforward,
+ nbnormal + nbforward, nexp);
/* Discard expdata. */
do_cleanups (back_to);
}
+
+/* Extract for BFD the offset of the .text section.
+ This offset is mainly related to the offset within the file.
+ The value was previously expected to be 0x1000 for all files,
+ but some Windows OS core DLLs seem to use 0x10000 section alignement
+ which modified the return value of that function.
+ Still return default 0x1000 value if ABFD is NULL or
+ if '.text' section is not found, but that should not happen... */
+
+#define DEFAULT_COFF_PE_TEXT_SECTION_OFFSET 0x1000
+
+CORE_ADDR
+pe_text_section_offset (struct bfd *abfd)
+
+{
+ unsigned long pe_header_offset, opthdr_ofs, num_entries, i;
+ unsigned long export_rva, export_size, nsections, secptr, expptr;
+ unsigned long exp_funcbase;
+ unsigned char *expdata, *erva;
+ unsigned long name_rvas, ordinals, nexp, ordbase;
+ char *dll_name;
+ int is_pe64 = 0;
+ int is_pe32 = 0;
+ char const *target;
+
+ if (!abfd)
+ return DEFAULT_COFF_PE_TEXT_SECTION_OFFSET;
+
+ target = bfd_get_target (abfd);
+
+ is_pe64 = (strcmp (target, "pe-x86-64") == 0
+ || strcmp (target, "pei-x86-64") == 0);
+ is_pe32 = (strcmp (target, "pe-i386") == 0
+ || strcmp (target, "pei-i386") == 0
+ || strcmp (target, "pe-arm-wince-little") == 0
+ || strcmp (target, "pei-arm-wince-little") == 0);
+
+ if (!is_pe32 && !is_pe64)
+ {
+ /* This is not a recognized PE format file. Abort now, because
+ the code is untested on anything else. *FIXME* test on
+ further architectures and loosen or remove this test. */
+ return DEFAULT_COFF_PE_TEXT_SECTION_OFFSET;
+ }
+
+ /* Get pe_header, optional header and numbers of sections. */
+ pe_header_offset = pe_get32 (abfd, 0x3c);
+ opthdr_ofs = pe_header_offset + 4 + 20;
+ nsections = pe_get16 (abfd, pe_header_offset + 4 + 2);
+ secptr = (pe_header_offset + 4 + 20 +
+ pe_get16 (abfd, pe_header_offset + 4 + 16));
+
+ /* Get the rva and size of the export section. */
+ for (i = 0; i < nsections; i++)
+ {
+ char sname[8];
+ unsigned long secptr1 = secptr + 40 * i;
+ unsigned long vaddr = pe_get32 (abfd, secptr1 + 12);
+
+ bfd_seek (abfd, (file_ptr) secptr1, SEEK_SET);
+ bfd_bread (sname, (bfd_size_type) 8, abfd);
+ if (strcmp (sname, ".text") == 0)
+ return vaddr;
+ }
+
+ return DEFAULT_COFF_PE_TEXT_SECTION_OFFSET;
+}
+
+static void
+show_debug_coff_pe_read (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c, const char *value)
+{
+ fprintf_filtered (file, _("Coff PE read debugging is %s.\n"), value);
+}
+
+void _initialize_coff_pe_read (void);
+
+void
+_initialize_coff_pe_read (void)
+{
+ add_setshow_uinteger_cmd ("coff_pe_read", class_maintenance,
+ &debug_coff_pe_read,
+ _("Set coff PE read debugging."),
+ _("Show coff PE read debugging."),
+ _("When set, debugging messages for coff reading "
+ "of exported symbols are displayed."),
+ NULL, show_debug_coff_pe_read,
+ &setdebuglist, &showdebuglist);
+}
Index: windows-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/windows-tdep.c,v
retrieving revision 1.16
diff -u -p -r1.16 windows-tdep.c
--- windows-tdep.c 5 Jun 2012 13:50:57 -0000 1.16
+++ windows-tdep.c 6 Nov 2012 13:37:01 -0000
@@ -27,6 +27,10 @@
#include "gdbcmd.h"
#include "gdbthread.h"
#include "objfiles.h"
+#include "symfile.h"
+#include "coff-pe-read.h"
+#include "gdb_bfd.h"
+#include "complaints.h"

struct cmd_list_element *info_w32_cmdlist;

@@ -387,15 +391,21 @@ windows_xfer_shared_library (const char*
struct gdbarch *gdbarch, struct obstack *obstack)
{
char *p;
+ struct bfd * dll;
+ CORE_ADDR text_offset;
+
obstack_grow_str (obstack, "<library name=\"");
p = xml_escape_text (so_name);
obstack_grow_str (obstack, p);
xfree (p);
obstack_grow_str (obstack, "\"><segment address=\"");
- /* The symbols in a dll are offset by 0x1000, which is the
- offset from 0 of the first byte in an image - because of the file
- header and the section alignment. */
- obstack_grow_str (obstack, paddress (gdbarch, load_addr + 0x1000));
+ dll = gdb_bfd_open_maybe_remote (so_name);
+ /* The following calls are OK even if dll is NULL.
+ The default value 0x1000 is returned by pe_text_section_offset
+ in that case. */
+ text_offset = pe_text_section_offset (dll);
+ gdb_bfd_unref (dll);
+ obstack_grow_str (obstack, paddress (gdbarch, load_addr + text_offset));
obstack_grow_str (obstack, "\"/></library>");
}