Implement P0035R4, C++17 new of over-aligned types.

gcc/cp/
	* cp-tree.h (enum cp_tree_index): Add CPTI_ALIGN_TYPE.
	(align_type_node): New macro.
	* call.c (build_operator_new_call): Handle C++17 aligned new.
	(second_parm_is_size_t, build_op_delete_call): Likewise.
	(non_placement_deallocation_fn_p): Likewise. Rename to
	usual_deallocation_fn_p.
	(aligned_allocation_fn_p, aligned_deallocation_fn_p): New.
	* decl.c (cxx_init_decl_processing): Add aligned new support.
	* init.c (type_has_new_extended_alignment): New.
	(build_new_1): Handle aligned new.
	* tree.c (vec_copy_and_insert): New.
gcc/c-family/
	* c.opt: Add -faligned-new and -Waligned-new.
	* c-common.c (max_align_t_align): Split out from...
	(cxx_fundamental_alignment_p): ...here.
	* c-common.h: Declare it.
	* c-cppbuiltin.c (c_cpp_builtins): Handle aligned new.
libstdc++-v3/
	* libsupc++/new: Declare aligned new/delete operators.
	* config/abi/pre/gnu.ver: Export them.
	* configure.ac: Check for aligned_alloc, posix_memalign, memalign,
	_aligned_malloc.
	* libsupc++/new_opa.cc: New.
	* libsupc++/new_opant.cc: New.
	* libsupc++/new_opva.cc: New.
	* libsupc++/new_opva.cc: New.
	* libsupc++/del_opa.cc: New.
	* libsupc++/del_opant.cc: New.
	* libsupc++/del_opsa.cc: New.
	* libsupc++/del_opva.cc: New.
	* libsupc++/del_opvant.cc: New.
	* libsupc++/del_opvsa.cc: New.
	* libsupc++/Makefile.am: Build them.

From-SVN: r240056

1 files changed, 22 insertions, 1 deletions

diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 20be9b7..b2eaea7 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -190,7 +190,7 @@ in the following sections.
 @item C++ Language Options
 @xref{C++ Dialect Options,,Options Controlling C++ Dialect}.
 @gccoptlist{-fabi-version=@var{n}  -fno-access-control @gol
--fargs-in-order=@var{n} -fcheck-new @gol
+-faligned-new=@var{n} -fargs-in-order=@var{n} -fcheck-new @gol
 -fconstexpr-depth=@var{n} -fconstexpr-loop-limit=@var{n} @gol
 -ffriend-injection @gol
 -fno-elide-constructors @gol
@@ -2237,6 +2237,15 @@ option is used for the warning.
 Turn off all access checking.  This switch is mainly useful for working
 around bugs in the access control code.
 
+@item -faligned-new
+@opindex faligned-new
+Enable support for C++17 @code{new} of types that require more
+alignment than @code{void* ::operator new(std::size_t)} provides.  A
+numeric argument such as @code{-faligned-new=32} can be used to
+specify how much alignment (in bytes) is provided by that function,
+but few users will need to override the default of
+@code{alignof(std::max_align_t)}.
+
 @item -fcheck-new
 @opindex fcheck-new
 Check that the pointer returned by @code{operator new} is non-null
@@ -5062,6 +5071,18 @@ disables the warnings about non-ISO @code{printf} / @code{scanf} format
 width specifiers @code{I32}, @code{I64}, and @code{I} used on Windows targets,
 which depend on the MS runtime.
 
+@item -Waligned-new
+@opindex Waligned-new
+@opindex Wno-aligned-new
+Warn about a new-expression of a type that requires greater alignment
+than the @code{alignof(std::max_align_t)} but uses an allocation
+function without an explicit alignment parameter. This option is
+enabled by @option{-Wall}.
+
+Normally this only warns about global allocation functions, but
+@option{-Waligned-new=all} also warns about class member allocation
+functions.
+
 @item -Wplacement-new
 @itemx -Wplacement-new=@var{n}
 @opindex Wplacement-new