Merge tree-ssa-20020619-branch into mainline.

From-SVN: r81764

1 files changed, 34 insertions, 790 deletions

diff --git a/gcc/c-semantics.c b/gcc/c-semantics.c
index a8693f9..b74fda6 100644
--- a/gcc/c-semantics.c
+++ b/gcc/c-semantics.c
@@ -44,23 +44,7 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 #include "timevar.h"
 #include "predict.h"
 #include "tree-inline.h"
-
-/* If non-NULL, the address of a language-specific function for
-   expanding statements.  */
-void (*lang_expand_stmt) (tree);
-
-/* If non-NULL, the address of a language-specific function for
-   expanding a DECL_STMT.  After the language-independent cases are
-   handled, this function will be called.  If this function is not
-   defined, it is assumed that declarations other than those for
-   variables and labels do not require any RTL generation.  */
-void (*lang_expand_decl_stmt) (tree);
-
-static tree find_reachable_label_1 (tree *, int *, void *);
-static tree find_reachable_label (tree);
-static bool expand_unreachable_if_stmt (tree);
-static tree expand_unreachable_stmt (tree, int);
-static void genrtl_do_stmt_1 (tree, tree);
+#include "langhooks.h"
 
 /* Create an empty statement tree rooted at T.  */
 
@@ -81,18 +65,8 @@ begin_stmt_tree (tree *t)
 tree
 add_stmt (tree t)
 {
-  if (input_filename != last_expr_filename)
-    {
-      /* If the filename has changed, also add in a FILE_STMT.  Do a string
-	 compare first, though, as it might be an equivalent string.  */
-      int add = (strcmp (input_filename, last_expr_filename) != 0);
-      last_expr_filename = input_filename;
-      if (add)
-	{
-	  tree pos = build_nt (FILE_STMT, get_identifier (input_filename));
-	  add_stmt (pos);
-	}
-    }
+  if (!EXPR_LOCUS (t))
+    annotate_with_locus (t, input_location);
 
   /* Add T to the statement-tree.  */
   TREE_CHAIN (last_tree) = t;
@@ -171,58 +145,53 @@ finish_stmt_tree (tree *t)
   stmt = TREE_CHAIN (*t);
   *t = stmt;
   last_tree = NULL_TREE;
-
-  if (cfun && stmt)
-    {
-      /* The line-number recorded in the outermost statement in a function
-	 is the line number of the end of the function.  */
-      STMT_LINENO (stmt) = input_line;
-      STMT_LINENO_FOR_FN_P (stmt) = 1;
-    }
 }
 
 /* Build a generic statement based on the given type of node and
    arguments. Similar to `build_nt', except that we set
-   STMT_LINENO to be the current line number.  */
+   EXPR_LOCUS to be the current source location.  */
 /* ??? This should be obsolete with the lineno_stmt productions
    in the grammar.  */
 
 tree
 build_stmt (enum tree_code code, ...)
 {
-  tree t;
-  int length;
-  int i;
+  tree ret;
+  int length, i;
   va_list p;
+  bool side_effects;
 
   va_start (p, code);
 
-  t = make_node (code);
+  ret = make_node (code);
   length = TREE_CODE_LENGTH (code);
-  STMT_LINENO (t) = input_line;
-
-  for (i = 0; i < length; i++)
-    TREE_OPERAND (t, i) = va_arg (p, tree);
-
-  va_end (p);
-  return t;
-}
+  annotate_with_locus (ret, input_location);
 
-/* Some statements, like for-statements or if-statements, require a
-   condition.  This condition can be a declaration.  If T is such a
-   declaration it is processed, and an expression appropriate to use
-   as the condition is returned.  Otherwise, T itself is returned.  */
+  /* Most statements have implicit side effects all on their own, 
+     such as control transfer.  For those that do, we'll compute
+     the real value of TREE_SIDE_EFFECTS from its arguments.  */
+  switch (code)
+    {
+    case EXPR_STMT:
+      side_effects = false;
+      break;
+    default:
+      side_effects = true;
+      break;
+    }
 
-tree
-expand_cond (tree t)
-{
-  if (t && TREE_CODE (t) == TREE_LIST)
+  for (i = 0; i < length; i++)
     {
-      expand_stmt (TREE_PURPOSE (t));
-      return TREE_VALUE (t);
+      tree t = va_arg (p, tree);
+      if (t && IS_NON_TYPE_CODE_CLASS (TREE_CODE_CLASS (TREE_CODE (t))))
+        side_effects |= TREE_SIDE_EFFECTS (t);
+      TREE_OPERAND (ret, i) = t;
     }
-  else
-    return t;
+
+  TREE_SIDE_EFFECTS (ret) = side_effects;
+
+  va_end (p);
+  return ret;
 }
 
 /* Create RTL for the local static variable DECL.  */
@@ -268,7 +237,7 @@ emit_local_var (tree decl)
   /* Create RTL for this variable.  */
   if (!DECL_RTL_SET_P (decl))
     {
-      if (DECL_C_HARD_REGISTER (decl))
+      if (DECL_HARD_REGISTER (decl))
 	/* The user specified an assembler name for this variable.
 	   Set that up now.  */
 	rest_of_decl_compilation
@@ -291,214 +260,6 @@ emit_local_var (tree decl)
     }
 }
 
-/* Helper for generating the RTL at the beginning of a scope.  */
-
-void
-genrtl_do_pushlevel (void)
-{
-  emit_line_note (input_location);
-  clear_last_expr ();
-}
-
-/* Generate the RTL for DESTINATION, which is a GOTO_STMT.  */
-
-void
-genrtl_goto_stmt (tree destination)
-{
-  if (TREE_CODE (destination) == IDENTIFIER_NODE)
-    abort ();
-
-  /* We warn about unused labels with -Wunused.  That means we have to
-     mark the used labels as used.  */
-  if (TREE_CODE (destination) == LABEL_DECL)
-    TREE_USED (destination) = 1;
-
-  emit_line_note (input_location);
-
-  if (TREE_CODE (destination) == LABEL_DECL)
-    {
-      label_rtx (destination);
-      expand_goto (destination);
-    }
-  else
-    expand_computed_goto (destination);
-}
-
-/* Generate the RTL for EXPR, which is an EXPR_STMT.  Provided just
-   for backward compatibility.  genrtl_expr_stmt_value() should be
-   used for new code.  */
-
-void
-genrtl_expr_stmt (tree expr)
-{
-  genrtl_expr_stmt_value (expr, -1, 1);
-}
-
-/* Generate the RTL for EXPR, which is an EXPR_STMT.  WANT_VALUE tells
-   whether to (1) save the value of the expression, (0) discard it or
-   (-1) use expr_stmts_for_value to tell.  The use of -1 is
-   deprecated, and retained only for backward compatibility.
-   MAYBE_LAST is nonzero if this EXPR_STMT might be the last statement
-   in expression statement.  */
-
-void
-genrtl_expr_stmt_value (tree expr, int want_value, int maybe_last)
-{
-  if (expr != NULL_TREE)
-    {
-      emit_line_note (input_location);
-
-      if (stmts_are_full_exprs_p ())
-	expand_start_target_temps ();
-
-      if (expr != error_mark_node)
-	expand_expr_stmt_value (expr, want_value, maybe_last);
-
-      if (stmts_are_full_exprs_p ())
-	expand_end_target_temps ();
-    }
-}
-
-/* Generate the RTL for T, which is a DECL_STMT.  */
-
-void
-genrtl_decl_stmt (tree t)
-{
-  tree decl;
-  emit_line_note (input_location);
-  decl = DECL_STMT_DECL (t);
-  /* If this is a declaration for an automatic local
-     variable, initialize it.  Note that we might also see a
-     declaration for a namespace-scope object (declared with
-     `extern').  We don't have to handle the initialization
-     of those objects here; they can only be declarations,
-     rather than definitions.  */
-  if (TREE_CODE (decl) == VAR_DECL
-      && !TREE_STATIC (decl)
-      && !DECL_EXTERNAL (decl))
-    {
-      /* Let the back-end know about this variable.  */
-      if (!anon_aggr_type_p (TREE_TYPE (decl)))
-	emit_local_var (decl);
-      else
-	expand_anon_union_decl (decl, NULL_TREE,
-				DECL_ANON_UNION_ELEMS (decl));
-    }
-  else if (TREE_CODE (decl) == VAR_DECL && TREE_STATIC (decl))
-    make_rtl_for_local_static (decl);
-  else if (TREE_CODE (decl) == LABEL_DECL
-	   && C_DECLARED_LABEL_FLAG (decl))
-    declare_nonlocal_label (decl);
-  else if (TREE_CODE (decl) == TYPE_DECL)
-    force_type_save_exprs (TREE_TYPE (decl));
-  else if (lang_expand_decl_stmt)
-    (*lang_expand_decl_stmt) (t);
-}
-
-/* Generate the RTL for T, which is an IF_STMT.  */
-
-void
-genrtl_if_stmt (tree t)
-{
-  tree cond;
-  genrtl_do_pushlevel ();
-  cond = expand_cond (IF_COND (t));
-  emit_line_note (input_location);
-  expand_start_cond (cond, 0);
-  if (THEN_CLAUSE (t))
-    {
-      tree nextt = THEN_CLAUSE (t);
-
-      if (cond && integer_zerop (cond))
-	nextt = expand_unreachable_stmt (nextt, warn_notreached);
-      expand_stmt (nextt);
-    }
-
-  if (ELSE_CLAUSE (t))
-    {
-      tree nextt = ELSE_CLAUSE (t);
-      expand_start_else ();
-      if (cond && integer_nonzerop (cond))
-	nextt = expand_unreachable_stmt (nextt, warn_notreached);
-      expand_stmt (nextt);
-    }
-  expand_end_cond ();
-}
-
-/* Generate the RTL for T, which is a WHILE_STMT.  */
-
-void
-genrtl_while_stmt (tree t)
-{
-  tree cond = WHILE_COND (t);
-
-  emit_line_note (input_location);
-  expand_start_loop (1);
-  genrtl_do_pushlevel ();
-
-  if (cond && !integer_nonzerop (cond))
-    {
-      cond = expand_cond (cond);
-      emit_line_note (input_location);
-      expand_exit_loop_top_cond (0, cond);
-      genrtl_do_pushlevel ();
-    }
-
-  expand_stmt (WHILE_BODY (t));
-
-  expand_end_loop ();
-}
-
-/* Generate the RTL for a DO_STMT with condition COND and loop BODY
-   body.  This is reused for expanding unreachable WHILE_STMTS.  */
-
-static void
-genrtl_do_stmt_1 (tree cond, tree body)
-{
-  /* Recognize the common special-case of do { ... } while (0) and do
-     not emit the loop widgetry in this case.  In particular this
-     avoids cluttering the rtl with dummy loop notes, which can affect
-     alignment of adjacent labels.  COND can be NULL due to parse
-     errors.  */
-  if (!cond || integer_zerop (cond))
-    {
-      expand_start_null_loop ();
-      expand_stmt (body);
-      expand_end_null_loop ();
-    }
-  else if (integer_nonzerop (cond))
-    {
-      emit_line_note (input_location);
-      expand_start_loop (1);
-
-      expand_stmt (body);
-
-      emit_line_note (input_location);
-      expand_end_loop ();
-    }
-  else
-    {
-      emit_line_note (input_location);
-      expand_start_loop_continue_elsewhere (1);
-
-      expand_stmt (body);
-
-      expand_loop_continue_here ();
-      cond = expand_cond (cond);
-      emit_line_note (input_location);
-      expand_exit_loop_if_false (0, cond);
-      expand_end_loop ();
-    }
-}
-
-/* Generate the RTL for T, which is a DO_STMT.  */
-
-void
-genrtl_do_stmt (tree t)
-{
-  genrtl_do_stmt_1 (DO_COND (t), DO_BODY (t));
-}
-
 /* Build the node for a return statement and return it.  */
 
 tree
@@ -507,74 +268,6 @@ build_return_stmt (tree expr)
   return (build_stmt (RETURN_STMT, expr));
 }
 
-/* Generate the RTL for STMT, which is a RETURN_STMT.  */
-
-void
-genrtl_return_stmt (tree stmt)
-{
-  tree expr;
-
-  expr = RETURN_STMT_EXPR (stmt);
-
-  emit_line_note (input_location);
-  if (!expr)
-    expand_null_return ();
-  else
-    {
-      expand_start_target_temps ();
-      expand_return (expr);
-      expand_end_target_temps ();
-    }
-}
-
-/* Generate the RTL for T, which is a FOR_STMT.  */
-
-void
-genrtl_for_stmt (tree t)
-{
-  tree cond = FOR_COND (t);
-  location_t saved_loc;
-
-  if (NEW_FOR_SCOPE_P (t))
-    genrtl_do_pushlevel ();
-
-  expand_stmt (FOR_INIT_STMT (t));
-
-  /* Expand the initialization.  */
-  emit_line_note (input_location);
-  if (FOR_EXPR (t))
-    expand_start_loop_continue_elsewhere (1);
-  else
-    expand_start_loop (1);
-  genrtl_do_pushlevel ();
-
-  /* Save the filename and line number so that we expand the FOR_EXPR
-     we can reset them back to the saved values.  */
-  saved_loc = input_location;
-
-  /* Expand the condition.  */
-  if (cond && !integer_nonzerop (cond))
-    {
-      cond = expand_cond (cond);
-      emit_line_note (input_location);
-      expand_exit_loop_top_cond (0, cond);
-      genrtl_do_pushlevel ();
-    }
-
-  /* Expand the body.  */
-  expand_stmt (FOR_BODY (t));
-
-  /* Expand the increment expression.  */
-  input_location = saved_loc;
-  emit_line_note (input_location);
-  if (FOR_EXPR (t))
-    {
-      expand_loop_continue_here ();
-      genrtl_expr_stmt (FOR_EXPR (t));
-    }
-  expand_end_loop ();
-}
-
 /* Build a break statement node and return it.  */
 
 tree
@@ -583,16 +276,6 @@ build_break_stmt (void)
   return (build_stmt (BREAK_STMT));
 }
 
-/* Generate the RTL for a BREAK_STMT.  */
-
-void
-genrtl_break_stmt (void)
-{
-  emit_line_note (input_location);
-  if ( ! expand_exit_something ())
-    abort ();
-}
-
 /* Build a continue statement node and return it.  */
 
 tree
@@ -601,80 +284,6 @@ build_continue_stmt (void)
   return (build_stmt (CONTINUE_STMT));
 }
 
-/* Generate the RTL for a CONTINUE_STMT.  */
-
-void
-genrtl_continue_stmt (void)
-{
-  emit_line_note (input_location);
-  if (! expand_continue_loop (0))
-    abort ();
-}
-
-/* Generate the RTL for T, which is a SCOPE_STMT.  */
-
-void
-genrtl_scope_stmt (tree t)
-{
-  tree block = SCOPE_STMT_BLOCK (t);
-
-  if (!SCOPE_NO_CLEANUPS_P (t))
-    {
-      if (SCOPE_BEGIN_P (t))
-	expand_start_bindings_and_block (2 * SCOPE_NULLIFIED_P (t), block);
-      else if (SCOPE_END_P (t))
-	expand_end_bindings (NULL_TREE, !SCOPE_NULLIFIED_P (t), 0);
-    }
-  else if (!SCOPE_NULLIFIED_P (t))
-    {
-      rtx note = emit_note (SCOPE_BEGIN_P (t)
-			    ? NOTE_INSN_BLOCK_BEG : NOTE_INSN_BLOCK_END);
-      NOTE_BLOCK (note) = block;
-    }
-
-  /* If we're at the end of a scope that contains inlined nested
-     functions, we have to decide whether or not to write them out.  */
-  if (block && SCOPE_END_P (t))
-    {
-      tree fn;
-
-      for (fn = BLOCK_VARS (block); fn; fn = TREE_CHAIN (fn))
-	{
-	  if (TREE_CODE (fn) == FUNCTION_DECL
-	      && DECL_CONTEXT (fn) == current_function_decl
-	      && DECL_STRUCT_FUNCTION (fn)
-	      && DECL_STRUCT_FUNCTION (fn)->saved_for_inline
-	      && !TREE_ASM_WRITTEN (fn)
-	      && TREE_ADDRESSABLE (fn))
-	    {
-	      push_function_context ();
-	      output_inline_function (fn);
-	      pop_function_context ();
-	    }
-	}
-    }
-}
-
-/* Generate the RTL for T, which is a SWITCH_STMT.  */
-
-void
-genrtl_switch_stmt (tree t)
-{
-  tree cond;
-  genrtl_do_pushlevel ();
-
-  cond = expand_cond (SWITCH_COND (t));
-  if (cond == error_mark_node)
-    /* The code is in error, but we don't want expand_end_case to
-       crash.  */
-    cond = truthvalue_false_node;
-
-  emit_line_note (input_location);
-  expand_start_case (1, cond, TREE_TYPE (cond), "switch statement");
-  expand_stmt (expand_unreachable_stmt (SWITCH_BODY (t), warn_notreached));
-  expand_end_case_type (cond, SWITCH_TYPE (t));
-}
-
 /* Create a CASE_LABEL tree node and return it.  */
 
 tree
@@ -683,378 +292,13 @@ build_case_label (tree low_value, tree high_value, tree label_decl)
   return build_stmt (CASE_LABEL, low_value, high_value, label_decl);
 }
 
-
-/* Generate the RTL for a CASE_LABEL.  */
-
-void
-genrtl_case_label (tree case_label)
-{
-  tree duplicate;
-  tree cleanup;
-
-  cleanup = last_cleanup_this_contour ();
-  if (cleanup)
-    {
-      static int explained = 0;
-      warning ("destructor needed for `%D'", (TREE_PURPOSE (cleanup)));
-      warning ("where case label appears here");
-      if (!explained)
-	{
-	  warning ("(enclose actions of previous case statements requiring destructors in their own scope.)");
-	  explained = 1;
-	}
-    }
-
-  add_case_node (CASE_LOW (case_label), CASE_HIGH (case_label),
-		 CASE_LABEL_DECL (case_label), &duplicate);
-}
-
-/* Generate the RTL for T, which is a COMPOUND_STMT.  */
-
-void
-genrtl_compound_stmt (tree t)
-{
-#ifdef ENABLE_CHECKING
-  struct nesting *n = current_nesting_level ();
-#endif
-
-  expand_stmt (COMPOUND_BODY (t));
-
-#ifdef ENABLE_CHECKING
-  /* Make sure that we've pushed and popped the same number of levels.  */
-  if (!COMPOUND_STMT_NO_SCOPE (t) && n != current_nesting_level ())
-    abort ();
-#endif
-}
-
-/* Generate the RTL for an ASM_STMT.  */
-
-void
-genrtl_asm_stmt (tree cv_qualifier, tree string, tree output_operands,
-		 tree input_operands, tree clobbers, int asm_input_p)
-{
-  if (cv_qualifier != NULL_TREE
-      && cv_qualifier != ridpointers[(int) RID_VOLATILE])
-    {
-      warning ("%s qualifier ignored on asm",
-	       IDENTIFIER_POINTER (cv_qualifier));
-      cv_qualifier = NULL_TREE;
-    }
-
-  emit_line_note (input_location);
-  if (asm_input_p)
-    expand_asm (string, cv_qualifier != NULL_TREE);
-  else
-    c_expand_asm_operands (string, output_operands, input_operands,
-			   clobbers, cv_qualifier != NULL_TREE,
-			   input_location);
-}
-
-/* Generate the RTL for a CLEANUP_STMT.  */
-
-void
-genrtl_cleanup_stmt (tree t)
-{
-  tree decl = CLEANUP_DECL (t);
-  if (!decl || !DECL_P (decl)
-      || (DECL_SIZE (decl) && TREE_TYPE (decl) != error_mark_node))
-    expand_decl_cleanup_eh (decl, CLEANUP_EXPR (t), CLEANUP_EH_ONLY (t));
-}
-
 /* We're about to expand T, a statement.  Set up appropriate context
    for the substitution.  */
 
 void
 prep_stmt (tree t)
 {
-  if (!STMT_LINENO_FOR_FN_P (t))
-    input_line = STMT_LINENO (t);
+  if (EXPR_LOCUS (t))
+    input_location = *EXPR_LOCUS (t);
   current_stmt_tree ()->stmts_are_full_exprs_p = STMT_IS_FULL_EXPR_P (t);
 }
-
-/* Generate the RTL for the statement T, its substatements, and any
-   other statements at its nesting level.  */
-
-void
-expand_stmt (tree t)
-{
-  while (t && t != error_mark_node)
-    {
-      int saved_stmts_are_full_exprs_p;
-
-      /* Set up context appropriately for handling this statement.  */
-      saved_stmts_are_full_exprs_p = stmts_are_full_exprs_p ();
-      prep_stmt (t);
-
-      switch (TREE_CODE (t))
-	{
-	case FILE_STMT:
-	  input_filename = FILE_STMT_FILENAME (t);
-	  break;
-
-	case RETURN_STMT:
-	  genrtl_return_stmt (t);
-	  t = expand_unreachable_stmt (TREE_CHAIN (t), warn_notreached);
-	  goto process_t;
-
-	case EXPR_STMT:
-	  genrtl_expr_stmt_value (EXPR_STMT_EXPR (t), TREE_ADDRESSABLE (t),
-				  TREE_CHAIN (t) == NULL
-				  || (TREE_CODE (TREE_CHAIN (t)) == SCOPE_STMT
-				      && TREE_CHAIN (TREE_CHAIN (t)) == NULL));
-	  break;
-
-	case DECL_STMT:
-	  genrtl_decl_stmt (t);
-	  break;
-
-	case FOR_STMT:
-	  genrtl_for_stmt (t);
-	  break;
-
-	case WHILE_STMT:
-	  genrtl_while_stmt (t);
-	  break;
-
-	case DO_STMT:
-	  genrtl_do_stmt (t);
-	  break;
-
-	case IF_STMT:
-	  genrtl_if_stmt (t);
-	  break;
-
-	case COMPOUND_STMT:
-	  genrtl_compound_stmt (t);
-	  break;
-
-	case BREAK_STMT:
-	  genrtl_break_stmt ();
-	  t = expand_unreachable_stmt (TREE_CHAIN (t), warn_notreached);
-	  goto process_t;
-
-	case CONTINUE_STMT:
-	  genrtl_continue_stmt ();
-	  t = expand_unreachable_stmt (TREE_CHAIN (t), warn_notreached);
-	  goto process_t;
-
-	case SWITCH_STMT:
-	  genrtl_switch_stmt (t);
-	  break;
-
-	case CASE_LABEL:
-	  genrtl_case_label (t);
-	  break;
-
-	case LABEL_STMT:
-	  expand_label (LABEL_STMT_LABEL (t));
-	  break;
-
-	case GOTO_STMT:
-	  /* Emit information for branch prediction.  */
-	  if (!GOTO_FAKE_P (t)
-	      && TREE_CODE (GOTO_DESTINATION (t)) == LABEL_DECL
-	      && flag_guess_branch_prob)
-	    {
-	      rtx note = emit_note (NOTE_INSN_PREDICTION);
-
-	      NOTE_PREDICTION (note) = NOTE_PREDICT (PRED_GOTO, NOT_TAKEN);
-	    }
-	  genrtl_goto_stmt (GOTO_DESTINATION (t));
-	  t = expand_unreachable_stmt (TREE_CHAIN (t), warn_notreached);
-	  goto process_t;
-
-	case ASM_STMT:
-	  genrtl_asm_stmt (ASM_CV_QUAL (t), ASM_STRING (t),
-			   ASM_OUTPUTS (t), ASM_INPUTS (t),
-			   ASM_CLOBBERS (t), ASM_INPUT_P (t));
-	  break;
-
-	case SCOPE_STMT:
-	  genrtl_scope_stmt (t);
-	  break;
-
-	case CLEANUP_STMT:
-	  genrtl_cleanup_stmt (t);
-	  break;
-
-	default:
-	  if (lang_expand_stmt)
-	    (*lang_expand_stmt) (t);
-	  else
-	    abort ();
-	  break;
-	}
-
-      /* Go on to the next statement in this scope.  */
-      t = TREE_CHAIN (t);
-
-    process_t:
-      /* Restore saved state.  */
-      current_stmt_tree ()->stmts_are_full_exprs_p
-	= saved_stmts_are_full_exprs_p;
-    }
-}
-
-/* If *TP is a potentially reachable label, return nonzero.  */
-
-static tree
-find_reachable_label_1 (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
-			void *data ATTRIBUTE_UNUSED)
-{
-  switch (TREE_CODE (*tp))
-    {
-    case LABEL_STMT:
-    case CASE_LABEL:
-      return *tp;
-
-    default:
-      break;
-    }
-  return NULL_TREE;
-}
-
-/* Determine whether expression EXP contains a potentially
-   reachable label.  */
-static tree
-find_reachable_label (tree exp)
-{
-  location_t saved_loc = input_location;
-  tree ret = walk_tree_without_duplicates
-		(&exp, find_reachable_label_1, NULL);
-  input_location = saved_loc;
-  return ret;
-}
-
-/* Expand an unreachable if statement, T.  This function returns
-   true if the IF_STMT contains a potentially reachable code_label.  */
-static bool
-expand_unreachable_if_stmt (tree t)
-{
-  tree n;
-
-  if (find_reachable_label (IF_COND (t)) != NULL_TREE)
-    {
-      genrtl_if_stmt (t);
-      return true;
-    }
-
-  if (THEN_CLAUSE (t) && ELSE_CLAUSE (t))
-    {
-      n = expand_unreachable_stmt (THEN_CLAUSE (t), 0);
-
-      if (n != NULL_TREE)
-	{
-	  rtx label;
-	  expand_stmt (n);
-	  label = gen_label_rtx ();
-	  emit_jump (label);
-	  expand_stmt (expand_unreachable_stmt (ELSE_CLAUSE (t), 0));
-	  emit_label (label);
-	  return true;
-	}
-      else
-	n = expand_unreachable_stmt (ELSE_CLAUSE (t), 0);
-    }
-  else if (THEN_CLAUSE (t))
-    n = expand_unreachable_stmt (THEN_CLAUSE (t), 0);
-  else if (ELSE_CLAUSE (t))
-    n = expand_unreachable_stmt (ELSE_CLAUSE (t), 0);
-  else
-    n = NULL_TREE;
-
-  expand_stmt (n);
-
-  return n != NULL_TREE;
-}
-
-/* Expand an unreachable statement list.  This function skips all
-   statements preceding the first potentially reachable label and
-   then returns the label (or, in same cases, the statement after
-   one containing the label).  */
-static tree
-expand_unreachable_stmt (tree t, int warn)
-{
-  int saved;
-
-  while (t && t != error_mark_node)
-    {
-      if (warn)
-	switch (TREE_CODE (t))
-	  {
-	  case BREAK_STMT:
-	  case CONTINUE_STMT:
-	  case EXPR_STMT:
-	  case GOTO_STMT:
-	  case IF_STMT:
-	  case RETURN_STMT:
-	    if (!STMT_LINENO_FOR_FN_P (t))
-	      input_line = STMT_LINENO (t);
-	    warning("will never be executed");
-	    warn = false;
-	    break;
-
-	  default:
-	    break;
-	  }
-
-      switch (TREE_CODE (t))
-	{
-	case GOTO_STMT:
-	case CONTINUE_STMT:
-	case BREAK_STMT:
-	  break;
-
-	case FILE_STMT:
-	  input_filename = FILE_STMT_FILENAME (t);
-	  break;
-
-	case RETURN_STMT:
-	  if (find_reachable_label (RETURN_STMT_EXPR (t)) != NULL_TREE)
-	    return t;
-	  break;
-
-	case EXPR_STMT:
-	  if (find_reachable_label (EXPR_STMT_EXPR (t)) != NULL_TREE)
-	    return t;
-	  break;
-
-	case IF_STMT:
-	  if (expand_unreachable_if_stmt (t))
-	    return TREE_CHAIN (t);
-	  break;
-
-	case WHILE_STMT:
-	  /* If the start of a while statement is unreachable, there is
-	     no need to rotate the loop, instead the WHILE_STMT can be
-	     expanded like a DO_STMT.  */
-	  genrtl_do_stmt_1 (WHILE_COND (t), WHILE_BODY (t));
-	  return TREE_CHAIN (t);
-
-	case COMPOUND_STMT:
-	  {
-	    tree n;
-	    n = expand_unreachable_stmt (COMPOUND_BODY (t), warn);
-	    if (n != NULL_TREE)
-	      {
-		expand_stmt (n);
-		return TREE_CHAIN (t);
-	      }
-	    warn = false;
-	    break;
-	  }
-
-	case SCOPE_STMT:
-	  saved = stmts_are_full_exprs_p ();
-	  prep_stmt (t);
-	  genrtl_scope_stmt (t);
-	  current_stmt_tree ()->stmts_are_full_exprs_p = saved;
-	  break;
-
-	default:
-	  return t;
-	}
-      t = TREE_CHAIN (t);
-    }
-  return NULL_TREE;
-}