destringize_and_run forgets to initialize all the fields of the
cpp_context that it pushes. Later _cpp_pop_context then gets confused
when it accesses context->tokens_kind via the call to macro_of_context
on context->prev.
The first hunk of this patch is the real obvious fix. The second hunk
is just an assert that I am adding to err on the safe side.
Tested by on x86_64-unknown-linux-gnu against trunk by running the
test gcc.dg/gomp/macro-4.c under Valgrind, and bootstrapped.
libcpp/
* directives.c (destringize_and_run): Properly initialize the new
context.
* macro.c (_cpp_pop_context): Assert that we shouldn't try to pop
the initial base context, which has the same life time as the
current instance of cpp_file.
From-SVN: r187054
