libdw: Handle DW_OP_GNU_uninit in dwarf_getlocation
Commit Message
dwarf_getlocation would return an error when it saw a
DW_OP_GNU_uninit. Handle it by simply recognizing as a no argument
operation.
DW_OP_GNU_uninit is emitted by GCC as a marker to flag the location
expression as referring to an uninitialized value.
Signed-off-by: Mark Wielaard <mark@klomp.org>
---
libdw/ChangeLog | 5 +++++
libdw/dwarf_getlocation.c | 1 +
tests/ChangeLog | 4 ++++
tests/varlocs.c | 6 ++++++
4 files changed, 16 insertions(+)
Comments
Hi,
On Fri, 2023-02-10 at 14:01 +0100, Mark Wielaard wrote:
> dwarf_getlocation would return an error when it saw a
> DW_OP_GNU_uninit. Handle it by simply recognizing as a no argument
> operation.
>
> DW_OP_GNU_uninit is emitted by GCC as a marker to flag the location
> expression as referring to an uninitialized value.
I pushed this.
Cheers,
Mark
@@ -1,3 +1,8 @@
+2023-02-10 Mark Wielaard <mark@klomp.org>
+
+ * dwarf_getlocation.c (__libdw_intern_expression): Handle
+ DW_OP_GNU_uninit.
+
2023-01-22 Mark Wielaard <mark@klomp.org>
* dwarf_getscopes.c (pc_record): Return nscopes when done.
@@ -396,6 +396,7 @@ __libdw_intern_expression (Dwarf *dbg, bool other_byte_order,
case DW_OP_form_tls_address:
case DW_OP_GNU_push_tls_address:
case DW_OP_stack_value:
+ case DW_OP_GNU_uninit:
/* No operand. */
break;
@@ -1,3 +1,7 @@
+2023-02-10 Mark Wielaard <mark@klomp.org>
+
+ * varlocs.c (print_expr): Handle DW_OP_GNU_uninit.
+
2023-02-03 Mark Wielaard <mark@klomp.org>
* run-addr2line-C-test.sh: Check ELFUTILS_DISABLE_DEMANGLE.
@@ -251,6 +251,12 @@ print_expr (Dwarf_Attribute *attr, Dwarf_Op *expr, Dwarf_Addr addr, int depth)
printf ("%s", opname);
break;
+ case DW_OP_GNU_uninit:
+ /* No arguments. Special. It means the expression describes
+ an value which hasn't been initialized (yet). */
+ printf ("%s", opname);
+ break;
+
case DW_OP_call_frame_cfa:
/* No arguments. Special. Pushes Call Frame Address as computed
by CFI data (dwarf_cfi_addrframe will fetch that info (either from