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, 41 insertions, 43 deletions

diff --git a/gcc/ada/gcc-interface/decl.c b/gcc/ada/gcc-interface/decl.c
index dfefff2..b3cf22c 100644
--- a/gcc/ada/gcc-interface/decl.c
+++ b/gcc/ada/gcc-interface/decl.c
@@ -106,8 +106,6 @@ typedef struct subst_pair_d {
   tree replacement;
 } subst_pair;
 
-DEF_VEC_O(subst_pair);
-DEF_VEC_ALLOC_O(subst_pair,heap);
 
 typedef struct variant_desc_d {
   /* The type of the variant.  */
@@ -123,8 +121,6 @@ typedef struct variant_desc_d {
   tree new_type;
 } variant_desc;
 
-DEF_VEC_O(variant_desc);
-DEF_VEC_ALLOC_O(variant_desc,heap);
 
 /* A hash table used to cache the result of annotate_value.  */
 static GTY ((if_marked ("tree_int_map_marked_p"),
@@ -153,21 +149,21 @@ static void components_to_record (tree, Node_Id, tree, int, bool, bool, bool,
 static Uint annotate_value (tree);
 static void annotate_rep (Entity_Id, tree);
 static tree build_position_list (tree, bool, tree, tree, unsigned int, tree);
-static VEC(subst_pair,heap) *build_subst_list (Entity_Id, Entity_Id, bool);
-static VEC(variant_desc,heap) *build_variant_list (tree,
-						   VEC(subst_pair,heap) *,
-						   VEC(variant_desc,heap) *);
+static vec<subst_pair> build_subst_list (Entity_Id, Entity_Id, bool);
+static vec<variant_desc> build_variant_list (tree,
+						   vec<subst_pair> ,
+						   vec<variant_desc> );
 static tree validate_size (Uint, tree, Entity_Id, enum tree_code, bool, bool);
 static void set_rm_size (Uint, tree, Entity_Id);
 static unsigned int validate_alignment (Uint, Entity_Id, unsigned int);
 static void check_ok_for_atomic (tree, Entity_Id, bool);
 static tree create_field_decl_from (tree, tree, tree, tree, tree,
-				    VEC(subst_pair,heap) *);
+				    vec<subst_pair> );
 static tree create_rep_part (tree, tree, tree);
 static tree get_rep_part (tree);
-static tree create_variant_part_from (tree, VEC(variant_desc,heap) *, tree,
-				      tree, VEC(subst_pair,heap) *);
-static void copy_and_substitute_in_size (tree, tree, VEC(subst_pair,heap) *);
+static tree create_variant_part_from (tree, vec<variant_desc> , tree,
+				      tree, vec<subst_pair> );
+static void copy_and_substitute_in_size (tree, tree, vec<subst_pair> );
 
 /* The relevant constituents of a subprogram binding to a GCC builtin.  Used
    to pass around calls performing profile compatibility checks.  */
@@ -1157,7 +1153,8 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, int definition)
 	      = TYPE_PADDING_P (gnu_type)
 		? TYPE_FIELDS (TREE_TYPE (TYPE_FIELDS (gnu_type)))
 		: TYPE_FIELDS (gnu_type);
-	    VEC(constructor_elt,gc) *v = VEC_alloc (constructor_elt, gc, 1);
+	    vec<constructor_elt, va_gc> *v;
+	    vec_alloc (v, 1);
 	    tree t = build_template (TREE_TYPE (template_field),
 				     TREE_TYPE (DECL_CHAIN (template_field)),
 				     NULL_TREE);
@@ -1329,8 +1326,7 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, int definition)
 		      = TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (gnu_alloc_type)));
 
 		    if (TREE_CODE (gnu_expr) == CONSTRUCTOR
-			&& 1 == VEC_length (constructor_elt,
-					    CONSTRUCTOR_ELTS (gnu_expr)))
+			&& 1 == vec_safe_length (CONSTRUCTOR_ELTS (gnu_expr)))
 		      gnu_expr = 0;
 		    else
 		      gnu_expr
@@ -3293,13 +3289,13 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, int definition)
 	      && Present (Discriminant_Constraint (gnat_entity))
 	      && Stored_Constraint (gnat_entity) != No_Elist)
 	    {
-	      VEC(subst_pair,heap) *gnu_subst_list
+	      vec<subst_pair> gnu_subst_list
 		= build_subst_list (gnat_entity, gnat_base_type, definition);
 	      tree gnu_unpad_base_type, gnu_rep_part, gnu_variant_part, t;
 	      tree gnu_pos_list, gnu_field_list = NULL_TREE;
 	      bool selected_variant = false;
 	      Entity_Id gnat_field;
-	      VEC(variant_desc,heap) *gnu_variant_list;
+	      vec<variant_desc> gnu_variant_list;
 
 	      gnu_type = make_node (RECORD_TYPE);
 	      TYPE_NAME (gnu_type) = gnu_entity_name;
@@ -3330,12 +3326,13 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, int definition)
 
 		  gnu_variant_list
 		    = build_variant_list (TREE_TYPE (gnu_variant_part),
-					  gnu_subst_list, NULL);
+					  gnu_subst_list,
+					  vec<variant_desc>());
 
 		  /* If all the qualifiers are unconditionally true, the
 		     innermost variant is statically selected.  */
 		  selected_variant = true;
-		  FOR_EACH_VEC_ELT (variant_desc, gnu_variant_list, i, v)
+		  FOR_EACH_VEC_ELT (gnu_variant_list, i, v)
 		    if (!integer_onep (v->qual))
 		      {
 			selected_variant = false;
@@ -3344,7 +3341,7 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, int definition)
 
 		  /* Otherwise, create the new variants.  */
 		  if (!selected_variant)
-		    FOR_EACH_VEC_ELT (variant_desc, gnu_variant_list, i, v)
+		    FOR_EACH_VEC_ELT (gnu_variant_list, i, v)
 		      {
 			tree old_variant = v->type;
 			tree new_variant = make_node (RECORD_TYPE);
@@ -3362,13 +3359,14 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, int definition)
 		}
 	      else
 		{
-		  gnu_variant_list = NULL;
+		  gnu_variant_list.create (0);
 		  selected_variant = false;
 		}
 
 	      gnu_pos_list
 		= build_position_list (gnu_unpad_base_type,
-				       gnu_variant_list && !selected_variant,
+				       gnu_variant_list.exists ()
+					  && !selected_variant,
 				       size_zero_node, bitsize_zero_node,
 				       BIGGEST_ALIGNMENT, NULL_TREE);
 
@@ -3449,7 +3447,7 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, int definition)
 			unsigned int i;
 
 			t = NULL_TREE;
-			FOR_EACH_VEC_ELT (variant_desc, gnu_variant_list, i, v)
+			FOR_EACH_VEC_ELT (gnu_variant_list, i, v)
 			  if (gnu_context == v->type
 			      || ((gnu_rep_part = get_rep_part (v->type))
 				  && gnu_context == TREE_TYPE (gnu_rep_part)))
@@ -3515,7 +3513,7 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, int definition)
 
 	      /* If there is a variant list and no selected variant, we need
 		 to create the nest of variant parts from the old nest.  */
-	      if (gnu_variant_list && !selected_variant)
+	      if (gnu_variant_list.exists () && !selected_variant)
 		{
 		  tree new_variant_part
 		    = create_variant_part_from (gnu_variant_part,
@@ -3587,8 +3585,8 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, int definition)
 					 gnat_entity);
 		}
 
-	      VEC_free (variant_desc, heap, gnu_variant_list);
-	      VEC_free (subst_pair, heap, gnu_subst_list);
+	      gnu_variant_list.release ();
+	      gnu_subst_list.release ();
 
 	      /* Now we can finalize it.  */
 	      rest_of_record_type_compilation (gnu_type);
@@ -7551,10 +7549,10 @@ build_position_list (tree gnu_type, bool do_not_flatten_variant, tree gnu_pos,
    of operands to SUBSTITUTE_IN_EXPR.  DEFINITION is true if this is for
    a definition of GNAT_SUBTYPE.  */
 
-static VEC(subst_pair,heap) *
+static vec<subst_pair> 
 build_subst_list (Entity_Id gnat_subtype, Entity_Id gnat_type, bool definition)
 {
-  VEC(subst_pair,heap) *gnu_list = NULL;
+  vec<subst_pair> gnu_list = vec<subst_pair>();
   Entity_Id gnat_discrim;
   Node_Id gnat_value;
 
@@ -7573,7 +7571,7 @@ build_subst_list (Entity_Id gnat_subtype, Entity_Id gnat_type, bool definition)
 				     get_entity_name (gnat_discrim),
 				     definition, true, false));
 	subst_pair s = {gnu_field, replacement};
-	VEC_safe_push (subst_pair, heap, gnu_list, s);
+	gnu_list.safe_push (s);
       }
 
   return gnu_list;
@@ -7584,9 +7582,9 @@ build_subst_list (Entity_Id gnat_subtype, Entity_Id gnat_type, bool definition)
    the substitutions described in SUBST_LIST.  GNU_LIST is a pre-existing
    list to be prepended to the newly created entries.  */
 
-static VEC(variant_desc,heap) *
-build_variant_list (tree qual_union_type, VEC(subst_pair,heap) *subst_list,
-		    VEC(variant_desc,heap) *gnu_list)
+static vec<variant_desc> 
+build_variant_list (tree qual_union_type, vec<subst_pair> subst_list,
+		    vec<variant_desc> gnu_list)
 {
   tree gnu_field;
 
@@ -7598,7 +7596,7 @@ build_variant_list (tree qual_union_type, VEC(subst_pair,heap) *subst_list,
       unsigned int i;
       subst_pair *s;
 
-      FOR_EACH_VEC_ELT (subst_pair, subst_list, i, s)
+      FOR_EACH_VEC_ELT (subst_list, i, s)
 	qual = SUBSTITUTE_IN_EXPR (qual, s->discriminant, s->replacement);
 
       /* If the new qualifier is not unconditionally false, its variant may
@@ -7608,7 +7606,7 @@ build_variant_list (tree qual_union_type, VEC(subst_pair,heap) *subst_list,
 	  tree variant_type = TREE_TYPE (gnu_field), variant_subpart;
 	  variant_desc v = {variant_type, gnu_field, qual, NULL_TREE};
 
-	  VEC_safe_push (variant_desc, heap, gnu_list, v);
+	  gnu_list.safe_push (v);
 
 	  /* Recurse on the variant subpart of the variant, if any.  */
 	  variant_subpart = get_variant_part (variant_type);
@@ -8170,7 +8168,7 @@ intrin_profiles_compatible_p (intrin_binding_t * inb)
 static tree
 create_field_decl_from (tree old_field, tree field_type, tree record_type,
 			tree size, tree pos_list,
-			VEC(subst_pair,heap) *subst_list)
+			vec<subst_pair> subst_list)
 {
   tree t = TREE_VALUE (purpose_member (old_field, pos_list));
   tree pos = TREE_VEC_ELT (t, 0), bitpos = TREE_VEC_ELT (t, 2);
@@ -8180,7 +8178,7 @@ create_field_decl_from (tree old_field, tree field_type, tree record_type,
   subst_pair *s;
 
   if (CONTAINS_PLACEHOLDER_P (pos))
-    FOR_EACH_VEC_ELT (subst_pair, subst_list, i, s)
+    FOR_EACH_VEC_ELT (subst_list, i, s)
       pos = SUBSTITUTE_IN_EXPR (pos, s->discriminant, s->replacement);
 
   /* If the position is now a constant, we can set it as the position of the
@@ -8276,9 +8274,9 @@ get_variant_part (tree record_type)
 
 static tree
 create_variant_part_from (tree old_variant_part,
-			  VEC(variant_desc,heap) *variant_list,
+			  vec<variant_desc> variant_list,
 			  tree record_type, tree pos_list,
-			  VEC(subst_pair,heap) *subst_list)
+			  vec<subst_pair> subst_list)
 {
   tree offset = DECL_FIELD_OFFSET (old_variant_part);
   tree old_union_type = TREE_TYPE (old_variant_part);
@@ -8315,7 +8313,7 @@ create_variant_part_from (tree old_variant_part,
     copy_and_substitute_in_size (new_union_type, old_union_type, subst_list);
 
   /* Now finish up the new variants and populate the union type.  */
-  FOR_EACH_VEC_ELT_REVERSE (variant_desc, variant_list, i, v)
+  FOR_EACH_VEC_ELT_REVERSE (variant_list, i, v)
     {
       tree old_field = v->field, new_field;
       tree old_variant, old_variant_subpart, new_variant, field_list;
@@ -8397,7 +8395,7 @@ create_variant_part_from (tree old_variant_part,
 
 static void
 copy_and_substitute_in_size (tree new_type, tree old_type,
-			     VEC(subst_pair,heap) *subst_list)
+			     vec<subst_pair> subst_list)
 {
   unsigned int i;
   subst_pair *s;
@@ -8409,19 +8407,19 @@ copy_and_substitute_in_size (tree new_type, tree old_type,
   relate_alias_sets (new_type, old_type, ALIAS_SET_COPY);
 
   if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (new_type)))
-    FOR_EACH_VEC_ELT (subst_pair, subst_list, i, s)
+    FOR_EACH_VEC_ELT (subst_list, i, s)
       TYPE_SIZE (new_type)
 	= SUBSTITUTE_IN_EXPR (TYPE_SIZE (new_type),
 			      s->discriminant, s->replacement);
 
   if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE_UNIT (new_type)))
-    FOR_EACH_VEC_ELT (subst_pair, subst_list, i, s)
+    FOR_EACH_VEC_ELT (subst_list, i, s)
       TYPE_SIZE_UNIT (new_type)
 	= SUBSTITUTE_IN_EXPR (TYPE_SIZE_UNIT (new_type),
 			      s->discriminant, s->replacement);
 
   if (CONTAINS_PLACEHOLDER_P (TYPE_ADA_SIZE (new_type)))
-    FOR_EACH_VEC_ELT (subst_pair, subst_list, i, s)
+    FOR_EACH_VEC_ELT (subst_list, i, s)
       SET_TYPE_ADA_SIZE
 	(new_type, SUBSTITUTE_IN_EXPR (TYPE_ADA_SIZE (new_type),
 				       s->discriminant, s->replacement));