This is the mail archive of the
elfutils-devel@sourceware.org
mailing list for the elfutils project.
[PATCH 2/3] libdw: Update acceptable forms and attributes for dwarf_getlocation.
- From: Mark Wielaard <mark at klomp dot org>
- To: elfutils-devel at sourceware dot org
- Cc: Mark Wielaard <mark at klomp dot org>
- Date: Sun, 5 Nov 2017 00:31:05 +0100
- Subject: [PATCH 2/3] libdw: Update acceptable forms and attributes for dwarf_getlocation.
- Authentication-results: sourceware.org; auth=none
- References: <1509838266-10337-1-git-send-email-mark@klomp.org>
dwarf_getlocation has to know which attributes can contain a DWARF
expression or location list because the form alone might be ambiguous.
Since DWARF4 there is DW_FORM_exprloc so always accept that. But for older
DWARF or location lists we cannot just check for DW_FORM_sec_offset since
that could be a reference to diffent kinds of sections (based on attribute).
Update the attribute list based on the latest DWARF5 encodings table.
Note that DW_AT_call_origin wasn't added because that seems to be a
typo in the DWARF5 spec. http://dwarfstd.org/ShowIssue.php?issue=171103.1
Signed-off-by: Mark Wielaard <mark@klomp.org>
---
libdw/ChangeLog | 5 +++++
libdw/dwarf_getlocation.c | 26 +++++++++++++++++++++++++-
2 files changed, 30 insertions(+), 1 deletion(-)
diff --git a/libdw/ChangeLog b/libdw/ChangeLog
index 7085649..bb9e849 100644
--- a/libdw/ChangeLog
+++ b/libdw/ChangeLog
@@ -1,5 +1,10 @@
2017-11-03 Mark Wielaard <mark@klomp.org>
+ * dwarf_getlocation.c (attr_ok): Always accept DW_FORM_exprloc.
+ Update list of acceptable attribute codes based on DWARF5.
+
+2017-11-03 Mark Wielaard <mark@klomp.org>
+
* dwarf.h: Add DW_OP_GNU_variable_value.
2017-10-03 Mark Wielaard <mark@klomp.org>
diff --git a/libdw/dwarf_getlocation.c b/libdw/dwarf_getlocation.c
index a4a2761..c59546e 100644
--- a/libdw/dwarf_getlocation.c
+++ b/libdw/dwarf_getlocation.c
@@ -45,10 +45,34 @@ attr_ok (Dwarf_Attribute *attr)
if (attr == NULL)
return false;
- /* Must be one of the attributes listed below. */
+ /* If it is an exprloc, it is obviously OK. */
+ if (dwarf_whatform (attr) == DW_FORM_exprloc)
+ return true;
+
+ /* Otherwise must be one of the attributes listed below. Older
+ DWARF versions might have encoded the exprloc as block, and we
+ cannot easily distinquish attributes in the loclist class because
+ the same forms are used for different classes. */
switch (attr->code)
{
case DW_AT_location:
+ case DW_AT_byte_size:
+ case DW_AT_bit_offset:
+ case DW_AT_bit_size:
+ case DW_AT_lower_bound:
+ case DW_AT_bit_stride:
+ case DW_AT_upper_bound:
+ case DW_AT_count:
+ case DW_AT_allocated:
+ case DW_AT_associated:
+ case DW_AT_data_location:
+ case DW_AT_byte_stride:
+ case DW_AT_rank:
+ case DW_AT_call_value:
+ case DW_AT_call_target:
+ case DW_AT_call_target_clobbered:
+ case DW_AT_call_data_location:
+ case DW_AT_call_data_value:
case DW_AT_data_member_location:
case DW_AT_vtable_elem_location:
case DW_AT_string_length:
--
1.8.3.1