Use correct sign in get_mpz
This changes dwarf2/read.c:get_mpz to use the correct sign-extension
function. Normally a rational constant uses signed values, but a
purely unsigned form also seems fine here. This adds a new
attribute::form_is_strictly_unsigned, which is more precise than
form_is_unsigned (which accepts a lot of forms that aren't really for
ordinary constants).
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32680
diff --git a/gdb/dwarf2/attribute.h b/gdb/dwarf2/attribute.h
index 460cbcf..31ff018 100644
--- a/gdb/dwarf2/attribute.h
+++ b/gdb/dwarf2/attribute.h
@@ -175,6 +175,15 @@ struct attribute
false. */
bool form_is_strictly_signed () const;
+ /* Check if the attribute's form is an unsigned constant form. This
+ only returns true for forms that are strictly unsigned -- that
+ is, for a context-dependent form like DW_FORM_data1, this returns
+ false. */
+ bool form_is_strictly_unsigned () const
+ {
+ return form == DW_FORM_udata;
+ }
+
/* Check if the attribute's form is a form that requires
"reprocessing". */
bool form_requires_reprocessing () const;
diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index aae74e9..c5e62dd 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -13216,10 +13216,10 @@ get_mpz (struct dwarf2_cu *cu, gdb_mpz *value, struct attribute *attr)
? BFD_ENDIAN_BIG : BFD_ENDIAN_LITTLE,
true);
}
- else if (attr->form_is_unsigned ())
+ else if (attr->form_is_strictly_unsigned ())
*value = gdb_mpz (attr->as_unsigned ());
else
- *value = gdb_mpz (attr->constant_value (1));
+ *value = gdb_mpz (attr->signed_constant ().value_or (1));
}
/* Assuming DIE is a rational DW_TAG_constant, read the DIE's
