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authorRichard Henderson <rth@redhat.com>1999-06-03 02:46:47 +0000
committerRichard Henderson <rth@redhat.com>1999-06-03 02:46:47 +0000
commit159002ff699be24840044a6f9d457266e88a9e7c (patch)
treed4fa3319a5c9dce521ccf673a078fe232f605c60 /bfd
parent49309057b4c45a2586735182830793c77633f51d (diff)
downloadgdb-159002ff699be24840044a6f9d457266e88a9e7c.zip
gdb-159002ff699be24840044a6f9d457266e88a9e7c.tar.gz
gdb-159002ff699be24840044a6f9d457266e88a9e7c.tar.bz2
David Mosberger <davidm@hpl.hp.com>
* dwarf2.c (struct line_info): Add member END_SEQUENCE to keep track of end_sequence markers. (add_line_info): Add END_SEQUENCE arg. (decode_line_info): Don't try to infer lo_pc and hi_pc from the debug-line info---it doesn't work right if a compilation unit consists of multiple discontiguous code-sequences. It would be worthwhile to optimize for the common case where a compilation unit results in a contiguous set of code sequences, but this is quite tricky to get right for arbitrary DWARF2 files. (lookup_address_in_line_info_table): Don't use the last line entry for a compilation unit for anything with an address higher than this line entry. Also, check for end_sequence markers to correctly handle discontinuities. (_bfd_dwarf2_find_nearest_line): When checking previously loaded compilation units, check all compilation units with each->high==0 just like when reading compilation units. * dwarf2.c (decode_line_info): Initialize table->files and table->last_line to NULL to avoid segfaults due to random values in these members. (concat_filename): Check for out-of-range file number before indexing filename table. Segfaults suck. * dwarf2.c (decode_line_info): Don't truncate address to least significant 32 bits (breaks 64 bit targets). (lookup_address_in_function_table): Ditto. (comp_unit_contains_address): Ditto.
Diffstat (limited to 'bfd')
-rw-r--r--bfd/ChangeLog30
-rw-r--r--bfd/dwarf2.c140
2 files changed, 140 insertions, 30 deletions
diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 1b33f40..3f1bae4 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,33 @@
+1999-06-03 David Mosberger <davidm@hpl.hp.com>
+
+ * dwarf2.c (struct line_info): Add member END_SEQUENCE to keep
+ track of end_sequence markers.
+ (add_line_info): Add END_SEQUENCE arg.
+ (decode_line_info): Don't try to infer lo_pc and hi_pc from the
+ debug-line info---it doesn't work right if a compilation unit
+ consists of multiple discontiguous code-sequences. It would be
+ worthwhile to optimize for the common case where a compilation
+ unit results in a contiguous set of code sequences, but this is
+ quite tricky to get right for arbitrary DWARF2 files.
+ (lookup_address_in_line_info_table): Don't use the last line entry
+ for a compilation unit for anything with an address higher than
+ this line entry. Also, check for end_sequence markers to
+ correctly handle discontinuities.
+ (_bfd_dwarf2_find_nearest_line): When checking previously loaded
+ compilation units, check all compilation units with each->high==0
+ just like when reading compilation units.
+
+ * dwarf2.c (decode_line_info): Initialize table->files and
+ table->last_line to NULL to avoid segfaults due to random
+ values in these members.
+ (concat_filename): Check for out-of-range file number before
+ indexing filename table. Segfaults suck.
+
+ * dwarf2.c (decode_line_info): Don't truncate address to least
+ significant 32 bits (breaks 64 bit targets).
+ (lookup_address_in_function_table): Ditto.
+ (comp_unit_contains_address): Ditto.
+
1999-06-02 Mark Mitchell <Mark Mitchell <mark@codesourcery.com>>
* elf32-mips.c (elf_mips_howto_table): Add R_MIPS_JALR.
diff --git a/bfd/dwarf2.c b/bfd/dwarf2.c
index 1ea7cff..3af1645 100644
--- a/bfd/dwarf2.c
+++ b/bfd/dwarf2.c
@@ -631,6 +631,7 @@ struct line_info {
char* filename;
unsigned int line;
unsigned int column;
+ int end_sequence; /* end of (sequential) code sequence */
};
struct fileinfo {
@@ -653,12 +654,13 @@ struct line_info_table {
};
static void
-add_line_info (table, address, filename, line, column)
+add_line_info (table, address, filename, line, column, end_sequence)
struct line_info_table* table;
bfd_vma address;
char* filename;
unsigned int line;
unsigned int column;
+ int end_sequence;
{
struct line_info* info = (struct line_info*)
bfd_alloc (table->abfd, sizeof (struct line_info));
@@ -670,6 +672,7 @@ add_line_info (table, address, filename, line, column)
info->filename = filename;
info->line = line;
info->column = column;
+ info->end_sequence = end_sequence;
}
static char*
@@ -677,7 +680,16 @@ concat_filename (table, file)
struct line_info_table* table;
unsigned int file;
{
- char* filename = table->files[file - 1].name;
+ char* filename;
+
+ if (file - 1 >= table->num_files)
+ {
+ (*_bfd_error_handler) (_("Dwarf Error: mangled line number "
+ "section (bad file number)."));
+ return "<unknown>";
+ }
+
+ filename = table->files[file - 1].name;
if (*filename == '/')
return filename;
@@ -708,6 +720,12 @@ decode_line_info (unit)
unsigned int i, bytes_read;
char *cur_file, *cur_dir;
unsigned char op_code, extended_op, adj_opcode;
+#if 0
+ /* This optimization unfortunately does not work well on programs
+ that have multiple sections containing text (such as Linux which
+ uses .text, and .text.init, for example. */
+ bfd_vma hi_pc = 0, lo_pc = ~ (bfd_vma) 0;
+#endif
if (! dwarf_line_buffer)
{
@@ -747,6 +765,9 @@ decode_line_info (unit)
table->num_dirs = 0;
table->dirs = NULL;
+ table->files = NULL;
+ table->last_line = NULL;
+
line_ptr = dwarf_line_buffer + unit->line_offset;
/* read in the prologue */
@@ -831,6 +852,7 @@ decode_line_info (unit)
int is_stmt = lh.default_is_stmt;
int basic_block = 0;
int end_sequence = 0;
+ boolean first_time = true;
/* Decode the table. */
while (! end_sequence)
@@ -847,7 +869,7 @@ decode_line_info (unit)
{
case DW_LNE_end_sequence:
end_sequence = 1;
- add_line_info (table, address, filename, line, column);
+ add_line_info (table, address, filename, line, column, end_sequence);
break;
case DW_LNE_set_address:
address = read_address (unit, line_ptr);
@@ -884,7 +906,7 @@ decode_line_info (unit)
}
break;
case DW_LNS_copy:
- add_line_info (table, address, filename, line, column);
+ add_line_info (table, address, filename, line, column, 0);
basic_block = 0;
break;
case DW_LNS_advance_pc:
@@ -918,7 +940,8 @@ decode_line_info (unit)
basic_block = 1;
break;
case DW_LNS_const_add_pc:
- address += (255 - lh.opcode_base) / lh.line_range;
+ address += lh.minimum_instruction_length
+ * ((255 - lh.opcode_base) / lh.line_range);
break;
case DW_LNS_fixed_advance_pc:
address += read_2_bytes (abfd, line_ptr);
@@ -930,11 +953,27 @@ decode_line_info (unit)
* lh.minimum_instruction_length;
line += lh.line_base + (adj_opcode % lh.line_range);
/* append row to matrix using current values */
- add_line_info (table, address, filename, line, column);
+ add_line_info (table, address, filename, line, column, 0);
basic_block = 1;
}
+#if 0
+ if (unit->high == 0)
+ {
+ if (address > hi_pc)
+ hi_pc = address;
+ if (address < lo_pc)
+ lo_pc = address;
+ }
+#endif
}
}
+#if 0
+ if (unit->high == 0 && hi_pc != 0)
+ {
+ unit->high = hi_pc;
+ unit->low = lo_pc;
+ }
+#endif
return table;
}
@@ -954,21 +993,25 @@ lookup_address_in_line_info_table (table,
const char **filename_ptr;
unsigned int *linenumber_ptr;
{
+ struct line_info* next_line = table->last_line;
struct line_info* each_line;
- struct line_info* next_line;
- for (next_line = 0, each_line = table->last_line;
- each_line;
- next_line = each_line, each_line = each_line->prev_line)
+ if (!next_line)
+ return false;
+
+ each_line = next_line->prev_line;
+
+ while (each_line && next_line)
{
- if (addr >= each_line->address
- && (next_line == 0
- || addr < next_line->address))
+ if (!each_line->end_sequence
+ && addr >= each_line->address && addr < next_line->address)
{
*filename_ptr = each_line->filename;
*linenumber_ptr = each_line->line;
return true;
}
+ next_line = each_line;
+ each_line = each_line->prev_line;
}
return false;
@@ -1363,6 +1406,8 @@ _bfd_dwarf2_find_nearest_line (abfd, section, symbols, offset,
struct comp_unit* each;
+ boolean found;
+
*filename_ptr = NULL;
*functionname_ptr = NULL;
*linenumber_ptr = 0;
@@ -1404,14 +1449,20 @@ _bfd_dwarf2_find_nearest_line (abfd, section, symbols, offset,
stash->info_ptr_end = stash->info_ptr + size;
- /* FIXME: There is a problem with the contents of the .debug_info section.
- The 'low' and 'high' addresses of the comp_units are computed by relocs
- against symbols in the .text segment. We need these addresses in
- order to determine the nearest line number, and so we have to resolve
- the relocs. There is a similar problem when the .debug_line section is
- processed as well.
+ /* FIXME: There is a problem with the contents of the
+ .debug_info section. The 'low' and 'high' addresses of the
+ comp_units are computed by relocs against symbols in the
+ .text segment. We need these addresses in order to determine
+ the nearest line number, and so we have to resolve the
+ relocs. There is a similar problem when the .debug_line
+ section is processed as well (e.g., there may be relocs
+ against the operand of the DW_LNE_set_address operator).
- Unfortunately getting hold of the reloc information is hard... */
+ Unfortunately getting hold of the reloc information is hard...
+
+ For now, this means that disassembling object files (as
+ opposed to fully executables) does not always work as well as
+ we would like. */
}
/* A null info_ptr indicates that there is no dwarf2 info
@@ -1424,11 +1475,23 @@ _bfd_dwarf2_find_nearest_line (abfd, section, symbols, offset,
for (each = stash->all_comp_units; each; each = each->next_unit)
{
- if (comp_unit_contains_address (each, addr))
- return comp_unit_find_nearest_line (each, addr,
- filename_ptr,
- functionname_ptr,
- linenumber_ptr);
+ if (each->high > 0)
+ {
+ if (comp_unit_contains_address (each, addr))
+ return comp_unit_find_nearest_line (each, addr,
+ filename_ptr,
+ functionname_ptr,
+ linenumber_ptr);
+ }
+ else
+ {
+ found = comp_unit_find_nearest_line (each, addr,
+ filename_ptr,
+ functionname_ptr,
+ linenumber_ptr);
+ if (found)
+ return true;
+ }
}
/* Read each remaining comp. units checking each as they are read. */
@@ -1451,11 +1514,28 @@ _bfd_dwarf2_find_nearest_line (abfd, section, symbols, offset,
each->next_unit = stash->all_comp_units;
stash->all_comp_units = each;
- if (comp_unit_contains_address (each, addr))
- return comp_unit_find_nearest_line (each, addr,
- filename_ptr,
- functionname_ptr,
- linenumber_ptr);
+ /* DW_AT_low_pc and DW_AT_high_pc are optional for
+ compilation units. If we don't have them (i.e.,
+ unit->high == 0), we need to consult the line info
+ table to see if a compilation unit contains the given
+ address. */
+ if (each->high > 0)
+ {
+ if (comp_unit_contains_address (each, addr))
+ return comp_unit_find_nearest_line (each, addr,
+ filename_ptr,
+ functionname_ptr,
+ linenumber_ptr);
+ }
+ else
+ {
+ found = comp_unit_find_nearest_line (each, addr,
+ filename_ptr,
+ functionname_ptr,
+ linenumber_ptr);
+ if (found)
+ return true;
+ }
}
}
}