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| author | Tom Tromey <tom@tromey.com> | 2019-10-03 17:21:52 -0600 |
|---|---|---|
| committer | Tom Tromey <tom@tromey.com> | 2019-10-03 20:56:22 -0600 |
| commit | 77c2dba3e843694fae090e237ccdf1b8f65b94e6 (patch) | |
| tree | 8076f2237aa8155c67f4adbad3c5e40317969d0d /gdb/dwarf2read.c | |
| parent | f0e21cb80940c065dcc373c29dc33388cf948dbc (diff) | |
| download | fsf-binutils-gdb-77c2dba3e843694fae090e237ccdf1b8f65b94e6.zip fsf-binutils-gdb-77c2dba3e843694fae090e237ccdf1b8f65b94e6.tar.gz fsf-binutils-gdb-77c2dba3e843694fae090e237ccdf1b8f65b94e6.tar.bz2 | |
Avoid crash on single-field union in Rust
PR rust/24976 points out a crash in gdb when a single-field union is
used in Rust.
The immediate problem was a NULL pointer dereference in
quirk_rust_enum. However, that code is also erroneously treating a
single-field union as if it were a univariant enum. Looking at the
output of an older Rust compiler, it turns out that univariant enums
are distinguished by having a single *anonymous* field. This patch
changes quirk_rust_enum to limit its fixup to this case.
Tested with a new-enough version of the Rust compiler to cause the
crash; plus by using an older executable that uses the old univariant
encoding.
gdb/ChangeLog
2019-10-03 Tom Tromey <tom@tromey.com>
PR rust/24976:
* dwarf2read.c (quirk_rust_enum): Handle single-element unions.
gdb/testsuite/ChangeLog
2019-10-03 Tom Tromey <tom@tromey.com>
PR rust/24976:
* gdb.rust/simple.rs (Union2): New type.
(main): Use Union2.
* gdb.rust/simple.exp: Add test.
Diffstat (limited to 'gdb/dwarf2read.c')
| -rw-r--r-- | gdb/dwarf2read.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c index c0dd199..ee9df34 100644 --- a/gdb/dwarf2read.c +++ b/gdb/dwarf2read.c @@ -10076,10 +10076,10 @@ quirk_rust_enum (struct type *type, struct objfile *objfile) SET_FIELD_BITPOS (TYPE_FIELD (type, 0), 0); TYPE_FIELD_NAME (type, 0) = "<<variants>>"; } - else if (TYPE_NFIELDS (type) == 1) + /* A union with a single anonymous field is probably an old-style + univariant enum. */ + else if (TYPE_NFIELDS (type) == 1 && streq (TYPE_FIELD_NAME (type, 0), "")) { - /* We assume that a union with a single field is a univariant - enum. */ /* Smash this type to be a structure type. We have to do this because the type has already been recorded. */ TYPE_CODE (type) = TYPE_CODE_STRUCT; |