re PR c++/54046 (wrong control reaches end of non-void function for switch case with throw and default)
PR c++/54046
* Makefile.in (gimple-low.o): Depend on langhooks.h.
* gimple-low.c: Include langhooks.c.
(block_may_fallthru): Handle TARGET_EXPR and ERROR_MARK,
by default call lang_hooks.block_may_fallthru.
* langhooks.h (struct lang_hooks): Add block_may_fallthru
langhook.
* langhooks-def.h (LANG_HOOKS_BLOCK_MAY_FALLTHRU): Define.
(LANG_HOOKS_INITIALIZER): Use it.
* cp-objcp-common.h (LANG_HOOKS_BLOCK_MAY_FALLTHRU): Redefine.
* cp-objcp-common.c (cxx_block_may_fallthru): New function.
* cp-tree.h (cxx_block_may_fallthru): New prototype.
* g++.dg/warn/Wreturn-type-8.C: New test.
From-SVN: r193762
