This patch rewrites the old VEC macro-based interface into a new one based on the template class 'vec'.

This patch rewrites the old VEC macro-based interface into a new one
based on the template class 'vec'.  The user-visible changes are
described in http://gcc.gnu.org/wiki/cxx-conversion/cxx-vec.

I have tested the patch pretty extensively:

- Regular bootstraps on x86_64, ppc, ia64, sparc and hppa.
- Bootstraps with --enable-checking=release
- Bootstraps with --enable-checking=gc,gcac
- Basic builds on all targets (using contrib/config-list.mk).

We no longer access the vectors via VEC_* macros.  The pattern is
"VEC_operation (T, A, V, args)" becomes "V.operation (args)".

The only thing I could not do is create proper ctors and dtors for the
vec class.  Since these vectors are stored in unions, we
have to keep them as PODs (C++03 does not allow non-PODs in unions).

This means that creation and destruction must be explicit.  There is a
new method vec<type, allocation, layout>::create() and another vec<type,
allocation, layout>::destroy() to allocate the internal vector.

For vectors that must be pointers, there is a family of free functions
that implement the operations that need to tolerate NULL vectors.
These functions all start with the prefix 'vec_safe_'.  See the wiki
page for details.

The gengtype change removes the special handling for VEC() that used
to exist in gengtype. Additionally, it allows gengtype to recognize
templates of more than one argument and introduces the concept of an
undefined type (useful for template arguments that may or may not be
types).

When a TYPE_UNDEFINED is reached, gengtype will ignore it if it
happens inside a type marked with GTY((user)).  Otherwise, it will
emit an error.

Finally, gengtype rejects root types marked GTY((user)) that are not
first class pointers.

2012-11-16  Diego Novillo  <dnovillo@google.com>

	VEC API overhaul (http://gcc.gnu.org/wiki/cxx-conversion/cxx-vec)

	* vec.c (register_overhead): Convert it into
	member function of vec_prefix.
	(release_overhead): Likewise.
	(calculate_allocation): Likewise.
	(vec_heap_free): Remove.
	(vec_gc_o_reserve_1): Remove.
	(vec_heap_o_reserve_1): Remove.
	(vec_stack_o_reserve_1): Remove.
	(vec_stack_o_reserve_exact): Remove.
	(register_stack_vec): New.
	(stack_vec_register_index): New.
	(unregister_stack_vec): New.
	(vec_assert_fail): Remove.
	* vec.h: Conditionally include ggc.h.  Document conditional
	hackery.
	Update top-level documentation.
	(ALONE_VEC_CHECK_INFO): Remove.
	(VEC_CHECK_INFO): Remove.
	(ALONE_VEC_CHECK_DECL): Remove.
	(VEC_CHECK_DECL): Remove.
	(ALONE_VEC_CHECK_PASS): Remove.
	(VEC_CHECK_PASS): Remove.
	(VEC_ASSERT): Remove.
	(vec_prefix): Add friends va_gc, va_gc_atomic, va_heap and
	va_stack.
	Mark fields alloc_ and num_ as protected.
	(struct vec_t): Remove.  Remove all function members.
	(struct vl_embed): Declare.
	(struct vl_ptr): Declare.
	(free): Remove.
	(reserve_exact): Remove.
	(reserve): Remove.
	(safe_splice): Remove.
	(safe_push): Remove.
	(safe_grow): Remove.
	(safe_grow_cleared): Remove.
	(safe_insert): Remove.
	(DEF_VEC_I): Remove.
	(DEF_VEC_ALLOC_I): Remove.
	(DEF_VEC_P): Remove.
	(DEF_VEC_ALLOC_P): Remove.
	(DEF_VEC_O): Remove.
	(DEF_VEC_ALLOC_O): Remove.
	(DEF_VEC_ALLOC_P_STACK): Remove.
	(DEF_VEC_ALLOC_O_STACK): Remove.
	(DEF_VEC_ALLOC_I_STACK): Remove.
	(DEF_VEC_A): Remove.
	(DEF_VEC_ALLOC_A): Remove.
	(vec_stack_p_reserve_exact_1): Remove.
	(vec_stack_o_reserve): Remove.
	(vec_stack_o_reserve_exact): Remove.
	(VEC_length): Remove.
	(VEC_empty): Remove.
	(VEC_address): Remove.
	(vec_address): Remove.
	(VEC_last): Remove.
	(VEC_index): Remove.
	(VEC_iterate): Remove.
	(VEC_embedded_size): Remove.
	(VEC_embedded_init): Remove.
	(VEC_free): Remove.
	(VEC_copy): Remove.
	(VEC_space): Remove.
	(VEC_reserve): Remove.
	(VEC_reserve_exact): Remove.
	(VEC_splice): Remove.
	(VEC_safe_splice): Remove.
	(VEC_quick_push): Remove.
	(VEC_safe_push): Remove.
	(VEC_pop): Remove.
	(VEC_truncate): Remove.
	(VEC_safe_grow): Remove.
	(VEC_replace): Remove.
	(VEC_quick_insert): Remove.
	(VEC_safe_insert): Remove.
	(VEC_ordered_remove): Remove.
	(VEC_unordered_remove): Remove.
	(VEC_block_remove): Remove.
	(VEC_lower_bound): Remove.
	(VEC_alloc): Remove.
	(VEC_qsort): Remove.

	(va_heap): Declare.
	(va_heap::default_layout): New typedef to vl_ptr.
	(va_heap::reserve): New.
	(va_heap::release): New.
	(va_gc): Declare.
	(va_gc::default_layout): New typedef to vl_embed.
	(va_gc::reserve): New.
	(va_gc::release): New.
	(va_gc_atomic): Declare.  Inherit from va_gc.
	(va_stack): Declare.
	(va_stack::default_layout): New typedef to vl_ptr.
	(va_stack::alloc): New.
	(va_stack::reserve): New.
	(va_stack::release): New.
	(register_stack_vec): Declare.
	(stack_vec_register_index): Declare.
	(unregister_stack_vec): Declare.

	(vec<T, A = va_heap, L = typename A::default_layout>): Declare
	empty vec template.
	(vec<T, A, vl_embed>): Partial specialization for embedded
	layout.
	(vec<T, A, vl_embed>::allocated): New.
	(vec<T, A, vl_embed>::length): New.
	(vec<T, A, vl_embed>::is_empty): New.
	(vec<T, A, vl_embed>::address): New.
	(vec<T, A, vl_embed>::operator[]): New.
	(vec<T, A, vl_embed>::last New.
	(vec<T, A, vl_embed>::space): New.
	(vec<T, A, vl_embed>::iterate): New.
	(vec<T, A, vl_embed>::iterate): New.
	(vec<T, A, vl_embed>::copy): New.
	(vec<T, A, vl_embed>::splice): New.
	(vec<T, A, vl_embed>::quick_push New.
	(vec<T, A, vl_embed>::pop New.
	(vec<T, A, vl_embed>::truncate): New.
	(vec<T, A, vl_embed>::quick_insert): New.
	(vec<T, A, vl_embed>::ordered_remove): New.
	(vec<T, A, vl_embed>::unordered_remove): New.
	(vec<T, A, vl_embed>::block_remove): New.
	(vec<T, A, vl_embed>::qsort): New.
	(vec<T, A, vl_embed>::lower_bound): New.
	(vec<T, A, vl_embed>::embedded_size): New.
	(vec<T, A, vl_embed>::embedded_init): New.
	(vec<T, A, vl_embed>::quick_grow): New.
	(vec<T, A, vl_embed>::quick_grow_cleared): New.
	(vec_safe_space): New.
	(vec_safe_length): New.
	(vec_safe_address): New.
	(vec_safe_is_empty): New.
	(vec_safe_reserve): New.
	(vec_safe_reserve_exact): New.
	(vec_alloc): New.
	(vec_free): New.
	(vec_safe_grow): New.
	(vec_safe_grow_cleared): New.
	(vec_safe_iterate): New.
	(vec_safe_push): New.
	(vec_safe_insert): New.
	(vec_safe_truncate): New.
	(vec_safe_copy): New.
	(vec_safe_splice): New.

	(vec<T, A, vl_ptr>): New partial specialization for the space
	efficient layout.
	(vec<T, A, vl_ptr>::exists): New.
	(vec<T, A, vl_ptr>::is_empty): New.
	(vec<T, A, vl_ptr>::length): New.
	(vec<T, A, vl_ptr>::address): New.
	(vec<T, A, vl_ptr>::operator[]): New.
	(vec<T, A, vl_ptr>::operator!=): New.
	(vec<T, A, vl_ptr>::operator==): New.
	(vec<T, A, vl_ptr>::last): New.
	(vec<T, A, vl_ptr>::space): New.
	(vec<T, A, vl_ptr>::iterate): New.
	(vec<T, A, vl_ptr>::copy): New.
	(vec<T, A, vl_ptr>::reserve): New.
	(vec<T, A, vl_ptr>::reserve_exact): New.
	(vec<T, A, vl_ptr>::splice): New.
	(vec<T, A, vl_ptr>::safe_splice): New.
	(vec<T, A, vl_ptr>::quick_push): New.
	(vec<T, A, vl_ptr>::safe_push): New.
	(vec<T, A, vl_ptr>::pop): New.
	(vec<T, A, vl_ptr>::truncate): New.
	(vec<T, A, vl_ptr>::safe_grow): New.
	(vec<T, A, vl_ptr>::safe_grow_cleared): New.
	(vec<T, A, vl_ptr>::quick_grow): New.
	(vec<T, A, vl_ptr>::quick_grow_cleared): New.
	(vec<T, A, vl_ptr>::quick_insert): New.
	(vec<T, A, vl_ptr>::safe_insert): New.
	(vec<T, A, vl_ptr>::ordered_remove): New.
	(vec<T, A, vl_ptr>::unordered_remove): New.
	(vec<T, A, vl_ptr>::block_remove): New.
	(vec<T, A, vl_ptr>::qsort): New.
	(vec<T, A, vl_ptr>::lower_bound): New.
	(vec_stack_alloc): Define.
	(FOR_EACH_VEC_SAFE_ELT): Define.
	* vecir.h: Remove.  Update all users.
	* vecprim.h: Remove.  Update all users.
	Move uchar to coretypes.h.

	* Makefile.in (VEC_H): Add $(GGC_H).
	Remove vecir.h and vecprim.h dependencies everywhere.

2012-11-16  Diego Novillo  <dnovillo@google.com>

	* gengtype-lex.l (VEC): Remove.
	Add characters in the set [\!\>\.-].
	* gengtype-parse.c (token_names): Remove "VEC".
	(require_template_declaration): Remove handling of VEC_TOKEN.
	(type): Likewise.
	Call create_user_defined_type when parsing GTY((user)).
	* gengtype-state.c (type_lineloc): handle TYPE_UNDEFINED.
	(write_state_undefined_type): New.
	(write_state_type): Call write_state_undefined_type for
	TYPE_UNDEFINED.
	(read_state_type): Call read_state_undefined_type for
	TYPE_UNDEFINED.
	* gengtype.c (dbgprint_count_type_at): Handle TYPE_UNDEFINED.
	(create_user_defined_type): Make extern.
	(type_for_name): Factor out of resolve_typedef.
	(create_undefined_type): New
	(resolve_typedef): Call it when we cannot find a previous
	typedef and the type is not a template.
	(find_structure): Accept TYPE_UNDEFINED.
	(set_gc_used_type): Add argument ALLOWED_UNDEFINED_TYPES,
	default to false.
	Emit an error for TYPE_UNDEFINED unless LEVEL is GC_UNUSED or
	ALLOWED_UNDEFINED_TYPES is set.
	Set ALLOWED_UNDEFINED_TYPES to true for TYPE_USER_STRUCT.
	(filter_type_name): Accept templates with more than one
	argument.
	(output_mangled_typename): Handle TYPE_UNDEFINED
	(walk_type): Likewise.
	(write_types_process_field): Likewise.
	(write_func_for_structure): If CHAIN_NEXT is set, ORIG_S
	should not be a user-defined type.
	(write_types_local_user_process_field): Handle TYPE_ARRAY,
	TYPE_NONE and TYPE_UNDEFINED.
	(write_types_local_process_field): Likewise.
	(contains_scalar_p): Return 0 for TYPE_USER_STRUCT.
	(write_root): Reject user-defined types that are not pointers.
	Handle TYPE_NONE, TYPE_UNDEFINED, TYPE_UNION, TYPE_LANG_STRUCT
	and TYPE_PARAM_STRUCT.
	(output_typename): Handle TYPE_NONE, TYPE_UNDEFINED, and
	TYPE_ARRAY.
	(dump_typekind): Handle TYPE_UNDEFINED.
	* gengtype.h (enum typekind): Add TYPE_UNDEFINED.
	(create_user_defined_type): Declare.
	(enum gty_token): Remove VEC_TOKEN.

2012-11-16  Diego Novillo  <dnovillo@google.com>

	Adjust for new vec API (http://gcc.gnu.org/wiki/cxx-conversion/cxx-vec)

	* coretypes.h (uchar): Define.
	* alias.c: Use new vec API in vec.h.
	* asan.c: Likewise.
	* attribs.c: Likewise.
	* basic-block.h: Likewise.
	* bb-reorder.c: Likewise.
	* builtins.c: Likewise.
	* calls.c: Likewise.
	* cfg.c: Likewise.
	* cfganal.c: Likewise.
	* cfgcleanup.c: Likewise.
	* cfgexpand.c: Likewise.
	* cfghooks.c: Likewise.
	* cfghooks.h: Likewise.
	* cfgloop.c: Likewise.
	* cfgloop.h: Likewise.
	* cfgloopanal.c: Likewise.
	* cfgloopmanip.c: Likewise.
	* cfgrtl.c: Likewise.
	* cgraph.c: Likewise.
	* cgraph.h: Likewise.
	* cgraphclones.c: Likewise.
	* cgraphunit.c: Likewise.
	* combine.c: Likewise.
	* compare-elim.c: Likewise.
	* coverage.c: Likewise.
	* cprop.c: Likewise.
	* data-streamer.h: Likewise.
	* dbxout.c: Likewise.
	* dce.c: Likewise.
	* df-core.c: Likewise.
	* df-problems.c: Likewise.
	* df-scan.c: Likewise.
	* dominance.c: Likewise.
	* domwalk.c: Likewise.
	* domwalk.h: Likewise.
	* dse.c: Likewise.
	* dwarf2cfi.c: Likewise.
	* dwarf2out.c: Likewise.
	* dwarf2out.h: Likewise.
	* emit-rtl.c: Likewise.
	* except.c: Likewise.
	* except.h: Likewise.
	* expr.c: Likewise.
	* expr.h: Likewise.
	* final.c: Likewise.
	* fold-const.c: Likewise.
	* function.c: Likewise.
	* function.h: Likewise.
	* fwprop.c: Likewise.
	* gcc.c: Likewise.
	* gcse.c: Likewise.
	* genattr.c: Likewise.
	* genattrtab.c: Likewise.
	* genautomata.c: Likewise.
	* genextract.c: Likewise.
	* genopinit.c: Likewise
	* ggc-common.c: Likewise.
	* ggc.h: Likewise.
	* gimple-low.c: Likewise.
	* gimple-ssa-strength-reduction.c: Likewise.
	* gimple-streamer-in.c: Likewise.
	* gimple.c: Likewise.
	* gimple.h: Likewise.
	* gimplify.c: Likewise.
	* graph.c: Likewise.
	* graphds.c: Likewise.
	* graphds.h: Likewise.
	* graphite-blocking.c: Likewise.
	* graphite-clast-to-gimple.c: Likewise.
	* graphite-dependences.c: Likewise.
	* graphite-interchange.c: Likewise.
	* graphite-optimize-isl.c: Likewise.
	* graphite-poly.c: Likewise.
	* graphite-poly.h: Likewise.
	* graphite-scop-detection.c: Likewise.
	* graphite-scop-detection.h: Likewise.
	* graphite-sese-to-poly.c: Likewise.
	* graphite.c: Likewise.
	* godump.c: Likewise.
	* haifa-sched.c: Likewise.
	* hw-doloop.c: Likewise.
	* hw-doloop.h: Likewise.
	* ifcvt.c: Likewise.
	* insn-addr.h: Likewise.
	* ipa-cp.c: Likewise.
	* ipa-inline-analysis.c: Likewise.
	* ipa-inline-transform.c: Likewise.
	* ipa-inline.c: Likewise.
	* ipa-inline.h: Likewise.
	* ipa-prop.c: Likewise.
	* ipa-prop.h: Likewise.
	* ipa-pure-const.c: Likewise.
	* ipa-ref-inline.h: Likewise.
	* ipa-ref.c: Likewise.
	* ipa-ref.h: Likewise.
	* ipa-reference.c: Likewise.
	* ipa-split.c: Likewise.
	* ipa-utils.c: Likewise.
	* ipa-utils.h: Likewise.
	* ipa.c: Likewise.
	* ira-build.c: Likewise.
	* ira-color.c: Likewise.
	* ira-emit.c: Likewise.
	* ira-int.h: Likewise.
	* ira.c: Likewise.
	* loop-invariant.c: Likewise.
	* loop-unroll.c: Likewise.
	* lower-subreg.c: Likewise.
	* lra-lives.c: Likewise.
	* lra.c: Likewise.
	* lto-cgraph.c: Likewise.
	* lto-section-out.c: Likewise.
	* lto-streamer-in.c: Likewise.
	* lto-streamer-out.c: Likewise.
	* lto-streamer.h: Likewise.
	* lto-symtab.c: Likewise.
	* mcf.c: Likewise.
	* modulo-sched.c: Likewise.
	* omp-low.c: Likewise.
	* opts-common.c: Likewise.
	* opts-global.c: Likewise.
	* opts.c: Likewise.
	* opts.h: Likewise.
	* passes.c: Likewise.
	* predict.c: Likewise.
	* print-tree.c: Likewise.
	* profile.c: Likewise.
	* profile.h: Likewise.
	* read-rtl.c: Likewise.
	* ree.c: Likewise.
	* reg-stack.c: Likewise.
	* regrename.c: Likewise.
	* regrename.h: Likewise.
	* reload.c: Likewise.
	* reload.h: Likewise.
	* reload1.c: Likewise.
	* rtl.h: Likewise.
	* sched-deps.c: Likewise.
	* sched-int.h: Likewise.
	* sdbout.c: Likewise.
	* sel-sched-dump.c: Likewise.
	* sel-sched-ir.c: Likewise.
	* sel-sched-ir.h: Likewise.
	* sel-sched.c: Likewise.
	* sese.c: Likewise.
	* sese.h: Likewise.
	* statistics.h: Likewise.
	* stmt.c: Likewise.
	* stor-layout.c: Likewise.
	* store-motion.c: Likewise.
	* tlink.c: Likewise.
	* toplev.c: Likewise.
	* trans-mem.c: Likewise.
	* tree-browser.c: Likewise.
	* tree-call-cdce.c: Likewise.
	* tree-cfg.c: Likewise.
	* tree-cfgcleanup.c: Likewise.
	* tree-chrec.c: Likewise.
	* tree-chrec.h: Likewise.
	* tree-complex.c: Likewise.
	* tree-data-ref.c: Likewise.
	* tree-data-ref.h: Likewise.
	* tree-dfa.c: Likewise.
	* tree-diagnostic.c: Likewise.
	* tree-dump.c: Likewise.
	* tree-eh.c: Likewise.
	* tree-emutls.c: Likewise.
	* tree-flow.h: Likewise.
	* tree-if-conv.c: Likewise.
	* tree-inline.c: Likewise.
	* tree-inline.h: Likewise.
	* tree-into-ssa.c: Likewise.
	* tree-iterator.c: Likewise.
	* tree-loop-distribution.c: Likewise.
	* tree-mudflap.c: Likewise.
	* tree-optimize.c: Likewise.
	* tree-outof-ssa.c: Likewise.
	* tree-parloops.c: Likewise.
	* tree-phinodes.c: Likewise.
	* tree-predcom.c: Likewise.
	* tree-pretty-print.c: Likewise.
	* tree-scalar-evolution.c: Likewise.
	* tree-sra.c: Likewise.
	* tree-ssa-address.c: Likewise.
	* tree-ssa-alias.c: Likewise.
	* tree-ssa-ccp.c: Likewise.
	* tree-ssa-coalesce.c: Likewise.
	* tree-ssa-dce.c: Likewise.
	* tree-ssa-dom.c: Likewise.
	* tree-ssa-forwprop.c: Likewise.
	* tree-ssa-live.c: Likewise.
	* tree-ssa-live.h: Likewise.
	* tree-ssa-loop-im.c: Likewise.
	* tree-ssa-loop-ivcanon.c: Likewise.
	* tree-ssa-loop-ivopts.c: Likewise.
	* tree-ssa-loop-manip.c: Likewise.
	* tree-ssa-loop-niter.c: Likewise.
	* tree-ssa-loop-prefetch.c: Likewise.
	* tree-ssa-math-opts.c: Likewise.
	* tree-ssa-operands.c: Likewise.
	* tree-ssa-phiopt.c: Likewise.
	* tree-ssa-phiprop.c: Likewise.
	* tree-ssa-pre.c: Likewise.
	* tree-ssa-propagate.c: Likewise.
	* tree-ssa-reassoc.c: Likewise.
	* tree-ssa-sccvn.c: Likewise.
	* tree-ssa-sccvn.h: Likewise.
	* tree-ssa-strlen.c: Likewise.
	* tree-ssa-structalias.c: Likewise.
	* tree-ssa-tail-merge.c: Likewise.
	* tree-ssa-threadedge.c: Likewise.
	* tree-ssa-threadupdate.c: Likewise.
	* tree-ssa-uncprop.c: Likewise.
	* tree-ssa-uninit.c: Likewise.
	* tree-ssa.c: Likewise.
	* tree-ssanames.c: Likewise.
	* tree-stdarg.c: Likewise.
	* tree-streamer-in.c: Likewise.
	* tree-streamer-out.c: Likewise.
	* tree-streamer.c: Likewise.
	* tree-streamer.h: Likewise.
	* tree-switch-conversion.c: Likewise.
	* tree-vect-data-refs.c: Likewise.
	* tree-vect-generic.c: Likewise.
	* tree-vect-loop-manip.c: Likewise.
	* tree-vect-loop.c: Likewise.
	* tree-vect-patterns.c: Likewise.
	* tree-vect-slp.c: Likewise.
	* tree-vect-stmts.c: Likewise.
	* tree-vectorizer.c: Likewise.
	* tree-vectorizer.h: Likewise.
	* tree-vrp.c: Likewise.
	* tree.c: Likewise.
	* tree.h: Likewise.
	* value-prof.c: Likewise.
	* value-prof.h: Likewise.
	* var-tracking.c: Likewise.
	* varasm.c: Likewise.
	* varpool.c: Likewise.
	* vmsdbgout.c: Likewise.
	* config/bfin/bfin.c: Likewise.
	* config/c6x/c6x.c: Likewise.
	* config/darwin.c: Likewise.
	* config/i386/i386.c: Likewise.
	* config/ia64/ia64.c: Likewise.
	* config/mep/mep.c: Likewise.
	* config/mips/mips.c: Likewise.
	* config/pa/pa.c: Likewise.
	* config/rs6000/rs6000-c.c: Likewise.
	* config/rs6000/rs6000.c: Likewise.
	* config/rx/rx.c: Likewise.
	* config/spu/spu-c.c: Likewise.
	* config/vms/vms.c: Likewise.
	* config/vxworks.c: Likewise.
	* config/epiphany/resolve-sw-modes.c: Likewise.

From-SVN: r193595

1 files changed, 108 insertions, 118 deletions

diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index de6461c..bbafa3a 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -92,7 +92,7 @@ static tree capture_decltype (tree);
 
    2. When a declaration such as a type, or a variable, is encountered,
       the function `perform_or_defer_access_check' is called.  It
-      maintains a VEC of all deferred checks.
+      maintains a vector of all deferred checks.
 
    3. The global `current_class_type' or `current_function_decl' is then
       setup by the parser.  `enforce_access' relies on these information
@@ -100,14 +100,14 @@ static tree capture_decltype (tree);
 
    4. Upon exiting the context mentioned in step 1,
       `perform_deferred_access_checks' is called to check all declaration
-      stored in the VEC. `pop_deferring_access_checks' is then
+      stored in the vector. `pop_deferring_access_checks' is then
       called to restore the previous access checking mode.
 
       In case of parsing error, we simply call `pop_deferring_access_checks'
       without `perform_deferred_access_checks'.  */
 
 typedef struct GTY(()) deferred_access {
-  /* A VEC representing name-lookups for which we have deferred
+  /* A vector representing name-lookups for which we have deferred
      checking access controls.  We cannot check the accessibility of
      names used in a decl-specifier-seq until we know what is being
      declared because code like:
@@ -120,17 +120,15 @@ typedef struct GTY(()) deferred_access {
        A::B* A::f() { return 0; }
 
      is valid, even though `A::B' is not generally accessible.  */
-  VEC (deferred_access_check,gc)* GTY(()) deferred_access_checks;
+  vec<deferred_access_check, va_gc> * GTY(()) deferred_access_checks;
 
   /* The current mode of access checks.  */
   enum deferring_kind deferring_access_checks_kind;
 
 } deferred_access;
-DEF_VEC_O (deferred_access);
-DEF_VEC_ALLOC_O (deferred_access,gc);
 
 /* Data for deferred access checking.  */
-static GTY(()) VEC(deferred_access,gc) *deferred_access_stack;
+static GTY(()) vec<deferred_access, va_gc> *deferred_access_stack;
 static GTY(()) unsigned deferred_access_no_check;
 
 /* Save the current deferred access states and start deferred
@@ -146,7 +144,7 @@ push_deferring_access_checks (deferring_kind deferring)
   else
     {
       deferred_access e = {NULL, deferring};
-      VEC_safe_push (deferred_access, gc, deferred_access_stack, e);
+      vec_safe_push (deferred_access_stack, e);
     }
 }
 
@@ -157,8 +155,7 @@ void
 resume_deferring_access_checks (void)
 {
   if (!deferred_access_no_check)
-    VEC_last (deferred_access, deferred_access_stack)
-      .deferring_access_checks_kind = dk_deferred;
+    deferred_access_stack->last().deferring_access_checks_kind = dk_deferred;
 }
 
 /* Stop deferring access checks.  */
@@ -167,8 +164,7 @@ void
 stop_deferring_access_checks (void)
 {
   if (!deferred_access_no_check)
-    VEC_last (deferred_access, deferred_access_stack)
-      .deferring_access_checks_kind = dk_no_deferred;
+    deferred_access_stack->last().deferring_access_checks_kind = dk_no_deferred;
 }
 
 /* Discard the current deferred access checks and restore the
@@ -180,7 +176,7 @@ pop_deferring_access_checks (void)
   if (deferred_access_no_check)
     deferred_access_no_check--;
   else
-    VEC_pop (deferred_access, deferred_access_stack);
+    deferred_access_stack->pop ();
 }
 
 /* Returns a TREE_LIST representing the deferred checks.
@@ -188,14 +184,13 @@ pop_deferring_access_checks (void)
    access occurred; the TREE_VALUE is the declaration named.
    */
 
-VEC (deferred_access_check,gc)*
+vec<deferred_access_check, va_gc> *
 get_deferred_access_checks (void)
 {
   if (deferred_access_no_check)
     return NULL;
   else
-    return (VEC_last (deferred_access, deferred_access_stack)
-	    .deferred_access_checks);
+    return (deferred_access_stack->last().deferred_access_checks);
 }
 
 /* Take current deferred checks and combine with the
@@ -209,14 +204,13 @@ pop_to_parent_deferring_access_checks (void)
     deferred_access_no_check--;
   else
     {
-      VEC (deferred_access_check,gc) *checks;
+      vec<deferred_access_check, va_gc> *checks;
       deferred_access *ptr;
 
-      checks = (VEC_last (deferred_access, deferred_access_stack)
-		.deferred_access_checks);
+      checks = (deferred_access_stack->last ().deferred_access_checks);
 
-      VEC_pop (deferred_access, deferred_access_stack);
-      ptr = &VEC_last (deferred_access, deferred_access_stack);
+      deferred_access_stack->pop ();
+      ptr = &deferred_access_stack->last ();
       if (ptr->deferring_access_checks_kind == dk_no_deferred)
 	{
 	  /* Check access.  */
@@ -228,10 +222,9 @@ pop_to_parent_deferring_access_checks (void)
 	  int i, j;
 	  deferred_access_check *chk, *probe;
 
-	  FOR_EACH_VEC_ELT (deferred_access_check, checks, i, chk)
+	  FOR_EACH_VEC_SAFE_ELT (checks, i, chk)
 	    {
-	      FOR_EACH_VEC_ELT (deferred_access_check,
-				ptr->deferred_access_checks, j, probe)
+	      FOR_EACH_VEC_SAFE_ELT (ptr->deferred_access_checks, j, probe)
 		{
 		  if (probe->binfo == chk->binfo &&
 		      probe->decl == chk->decl &&
@@ -239,8 +232,7 @@ pop_to_parent_deferring_access_checks (void)
 		    goto found;
 		}
 	      /* Insert into parent's checks.  */
-	      VEC_safe_push (deferred_access_check, gc,
-			     ptr->deferred_access_checks, *chk);
+	      vec_safe_push (ptr->deferred_access_checks, *chk);
 	    found:;
 	    }
 	}
@@ -254,7 +246,7 @@ pop_to_parent_deferring_access_checks (void)
    otherwise FALSE.  */
 
 bool
-perform_access_checks (VEC (deferred_access_check,gc)* checks,
+perform_access_checks (vec<deferred_access_check, va_gc> *checks,
 		       tsubst_flags_t complain)
 {
   int i;
@@ -265,7 +257,7 @@ perform_access_checks (VEC (deferred_access_check,gc)* checks,
   if (!checks)
     return true;
 
-  FOR_EACH_VEC_ELT (deferred_access_check, checks, i, chk)
+  FOR_EACH_VEC_SAFE_ELT (checks, i, chk)
     {
       input_location = chk->loc;
       ok &= enforce_access (chk->binfo, chk->decl, chk->diag_decl, complain);
@@ -317,7 +309,7 @@ perform_or_defer_access_check (tree binfo, tree decl, tree diag_decl,
 
   gcc_assert (TREE_CODE (binfo) == TREE_BINFO);
 
-  ptr = &VEC_last (deferred_access, deferred_access_stack);
+  ptr = &deferred_access_stack->last ();
 
   /* If we are not supposed to defer access checks, just check now.  */
   if (ptr->deferring_access_checks_kind == dk_no_deferred)
@@ -327,8 +319,7 @@ perform_or_defer_access_check (tree binfo, tree decl, tree diag_decl,
     }
 
   /* See if we are already going to perform this check.  */
-  FOR_EACH_VEC_ELT  (deferred_access_check,
-		     ptr->deferred_access_checks, i, chk)
+  FOR_EACH_VEC_SAFE_ELT (ptr->deferred_access_checks, i, chk)
     {
       if (chk->decl == decl && chk->binfo == binfo &&
 	  chk->diag_decl == diag_decl)
@@ -338,8 +329,7 @@ perform_or_defer_access_check (tree binfo, tree decl, tree diag_decl,
     }
   /* If not, record the check.  */
   deferred_access_check new_access = {binfo, decl, diag_decl, input_location};
-  VEC_safe_push (deferred_access_check, gc, ptr->deferred_access_checks,
-		 new_access);
+  vec_safe_push (ptr->deferred_access_checks, new_access);
 
   return true;
 }
@@ -375,7 +365,7 @@ add_stmt (tree t)
 
   /* Add T to the statement-tree.  Non-side-effect statements need to be
      recorded during statement expressions.  */
-  gcc_checking_assert (!VEC_empty (tree, stmt_list_stack));
+  gcc_checking_assert (!stmt_list_stack->is_empty ());
   append_to_statement_list_force (t, &cur_stmt_list);
 
   return t;
@@ -1972,7 +1962,7 @@ empty_expr_stmt_p (tree expr_stmt)
    Returns the functions to be considered by overload resolution.  */
 
 tree
-perform_koenig_lookup (tree fn, VEC(tree,gc) *args, bool include_std,
+perform_koenig_lookup (tree fn, vec<tree, va_gc> *args, bool include_std,
 		       tsubst_flags_t complain)
 {
   tree identifier = NULL_TREE;
@@ -2038,12 +2028,12 @@ perform_koenig_lookup (tree fn, VEC(tree,gc) *args, bool include_std,
    Returns code for the call.  */
 
 tree
-finish_call_expr (tree fn, VEC(tree,gc) **args, bool disallow_virtual,
+finish_call_expr (tree fn, vec<tree, va_gc> **args, bool disallow_virtual,
 		  bool koenig_p, tsubst_flags_t complain)
 {
   tree result;
   tree orig_fn;
-  VEC(tree,gc) *orig_args = NULL;
+  vec<tree, va_gc> *orig_args = NULL;
 
   if (fn == error_mark_node)
     return error_mark_node;
@@ -2172,7 +2162,7 @@ finish_call_expr (tree fn, VEC(tree,gc) **args, bool disallow_virtual,
       if (!result)
 	{
 	  if (warn_sizeof_pointer_memaccess
-	      && !VEC_empty(tree, *args)
+	      && !vec_safe_is_empty (*args)
 	      && !processing_template_decl)
 	    {
 	      location_t sizeof_arg_loc[3];
@@ -2184,9 +2174,9 @@ finish_call_expr (tree fn, VEC(tree,gc) **args, bool disallow_virtual,
 
 		  sizeof_arg_loc[i] = UNKNOWN_LOCATION;
 		  sizeof_arg[i] = NULL_TREE;
-		  if (i >= VEC_length (tree, *args))
+		  if (i >= (*args)->length ())
 		    continue;
-		  t = VEC_index (tree, *args, i);
+		  t = (**args)[i];
 		  if (TREE_CODE (t) != SIZEOF_EXPR)
 		    continue;
 		  if (SIZEOF_EXPR_TYPE_P (t))
@@ -2206,7 +2196,7 @@ finish_call_expr (tree fn, VEC(tree,gc) **args, bool disallow_virtual,
     }
   else if (TREE_CODE (fn) == PSEUDO_DTOR_EXPR)
     {
-      if (!VEC_empty (tree, *args))
+      if (!vec_safe_is_empty (*args))
 	error ("arguments to destructor are not allowed");
       /* Mark the pseudo-destructor call as having side-effects so
 	 that we do not issue warnings about its use.  */
@@ -3448,9 +3438,9 @@ finish_underlying_type (tree type)
 tree
 calculate_direct_bases (tree type)
 {
-  VEC(tree, gc) *vector = make_tree_vector();
+  vec<tree, va_gc> *vector = make_tree_vector();
   tree bases_vec = NULL_TREE;
-  VEC(tree, none) *base_binfos;
+  vec<tree, va_gc> *base_binfos;
   tree binfo;
   unsigned i;
 
@@ -3462,29 +3452,29 @@ calculate_direct_bases (tree type)
   base_binfos = BINFO_BASE_BINFOS (TYPE_BINFO (type));
 
   /* Virtual bases are initialized first */
-  for (i = 0; VEC_iterate (tree, base_binfos, i, binfo); i++)
+  for (i = 0; base_binfos->iterate (i, &binfo); i++)
     {
       if (BINFO_VIRTUAL_P (binfo))
        {
-         VEC_safe_push (tree, gc, vector, binfo);
+         vec_safe_push (vector, binfo);
        }
     }
 
   /* Now non-virtuals */
-  for (i = 0; VEC_iterate (tree, base_binfos, i, binfo); i++)
+  for (i = 0; base_binfos->iterate (i, &binfo); i++)
     {
       if (!BINFO_VIRTUAL_P (binfo))
        {
-         VEC_safe_push (tree, gc, vector, binfo);
+         vec_safe_push (vector, binfo);
        }
     }
 
 
-  bases_vec = make_tree_vec (VEC_length (tree, vector));
+  bases_vec = make_tree_vec (vector->length ());
 
-  for (i = 0; i < VEC_length (tree, vector); ++i)
+  for (i = 0; i < vector->length (); ++i)
     {
-      TREE_VEC_ELT (bases_vec, i) = BINFO_TYPE (VEC_index (tree, vector, i));
+      TREE_VEC_ELT (bases_vec, i) = BINFO_TYPE ((*vector)[i]);
     }
   return bases_vec;
 }
@@ -3505,19 +3495,19 @@ dfs_calculate_bases_pre (tree binfo, void * /*data_*/)
 static tree
 dfs_calculate_bases_post (tree binfo, void *data_)
 {
-  VEC(tree, gc) **data = (VEC(tree, gc) **) data_;
+  vec<tree, va_gc> **data = ((vec<tree, va_gc> **) data_);
   if (!BINFO_VIRTUAL_P (binfo))
     {
-      VEC_safe_push (tree, gc, *data, BINFO_TYPE (binfo));
+      vec_safe_push (*data, BINFO_TYPE (binfo));
     }
   return NULL_TREE;
 }
 
 /* Calculates the morally non-virtual base classes of a class */
-static VEC(tree, gc) *
+static vec<tree, va_gc> *
 calculate_bases_helper (tree type)
 {
-  VEC(tree, gc) *vector = make_tree_vector();
+  vec<tree, va_gc> *vector = make_tree_vector();
 
   /* Now add non-virtual base classes in order of construction */
   dfs_walk_all (TYPE_BINFO (type),
@@ -3528,11 +3518,11 @@ calculate_bases_helper (tree type)
 tree
 calculate_bases (tree type)
 {
-  VEC(tree, gc) *vector = make_tree_vector();
+  vec<tree, va_gc> *vector = make_tree_vector();
   tree bases_vec = NULL_TREE;
   unsigned i;
-  VEC(tree, gc) *vbases;
-  VEC(tree, gc) *nonvbases;
+  vec<tree, va_gc> *vbases;
+  vec<tree, va_gc> *nonvbases;
   tree binfo;
 
   complete_type (type);
@@ -3542,24 +3532,25 @@ calculate_bases (tree type)
 
   /* First go through virtual base classes */
   for (vbases = CLASSTYPE_VBASECLASSES (type), i = 0;
-       VEC_iterate (tree, vbases, i, binfo); i++)
+       vec_safe_iterate (vbases, i, &binfo); i++)
     {
-      VEC(tree, gc) *vbase_bases = calculate_bases_helper (BINFO_TYPE (binfo));
-      VEC_safe_splice (tree, gc, vector, vbase_bases);
+      vec<tree, va_gc> *vbase_bases;
+      vbase_bases = calculate_bases_helper (BINFO_TYPE (binfo));
+      vec_safe_splice (vector, vbase_bases);
       release_tree_vector (vbase_bases);
     }
 
   /* Now for the non-virtual bases */
   nonvbases = calculate_bases_helper (type);
-  VEC_safe_splice (tree, gc, vector, nonvbases);
+  vec_safe_splice (vector, nonvbases);
   release_tree_vector (nonvbases);
 
   /* Last element is entire class, so don't copy */
-  bases_vec = make_tree_vec (VEC_length (tree, vector) - 1);
+  bases_vec = make_tree_vec (vector->length () - 1);
 
-  for (i = 0; i < VEC_length (tree, vector) - 1; ++i)
+  for (i = 0; i < vector->length () - 1; ++i)
     {
-      TREE_VEC_ELT (bases_vec, i) = VEC_index (tree, vector, i);
+      TREE_VEC_ELT (bases_vec, i) = (*vector)[i];
     }
   release_tree_vector (vector);
   return bases_vec;
@@ -5010,7 +5001,7 @@ void
 finish_omp_barrier (void)
 {
   tree fn = builtin_decl_explicit (BUILT_IN_GOMP_BARRIER);
-  VEC(tree,gc) *vec = make_tree_vector ();
+  vec<tree, va_gc> *vec = make_tree_vector ();
   tree stmt = finish_call_expr (fn, &vec, false, false, tf_warning_or_error);
   release_tree_vector (vec);
   finish_expr_stmt (stmt);
@@ -5020,7 +5011,7 @@ void
 finish_omp_flush (void)
 {
   tree fn = builtin_decl_explicit (BUILT_IN_SYNC_SYNCHRONIZE);
-  VEC(tree,gc) *vec = make_tree_vector ();
+  vec<tree, va_gc> *vec = make_tree_vector ();
   tree stmt = finish_call_expr (fn, &vec, false, false, tf_warning_or_error);
   release_tree_vector (vec);
   finish_expr_stmt (stmt);
@@ -5030,7 +5021,7 @@ void
 finish_omp_taskwait (void)
 {
   tree fn = builtin_decl_explicit (BUILT_IN_GOMP_TASKWAIT);
-  VEC(tree,gc) *vec = make_tree_vector ();
+  vec<tree, va_gc> *vec = make_tree_vector ();
   tree stmt = finish_call_expr (fn, &vec, false, false, tf_warning_or_error);
   release_tree_vector (vec);
   finish_expr_stmt (stmt);
@@ -5040,7 +5031,7 @@ void
 finish_omp_taskyield (void)
 {
   tree fn = builtin_decl_explicit (BUILT_IN_GOMP_TASKYIELD);
-  VEC(tree,gc) *vec = make_tree_vector ();
+  vec<tree, va_gc> *vec = make_tree_vector ();
   tree stmt = finish_call_expr (fn, &vec, false, false, tf_warning_or_error);
   release_tree_vector (vec);
   finish_expr_stmt (stmt);
@@ -5380,7 +5371,7 @@ classtype_has_nothrow_assign_or_copy_p (tree type, bool assign_p)
       ix = lookup_fnfields_1 (type, ansi_assopname (NOP_EXPR));
       if (ix < 0)
 	return false;
-      fns = VEC_index (tree, CLASSTYPE_METHOD_VEC (type), ix);
+      fns = (*CLASSTYPE_METHOD_VEC (type))[ix];
     } 
   else if (TYPE_HAS_COPY_CTOR (type))
     {
@@ -5806,7 +5797,7 @@ is_valid_constexpr_fn (tree fun, bool complain)
    to the existing initialization pair INITS.  */
 
 static bool
-build_data_member_initialization (tree t, VEC(constructor_elt,gc) **vec)
+build_data_member_initialization (tree t, vec<constructor_elt, va_gc> **vec)
 {
   tree member, init;
   if (TREE_CODE (t) == CLEANUP_POINT_EXPR)
@@ -5933,13 +5924,13 @@ check_constexpr_ctor_body (tree last, tree list)
   return ok;
 }
 
-/* VEC is a vector of constructor elements built up for the base and member
+/* V is a vector of constructor elements built up for the base and member
    initializers of a constructor for TYPE.  They need to be in increasing
    offset order, which they might not be yet if TYPE has a primary base
    which is not first in the base-clause.  */
 
-static VEC(constructor_elt,gc) *
-sort_constexpr_mem_initializers (tree type, VEC(constructor_elt,gc) *vec)
+static vec<constructor_elt, va_gc> *
+sort_constexpr_mem_initializers (tree type, vec<constructor_elt, va_gc> *v)
 {
   tree pri = CLASSTYPE_PRIMARY_BINFO (type);
   constructor_elt elt;
@@ -5947,21 +5938,21 @@ sort_constexpr_mem_initializers (tree type, VEC(constructor_elt,gc) *vec)
 
   if (pri == NULL_TREE
       || pri == BINFO_BASE_BINFO (TYPE_BINFO (type), 0))
-    return vec;
+    return v;
 
   /* Find the element for the primary base and move it to the beginning of
      the vec.  */
-  VEC(constructor_elt,gc) &v = *vec;
+  vec<constructor_elt, va_gc> &vref = *v;
   pri = BINFO_TYPE (pri);
   for (i = 1; ; ++i)
-    if (TREE_TYPE (v[i].index) == pri)
+    if (TREE_TYPE (vref[i].index) == pri)
       break;
 
-  elt = v[i];
+  elt = vref[i];
   for (; i > 0; --i)
-    v[i] = v[i-1];
-  v[0] = elt;
-  return vec;
+    vref[i] = vref[i-1];
+  vref[0] = elt;
+  return v;
 }
 
 /* Build compile-time evalable representations of member-initializer list
@@ -5970,7 +5961,7 @@ sort_constexpr_mem_initializers (tree type, VEC(constructor_elt,gc) *vec)
 static tree
 build_constexpr_constructor_member_initializers (tree type, tree body)
 {
-  VEC(constructor_elt,gc) *vec = NULL;
+  vec<constructor_elt, va_gc> *vec = NULL;
   bool ok = true;
   if (TREE_CODE (body) == MUST_NOT_THROW_EXPR
       || TREE_CODE (body) == EH_SPEC_BLOCK)
@@ -6015,14 +6006,14 @@ build_constexpr_constructor_member_initializers (tree type, tree body)
     gcc_assert (errorcount > 0);
   if (ok)
     {
-      if (VEC_length (constructor_elt, vec) > 0)
+      if (vec_safe_length (vec) > 0)
 	{
 	  /* In a delegating constructor, return the target.  */
-	  constructor_elt *ce = &VEC_index (constructor_elt, vec, 0);
+	  constructor_elt *ce = &(*vec)[0];
 	  if (ce->index == current_class_ptr)
 	    {
 	      body = ce->value;
-	      VEC_free (constructor_elt, gc, vec);
+	      vec_free (vec);
 	      return body;
 	    }
 	}
@@ -6519,7 +6510,7 @@ cxx_bind_parameters_in_call (const constexpr_call *old_call, tree t,
    These do not need to be marked for PCH or GC.  */
 
 /* FIXME remember and print actual constant arguments.  */
-static VEC(tree,heap) *call_stack = NULL;
+static vec<tree> call_stack = vec<tree>();
 static int call_stack_tick;
 static int last_cx_error_tick;
 
@@ -6529,8 +6520,8 @@ push_cx_call_context (tree call)
   ++call_stack_tick;
   if (!EXPR_HAS_LOCATION (call))
     SET_EXPR_LOCATION (call, input_location);
-  VEC_safe_push (tree, heap, call_stack, call);
-  if (VEC_length (tree, call_stack) > (unsigned) max_constexpr_depth)
+  call_stack.safe_push (call);
+  if (call_stack.length () > (unsigned) max_constexpr_depth)
     return false;
   return true;
 }
@@ -6539,15 +6530,15 @@ static void
 pop_cx_call_context (void)
 {
   ++call_stack_tick;
-  VEC_pop (tree, call_stack);
+  call_stack.pop ();
 }
 
-VEC(tree,heap) *
+vec<tree> 
 cx_error_context (void)
 {
-  VEC(tree,heap) *r = NULL;
+  vec<tree> r = vec<tree>();
   if (call_stack_tick != last_cx_error_tick
-      && !VEC_empty (tree, call_stack))
+      && !call_stack.is_empty ())
     r = call_stack;
   last_cx_error_tick = call_stack_tick;
   return r;
@@ -6893,7 +6884,7 @@ cxx_eval_array_reference (const constexpr_call *call, tree t,
     }
   i = tree_low_cst (index, 0);
   if (TREE_CODE (ary) == CONSTRUCTOR)
-    return VEC_index (constructor_elt, CONSTRUCTOR_ELTS (ary), i).value;
+    return (*CONSTRUCTOR_ELTS (ary))[i].value;
   else if (elem_nchars == 1)
     return build_int_cst (cv_unqualified (TREE_TYPE (TREE_TYPE (ary))),
 			  TREE_STRING_POINTER (ary)[i]);
@@ -7076,7 +7067,7 @@ cxx_eval_logical_expression (const constexpr_call *call, tree t,
    initialization of the field.  */
 
 static constructor_elt *
-base_field_constructor_elt (VEC(constructor_elt,gc) *v, tree ref)
+base_field_constructor_elt (vec<constructor_elt, va_gc> *v, tree ref)
 {
   tree aggr = TREE_OPERAND (ref, 0);
   tree field = TREE_OPERAND (ref, 1);
@@ -7092,7 +7083,7 @@ base_field_constructor_elt (VEC(constructor_elt,gc) *v, tree ref)
       v = CONSTRUCTOR_ELTS (base_ce->value);
     }
 
-  for (i = 0; VEC_iterate (constructor_elt, v, i, ce); ++i)
+  for (i = 0; vec_safe_iterate (v, i, &ce); ++i)
     if (ce->index == field)
       return ce;
 
@@ -7109,14 +7100,14 @@ cxx_eval_bare_aggregate (const constexpr_call *call, tree t,
 			 bool allow_non_constant, bool addr,
 			 bool *non_constant_p)
 {
-  VEC(constructor_elt,gc) *v = CONSTRUCTOR_ELTS (t);
-  VEC(constructor_elt,gc) *n = VEC_alloc (constructor_elt, gc,
-					  VEC_length (constructor_elt, v));
+  vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (t);
+  vec<constructor_elt, va_gc> *n;
+  vec_alloc (n, vec_safe_length (v));
   constructor_elt *ce;
   HOST_WIDE_INT i;
   bool changed = false;
   gcc_assert (!BRACE_ENCLOSED_INITIALIZER_P (t));
-  for (i = 0; VEC_iterate (constructor_elt, v, i, ce); ++i)
+  for (i = 0; vec_safe_iterate (v, i, &ce); ++i)
     {
       tree elt = cxx_eval_constant_expression (call, ce->value,
 					       allow_non_constant, addr,
@@ -7146,7 +7137,7 @@ cxx_eval_bare_aggregate (const constexpr_call *call, tree t,
   if (*non_constant_p || !changed)
     {
     fail:
-      VEC_free (constructor_elt, gc, n);
+      vec_free (n);
       return t;
     }
   t = build_constructor (TREE_TYPE (t), n);
@@ -7173,7 +7164,8 @@ cxx_eval_vec_init_1 (const constexpr_call *call, tree atype, tree init,
 {
   tree elttype = TREE_TYPE (atype);
   int max = tree_low_cst (array_type_nelts (atype), 0);
-  VEC(constructor_elt,gc) *n = VEC_alloc (constructor_elt, gc, max + 1);
+  vec<constructor_elt, va_gc> *n;
+  vec_alloc (n, max + 1);
   bool pre_init = false;
   int i;
 
@@ -7193,7 +7185,7 @@ cxx_eval_vec_init_1 (const constexpr_call *call, tree atype, tree init,
     }
   else if (!init)
     {
-      VEC(tree,gc) *argvec = make_tree_vector ();
+      vec<tree, va_gc> *argvec = make_tree_vector ();
       init = build_special_member_call (NULL_TREE, complete_ctor_identifier,
 					&argvec, elttype, LOOKUP_NORMAL,
 					tf_warning_or_error);
@@ -7234,7 +7226,7 @@ cxx_eval_vec_init_1 (const constexpr_call *call, tree atype, tree init,
       else
 	{
 	  /* Copying an element.  */
-	  VEC(tree,gc) *argvec;
+	  vec<tree, va_gc> *argvec;
 	  gcc_assert (same_type_ignoring_top_level_qualifiers_p
 		      (atype, TREE_TYPE (init)));
 	  eltinit = cp_build_array_ref (input_location, init, idx,
@@ -7242,7 +7234,7 @@ cxx_eval_vec_init_1 (const constexpr_call *call, tree atype, tree init,
 	  if (!real_lvalue_p (init))
 	    eltinit = move (eltinit);
 	  argvec = make_tree_vector ();
-	  VEC_quick_push (tree, argvec, eltinit);
+	  argvec->quick_push (eltinit);
 	  eltinit = (build_special_member_call
 		     (NULL_TREE, complete_ctor_identifier, &argvec,
 		      elttype, LOOKUP_NORMAL, tf_warning_or_error));
@@ -7263,7 +7255,7 @@ cxx_eval_vec_init_1 (const constexpr_call *call, tree atype, tree init,
     }
 
  fail:
-  VEC_free (constructor_elt, gc, n);
+  vec_free (n);
   return init;
 }
 
@@ -8517,9 +8509,9 @@ potential_constant_expression_1 (tree t, bool want_rval, tsubst_flags_t flags)
 
     case CONSTRUCTOR:
       {
-        VEC(constructor_elt, gc) *v = CONSTRUCTOR_ELTS (t);
+        vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (t);
         constructor_elt *ce;
-        for (i = 0; VEC_iterate (constructor_elt, v, i, ce); ++i)
+        for (i = 0; vec_safe_iterate (v, i, &ce); ++i)
 	  if (!potential_constant_expression_1 (ce->value, want_rval, flags))
 	    return false;
 	return true;
@@ -8747,7 +8739,7 @@ build_lambda_object (tree lambda_expr)
   /* Build aggregate constructor call.
      - cp_parser_braced_list
      - cp_parser_functional_cast  */
-  VEC(constructor_elt,gc) *elts = NULL;
+  vec<constructor_elt, va_gc> *elts = NULL;
   tree node, expr, type;
   location_t saved_loc;
 
@@ -9067,8 +9059,7 @@ insert_capture_proxy (tree var)
 
   /* And put a DECL_EXPR in the STATEMENT_LIST for the same block.  */
   var = build_stmt (DECL_SOURCE_LOCATION (var), DECL_EXPR, var);
-  stmt_list = VEC_index (tree, stmt_list_stack,
-			 VEC_length (tree, stmt_list_stack) - 1 - skip);
+  stmt_list = (*stmt_list_stack)[stmt_list_stack->length () - 1 - skip];
   gcc_assert (stmt_list);
   append_to_statement_list_force (var, &stmt_list);
 }
@@ -9081,7 +9072,7 @@ void
 insert_pending_capture_proxies (void)
 {
   tree lam;
-  VEC(tree,gc) *proxies;
+  vec<tree, va_gc> *proxies;
   unsigned i;
 
   if (!current_function_decl || !LAMBDA_FUNCTION_P (current_function_decl))
@@ -9089,9 +9080,9 @@ insert_pending_capture_proxies (void)
 
   lam = CLASSTYPE_LAMBDA_EXPR (DECL_CONTEXT (current_function_decl));
   proxies = LAMBDA_EXPR_PENDING_PROXIES (lam);
-  for (i = 0; i < VEC_length (tree, proxies); ++i)
+  for (i = 0; i < vec_safe_length (proxies); ++i)
     {
-      tree var = VEC_index (tree, proxies, i);
+      tree var = (*proxies)[i];
       insert_capture_proxy (var);
     }
   release_tree_vector (LAMBDA_EXPR_PENDING_PROXIES (lam));
@@ -9158,7 +9149,7 @@ build_capture_proxy (tree member)
   if (fn == current_function_decl)
     insert_capture_proxy (var);
   else
-    VEC_safe_push (tree, gc, LAMBDA_EXPR_PENDING_PROXIES (lam), var);
+    vec_safe_push (LAMBDA_EXPR_PENDING_PROXIES (lam), var);
 
   return var;
 }
@@ -9405,7 +9396,7 @@ maybe_add_lambda_conv_op (tree type)
   tree callop = lambda_function (type);
   tree rettype, name, fntype, fn, body, compound_stmt;
   tree thistype, stattype, statfn, convfn, call, arg;
-  VEC (tree, gc) *argvec;
+  vec<tree, va_gc> *argvec;
 
   if (LAMBDA_EXPR_CAPTURE_LIST (CLASSTYPE_LAMBDA_EXPR (type)) != NULL_TREE)
     return;
@@ -9495,14 +9486,13 @@ maybe_add_lambda_conv_op (tree type)
   arg = build1 (NOP_EXPR, TREE_TYPE (DECL_ARGUMENTS (callop)),
 		null_pointer_node);
   argvec = make_tree_vector ();
-  VEC_quick_push (tree, argvec, arg);
+  argvec->quick_push (arg);
   for (arg = DECL_ARGUMENTS (statfn); arg; arg = DECL_CHAIN (arg))
     {
       mark_exp_read (arg);
-      VEC_safe_push (tree, gc, argvec, arg);
+      vec_safe_push (argvec, arg);
     }
-  call = build_call_a (callop, VEC_length (tree, argvec),
-		       VEC_address (tree, argvec));
+  call = build_call_a (callop, argvec->length (), argvec->address ());
   CALL_FROM_THUNK_P (call) = 1;
   if (MAYBE_CLASS_TYPE_P (TREE_TYPE (call)))
     call = build_cplus_new (TREE_TYPE (call), call, tf_warning_or_error);