[PATCH 15/20] Add attribute::get_unsigned method

Tom Tromey
2020-03-28T19:22:13Z

This introduces a new attribute::get_unsigned method and changes a few
spots to use it.

gdb/ChangeLog
2020-03-28 Tom Tromey <tom@tromey.com>

* dwarf2/read.c (dw2_get_file_names_reader)
(dwarf2_build_include_psymtabs, handle_DW_AT_stmt_list)
(dwarf2_cu::setup_type_unit_groups, fill_in_loclist_baton)
(dwarf2_symbol_mark_computed): Use get_unsigned.
* dwarf2/attribute.h (struct attribute) <get_unsigned>: New
method.
<form_is_section_offset>: Update comment.
---
gdb/ChangeLog | 10 ++++++++++
gdb/dwarf2/attribute.h | 11 ++++++++++-
gdb/dwarf2/read.c | 22 +++++++++++-----------
3 files changed, 31 insertions(+), 12 deletions(-)

diff --git a/gdb/dwarf2/attribute.h b/gdb/dwarf2/attribute.h
index 9b387e5df05..546156283b3 100644
--- a/gdb/dwarf2/attribute.h
+++ b/gdb/dwarf2/attribute.h
@@ -82,9 +82,18 @@ struct attribute
return u.unsnd;
}

+ /* Return the unsigned value. Requires that the form be an unsigned
+ form, and that reprocessing not be needed. */
+ ULONGEST get_unsigned () const
+ {
+ gdb_assert (form_is_unsigned ());
+ gdb_assert (!requires_reprocessing);
+ return u.unsnd;
+ }
+
/* Return non-zero if ATTR's value is a section offset --- classes
lineptr, loclistptr, macptr or rangelistptr --- or zero, otherwise.
- You may use DW_UNSND (attr) to retrieve such offsets.
+ You may use the get_unsigned method to retrieve such offsets.

Section 7.5.4, "Attribute Encodings", explains that no attribute
may have a value that belongs to more than one of these classes; it
diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index efa59fcab4d..abeb0e1a4e9 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -3046,11 +3046,11 @@ dw2_get_file_names_reader (const struct die_reader_specs *reader,
sect_offset line_offset {};

attr = dwarf2_attr (comp_unit_die, DW_AT_stmt_list, cu);
- if (attr != nullptr)
+ if (attr != nullptr && attr->form_is_unsigned ())
{
struct quick_file_names find_entry;

- line_offset = (sect_offset) DW_UNSND (attr);
+ line_offset = (sect_offset) attr->get_unsigned ();

/* We may have already read in this line header (TU line header sharing).
If we have we're done. */
@@ -5892,8 +5892,8 @@ dwarf2_build_include_psymtabs (struct dwarf2_cu *cu,
struct attribute *attr;

attr = dwarf2_attr (die, DW_AT_stmt_list, cu);
- if (attr != nullptr)
- lh = dwarf_decode_line_header ((sect_offset) DW_UNSND (attr), cu);
+ if (attr != nullptr && attr->form_is_unsigned ())
+ lh = dwarf_decode_line_header ((sect_offset) attr->get_unsigned (), cu);
if (lh == NULL)
return; /* No linetable, so no includes. */

@@ -10560,10 +10560,10 @@ handle_DW_AT_stmt_list (struct die_info *die, struct dwarf2_cu *cu,
gdb_assert (! cu->per_cu->is_debug_types);

attr = dwarf2_attr (die, DW_AT_stmt_list, cu);
- if (attr == NULL)
+ if (attr == NULL || !attr->form_is_unsigned ())
return;

- sect_offset line_offset = (sect_offset) DW_UNSND (attr);
+ sect_offset line_offset = (sect_offset) attr->get_unsigned ();

/* The line header hash table is only created if needed (it exists to
prevent redundant reading of the line table for partial_units).
@@ -10752,9 +10752,9 @@ dwarf2_cu::setup_type_unit_groups (struct die_info *die)
/* We have to handle the case of both a missing DW_AT_stmt_list or bad
debug info. */
line_header_up lh;
- if (attr != NULL)
+ if (attr != NULL && attr->form_is_unsigned ())
{
- sect_offset line_offset = (sect_offset) DW_UNSND (attr);
+ sect_offset line_offset = (sect_offset) attr->get_unsigned ();
lh = dwarf_decode_line_header (line_offset, this);
}
if (lh == NULL)
@@ -22526,8 +22526,8 @@ fill_in_loclist_baton (struct dwarf2_cu *cu,
gdb_assert (baton->per_cu);
/* We don't know how long the location list is, but make sure we
don't run off the edge of the section. */
- baton->size = section->size - DW_UNSND (attr);
- baton->data = section->buffer + DW_UNSND (attr);
+ baton->size = section->size - attr->get_unsigned ();
+ baton->data = section->buffer + attr->get_unsigned ();
if (cu->base_address.has_value ())
baton->base_address = *cu->base_address;
else
@@ -22548,7 +22548,7 @@ dwarf2_symbol_mark_computed (const struct attribute *attr, struct symbol *sym,
/* .debug_loc{,.dwo} may not exist at all, or the offset may be outside
the section. If so, fall through to the complaint in the
other branch. */
- && DW_UNSND (attr) < section->get_size (objfile))
+ && attr->get_unsigned () < section->get_size (objfile))
{
struct dwarf2_loclist_baton *baton;

--
2.17.2