The idea behind Nuxi CloudABI is that it is targeted at (but not limited to)
running networked services in a sandboxed environment. The model behind stdin,
stdout and stderr is strongly focused on interactive tools in a command shell.
CloudABI does not support the notion of stdin and stdout, as 'standard
input/output' does not apply to services. The concept of stderr does makes
sense though, as services do need some mechanism to log error messages in a
uniform way.
This patch extends libc++ in such a way that std::cin and std::cout and the
associated <cstdio>/<cwchar> functions can be disabled through the flags
_LIBCPP_HAS_NO_STDIN and _LIBCPP_HAS_NO_STDOUT, respectively. At the same time
it attempts to clean up src/iostream.cpp a bit. Instead of using a single array
of mbstate_t objects and hardcoding the array indices, it creates separate
objects that declared next to the iostream objects and their buffers. The code
is also restructured by interleaving the construction and setup of c* and wc*
objects. That way it is more obvious that this is done identically.
The c* and wc* objects already have separate unit tests. Make use of this fact
by adding XFAILs in case libcpp-has-no-std* is set. That way the tests work in
both directions. If stdin or stdout is disabled, these tests will therefore
test for the absence of c* and wc*.
Differential Revision: http://reviews.llvm.org/D8340
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@233275 91177308-0d34-0410-b5e6-96231b3b80d8
If we want to add support for making std::cin and std::cout optional, it
is impractical to have all of the mbstate_t objects in one array. This
would mean that if std::cin and std::cout are omitted, the state_types
array is only used partially.
Solve this by using separate global variables. These are placed right
next to the iostream object and the buffer, meaning we can easily #ifdef
them away.
Differential Revision: http://reviews.llvm.org/D8359
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@233274 91177308-0d34-0410-b5e6-96231b3b80d8
Interleave the code for narrow and wide character streams. This makes it
more obvious that the two pieces of code are identical. Furthermore, it
makes it easier to conditionally compile support for certain streams, as
less #ifdef blocks are needed.
Differential Revision: http://reviews.llvm.org/D8342
Reviewed by: marshall
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@232516 91177308-0d34-0410-b5e6-96231b3b80d8
