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| author | Martin Galvan <martin.galvan@tallertechnologies.com> | 2016-04-18 10:58:14 -0300 |
|---|---|---|
| committer | Martin Galvan <martin.galvan@tallertechnologies.com> | 2016-04-18 10:58:14 -0300 |
| commit | a22df60ad216517bbca4b391bec09f9ded06ab7b (patch) | |
| tree | ed1d096713275c5bbe3a117a669bb5f943b9a049 /gdb/valops.c | |
| parent | 0c13f7e559afe5f973a59311b0e401296c48d96c (diff) | |
| download | gdb-a22df60ad216517bbca4b391bec09f9ded06ab7b.zip gdb-a22df60ad216517bbca4b391bec09f9ded06ab7b.tar.gz gdb-a22df60ad216517bbca4b391bec09f9ded06ab7b.tar.bz2 | |
Fix gdb crash when trying to print the address of a synthetic C++ reference
After compiling a program which uses C++ references some optimizations may
convert the references into synthetic "pointers". Trying to print the address
of one of such synthetic references causes gdb to crash with the following
error:
(gdb) print &ref
/build/buildd/gdb-7.7.1/gdb/dwarf2loc.c:1624: internal-error: Should not be able to create a lazy value with an enclosing type
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Apparently, what was causing it was that value_addr returns a copy of the value
that represents the reference with its type set to T* instead of T&. However,
its enclosing_type is left untouched, which fails a check made in
read_pieced_value. We only see the crash happen for references that are
synthetic because they're treated as pieced values, thus the call to
read_pieced_value.
On a related note, it seems that in general there are all sorts of breakage
when working with synthetic references. This is reported here:
https://sourceware.org/bugzilla/show_bug.cgi?id=19893
gdb/ChangeLog:
2016-04-18 Martin Galvan <martin.galvan@tallertechnologies.com>
* valops.c (value_addr): For C++ references, set the copied value's
enclosing_type as well.
gdb/testsuite/ChangeLog:
2016-04-18 Martin Galvan <martin.galvan@tallertechnologies.com>
* gdb.dwarf2/implref.exp: New file.
Diffstat (limited to 'gdb/valops.c')
| -rw-r--r-- | gdb/valops.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/gdb/valops.c b/gdb/valops.c index 5a244a9..8a555f3 100644 --- a/gdb/valops.c +++ b/gdb/valops.c @@ -1463,11 +1463,20 @@ value_addr (struct value *arg1) if (TYPE_CODE (type) == TYPE_CODE_REF) { /* Copy the value, but change the type from (T&) to (T*). We - keep the same location information, which is efficient, and - allows &(&X) to get the location containing the reference. */ + keep the same location information, which is efficient, and + allows &(&X) to get the location containing the reference. + Do the same to its enclosing type for consistency. */ + struct type *type_ptr + = lookup_pointer_type (TYPE_TARGET_TYPE (type)); + struct type *enclosing_type + = check_typedef (value_enclosing_type (arg1)); + struct type *enclosing_type_ptr + = lookup_pointer_type (TYPE_TARGET_TYPE (enclosing_type)); + arg2 = value_copy (arg1); - deprecated_set_value_type (arg2, - lookup_pointer_type (TYPE_TARGET_TYPE (type))); + deprecated_set_value_type (arg2, type_ptr); + set_value_enclosing_type (arg2, enclosing_type_ptr); + return arg2; } if (TYPE_CODE (type) == TYPE_CODE_FUNC) |