[PATCH v3 13/28] Add is_optimized_out to dwarf_location class
Zoran Zaric
zoran.zaric@amd.com
Thu Oct 14 09:32:20 GMT 2021
Similarly to the is_implicit_ptr_at method, the existing function
callback interface of the computed struct value, requiers a way to
check if the underlying location description describes any part as
optimized out.
gdb/ChangeLog:
* dwarf2/expr.c (dwarf_location::is_optimized_out):
New method.
(dwarf_implicit::is_optimized_out): New method.
(dwarf_register::is_optimized_out): New method.
(dwarf_composite::is_optimized_out): New method.
---
gdb/dwarf2/expr.c | 97 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 97 insertions(+)
diff --git a/gdb/dwarf2/expr.c b/gdb/dwarf2/expr.c
index af84710b054..1b6622d5f59 100644
--- a/gdb/dwarf2/expr.c
+++ b/gdb/dwarf2/expr.c
@@ -492,6 +492,21 @@ class dwarf_location : public dwarf_entry
return nullptr;
}
+ /* Check if location description resolves into optimized out.
+
+ The check operation is performed in the context of a FRAME.
+ BIG_ENDIAN defines the endianness of the target, BIT_SIZE is the
+ number of bits to read and BITS_TO_SKIP is a bit offset into the
+ location. LOCATION_BIT_LIMIT is a maximum number of bits that
+ location can hold, where value zero signifies that there is
+ no such restriction. */
+ virtual bool is_optimized_out (frame_info *frame, bool big_endian,
+ LONGEST bits_to_skip, size_t bit_size,
+ size_t location_bit_limit) const
+ {
+ return false;
+ }
+
protected:
/* Architecture of the location. */
gdbarch *m_arch;
@@ -666,6 +681,13 @@ class dwarf_undefined final : public dwarf_location
*unavailable = 0;
*optimized = 1;
}
+
+ bool is_optimized_out (frame_info *frame, bool big_endian,
+ LONGEST bits_to_skip, size_t bit_size,
+ size_t location_bit_limit) const override
+ {
+ return true;
+ }
};
class dwarf_memory final : public dwarf_location
@@ -904,6 +926,10 @@ class dwarf_register final : public dwarf_location
size_t location_bit_limit, bool big_endian,
int *optimized, int *unavailable) const override;
+ bool is_optimized_out (frame_info *frame, bool big_endian,
+ LONGEST bits_to_skip, size_t bit_size,
+ size_t location_bit_limit) const override;
+
private:
/* DWARF register number. */
unsigned int m_regnum;
@@ -997,6 +1023,24 @@ dwarf_register::write (frame_info *frame, const gdb_byte *buf,
temp_buf, optimized, unavailable);
}
+bool
+dwarf_register::is_optimized_out (frame_info *frame, bool big_endian,
+ LONGEST bits_to_skip, size_t bit_size,
+ size_t location_bit_limit) const
+{
+ int optimized, unavailable;
+ gdb::byte_vector temp_buf (bit_size);
+
+ this->read (frame, temp_buf.data (), 0, bit_size,
+ bits_to_skip, location_bit_limit,
+ big_endian, &optimized, &unavailable);
+
+ if (optimized)
+ return true;
+
+ return false;
+}
+
/* Implicit location description entry. Describes a location
description not found on the target but instead saved in a
gdb-allocated buffer. */
@@ -1025,6 +1069,13 @@ class dwarf_implicit final : public dwarf_location
*unavailable = 0;
}
+ bool is_optimized_out (frame_info *frame, bool big_endian,
+ LONGEST bits_to_skip, size_t bit_size,
+ size_t location_bit_limit) const override
+ {
+ return true;
+ }
+
private:
/* Implicit location contents as a stream of bytes in target byte-order. */
gdb::byte_vector m_contents;
@@ -1230,6 +1281,10 @@ class dwarf_composite final : public dwarf_location
LONGEST bit_offset = 0,
int bit_length = 0) const override;
+ bool is_optimized_out (frame_info *frame, bool big_endian,
+ LONGEST bits_to_skip, size_t bit_size,
+ size_t location_bit_limit) const override;
+
private:
/* Composite piece that contains a piece location
description and it's size. */
@@ -1497,6 +1552,48 @@ dwarf_composite::indirect_implicit_ptr (frame_info *frame, struct type *type,
return nullptr;
}
+bool
+dwarf_composite::is_optimized_out (frame_info *frame, bool big_endian,
+ LONGEST bits_to_skip, size_t bit_size,
+ size_t location_bit_limit) const
+{
+ ULONGEST total_bits_to_skip
+ = bits_to_skip + HOST_CHAR_BIT * m_offset + m_bit_suboffset;
+ ULONGEST remaining_bit_size = bit_size;
+ unsigned int pieces_num = m_pieces.size ();
+ unsigned int i;
+
+ /* Advance to the first non-skipped piece. */
+ for (i = 0; i < pieces_num; i++)
+ {
+ ULONGEST piece_bit_size = m_pieces[i].size;
+
+ if (total_bits_to_skip < piece_bit_size)
+ break;
+
+ total_bits_to_skip -= piece_bit_size;
+ }
+
+ for (; i < pieces_num; i++)
+ {
+ const dwarf_location &location = *m_pieces[i].location;
+ ULONGEST piece_bit_size = m_pieces[i].size;
+ size_t this_bit_size = piece_bit_size - total_bits_to_skip;
+
+ if (this_bit_size > remaining_bit_size)
+ this_bit_size = remaining_bit_size;
+
+ if (location.is_optimized_out (frame, big_endian, total_bits_to_skip,
+ this_bit_size, piece_bit_size))
+ return true;
+
+ remaining_bit_size -= this_bit_size;
+ total_bits_to_skip = 0;
+ }
+
+ return false;
+}
+
struct piece_closure
{
/* Reference count. */
--
2.17.1
More information about the Gdb-patches
mailing list