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authorTom Tromey <tromey@redhat.com>2010-06-02 19:37:56 +0000
committerTom Tromey <tromey@redhat.com>2010-06-02 19:37:56 +0000
commit9eae7c5264c14e142dd52988f70d58f62755b2d0 (patch)
tree526ab8c146436f412c8cb66a4e5b0457714ad482 /gdb/dwarf2loc.c
parent359cc68c808f70750a020c9bb76de330735a3202 (diff)
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* dwarf2loc.h (dwarf2_per_cu_data): Declare. * dwarf2read.c (dwarf_stack_op_name): No longer static. Return type is const. Add 'def' argument. Add missing operators, remove unhandled ones. (decode_locdesc): Update. (dwarf2_always_disassemble): New global. (show_dwarf2_always_disassemble): New function. (_initialize_dwarf2_read): Add always-disassemble. (dwarf2_per_cu_offset_size): New function. * dwarf2loc.c (dwarf2_always_disassemble): Declare. (piece_end_p): New function. (locexpr_describe_location_piece): Replace 'size' argument with 'end'. Use piece_end_p. Rewrite recognition of TLS. Recognize some constants. Remove errors. (disassemble_dwarf_expression): New function. (locexpr_describe_location_1): Use disassemble_dwarf_expression. Add 'offset_size' argument. (loclist_describe_location): Change output formatting. * dwarf2expr.h (dwarf_stack_op_name): Declare. gdb/doc * gdb.texinfo (Maintenance Commands): Document maint set dwarf2 always-disassemble.
Diffstat (limited to 'gdb/dwarf2loc.c')
-rw-r--r--gdb/dwarf2loc.c424
1 files changed, 370 insertions, 54 deletions
diff --git a/gdb/dwarf2loc.c b/gdb/dwarf2loc.c
index 79d2277..30464ff 100644
--- a/gdb/dwarf2loc.c
+++ b/gdb/dwarf2loc.c
@@ -42,6 +42,8 @@
#include "gdb_string.h"
#include "gdb_assert.h"
+extern int dwarf2_always_disassemble;
+
static void
dwarf_expr_frame_base_1 (struct symbol *framefunc, CORE_ADDR pc,
const gdb_byte **start, size_t *length);
@@ -1291,13 +1293,24 @@ locexpr_read_needs_frame (struct symbol *symbol)
dlbaton->per_cu);
}
-/* Describe a single piece of a location, returning an updated
- position in the bytecode sequence. */
+/* Return true if DATA points to the end of a piece. END is one past
+ the last byte in the expression. */
+
+static int
+piece_end_p (const gdb_byte *data, const gdb_byte *end)
+{
+ return data == end || data[0] == DW_OP_piece || data[0] == DW_OP_bit_piece;
+}
+
+/* Nicely describe a single piece of a location, returning an updated
+ position in the bytecode sequence. This function cannot recognize
+ all locations; if a location is not recognized, it simply returns
+ DATA. */
static const gdb_byte *
locexpr_describe_location_piece (struct symbol *symbol, struct ui_file *stream,
CORE_ADDR addr, struct objfile *objfile,
- const gdb_byte *data, int size,
+ const gdb_byte *data, const gdb_byte *end,
unsigned int addr_size)
{
struct gdbarch *gdbarch = get_objfile_arch (objfile);
@@ -1314,7 +1327,7 @@ locexpr_describe_location_piece (struct symbol *symbol, struct ui_file *stream,
{
ULONGEST reg;
- data = read_uleb128 (data + 1, data + size, &reg);
+ data = read_uleb128 (data + 1, end, &reg);
regno = gdbarch_dwarf2_reg_to_regnum (gdbarch, reg);
fprintf_filtered (stream, _("a variable in $%s"),
gdbarch_register_name (gdbarch, regno));
@@ -1325,10 +1338,15 @@ locexpr_describe_location_piece (struct symbol *symbol, struct ui_file *stream,
struct symbol *framefunc;
int frame_reg = 0;
LONGEST frame_offset;
- const gdb_byte *base_data;
+ const gdb_byte *base_data, *new_data;
size_t base_size;
LONGEST base_offset = 0;
+ new_data = read_sleb128 (data + 1, end, &frame_offset);
+ if (!piece_end_p (new_data, end))
+ return data;
+ data = new_data;
+
b = block_for_pc (addr);
if (!b)
@@ -1372,19 +1390,18 @@ locexpr_describe_location_piece (struct symbol *symbol, struct ui_file *stream,
regno = gdbarch_dwarf2_reg_to_regnum (gdbarch, frame_reg);
- data = read_sleb128 (data + 1, data + size, &frame_offset);
-
fprintf_filtered (stream, _("a variable at frame base reg $%s offset %s+%s"),
gdbarch_register_name (gdbarch, regno),
plongest (base_offset), plongest (frame_offset));
}
- else if (data[0] >= DW_OP_breg0 && data[0] <= DW_OP_breg31)
+ else if (data[0] >= DW_OP_breg0 && data[0] <= DW_OP_breg31
+ && piece_end_p (data, end))
{
LONGEST offset;
regno = gdbarch_dwarf2_reg_to_regnum (gdbarch, data[0] - DW_OP_breg0);
- data = read_sleb128 (data + 1, data + size, &offset);
+ data = read_sleb128 (data + 1, end, &offset);
fprintf_filtered (stream,
_("a variable at offset %s from base reg $%s"),
@@ -1404,13 +1421,14 @@ locexpr_describe_location_piece (struct symbol *symbol, struct ui_file *stream,
The operand represents the offset at which the variable is within
the thread local storage. */
- else if (size > 1
- && data[size - 1] == DW_OP_GNU_push_tls_address
- && data[0] == DW_OP_addr)
+ else if (data + 1 + addr_size < end
+ && data[0] == DW_OP_addr
+ && data[1 + addr_size] == DW_OP_GNU_push_tls_address
+ && piece_end_p (data + 2 + addr_size, end))
{
CORE_ADDR offset = dwarf2_read_address (gdbarch,
data + 1,
- data + size - 1,
+ end,
addr_size);
fprintf_filtered (stream,
@@ -1420,9 +1438,275 @@ locexpr_describe_location_piece (struct symbol *symbol, struct ui_file *stream,
data += 1 + addr_size + 1;
}
- else
- fprintf_filtered (stream,
- _("a variable with complex or multiple locations (DWARF2)"));
+ else if (data[0] >= DW_OP_lit0
+ && data[0] <= DW_OP_lit31
+ && data + 1 < end
+ && data[1] == DW_OP_stack_value)
+ {
+ fprintf_filtered (stream, _("the constant %d"), data[0] - DW_OP_lit0);
+ data += 2;
+ }
+
+ return data;
+}
+
+/* Disassemble an expression, stopping at the end of a piece or at the
+ end of the expression. Returns a pointer to the next unread byte
+ in the input expression. If ALL is nonzero, then this function
+ will keep going until it reaches the end of the expression. */
+
+static const gdb_byte *
+disassemble_dwarf_expression (struct ui_file *stream,
+ struct gdbarch *arch, unsigned int addr_size,
+ int offset_size,
+ const gdb_byte *data, const gdb_byte *end,
+ int all)
+{
+ const gdb_byte *start = data;
+
+ fprintf_filtered (stream, _("a complex DWARF expression:\n"));
+
+ while (data < end
+ && (all
+ || (data[0] != DW_OP_piece && data[0] != DW_OP_bit_piece)))
+ {
+ enum dwarf_location_atom op = *data++;
+ CORE_ADDR addr;
+ ULONGEST ul;
+ LONGEST l;
+ const char *name;
+
+ name = dwarf_stack_op_name (op, 0);
+
+ if (!name)
+ error (_("Unrecognized DWARF opcode 0x%02x at %ld"),
+ op, (long) (data - start));
+ fprintf_filtered (stream, " % 4ld: %s", (long) (data - start), name);
+
+ switch (op)
+ {
+ case DW_OP_addr:
+ addr = dwarf2_read_address (arch, data, end, addr_size);
+ data += addr_size;
+ fprintf_filtered (stream, " %s", paddress (arch, addr));
+ break;
+
+ case DW_OP_const1u:
+ ul = extract_unsigned_integer (data, 1, gdbarch_byte_order (arch));
+ data += 1;
+ fprintf_filtered (stream, " %s", pulongest (ul));
+ break;
+ case DW_OP_const1s:
+ l = extract_signed_integer (data, 1, gdbarch_byte_order (arch));
+ data += 1;
+ fprintf_filtered (stream, " %s", plongest (l));
+ break;
+ case DW_OP_const2u:
+ ul = extract_unsigned_integer (data, 2, gdbarch_byte_order (arch));
+ data += 2;
+ fprintf_filtered (stream, " %s", pulongest (ul));
+ break;
+ case DW_OP_const2s:
+ l = extract_signed_integer (data, 2, gdbarch_byte_order (arch));
+ data += 2;
+ fprintf_filtered (stream, " %s", plongest (l));
+ break;
+ case DW_OP_const4u:
+ ul = extract_unsigned_integer (data, 4, gdbarch_byte_order (arch));
+ data += 4;
+ fprintf_filtered (stream, " %s", pulongest (ul));
+ break;
+ case DW_OP_const4s:
+ l = extract_signed_integer (data, 4, gdbarch_byte_order (arch));
+ data += 4;
+ fprintf_filtered (stream, " %s", plongest (l));
+ break;
+ case DW_OP_const8u:
+ ul = extract_unsigned_integer (data, 8, gdbarch_byte_order (arch));
+ data += 8;
+ fprintf_filtered (stream, " %s", pulongest (ul));
+ break;
+ case DW_OP_const8s:
+ l = extract_signed_integer (data, 8, gdbarch_byte_order (arch));
+ data += 8;
+ fprintf_filtered (stream, " %s", plongest (l));
+ break;
+ case DW_OP_constu:
+ data = read_uleb128 (data, end, &ul);
+ fprintf_filtered (stream, " %s", pulongest (ul));
+ break;
+ case DW_OP_consts:
+ data = read_sleb128 (data, end, &ul);
+ fprintf_filtered (stream, " %s", plongest (l));
+ break;
+
+ case DW_OP_reg0:
+ case DW_OP_reg1:
+ case DW_OP_reg2:
+ case DW_OP_reg3:
+ case DW_OP_reg4:
+ case DW_OP_reg5:
+ case DW_OP_reg6:
+ case DW_OP_reg7:
+ case DW_OP_reg8:
+ case DW_OP_reg9:
+ case DW_OP_reg10:
+ case DW_OP_reg11:
+ case DW_OP_reg12:
+ case DW_OP_reg13:
+ case DW_OP_reg14:
+ case DW_OP_reg15:
+ case DW_OP_reg16:
+ case DW_OP_reg17:
+ case DW_OP_reg18:
+ case DW_OP_reg19:
+ case DW_OP_reg20:
+ case DW_OP_reg21:
+ case DW_OP_reg22:
+ case DW_OP_reg23:
+ case DW_OP_reg24:
+ case DW_OP_reg25:
+ case DW_OP_reg26:
+ case DW_OP_reg27:
+ case DW_OP_reg28:
+ case DW_OP_reg29:
+ case DW_OP_reg30:
+ case DW_OP_reg31:
+ fprintf_filtered (stream, " [$%s]",
+ gdbarch_register_name (arch, op - DW_OP_reg0));
+ break;
+
+ case DW_OP_regx:
+ data = read_uleb128 (data, end, &ul);
+ fprintf_filtered (stream, " %s [$%s]", pulongest (ul),
+ gdbarch_register_name (arch, (int) ul));
+ break;
+
+ case DW_OP_implicit_value:
+ data = read_uleb128 (data, end, &ul);
+ data += ul;
+ fprintf_filtered (stream, " %s", pulongest (ul));
+ break;
+
+ case DW_OP_breg0:
+ case DW_OP_breg1:
+ case DW_OP_breg2:
+ case DW_OP_breg3:
+ case DW_OP_breg4:
+ case DW_OP_breg5:
+ case DW_OP_breg6:
+ case DW_OP_breg7:
+ case DW_OP_breg8:
+ case DW_OP_breg9:
+ case DW_OP_breg10:
+ case DW_OP_breg11:
+ case DW_OP_breg12:
+ case DW_OP_breg13:
+ case DW_OP_breg14:
+ case DW_OP_breg15:
+ case DW_OP_breg16:
+ case DW_OP_breg17:
+ case DW_OP_breg18:
+ case DW_OP_breg19:
+ case DW_OP_breg20:
+ case DW_OP_breg21:
+ case DW_OP_breg22:
+ case DW_OP_breg23:
+ case DW_OP_breg24:
+ case DW_OP_breg25:
+ case DW_OP_breg26:
+ case DW_OP_breg27:
+ case DW_OP_breg28:
+ case DW_OP_breg29:
+ case DW_OP_breg30:
+ case DW_OP_breg31:
+ data = read_sleb128 (data, end, &ul);
+ fprintf_filtered (stream, " %s [$%s]", pulongest (ul),
+ gdbarch_register_name (arch, op - DW_OP_breg0));
+ break;
+
+ case DW_OP_bregx:
+ {
+ ULONGEST offset;
+
+ data = read_uleb128 (data, end, &ul);
+ data = read_sleb128 (data, end, &offset);
+ fprintf_filtered (stream, " register %s [$%s] offset %s",
+ pulongest (ul),
+ gdbarch_register_name (arch, (int) ul),
+ pulongest (offset));
+ }
+ break;
+
+ case DW_OP_fbreg:
+ data = read_sleb128 (data, end, &ul);
+ fprintf_filtered (stream, " %s", pulongest (ul));
+ break;
+
+ case DW_OP_xderef_size:
+ case DW_OP_deref_size:
+ case DW_OP_pick:
+ fprintf_filtered (stream, " %d", *data);
+ ++data;
+ break;
+
+ case DW_OP_plus_uconst:
+ data = read_uleb128 (data, end, &ul);
+ fprintf_filtered (stream, " %s", pulongest (ul));
+ break;
+
+ case DW_OP_skip:
+ l = extract_signed_integer (data, 2, gdbarch_byte_order (arch));
+ data += 2;
+ fprintf_filtered (stream, " to %ld",
+ (long) (data + l - start));
+ break;
+
+ case DW_OP_bra:
+ l = extract_signed_integer (data, 2, gdbarch_byte_order (arch));
+ data += 2;
+ fprintf_filtered (stream, " %ld",
+ (long) (data + l - start));
+ break;
+
+ case DW_OP_call2:
+ ul = extract_unsigned_integer (data, 2, gdbarch_byte_order (arch));
+ data += 2;
+ fprintf_filtered (stream, " offset %s", phex_nz (ul, 2));
+ break;
+
+ case DW_OP_call4:
+ ul = extract_unsigned_integer (data, 4, gdbarch_byte_order (arch));
+ data += 4;
+ fprintf_filtered (stream, " offset %s", phex_nz (ul, 4));
+ break;
+
+ case DW_OP_call_ref:
+ ul = extract_unsigned_integer (data, offset_size,
+ gdbarch_byte_order (arch));
+ data += offset_size;
+ fprintf_filtered (stream, " offset %s", phex_nz (ul, offset_size));
+ break;
+
+ case DW_OP_piece:
+ data = read_uleb128 (data, end, &ul);
+ fprintf_filtered (stream, " %s (bytes)", pulongest (ul));
+ break;
+
+ case DW_OP_bit_piece:
+ {
+ ULONGEST offset;
+
+ data = read_uleb128 (data, end, &ul);
+ data = read_uleb128 (data, end, &offset);
+ fprintf_filtered (stream, " size %s offset %s (bits)",
+ pulongest (ul), pulongest (offset));
+ }
+ break;
+ }
+
+ fprintf_filtered (stream, "\n");
+ }
return data;
}
@@ -1434,40 +1718,78 @@ static void
locexpr_describe_location_1 (struct symbol *symbol, CORE_ADDR addr,
struct ui_file *stream,
const gdb_byte *data, int size,
- struct objfile *objfile, unsigned int addr_size)
+ struct objfile *objfile, unsigned int addr_size,
+ int offset_size)
{
const gdb_byte *end = data + size;
- int piece_done = 0, first_piece = 1, bad = 0;
+ int first_piece = 1, bad = 0;
- /* A multi-piece description consists of multiple sequences of bytes
- each followed by DW_OP_piece + length of piece. */
while (data < end)
{
- if (!piece_done)
- {
- if (first_piece)
- first_piece = 0;
- else
- fprintf_filtered (stream, _(", and "));
+ const gdb_byte *here = data;
+ int disassemble = 1;
+
+ if (first_piece)
+ first_piece = 0;
+ else
+ fprintf_filtered (stream, _(", and "));
+ if (!dwarf2_always_disassemble)
+ {
data = locexpr_describe_location_piece (symbol, stream, addr, objfile,
- data, size, addr_size);
- piece_done = 1;
+ data, end, addr_size);
+ /* If we printed anything, or if we have an empty piece,
+ then don't disassemble. */
+ if (data != here
+ || data[0] == DW_OP_piece
+ || data[0] == DW_OP_bit_piece)
+ disassemble = 0;
}
- else if (data[0] == DW_OP_piece)
+ if (disassemble)
+ data = disassemble_dwarf_expression (stream, get_objfile_arch (objfile),
+ addr_size, offset_size, data, end,
+ dwarf2_always_disassemble);
+
+ if (data < end)
{
- ULONGEST bytes;
+ int empty = data == here;
- data = read_uleb128 (data + 1, end, &bytes);
+ if (disassemble)
+ fprintf_filtered (stream, " ");
+ if (data[0] == DW_OP_piece)
+ {
+ ULONGEST bytes;
- fprintf_filtered (stream, _(" [%s-byte piece]"), pulongest (bytes));
+ data = read_uleb128 (data + 1, end, &bytes);
- piece_done = 0;
- }
- else
- {
- bad = 1;
- break;
+ if (empty)
+ fprintf_filtered (stream, _("an empty %s-byte piece"),
+ pulongest (bytes));
+ else
+ fprintf_filtered (stream, _(" [%s-byte piece]"),
+ pulongest (bytes));
+ }
+ else if (data[0] == DW_OP_bit_piece)
+ {
+ ULONGEST bits, offset;
+
+ data = read_uleb128 (data + 1, end, &bits);
+ data = read_uleb128 (data, end, &offset);
+
+ if (empty)
+ fprintf_filtered (stream,
+ _("an empty %s-bit piece"),
+ pulongest (bits));
+ else
+ fprintf_filtered (stream,
+ _(" [%s-bit piece, offset %s bits]"),
+ pulongest (bits), pulongest (offset));
+ }
+ else
+ {
+ bad = 1;
+ break;
+ }
}
}
@@ -1486,9 +1808,10 @@ locexpr_describe_location (struct symbol *symbol, CORE_ADDR addr,
struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
struct objfile *objfile = dwarf2_per_cu_objfile (dlbaton->per_cu);
unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
+ int offset_size = dwarf2_per_cu_offset_size (dlbaton->per_cu);
locexpr_describe_location_1 (symbol, addr, stream, dlbaton->data, dlbaton->size,
- objfile, addr_size);
+ objfile, addr_size, offset_size);
}
/* Describe the location of SYMBOL as an agent value in VALUE, generating
@@ -1572,6 +1895,7 @@ loclist_describe_location (struct symbol *symbol, CORE_ADDR addr,
struct gdbarch *gdbarch = get_objfile_arch (objfile);
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
+ int offset_size = dwarf2_per_cu_offset_size (dlbaton->per_cu);
CORE_ADDR base_mask = ~(~(CORE_ADDR)1 << (addr_size * 8 - 1));
/* Adjust base_address for relocatable objects. */
CORE_ADDR base_offset = ANOFFSET (objfile->section_offsets,
@@ -1581,7 +1905,7 @@ loclist_describe_location (struct symbol *symbol, CORE_ADDR addr,
loc_ptr = dlbaton->data;
buf_end = dlbaton->data + dlbaton->size;
- fprintf_filtered (stream, _("multi-location ("));
+ fprintf_filtered (stream, _("multi-location:\n"));
/* Iterate through locations until we run out. */
while (1)
@@ -1598,7 +1922,7 @@ loclist_describe_location (struct symbol *symbol, CORE_ADDR addr,
{
base_address = dwarf2_read_address (gdbarch,
loc_ptr, buf_end, addr_size);
- fprintf_filtered (stream, _("[base address %s]"),
+ fprintf_filtered (stream, _(" Base address %s"),
paddress (gdbarch, base_address));
loc_ptr += addr_size;
continue;
@@ -1609,11 +1933,7 @@ loclist_describe_location (struct symbol *symbol, CORE_ADDR addr,
/* An end-of-list entry. */
if (low == 0 && high == 0)
- {
- /* Indicate the end of the list, for readability. */
- fprintf_filtered (stream, _(")"));
- return;
- }
+ break;
/* Otherwise, a location expression entry. */
low += base_address;
@@ -1622,20 +1942,16 @@ loclist_describe_location (struct symbol *symbol, CORE_ADDR addr,
length = extract_unsigned_integer (loc_ptr, 2, byte_order);
loc_ptr += 2;
- /* Separate the different locations with a semicolon. */
- if (first)
- first = 0;
- else
- fprintf_filtered (stream, _("; "));
-
/* (It would improve readability to print only the minimum
necessary digits of the second number of the range.) */
- fprintf_filtered (stream, _("range %s-%s, "),
+ fprintf_filtered (stream, _(" Range %s-%s: "),
paddress (gdbarch, low), paddress (gdbarch, high));
/* Now describe this particular location. */
locexpr_describe_location_1 (symbol, low, stream, loc_ptr, length,
- objfile, addr_size);
+ objfile, addr_size, offset_size);
+
+ fprintf_filtered (stream, "\n");
loc_ptr += length;
}