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-rw-r--r--gas/dwarf2dbg.c155
1 files changed, 107 insertions, 48 deletions
diff --git a/gas/dwarf2dbg.c b/gas/dwarf2dbg.c
index 8befbd0..615d644 100644
--- a/gas/dwarf2dbg.c
+++ b/gas/dwarf2dbg.c
@@ -1,5 +1,5 @@
/* dwarf2dbg.c - DWARF2 debug support
- Copyright 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
+ Copyright 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
Free Software Foundation, Inc.
Contributed by David Mosberger-Tang <davidm@hpl.hp.com>
@@ -198,13 +198,13 @@ static void out_two (int);
static void out_four (int);
static void out_abbrev (int, int);
static void out_uleb128 (addressT);
-static void out_sleb128 (addressT);
static offsetT get_frag_fix (fragS *, segT);
static void out_set_addr (symbolS *);
static int size_inc_line_addr (int, addressT);
static void emit_inc_line_addr (int, addressT, char *, int);
+static int size_fixed_inc_line_addr (int, addressT);
+static void emit_fixed_inc_line_addr (int, addressT, fragS *, char *, int);
static void out_inc_line_addr (int, addressT);
-static void out_fixed_inc_line_addr (int, symbolS *, symbolS *);
static void relax_inc_line_addr (int, symbolS *, symbolS *);
static void process_entries (segT, struct line_entry *);
static void out_file_list (void);
@@ -762,14 +762,6 @@ out_uleb128 (addressT value)
output_leb128 (frag_more (sizeof_leb128 (value, 0)), value, 0);
}
-/* Emit a signed "little-endian base 128" number. */
-
-static void
-out_sleb128 (addressT value)
-{
- output_leb128 (frag_more (sizeof_leb128 (value, 1)), value, 1);
-}
-
/* Emit a tuple for .debug_abbrev. */
static inline void
@@ -1005,41 +997,103 @@ out_inc_line_addr (int line_delta, addressT addr_delta)
/* Write out an alternative form of line and address skips using
DW_LNS_fixed_advance_pc opcodes. This uses more space than the default
- line and address information, but it helps support linker relaxation that
- changes the code offsets. */
+ line and address information, but it is required if linker relaxation
+ could change the code offsets. The following two routines *must* be
+ kept in sync. */
-static void
-out_fixed_inc_line_addr (int line_delta, symbolS *to_sym, symbolS *from_sym)
+static int
+size_fixed_inc_line_addr (int line_delta, addressT addr_delta)
{
- expressionS expr;
+ int len = 0;
/* INT_MAX is a signal that this is actually a DW_LNE_end_sequence. */
+ if (line_delta != INT_MAX)
+ len = 1 + sizeof_leb128 (line_delta, 1);
+
+ if (addr_delta > 50000)
+ {
+ /* DW_LNS_extended_op */
+ len += 1 + sizeof_leb128 (sizeof_address + 1, 0);
+ /* DW_LNE_set_address */
+ len += 1 + sizeof_address;
+ }
+ else
+ /* DW_LNS_fixed_advance_pc */
+ len += 3;
+
if (line_delta == INT_MAX)
+ /* DW_LNS_extended_op + DW_LNE_end_sequence */
+ len += 3;
+ else
+ /* DW_LNS_copy */
+ len += 1;
+
+ return len;
+}
+
+static void
+emit_fixed_inc_line_addr (int line_delta, addressT addr_delta, fragS *frag,
+ char *p, int len)
+{
+ expressionS *exp;
+ segT line_seg;
+ char *end = p + len;
+
+ /* Line number sequences cannot go backward in addresses. This means
+ we've incorrectly ordered the statements in the sequence. */
+ assert ((offsetT) addr_delta >= 0);
+
+ /* INT_MAX is a signal that this is actually a DW_LNE_end_sequence. */
+ if (line_delta != INT_MAX)
{
- out_opcode (DW_LNS_fixed_advance_pc);
- expr.X_op = O_subtract;
+ *p++ = DW_LNS_advance_line;
+ p += output_leb128 (p, line_delta, 1);
+ }
+
+ exp = symbol_get_value_expression (frag->fr_symbol);
+ line_seg = subseg_get (".debug_line", 0);
+
+ /* The DW_LNS_fixed_advance_pc opcode has a 2-byte operand so it can
+ advance the address by at most 64K. Linker relaxation (without
+ which this function would not be used) could change the operand by
+ an unknown amount. If the address increment is getting close to
+ the limit, just reset the address. */
+ if (addr_delta > 50000)
+ {
+ symbolS *to_sym;
+ expressionS expr;
+
+ assert (exp->X_op = O_subtract);
+ to_sym = exp->X_add_symbol;
+
+ *p++ = DW_LNS_extended_op;
+ p += output_leb128 (p, sizeof_address + 1, 0);
+ *p++ = DW_LNE_set_address;
+ expr.X_op = O_symbol;
expr.X_add_symbol = to_sym;
- expr.X_op_symbol = from_sym;
expr.X_add_number = 0;
- emit_expr (&expr, 2);
-
- out_opcode (DW_LNS_extended_op);
- out_byte (1);
- out_opcode (DW_LNE_end_sequence);
- return;
+ subseg_change (line_seg, 0);
+ emit_expr_fix (&expr, sizeof_address, frag, p);
+ p += sizeof_address;
+ }
+ else
+ {
+ *p++ = DW_LNS_fixed_advance_pc;
+ subseg_change (line_seg, 0);
+ emit_expr_fix (exp, 2, frag, p);
+ p += 2;
}
- out_opcode (DW_LNS_advance_line);
- out_sleb128 (line_delta);
-
- out_opcode (DW_LNS_fixed_advance_pc);
- expr.X_op = O_subtract;
- expr.X_add_symbol = to_sym;
- expr.X_op_symbol = from_sym;
- expr.X_add_number = 0;
- emit_expr (&expr, 2);
+ if (line_delta == INT_MAX)
+ {
+ *p++ = DW_LNS_extended_op;
+ *p++ = 1;
+ *p++ = DW_LNE_end_sequence;
+ }
+ else
+ *p++ = DW_LNS_copy;
- out_opcode (DW_LNS_copy);
+ assert (p == end);
}
/* Generate a variant frag that we can use to relax address/line
@@ -1058,7 +1112,11 @@ relax_inc_line_addr (int line_delta, symbolS *to_sym, symbolS *from_sym)
/* The maximum size of the frag is the line delta with a maximum
sized address delta. */
- max_chars = size_inc_line_addr (line_delta, -DWARF2_LINE_MIN_INSN_LENGTH);
+ if (DWARF2_USE_FIXED_ADVANCE_PC)
+ max_chars = size_fixed_inc_line_addr (line_delta,
+ -DWARF2_LINE_MIN_INSN_LENGTH);
+ else
+ max_chars = size_inc_line_addr (line_delta, -DWARF2_LINE_MIN_INSN_LENGTH);
frag_var (rs_dwarf2dbg, max_chars, max_chars, 1,
make_expr_symbol (&expr), line_delta, NULL);
@@ -1075,7 +1133,10 @@ dwarf2dbg_estimate_size_before_relax (fragS *frag)
int size;
addr_delta = resolve_symbol_value (frag->fr_symbol);
- size = size_inc_line_addr (frag->fr_offset, addr_delta);
+ if (DWARF2_USE_FIXED_ADVANCE_PC)
+ size = size_fixed_inc_line_addr (frag->fr_offset, addr_delta);
+ else
+ size = size_inc_line_addr (frag->fr_offset, addr_delta);
frag->fr_subtype = size;
@@ -1113,8 +1174,13 @@ dwarf2dbg_convert_frag (fragS *frag)
course, have allocated enough memory earlier. */
assert (frag->fr_var >= (int) frag->fr_subtype);
- emit_inc_line_addr (frag->fr_offset, addr_diff,
- frag->fr_literal + frag->fr_fix, frag->fr_subtype);
+ if (DWARF2_USE_FIXED_ADVANCE_PC)
+ emit_fixed_inc_line_addr (frag->fr_offset, addr_diff, frag,
+ frag->fr_literal + frag->fr_fix,
+ frag->fr_subtype);
+ else
+ emit_inc_line_addr (frag->fr_offset, addr_diff,
+ frag->fr_literal + frag->fr_fix, frag->fr_subtype);
frag->fr_fix += frag->fr_subtype;
frag->fr_type = rs_fill;
@@ -1192,9 +1258,7 @@ process_entries (segT seg, struct line_entry *e)
out_set_addr (lab);
out_inc_line_addr (line_delta, 0);
}
- else if (DWARF2_USE_FIXED_ADVANCE_PC)
- out_fixed_inc_line_addr (line_delta, lab, last_lab);
- else if (frag == last_frag)
+ else if (frag == last_frag && ! DWARF2_USE_FIXED_ADVANCE_PC)
out_inc_line_addr (line_delta, frag_ofs - last_frag_ofs);
else
relax_inc_line_addr (line_delta, lab, last_lab);
@@ -1213,12 +1277,7 @@ process_entries (segT seg, struct line_entry *e)
/* Emit a DW_LNE_end_sequence for the end of the section. */
frag = last_frag_for_seg (seg);
frag_ofs = get_frag_fix (frag, seg);
- if (DWARF2_USE_FIXED_ADVANCE_PC)
- {
- lab = symbol_temp_new (seg, frag_ofs, frag);
- out_fixed_inc_line_addr (INT_MAX, lab, last_lab);
- }
- else if (frag == last_frag)
+ if (frag == last_frag && ! DWARF2_USE_FIXED_ADVANCE_PC)
out_inc_line_addr (INT_MAX, frag_ofs - last_frag_ofs);
else
{