Introduce vNULL to use as a nil initializer for vec<>.

This patch implements Jakub's idea of adding an empty struct with
a typecast operator that returns nil vectors.  This is useful to
shorten all the initializers when declaring vec instances or passing
nil vectors as function arguments.

2012-11-20  Diego Novillo  <dnovillo@google.com>
	    Jakub Jelinek  <jakub@redhat.com>

ChangeLog
	* vec.h (struct vnull): Declare.
	(vNULL): Declare.
	* vec.c (vNULL): Define.
	* bb-reorder.c: Replace all vec<T, A>() initializers with vNULL.
	* cfgexpand.c: Likewise.
	* cfgloop.c: Likewise.
	* cfgloopanal.c: Likewise.
	* cfgloopmanip.c: Likewise.
	* cgraph.c: Likewise.
	* config/c6x/c6x.c: Likewise.
	* config/i386/i386.c: Likewise.
	* df-core.c: Likewise.
	* dominance.c: Likewise.
	* dwarf2out.c: Likewise.
	* except.c: Likewise.
	* function.c: Likewise.
	* gcse.c: Likewise.
	* genautomata.c: Likewise.
	* graphds.c: Likewise.
	* graphite-scop-detection.c: Likewise.
	* graphite.c: Likewise.
	* haifa-sched.c: Likewise.
	* ifcvt.c: Likewise.
	* ipa-cp.c: Likewise.
	* ipa-inline-analysis.c: Likewise.
	* ipa-inline-transform.c: Likewise.
	* ipa-inline.c: Likewise.
	* ipa-prop.c: Likewise.
	* ipa-split.c: Likewise.
	* ipa-utils.c: Likewise.
	* ira-build.c: Likewise.
	* lto-cgraph.c: Likewise.
	* lto-streamer-in.c: Likewise.
	* lto-symtab.c: Likewise.
	* opts-global.c: Likewise.
	* passes.c: Likewise.
	* ree.c: Likewise.
	* sched-deps.c: Likewise.
	* sel-sched-ir.c: Likewise.
	* sel-sched-ir.h: Likewise.
	* sel-sched.c: Likewise.
	* stor-layout.c: Likewise.
	* trans-mem.c: Likewise.
	* tree-call-cdce.c: Likewise.
	* tree-cfg.c: Likewise.
	* tree-data-ref.c: Likewise.
	* tree-diagnostic.c: Likewise.
	* tree-eh.c: Likewise.
	* tree-loop-distribution.c: Likewise.
	* tree-predcom.c: Likewise.
	* tree-ssa-loop-im.c: Likewise.
	* tree-ssa-loop-ivcanon.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-phiopt.c: Likewise.
	* tree-ssa-pre.c: Likewise.
	* tree-ssa-propagate.c: Likewise.
	* tree-ssa-reassoc.c: Likewise.
	* tree-ssa-sccvn.c: Likewise.
	* tree-ssa-structalias.c: Likewise.
	* tree-ssa-threadedge.c: Likewise.
	* tree-ssa-uninit.c: Likewise.
	* tree-stdarg.c: Likewise.
	* tree-switch-conversion.c: Likewise.
	* tree-vect-data-refs.c: Likewise.
	* tree-vect-loop.c: Likewise.
	* tree-vect-slp.c: Likewise.
	* tree-vect-stmts.c: Likewise.
	* value-prof.c: Likewise.
	* varasm.c: Likewise.

ada/ChangeLog
	* gcc-interface/decl.c: Replace all vec<T,A>()
	initializers with vNULL.

cp/ChangeLog
	* name-lookup.c: Replace all vec<T, A>() initializers
	with vNULL.
	* semantics.c: Likewise.

fortran/ChangeLog
	* trans-openmp.c: Replace all vec<T, A>() initializers
	with vNULL.

lto/ChangeLog
	* lto.c: Replace all vec<T, A>() initializers with vNULL.

objc/ChangeLog
	* objc-act.c: Replace all vec<T, A>() initializers with vNULL.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@193677 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 4 insertions, 5 deletions

diff --git a/gcc/lto-cgraph.c b/gcc/lto-cgraph.c
index 7d936efa2c5..427362230df 100644
--- a/gcc/lto-cgraph.c
+++ b/gcc/lto-cgraph.c
@@ -913,7 +913,7 @@ input_node (struct lto_file_decl_data *file_data,
     {
       node = cgraph_clone_node (cgraph (nodes[clone_ref]), fn_decl,
 				0, CGRAPH_FREQ_BASE, false,
-				vec<cgraph_edge_p>(), false);
+				vNULL, false);
     }
   else
     node = cgraph_get_create_node (fn_decl);
@@ -926,7 +926,7 @@ input_node (struct lto_file_decl_data *file_data,
   node->count_materialization_scale = streamer_read_hwi (ib);
 
   count = streamer_read_hwi (ib);
-  node->ipa_transforms_to_apply = vec<ipa_opt_pass>();
+  node->ipa_transforms_to_apply = vNULL;
   for (i = 0; i < count; i++)
     {
       struct opt_pass *pass;
@@ -1126,7 +1126,7 @@ input_cgraph_1 (struct lto_file_decl_data *file_data,
 		struct lto_input_block *ib)
 {
   enum LTO_symtab_tags tag;
-  vec<symtab_node> nodes = vec<symtab_node>();
+  vec<symtab_node> nodes = vNULL;
   symtab_node node;
   unsigned i;
 
@@ -1573,8 +1573,7 @@ input_cgraph_opt_section (struct lto_file_decl_data *file_data,
 
   data_in =
     lto_data_in_create (file_data, (const char *) data + string_offset,
-			header->string_size,
-			vec<ld_plugin_symbol_resolution_t>());
+			header->string_size, vNULL);
   count = streamer_read_uhwi (&ib_main);
 
   for (i = 0; i < count; i++)