[PATCHv3 1/2] gdb/amd64: Ignore zero sized fields when calling functions
Andrew Burgess
andrew.burgess@embecosm.com
Fri Mar 2 20:10:00 GMT 2018
In some cases passing an argument to a function on amd64, or attempting
to fetch the return value, can trigger an assertion failure within GDB.
An example of a type that would trigger such an error is:
struct foo_t
{
long double a;
struct {
struct {
/* Empty. */
} es1;
} s1;
};
GCC does permit empty structures, so we should probably support this.
The test that exposes this bug is in the next commit along with the
RiscV support.
gdb/ChangeLog:
* amd64-tdep.c (amd64_classify_aggregate): Ignore zero sized
fields within aggregates.
---
gdb/ChangeLog | 5 +++++
gdb/amd64-tdep.c | 5 +++--
2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/gdb/amd64-tdep.c b/gdb/amd64-tdep.c
index 6b92c9244c6..07eef5ea9f0 100644
--- a/gdb/amd64-tdep.c
+++ b/gdb/amd64-tdep.c
@@ -601,8 +601,9 @@ amd64_classify_aggregate (struct type *type, enum amd64_reg_class theclass[2])
bitsize = TYPE_LENGTH (subtype) * 8;
endpos = (TYPE_FIELD_BITPOS (type, i) + bitsize - 1) / 64;
- /* Ignore static fields. */
- if (field_is_static (&TYPE_FIELD (type, i)))
+ /* Ignore static fields, or empty fields, for example nested
+ empty structures.*/
+ if (field_is_static (&TYPE_FIELD (type, i)) || bitsize == 0)
continue;
gdb_assert (pos == 0 || pos == 1);
--
2.14.3
More information about the Gdb-patches
mailing list