Jiahao Li c1cf82f9c8 variant: fix uninitialized memory access in variant<> ...

Currently, in bison's C++ parser template (`lalr.cc`), the `variant<>`
struct's `build()` method uses placement-new in the form `new (...) T`
to initialize a variant type.  However, for POD variant types, this
will leave the memory space uninitialized.  If we subsequently tries
to `::move` into a variant object in such state, the call can trigger
clang's undefined behavior sanitizer due to accessing the
uninitialized memory.

https://lists.gnu.org/archive/html/bison-patches/2018-08/msg00098.html

* data/variant.hh (build): Always initialize the stored value.

Signed-off-by: Akim Demaille <akim@lrde.epita.fr>

2018-08-25 07:25:05 +02:00

9.8 KiB

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