According to MSVC manual (*1), cl.exe can skip including a header file
when that:
- contains #pragma once, or
- starts with #ifndef, or
- starts with #if ! defined.
GCC has a similar trick (*2), but it acts more stricter (e. g. there
must be _no tokens_ outside of #ifndef...#endif).
Sun C lacked #pragma once for a looong time. Oracle Developer Studio
12.5 finally implemented it, but we cannot assume such recent version.
This changeset modifies header files so that each of them include
strictly one #ifndef...#endif. I believe this is the most portable way
to trigger compiler optimizations. [Bug #16770]
*1: https://docs.microsoft.com/en-us/cpp/preprocessor/once
*2: https://gcc.gnu.org/onlinedocs/cppinternals/Guard-Macros.html
hook a VM termination. Right now, because the VM we have is
process global, most extensions do not deallocate resources and
leave them to Operating System's reaping userland processes. But
in a future we plan to have multiple VMs to run simultaneously in
a single process (MVM project). At that stage we can no longer
rely on OSes and have to manage every resources to be reclaimed
properly. So it is. For a forward-compatibility reason this API
is introduced now, encouraging you to be as gentle as you can for
your resources; that is, tidy up your room.
* include/ruby/vm.h: ditto.
* vm_core.h (rb_vm_struct): new field.
* vm.c (vm_init2): initialize above new field.
* eval.c (ruby_cleanup): trigger those hooks.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@30050 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* eval.c (ruby_cleanup): destruct current VM before exit.
* gc.c (rb_objspace_free): free object space.
* vm.c (ruby_vm_destruct): destruct and free VM struct.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@25000 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* common.mk: remove vm.h from any rules.
vm.h is not needed on this version.
* vm_core.h: ditto.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@19882 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
