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-rw-r--r--gdb/dwarf2read.c197
1 files changed, 174 insertions, 23 deletions
diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
index e000e2b..4b08e43 100644
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -50,6 +50,9 @@
#include "gdb_string.h"
#include "gdb_assert.h"
#include <sys/types.h>
+#ifdef HAVE_ZLIB_H
+#include <zlib.h>
+#endif
/* A note on memory usage for this file.
@@ -195,17 +198,20 @@ asection *dwarf_eh_frame_section;
/* names of the debugging sections */
-#define INFO_SECTION ".debug_info"
-#define ABBREV_SECTION ".debug_abbrev"
-#define LINE_SECTION ".debug_line"
-#define PUBNAMES_SECTION ".debug_pubnames"
-#define ARANGES_SECTION ".debug_aranges"
-#define LOC_SECTION ".debug_loc"
-#define MACINFO_SECTION ".debug_macinfo"
-#define STR_SECTION ".debug_str"
-#define RANGES_SECTION ".debug_ranges"
-#define FRAME_SECTION ".debug_frame"
-#define EH_FRAME_SECTION ".eh_frame"
+/* Note that if the debugging section has been compressed, it might
+ have a name like .zdebug_info. */
+
+#define INFO_SECTION "debug_info"
+#define ABBREV_SECTION "debug_abbrev"
+#define LINE_SECTION "debug_line"
+#define PUBNAMES_SECTION "debug_pubnames"
+#define ARANGES_SECTION "debug_aranges"
+#define LOC_SECTION "debug_loc"
+#define MACINFO_SECTION "debug_macinfo"
+#define STR_SECTION "debug_str"
+#define RANGES_SECTION "debug_ranges"
+#define FRAME_SECTION "debug_frame"
+#define EH_FRAME_SECTION "eh_frame"
/* local data types */
@@ -1109,6 +1115,18 @@ dwarf2_has_info (struct objfile *objfile)
return (dwarf_info_section != NULL && dwarf_abbrev_section != NULL);
}
+/* When loading sections, we can either look for ".<name>", or for
+ * ".z<name>", which indicates a compressed section. */
+
+static int
+section_is_p (asection *sectp, const char *name)
+{
+ return ((sectp->name[0] == '.'
+ && strcmp (sectp->name + 1, name) == 0)
+ || (sectp->name[0] == '.' && sectp->name[1] == 'z'
+ && strcmp (sectp->name + 2, name) == 0));
+}
+
/* This function is mapped across the sections and remembers the
offset and size of each of the debugging sections we are interested
in. */
@@ -1116,52 +1134,52 @@ dwarf2_has_info (struct objfile *objfile)
static void
dwarf2_locate_sections (bfd *abfd, asection *sectp, void *ignore_ptr)
{
- if (strcmp (sectp->name, INFO_SECTION) == 0)
+ if (section_is_p (sectp, INFO_SECTION))
{
dwarf2_per_objfile->info_size = bfd_get_section_size (sectp);
dwarf_info_section = sectp;
}
- else if (strcmp (sectp->name, ABBREV_SECTION) == 0)
+ else if (section_is_p (sectp, ABBREV_SECTION))
{
dwarf2_per_objfile->abbrev_size = bfd_get_section_size (sectp);
dwarf_abbrev_section = sectp;
}
- else if (strcmp (sectp->name, LINE_SECTION) == 0)
+ else if (section_is_p (sectp, LINE_SECTION))
{
dwarf2_per_objfile->line_size = bfd_get_section_size (sectp);
dwarf_line_section = sectp;
}
- else if (strcmp (sectp->name, PUBNAMES_SECTION) == 0)
+ else if (section_is_p (sectp, PUBNAMES_SECTION))
{
dwarf2_per_objfile->pubnames_size = bfd_get_section_size (sectp);
dwarf_pubnames_section = sectp;
}
- else if (strcmp (sectp->name, ARANGES_SECTION) == 0)
+ else if (section_is_p (sectp, ARANGES_SECTION))
{
dwarf2_per_objfile->aranges_size = bfd_get_section_size (sectp);
dwarf_aranges_section = sectp;
}
- else if (strcmp (sectp->name, LOC_SECTION) == 0)
+ else if (section_is_p (sectp, LOC_SECTION))
{
dwarf2_per_objfile->loc_size = bfd_get_section_size (sectp);
dwarf_loc_section = sectp;
}
- else if (strcmp (sectp->name, MACINFO_SECTION) == 0)
+ else if (section_is_p (sectp, MACINFO_SECTION))
{
dwarf2_per_objfile->macinfo_size = bfd_get_section_size (sectp);
dwarf_macinfo_section = sectp;
}
- else if (strcmp (sectp->name, STR_SECTION) == 0)
+ else if (section_is_p (sectp, STR_SECTION))
{
dwarf2_per_objfile->str_size = bfd_get_section_size (sectp);
dwarf_str_section = sectp;
}
- else if (strcmp (sectp->name, FRAME_SECTION) == 0)
+ else if (section_is_p (sectp, FRAME_SECTION))
{
dwarf2_per_objfile->frame_size = bfd_get_section_size (sectp);
dwarf_frame_section = sectp;
}
- else if (strcmp (sectp->name, EH_FRAME_SECTION) == 0)
+ else if (section_is_p (sectp, EH_FRAME_SECTION))
{
flagword aflag = bfd_get_section_flags (ignore_abfd, sectp);
if (aflag & SEC_HAS_CONTENTS)
@@ -1170,7 +1188,7 @@ dwarf2_locate_sections (bfd *abfd, asection *sectp, void *ignore_ptr)
dwarf_eh_frame_section = sectp;
}
}
- else if (strcmp (sectp->name, RANGES_SECTION) == 0)
+ else if (section_is_p (sectp, RANGES_SECTION))
{
dwarf2_per_objfile->ranges_size = bfd_get_section_size (sectp);
dwarf_ranges_section = sectp;
@@ -1181,6 +1199,40 @@ dwarf2_locate_sections (bfd *abfd, asection *sectp, void *ignore_ptr)
dwarf2_per_objfile->has_section_at_zero = 1;
}
+/* This function is called after decompressing a section, so
+ dwarf2_per_objfile can record its new, uncompressed size. */
+
+static void
+dwarf2_resize_section (asection *sectp, bfd_size_type new_size)
+{
+ if (section_is_p (sectp, INFO_SECTION))
+ dwarf2_per_objfile->info_size = new_size;
+ else if (section_is_p (sectp, ABBREV_SECTION))
+ dwarf2_per_objfile->abbrev_size = new_size;
+ else if (section_is_p (sectp, LINE_SECTION))
+ dwarf2_per_objfile->line_size = new_size;
+ else if (section_is_p (sectp, PUBNAMES_SECTION))
+ dwarf2_per_objfile->pubnames_size = new_size;
+ else if (section_is_p (sectp, ARANGES_SECTION))
+ dwarf2_per_objfile->aranges_size = new_size;
+ else if (section_is_p (sectp, LOC_SECTION))
+ dwarf2_per_objfile->loc_size = new_size;
+ else if (section_is_p (sectp, MACINFO_SECTION))
+ dwarf2_per_objfile->macinfo_size = new_size;
+ else if (section_is_p (sectp, STR_SECTION))
+ dwarf2_per_objfile->str_size = new_size;
+ else if (section_is_p (sectp, FRAME_SECTION))
+ dwarf2_per_objfile->frame_size = new_size;
+ else if (section_is_p (sectp, EH_FRAME_SECTION))
+ dwarf2_per_objfile->eh_frame_size = new_size;
+ else if (section_is_p (sectp, RANGES_SECTION))
+ dwarf2_per_objfile->ranges_size = new_size;
+ else
+ internal_error (__FILE__, __LINE__,
+ _("dwarf2_resize_section: missing section_is_p check: %s"),
+ sectp->name);
+}
+
/* Build a partial symbol table. */
void
@@ -5236,8 +5288,87 @@ free_die_list (struct die_info *dies)
}
}
+/* Decompress a section that was compressed using zlib. Store the
+ decompressed buffer, and its size, in OUTBUF and OUTSIZE. */
+
+static void
+zlib_decompress_section (struct objfile *objfile, asection *sectp,
+ gdb_byte **outbuf, bfd_size_type *outsize)
+{
+#ifndef HAVE_ZLIB_H
+ error (_("Support for zlib-compressed DWARF data (from '%s') "
+ "is disabled in this copy of GDB"),
+ bfd_get_filename (abfd));
+#else
+ bfd *abfd = objfile->obfd;
+ bfd_size_type compressed_size = bfd_get_section_size (sectp);
+ gdb_byte *compressed_buffer = xmalloc (compressed_size);
+ bfd_size_type uncompressed_size;
+ gdb_byte *uncompressed_buffer;
+ z_stream strm;
+ int rc;
+ int header_size = 12;
+
+ if (bfd_seek (abfd, sectp->filepos, SEEK_SET) != 0
+ || bfd_bread (compressed_buffer, compressed_size, abfd) != compressed_size)
+ error (_("Dwarf Error: Can't read DWARF data from '%s'"),
+ bfd_get_filename (abfd));
+
+ /* Read the zlib header. In this case, it should be "ZLIB" followed
+ by the uncompressed section size, 8 bytes in big-endian order. */
+ if (compressed_size < header_size
+ || strncmp (compressed_buffer, "ZLIB", 4) != 0)
+ error (_("Dwarf Error: Corrupt DWARF ZLIB header from '%s'"),
+ bfd_get_filename (abfd));
+ uncompressed_size = compressed_buffer[4]; uncompressed_size <<= 8;
+ uncompressed_size += compressed_buffer[5]; uncompressed_size <<= 8;
+ uncompressed_size += compressed_buffer[6]; uncompressed_size <<= 8;
+ uncompressed_size += compressed_buffer[7]; uncompressed_size <<= 8;
+ uncompressed_size += compressed_buffer[8]; uncompressed_size <<= 8;
+ uncompressed_size += compressed_buffer[9]; uncompressed_size <<= 8;
+ uncompressed_size += compressed_buffer[10]; uncompressed_size <<= 8;
+ uncompressed_size += compressed_buffer[11];
+
+ /* It is possible the section consists of several compressed
+ buffers concatenated together, so we uncompress in a loop. */
+ strm.zalloc = NULL;
+ strm.zfree = NULL;
+ strm.opaque = NULL;
+ strm.avail_in = compressed_size - header_size;
+ strm.next_in = (Bytef*) compressed_buffer + header_size;
+ strm.avail_out = uncompressed_size;
+ uncompressed_buffer = obstack_alloc (&objfile->objfile_obstack,
+ uncompressed_size);
+ rc = inflateInit (&strm);
+ while (strm.avail_in > 0)
+ {
+ if (rc != Z_OK)
+ error (_("Dwarf Error: setting up DWARF uncompression in '%s': %d"),
+ bfd_get_filename (abfd), rc);
+ strm.next_out = ((Bytef*) uncompressed_buffer
+ + (uncompressed_size - strm.avail_out));
+ rc = inflate (&strm, Z_FINISH);
+ if (rc != Z_STREAM_END)
+ error (_("Dwarf Error: zlib error uncompressing from '%s': %d"),
+ bfd_get_filename (abfd), rc);
+ rc = inflateReset (&strm);
+ }
+ rc = inflateEnd (&strm);
+ if (rc != Z_OK
+ || strm.avail_out != 0)
+ error (_("Dwarf Error: concluding DWARF uncompression in '%s': %d"),
+ bfd_get_filename (abfd), rc);
+
+ xfree (compressed_buffer);
+ *outbuf = uncompressed_buffer;
+ *outsize = uncompressed_size;
+#endif
+}
+
+
/* Read the contents of the section at OFFSET and of size SIZE from the
- object file specified by OBJFILE into the objfile_obstack and return it. */
+ object file specified by OBJFILE into the objfile_obstack and return it.
+ If the section is compressed, uncompress it before returning. */
gdb_byte *
dwarf2_read_section (struct objfile *objfile, asection *sectp)
@@ -5245,11 +5376,31 @@ dwarf2_read_section (struct objfile *objfile, asection *sectp)
bfd *abfd = objfile->obfd;
gdb_byte *buf, *retbuf;
bfd_size_type size = bfd_get_section_size (sectp);
+ unsigned char header[4];
if (size == 0)
return NULL;
+ /* Check if the file has a 4-byte header indicating compression. */
+ if (size > sizeof (header)
+ && bfd_seek (abfd, sectp->filepos, SEEK_SET) == 0
+ && bfd_bread (header, sizeof (header), abfd) == sizeof (header))
+ {
+ /* Upon decompression, update the buffer and its size. */
+ if (strncmp (header, "ZLIB", sizeof (header)) == 0)
+ {
+ zlib_decompress_section (objfile, sectp, &buf, &size);
+ dwarf2_resize_section (sectp, size);
+ return buf;
+ }
+ }
+
+ /* If we get here, we are a normal, not-compressed section. */
buf = obstack_alloc (&objfile->objfile_obstack, size);
+ /* When debugging .o files, we may need to apply relocations; see
+ http://sourceware.org/ml/gdb-patches/2002-04/msg00136.html .
+ We never compress sections in .o files, so we only need to
+ try this when the section is not compressed. */
retbuf = symfile_relocate_debug_section (abfd, sectp, buf);
if (retbuf != NULL)
return retbuf;
generated by cgit v1.1 at 2025-01-22 10:45:43 +0000