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[PATCH] Dwarf location expressions, tracing and printing
- From: Stan Shebs <stan at codesourcery dot com>
- To: "gdb-patches at sourceware dot org" <gdb-patches at sourceware dot org>
- Date: Thu, 15 Apr 2010 18:06:43 -0700
- Subject: [PATCH] Dwarf location expressions, tracing and printing
This patch solves a number of problems related to variables with Dwarf2
location expressions - which these days, means just about every local in
optimized code. :-) Perhaps the most interesting part is that I finally
got tired of working blind and filled out description location
functions, so now both "info scope" and "info address" have quite a lot
of say about variables. Try things like "info scope
handle_inferior_event" to get some truly awesome verbiage. :-)
Since there's a lot of new code here, I'll leave it up for a couple days
before committing.
Stan
2010-04-15 Stan Shebs <stan@codesourcery.com>
Nathan Sidwell <nathan@codesourcery.com>
* dwarf2loc.c (struct axs_var_loc): New struct.
(dwarf2_tracepoint_var_loc): New function.
(dwarf2_tracepoint_var_access): New function.
(dwarf2_tracepoint_var_ref): Use dwarf2_tracepoint_var_loc, deal
with DW_OP_piece.
(locexpr_describe_location_piece): New function.
(locexpr_describe_location_1): New function.
(locexpr_describe_location): Call it, update signature.
(loclist_describe_location): Rewrite to loop over locations,
update signature.
* symtab.h (struct symbol_computed_ops): Add address to
describe_location arguments, return void.
* printcmd.c (address_info): Get context PC, pass to computed
location description.
* tracepoint.c (scope_info): Ditto.
* ax-gdb.c (trace_kludge): Export.
Index: ax-gdb.c
===================================================================
RCS file: /cvs/src/src/gdb/ax-gdb.c,v
retrieving revision 1.72
diff -p -r1.72 ax-gdb.c
*** ax-gdb.c 19 Mar 2010 22:00:17 -0000 1.72
--- ax-gdb.c 16 Apr 2010 00:14:41 -0000
*************** maybe_const_expr (union exp_element **pc
*** 329,335 ****
Setting the flag trace_kludge to non-zero enables the code that
emits the trace bytecodes at the appropriate points. */
! static int trace_kludge;
/* Scan for all static fields in the given class, including any base
classes, and generate tracing bytecodes for each. */
--- 329,335 ----
Setting the flag trace_kludge to non-zero enables the code that
emits the trace bytecodes at the appropriate points. */
! int trace_kludge;
/* Scan for all static fields in the given class, including any base
classes, and generate tracing bytecodes for each. */
Index: dwarf2loc.c
===================================================================
RCS file: /cvs/src/src/gdb/dwarf2loc.c,v
retrieving revision 1.74
diff -p -r1.74 dwarf2loc.c
*** dwarf2loc.c 17 Mar 2010 22:04:43 -0000 1.74
--- dwarf2loc.c 16 Apr 2010 00:14:41 -0000
*************** dwarf2_loc_desc_needs_frame (gdb_byte *d
*** 614,641 ****
return baton.needs_frame || in_reg;
}
! static void
! dwarf2_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch,
! struct agent_expr *ax, struct axs_value *value,
! gdb_byte *data, int size)
{
! if (!data || size == 0)
! {
! value->optimized_out = 1;
! }
! else if (size == 1
! && data[0] >= DW_OP_reg0
! && data[0] <= DW_OP_reg31)
{
! value->kind = axs_lvalue_register;
! value->u.reg = data[0] - DW_OP_reg0;
}
else if (data[0] == DW_OP_regx)
{
ULONGEST reg;
! read_uleb128 (data + 1, data + size, ®);
! value->kind = axs_lvalue_register;
! value->u.reg = reg;
}
else if (data[0] == DW_OP_fbreg)
{
--- 614,660 ----
return baton.needs_frame || in_reg;
}
! /* This struct keeps track of the pieces that make up a multi-location
! object, for use in agent expression generation. It is
! superficially similar to struct dwarf_expr_piece, but
! dwarf_expr_piece is designed for use in immediate evaluation, and
! does not, for example, have a way to record both base register and
! offset. */
!
! struct axs_var_loc
{
! /* Memory vs register, etc */
! enum axs_lvalue_kind kind;
!
! /* If non-zero, number of bytes in this fragment */
! unsigned bytes;
!
! /* (GDB-numbered) reg, or base reg if >= 0 */
! int reg;
!
! /* offset from reg */
! LONGEST offset;
! };
!
! static gdb_byte *
! dwarf2_tracepoint_var_loc (struct symbol *symbol,
! struct agent_expr *ax,
! struct axs_var_loc *loc,
! struct gdbarch *gdbarch,
! gdb_byte *data, gdb_byte *end)
! {
! if (data[0] >= DW_OP_reg0 && data[0] <= DW_OP_reg31)
{
! loc->kind = axs_lvalue_register;
! loc->reg = gdbarch_dwarf2_reg_to_regnum (gdbarch, data[0] - DW_OP_reg0);
! data += 1;
}
else if (data[0] == DW_OP_regx)
{
ULONGEST reg;
! data = read_uleb128 (data + 1, end, ®);
! loc->kind = axs_lvalue_register;
! loc->reg = gdbarch_dwarf2_reg_to_regnum (gdbarch, reg);
}
else if (data[0] == DW_OP_fbreg)
{
*************** dwarf2_tracepoint_var_ref (struct symbol
*** 643,649 ****
struct symbol *framefunc;
int frame_reg = 0;
LONGEST frame_offset;
- gdb_byte *buf_end;
gdb_byte *base_data;
size_t base_size;
LONGEST base_offset = 0;
--- 662,667 ----
*************** dwarf2_tracepoint_var_ref (struct symbol
*** 661,717 ****
dwarf_expr_frame_base_1 (framefunc, ax->scope,
&base_data, &base_size);
! if (base_data[0] >= DW_OP_breg0
! && base_data[0] <= DW_OP_breg31)
{
frame_reg = base_data[0] - DW_OP_breg0;
! buf_end = read_sleb128 (base_data + 1, base_data + base_size, &base_offset);
if (buf_end != base_data + base_size)
error (_("Unexpected opcode after DW_OP_breg%u for symbol \"%s\"."),
frame_reg, SYMBOL_PRINT_NAME (symbol));
}
else
{
/* We don't know what to do with the frame base expression,
so we can't trace this variable; give up. */
! error (_("Cannot generate expression to collect symbol \"%s\"; DWARF 2 encoding not handled"),
! SYMBOL_PRINT_NAME (symbol));
}
! buf_end = read_sleb128 (data + 1, data + size, &frame_offset);
! if (buf_end != data + size)
! error (_("Unexpected opcode after DW_OP_fbreg for symbol \"%s\"."),
! SYMBOL_PRINT_NAME (symbol));
! ax_reg (ax, frame_reg);
! ax_const_l (ax, base_offset + frame_offset);
! ax_simple (ax, aop_add);
!
! value->kind = axs_lvalue_memory;
}
! else if (data[0] >= DW_OP_breg0
! && data[0] <= DW_OP_breg31)
{
unsigned int reg;
LONGEST offset;
- gdb_byte *buf_end;
reg = data[0] - DW_OP_breg0;
! buf_end = read_sleb128 (data + 1, data + size, &offset);
! if (buf_end != data + size)
! error (_("Unexpected opcode after DW_OP_breg%u for symbol \"%s\"."),
! reg, SYMBOL_PRINT_NAME (symbol));
!
! ax_reg (ax, reg);
! ax_const_l (ax, offset);
! ax_simple (ax, aop_add);
! value->kind = axs_lvalue_memory;
}
else
error (_("Unsupported DWARF opcode 0x%x in the location of \"%s\"."),
data[0], SYMBOL_PRINT_NAME (symbol));
}
/* Return the value of SYMBOL in FRAME using the DWARF-2 expression
evaluator to calculate the location. */
--- 679,880 ----
dwarf_expr_frame_base_1 (framefunc, ax->scope,
&base_data, &base_size);
! if (base_data[0] >= DW_OP_breg0 && base_data[0] <= DW_OP_breg31)
{
+ gdb_byte *buf_end;
+
frame_reg = base_data[0] - DW_OP_breg0;
! buf_end = read_sleb128 (base_data + 1,
! base_data + base_size, &base_offset);
if (buf_end != base_data + base_size)
error (_("Unexpected opcode after DW_OP_breg%u for symbol \"%s\"."),
frame_reg, SYMBOL_PRINT_NAME (symbol));
}
+ else if (base_data[0] >= DW_OP_reg0 && base_data[0] <= DW_OP_reg31)
+ {
+ /* The frame base is just the register, with no offset. */
+ frame_reg = base_data[0] - DW_OP_reg0;
+ base_offset = 0;
+ }
else
{
/* We don't know what to do with the frame base expression,
so we can't trace this variable; give up. */
! error (_("Cannot generate expression to collect symbol \"%s\"; DWARF 2 encoding not handled, first opcode in base data is 0x%x."),
! SYMBOL_PRINT_NAME (symbol), base_data[0]);
}
! data = read_sleb128 (data + 1, end, &frame_offset);
! loc->kind = axs_lvalue_memory;
! loc->reg = gdbarch_dwarf2_reg_to_regnum (gdbarch, frame_reg);
! loc->offset = base_offset + frame_offset;
}
! else if (data[0] >= DW_OP_breg0 && data[0] <= DW_OP_breg31)
{
unsigned int reg;
LONGEST offset;
reg = data[0] - DW_OP_breg0;
! data = read_sleb128 (data + 1, end, &offset);
! loc->kind = axs_lvalue_memory;
! loc->reg = gdbarch_dwarf2_reg_to_regnum (gdbarch, reg);
! loc->offset = offset;
}
else
error (_("Unsupported DWARF opcode 0x%x in the location of \"%s\"."),
data[0], SYMBOL_PRINT_NAME (symbol));
+
+ return data;
}
+
+ /* Given the location of a piece, issue bytecodes that will access it. */
+
+ static void
+ dwarf2_tracepoint_var_access (struct agent_expr *ax,
+ struct axs_value *value,
+ struct axs_var_loc *loc)
+ {
+ value->kind = loc->kind;
+
+ switch (loc->kind)
+ {
+ case axs_lvalue_register:
+ value->u.reg = loc->reg;
+ break;
+
+ case axs_lvalue_memory:
+ ax_reg (ax, loc->reg);
+ if (loc->offset)
+ {
+ ax_const_l (ax, loc->offset);
+ ax_simple (ax, aop_add);
+ }
+ break;
+
+ default:
+ internal_error (__FILE__, __LINE__, _("Unhandled value kind in dwarf2_tracepoint_var_access"));
+ }
+ }
+
+ static void
+ dwarf2_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch,
+ struct agent_expr *ax, struct axs_value *value,
+ gdb_byte *data, int size)
+ {
+ gdb_byte *end = data + size;
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ /* In practice, a variable is not going to be spread across
+ dozens of registers or memory locations. If someone comes up
+ with a real-world example, revisit this. */
+ #define MAX_FRAGS 16
+ struct axs_var_loc fragments[MAX_FRAGS];
+ int nfrags = 0, frag;
+ int length = 0;
+ int piece_ok = 0;
+ int bad = 0;
+ int first = 1;
+
+ if (!data || size == 0)
+ {
+ value->optimized_out = 1;
+ return;
+ }
+
+ while (data < end)
+ {
+ if (!piece_ok)
+ {
+ if (nfrags == MAX_FRAGS)
+ error (_("Too many pieces in location for \"%s\"."),
+ SYMBOL_PRINT_NAME (symbol));
+
+ fragments[nfrags].bytes = 0;
+ data = dwarf2_tracepoint_var_loc (symbol, ax, &fragments[nfrags],
+ gdbarch, data, end);
+ nfrags++;
+ piece_ok = 1;
+ }
+ else if (data[0] == DW_OP_piece)
+ {
+ ULONGEST bytes;
+
+ data = read_uleb128 (data + 1, end, &bytes);
+ /* Only deal with 4 byte fragments for now. */
+ if (bytes != 4)
+ error (_("DW_OP_piece %s not supported in location for \"%s\"."),
+ pulongest (bytes), SYMBOL_PRINT_NAME (symbol));
+ fragments[nfrags - 1].bytes = bytes;
+ length += bytes;
+ piece_ok = 0;
+ }
+ else
+ {
+ bad = 1;
+ break;
+ }
+ }
+
+ if (bad || data > end)
+ error (_("Corrupted DWARF expression for \"%s\"."),
+ SYMBOL_PRINT_NAME (symbol));
+
+ /* If single expression, no pieces, convert to external format. */
+ if (length == 0)
+ {
+ dwarf2_tracepoint_var_access (ax, value, &fragments[0]);
+ return;
+ }
+
+ if (length != TYPE_LENGTH (value->type))
+ error (_("Inconsistent piece information for \"%s\"."),
+ SYMBOL_PRINT_NAME (symbol));
+
+ /* Emit bytecodes to assemble the pieces into a single stack entry. */
+
+ for ((frag = (byte_order == BFD_ENDIAN_BIG ? 0 : nfrags - 1));
+ nfrags--;
+ (frag += (byte_order == BFD_ENDIAN_BIG ? 1 : -1)))
+ {
+ if (!first)
+ {
+ /* shift the previous fragment up 32 bits */
+ ax_const_l (ax, 32);
+ ax_simple (ax, aop_lsh);
+ }
+
+ dwarf2_tracepoint_var_access (ax, value, &fragments[frag]);
+
+ switch (value->kind)
+ {
+ case axs_lvalue_register:
+ ax_reg (ax, value->u.reg);
+ break;
+
+ case axs_lvalue_memory:
+ {
+ extern int trace_kludge; /* Ugh. */
+
+ gdb_assert (fragments[frag].bytes == 4);
+ if (trace_kludge)
+ ax_trace_quick (ax, 4);
+ ax_simple (ax, aop_ref32);
+ }
+ break;
+ }
+
+ if (!first)
+ {
+ /* or the new fragment into the previous */
+ ax_zero_ext (ax, 32);
+ ax_simple (ax, aop_bit_or);
+ }
+ first = 0;
+ }
+ value->kind = axs_rvalue;
+ }
+
/* Return the value of SYMBOL in FRAME using the DWARF-2 expression
evaluator to calculate the location. */
*************** locexpr_read_needs_frame (struct symbol
*** 735,760 ****
dlbaton->per_cu);
}
! /* Print a natural-language description of SYMBOL to STREAM. */
! static int
! locexpr_describe_location (struct symbol *symbol, struct ui_file *stream)
{
! /* FIXME: be more extensive. */
! struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
! int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
- if (dlbaton->size == 1
- && dlbaton->data[0] >= DW_OP_reg0
- && dlbaton->data[0] <= DW_OP_reg31)
- {
- struct objfile *objfile = dwarf2_per_cu_objfile (dlbaton->per_cu);
- struct gdbarch *gdbarch = get_objfile_arch (objfile);
- int regno = gdbarch_dwarf2_reg_to_regnum (gdbarch,
- dlbaton->data[0] - DW_OP_reg0);
fprintf_filtered (stream,
! "a variable in register %s",
gdbarch_register_name (gdbarch, regno));
- return 1;
}
/* The location expression for a TLS variable looks like this (on a
--- 898,1001 ----
dlbaton->per_cu);
}
! /* Describe a single piece of a location, returning an updated
! position in the bytecode sequence. */
!
! static gdb_byte *
! locexpr_describe_location_piece (struct symbol *symbol, struct ui_file *stream,
! CORE_ADDR addr, struct objfile *objfile,
! gdb_byte *data, int size, unsigned int addr_size)
{
! struct gdbarch *gdbarch = get_objfile_arch (objfile);
! int regno;
!
! if (data[0] >= DW_OP_reg0 && data[0] <= DW_OP_reg31)
! {
! regno = gdbarch_dwarf2_reg_to_regnum (gdbarch, data[0] - DW_OP_reg0);
! fprintf_filtered (stream, _("a variable in $%s"),
! gdbarch_register_name (gdbarch, regno));
! data += 1;
! }
! else if (data[0] == DW_OP_regx)
! {
! ULONGEST reg;
!
! data = read_uleb128 (data + 1, data + size, ®);
! regno = gdbarch_dwarf2_reg_to_regnum (gdbarch, reg);
! fprintf_filtered (stream, _("a variable in $%s"),
! gdbarch_register_name (gdbarch, regno));
! }
! else if (data[0] == DW_OP_fbreg)
! {
! struct block *b;
! struct symbol *framefunc;
! int frame_reg = 0;
! LONGEST frame_offset;
! gdb_byte *base_data;
! size_t base_size;
! LONGEST base_offset = 0;
!
! b = block_for_pc (addr);
!
! if (!b)
! error (_("No block found for address for symbol \"%s\"."),
! SYMBOL_PRINT_NAME (symbol));
!
! framefunc = block_linkage_function (b);
!
! if (!framefunc)
! error (_("No function found for block for symbol \"%s\"."),
! SYMBOL_PRINT_NAME (symbol));
!
! dwarf_expr_frame_base_1 (framefunc, addr, &base_data, &base_size);
!
! if (base_data[0] >= DW_OP_breg0 && base_data[0] <= DW_OP_breg31)
! {
! gdb_byte *buf_end;
!
! frame_reg = base_data[0] - DW_OP_breg0;
! buf_end = read_sleb128 (base_data + 1,
! base_data + base_size, &base_offset);
! if (buf_end != base_data + base_size)
! error (_("Unexpected opcode after DW_OP_breg%u for symbol \"%s\"."),
! frame_reg, SYMBOL_PRINT_NAME (symbol));
! }
! else if (base_data[0] >= DW_OP_reg0 && base_data[0] <= DW_OP_reg31)
! {
! /* The frame base is just the register, with no offset. */
! frame_reg = base_data[0] - DW_OP_reg0;
! base_offset = 0;
! }
! else
! {
! /* We don't know what to do with the frame base expression,
! so we can't trace this variable; give up. */
! error (_("Cannot describe location of symbol \"%s\"; "
! "DWARF 2 encoding not handled, "
! "first opcode in base data is 0x%x."),
! SYMBOL_PRINT_NAME (symbol), base_data[0]);
! }
!
! 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)
! {
! LONGEST offset;
!
! regno = gdbarch_dwarf2_reg_to_regnum (gdbarch, data[0] - DW_OP_breg0);
!
! data = read_sleb128 (data + 1, data + size, &offset);
fprintf_filtered (stream,
! _("a variable at offset %s from base reg $%s"),
! plongest (offset),
gdbarch_register_name (gdbarch, regno));
}
/* The location expression for a TLS variable looks like this (on a
*************** locexpr_describe_location (struct symbol
*** 769,805 ****
The operand represents the offset at which the variable is within
the thread local storage. */
! if (dlbaton->size > 1
! && dlbaton->data[dlbaton->size - 1] == DW_OP_GNU_push_tls_address)
! if (dlbaton->data[0] == DW_OP_addr)
! {
! struct objfile *objfile = dwarf2_per_cu_objfile (dlbaton->per_cu);
! struct gdbarch *gdbarch = get_objfile_arch (objfile);
! CORE_ADDR offset = dwarf2_read_address (gdbarch,
! &dlbaton->data[1],
! &dlbaton->data[dlbaton->size - 1],
! addr_size);
! fprintf_filtered (stream,
! "a thread-local variable at offset %s in the "
! "thread-local storage for `%s'",
! paddress (gdbarch, offset), objfile->name);
! return 1;
! }
!
! fprintf_filtered (stream,
! "a variable with complex or multiple locations (DWARF2)");
! return 1;
}
! /* Describe the location of SYMBOL as an agent value in VALUE, generating
! any necessary bytecode in AX.
! NOTE drow/2003-02-26: This function is extremely minimal, because
! doing it correctly is extremely complicated and there is no
! publicly available stub with tracepoint support for me to test
! against. When there is one this function should be revisited. */
static void
locexpr_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch,
--- 1010,1102 ----
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)
! {
! CORE_ADDR offset = dwarf2_read_address (gdbarch,
! data + 1,
! data + size - 1,
! addr_size);
! fprintf_filtered (stream,
! _("a thread-local variable at offset %s "
! "in the thread-local storage for `%s'"),
! paddress (gdbarch, offset), objfile->name);
! data += 1 + addr_size + 1;
! }
! else
! fprintf_filtered (stream,
! _("a variable with complex or multiple locations (DWARF2)"));
!
! return data;
}
+ /* Describe a single location, which may in turn consist of multiple
+ pieces. */
! static void
! locexpr_describe_location_1 (struct symbol *symbol, CORE_ADDR addr,
! struct ui_file *stream, gdb_byte *data, int size,
! struct objfile *objfile, unsigned int addr_size)
! {
! gdb_byte *end = data + size;
! int piece_done = 0, 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 "));
!
! data = locexpr_describe_location_piece (symbol, stream, addr, objfile,
! data, size, addr_size);
! piece_done = 1;
! }
! else if (data[0] == DW_OP_piece)
! {
! ULONGEST bytes;
!
! data = read_uleb128 (data + 1, end, &bytes);
!
! fprintf_filtered (stream, _(" [%s-byte piece]"), pulongest (bytes));
!
! piece_done = 0;
! }
! else
! {
! bad = 1;
! break;
! }
! }
!
! if (bad || data > end)
! error (_("Corrupted DWARF2 expression for \"%s\"."),
! SYMBOL_PRINT_NAME (symbol));
! }
! /* Print a natural-language description of SYMBOL to STREAM. This
! version is for a symbol with a single location. */
!
! static void
! locexpr_describe_location (struct symbol *symbol, CORE_ADDR addr,
! struct ui_file *stream)
! {
! 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);
!
! locexpr_describe_location_1 (symbol, addr, stream, dlbaton->data, dlbaton->size,
! objfile, addr_size);
! }
!
! /* Describe the location of SYMBOL as an agent value in VALUE, generating
! any necessary bytecode in AX. */
static void
locexpr_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch,
*************** loclist_read_needs_frame (struct symbol
*** 863,875 ****
return 1;
}
! /* Print a natural-language description of SYMBOL to STREAM. */
! static int
! loclist_describe_location (struct symbol *symbol, struct ui_file *stream)
{
! /* FIXME: Could print the entire list of locations. */
! fprintf_filtered (stream, "a variable with multiple locations");
! return 1;
}
/* Describe the location of SYMBOL as an agent value in VALUE, generating
--- 1160,1248 ----
return 1;
}
! /* Print a natural-language description of SYMBOL to STREAM. This
! version applies when there is a list of different locations, each
! with a specified address range. */
!
! static void
! loclist_describe_location (struct symbol *symbol, CORE_ADDR addr,
! struct ui_file *stream)
{
! struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
! CORE_ADDR low, high;
! gdb_byte *loc_ptr, *buf_end;
! int length, first = 1;
! struct objfile *objfile = dwarf2_per_cu_objfile (dlbaton->per_cu);
! 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);
! 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,
! SECT_OFF_TEXT (objfile));
! CORE_ADDR base_address = dlbaton->base_address + base_offset;
!
! loc_ptr = dlbaton->data;
! buf_end = dlbaton->data + dlbaton->size;
!
! fprintf_filtered (stream, _("multi-location ("));
!
! /* Iterate through locations until we run out. */
! while (1)
! {
! if (buf_end - loc_ptr < 2 * addr_size)
! error (_("Corrupted DWARF expression for symbol \"%s\"."),
! SYMBOL_PRINT_NAME (symbol));
!
! low = extract_unsigned_integer (loc_ptr, addr_size, byte_order);
! loc_ptr += addr_size;
!
! /* A base-address-selection entry. */
! if (low == base_mask)
! {
! base_address = dwarf2_read_address (gdbarch,
! loc_ptr, buf_end, addr_size);
! fprintf_filtered (stream, _("[base address %s]"),
! paddress (gdbarch, base_address));
! loc_ptr += addr_size;
! continue;
! }
!
! high = extract_unsigned_integer (loc_ptr, addr_size, byte_order);
! loc_ptr += addr_size;
!
! /* An end-of-list entry. */
! if (low == 0 && high == 0)
! {
! /* Indicate the end of the list, for readability. */
! fprintf_filtered (stream, _(")"));
! return;
! }
!
! /* Otherwise, a location expression entry. */
! low += base_address;
! high += base_address;
!
! 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, "),
! paddress (gdbarch, low), paddress (gdbarch, high));
!
! /* Now describe this particular location. */
! locexpr_describe_location_1 (symbol, low, stream, loc_ptr, length,
! objfile, addr_size);
!
! loc_ptr += length;
! }
}
/* Describe the location of SYMBOL as an agent value in VALUE, generating
Index: printcmd.c
===================================================================
RCS file: /cvs/src/src/gdb/printcmd.c,v
retrieving revision 1.173
diff -p -r1.173 printcmd.c
*** printcmd.c 5 Mar 2010 20:18:14 -0000 1.173
--- printcmd.c 16 Apr 2010 00:14:41 -0000
*************** sym_info (char *arg, int from_tty)
*** 1148,1167 ****
static void
address_info (char *exp, int from_tty)
{
struct gdbarch *gdbarch;
int regno;
struct symbol *sym;
struct minimal_symbol *msymbol;
long val;
struct obj_section *section;
! CORE_ADDR load_addr;
int is_a_field_of_this; /* C++: lookup_symbol sets this to nonzero
if exp is a field of `this'. */
if (exp == 0)
error (_("Argument required."));
! sym = lookup_symbol (exp, get_selected_block (0), VAR_DOMAIN,
&is_a_field_of_this);
if (sym == NULL)
{
--- 1148,1168 ----
static void
address_info (char *exp, int from_tty)
{
+ struct block *block;
struct gdbarch *gdbarch;
int regno;
struct symbol *sym;
struct minimal_symbol *msymbol;
long val;
struct obj_section *section;
! CORE_ADDR load_addr, context_pc = 0;
int is_a_field_of_this; /* C++: lookup_symbol sets this to nonzero
if exp is a field of `this'. */
if (exp == 0)
error (_("Argument required."));
! sym = lookup_symbol (exp, get_selected_block (&context_pc), VAR_DOMAIN,
&is_a_field_of_this);
if (sym == NULL)
{
*************** address_info (char *exp, int from_tty)
*** 1242,1248 ****
Unfortunately DWARF 2 stores the frame-base (instead of the
function) location in a function's symbol. Oops! For the
moment enable this when/where applicable. */
! SYMBOL_COMPUTED_OPS (sym)->describe_location (sym, gdb_stdout);
break;
case LOC_REGISTER:
--- 1243,1249 ----
Unfortunately DWARF 2 stores the frame-base (instead of the
function) location in a function's symbol. Oops! For the
moment enable this when/where applicable. */
! SYMBOL_COMPUTED_OPS (sym)->describe_location (sym, context_pc, gdb_stdout);
break;
case LOC_REGISTER:
Index: symtab.h
===================================================================
RCS file: /cvs/src/src/gdb/symtab.h,v
retrieving revision 1.150
diff -p -r1.150 symtab.h
*** symtab.h 26 Mar 2010 19:41:50 -0000 1.150
--- symtab.h 16 Apr 2010 00:14:41 -0000
*************** struct symbol_computed_ops
*** 516,523 ****
int (*read_needs_frame) (struct symbol * symbol);
/* Write to STREAM a natural-language description of the location of
! SYMBOL. */
! int (*describe_location) (struct symbol * symbol, struct ui_file * stream);
/* Tracepoint support. Append bytecodes to the tracepoint agent
expression AX that push the address of the object SYMBOL. Set
--- 516,524 ----
int (*read_needs_frame) (struct symbol * symbol);
/* Write to STREAM a natural-language description of the location of
! SYMBOL, in the context of ADDR. */
! void (*describe_location) (struct symbol * symbol, CORE_ADDR addr,
! struct ui_file * stream);
/* Tracepoint support. Append bytecodes to the tracepoint agent
expression AX that push the address of the object SYMBOL. Set
Index: tracepoint.c
===================================================================
RCS file: /cvs/src/src/gdb/tracepoint.c,v
retrieving revision 1.178
diff -p -r1.178 tracepoint.c
*** tracepoint.c 13 Apr 2010 03:53:50 -0000 1.178
--- tracepoint.c 16 Apr 2010 00:14:41 -0000
*************** scope_info (char *args, int from_tty)
*** 2361,2367 ****
printf_filtered ("optimized out.\n");
continue;
case LOC_COMPUTED:
! SYMBOL_COMPUTED_OPS (sym)->describe_location (sym, gdb_stdout);
break;
}
if (SYMBOL_TYPE (sym))
--- 2361,2369 ----
printf_filtered ("optimized out.\n");
continue;
case LOC_COMPUTED:
! SYMBOL_COMPUTED_OPS (sym)->describe_location (sym,
! BLOCK_START (block),
! gdb_stdout);
break;
}
if (SYMBOL_TYPE (sym))