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)
+/* 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
{
- if (!data || size == 0)
- {
- value->optimized_out = 1;
- }
- else if (size == 1
- && data[0] >= DW_OP_reg0
- && data[0] <= DW_OP_reg31)
+ /* 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)
{
- value->kind = axs_lvalue_register;
- value->u.reg = data[0] - DW_OP_reg0;
+ 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;
- read_uleb128 (data + 1, data + size, ®);
- value->kind = axs_lvalue_register;
- value->u.reg = 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)
{
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;
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)
+ 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);
+ 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"),
- SYMBOL_PRINT_NAME (symbol));
+ 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]);
}
- 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);
+ data = read_sleb128 (data + 1, end, &frame_offset);
- value->kind = axs_lvalue_memory;
+ 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)
+ 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));
+ data = read_sleb128 (data + 1, end, &offset);
- ax_reg (ax, reg);
- ax_const_l (ax, offset);
- ax_simple (ax, aop_add);
-
- value->kind = axs_lvalue_memory;
+ 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;
+}
+
\f
/* Return the value of SYMBOL in FRAME using the DWARF-2 expression
evaluator to calculate the location. */
dlbaton->per_cu);
}
-/* Print a natural-language description of SYMBOL to STREAM. */
-static int
-locexpr_describe_location (struct symbol *symbol, struct ui_file *stream)
+/* 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)
{
- /* FIXME: be more extensive. */
- struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
- int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
+ 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;
- if (dlbaton->size == 1
- && dlbaton->data[0] >= DW_OP_reg0
- && dlbaton->data[0] <= DW_OP_reg31)
+ 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 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);
+ 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 in register %s",
+ _("a variable at offset %s from base reg $%s"),
+ plongest (offset),
gdbarch_register_name (gdbarch, regno));
- return 1;
}
/* The location expression for a TLS variable looks like this (on a
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;
- }
-
+ 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)"));
- fprintf_filtered (stream,
- "a variable with complex or multiple locations (DWARF2)");
- return 1;
+ return data;
}
+/* Describe a single location, which may in turn consist of multiple
+ pieces. */
-/* Describe the location of SYMBOL as an agent value in VALUE, generating
- any necessary bytecode in AX.
+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. */
- 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_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,
return 1;
}
-/* Print a natural-language description of SYMBOL to STREAM. */
-static int
-loclist_describe_location (struct symbol *symbol, struct ui_file *stream)
+/* 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)
{
- /* FIXME: Could print the entire list of locations. */
- fprintf_filtered (stream, "a variable with multiple locations");
- return 1;
+ 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
projects / external / binutils.git / commitdiff