splay-tree.c (splay_tree_predecessor): Fix typo in comment.

	* splay-tree.c (splay_tree_predecessor): Fix typo in comment.

	Convert the C front-end to use function-at-a-time mode.
	* c-common.h: Include splay-tree.h.
	(C_DECLARED_LABEL_FLAG): New macro.
	(struct language_function): Add x_scope_stmt_stack and
	x_function_name_declared_p.
	(RECHAIN_STMTS): Move definition.
	(lang_statment_code_p): Likewise.
	(lang_expand_stmt): Likewise.
	(lang_expand_decl_stmt): New variable.
	(lang_expand_function_end): Likewise.
	(current_scope_stmt_stack): New function.
	(add_decl_stmt): Likewise.
	(add_scope_stmt): Likewise.
	(mark_stmt_tree): Likewise.
	(struct c_lang_decl): New structure.
	(DECL_SAVED_TREE): Define.
	(c_mark_lang_decl): New function.
	(c_expand_start_cond): Change prototype.
	(c_finish_then): New function.
	(c_finish_else): Likewise.
	(current_function_name_declared): Remove.
	(set_current_function_name_declared): Likewise.
	(mark_c_language_function): Declare.
	(case_compare): Likewise.
	(c_add_case_label): Likewise.
	(c_expand_expr): Likewise.
	(c_safe_from_p): Likewise.
	* c-common.c (lang_expand_function_end): New variable.
	(struct if_elt): Add if_stmt.
	(c_expand_start_cond): Add the if-statement to the statement-tree,
	rather than generating RTL.
	(c_finish_then): New function.
	(c_expand_start_else): Don't generate RTL.
	(c_finish_else): New function.
	(c_expand_expr_stmt): Don't generate RTL.
	(statement_code_p): Add SCOPE_STMT.
	(case_compare): New function.
	(c_add_case_label): Likewise.
	(mark_stmt_tree): Likewise.
	(c_mark_lang_decl): Likewise.
	(mark_c_language_function): Likewise.
	(c_expand_expr): Likewise.
	(c_safe_from_p): Likewise.
	* c-decl.c (c_stmt_tree): New variable
	(c_scope_stmt_stack): Likewise.
	(c_function_name_declared_p): Likewise.
	(lang_expand_expr_stmt): Remove.
	(poplevel): Don't call output_inline_function for nested
	functions.
	(pushdecl): Don't set DECL_CONTEXT for a local declaration of an
	`extern' function.
	(redeclaration_error_message): Change means of computing whether
	or not a function is nested.
	(lookup_label): Don't call label_rtx.
	(init_decl_processing): Add more GC roots.
	(start_decl): Add DECL_STMTs to the statement-tree, rather than
	calling rest_of_decl_compilation.
	(finish_decl): Don't call expand_decl.
	(store_parm_decls): Begin the statement-tree, but don't generate
	RTL.
	(finish_function): Tie off the statement-tree.  Call c_expand_body
	if appropriate.
	(c_expand_body): New function.
	(push_c_function_context): Save more information.
	(pop_c_function_contxt): Likewise.
	(copy_lang_decl): Now that we use DECL_LANG_SPECIFIC, copy it.
	(lang_mark_tree): Mark it.
	(current_stmt_tree): Adjust.
	(current_scope_stmt_stack): New function.
	(do_case): Remove.
	(set_current_name_declared): Likewise.
	(c_begin_compound_stmt): Define.
	(c_expand_decl_stmt): Likewise.
	* c-lang.c: Include rtl.h and expr.h.
	(lang_init): Set more language-specific hooks.
	* c-lex.c: Include expr.h.
	* c-parse.in: Changes throughout to add statements to the
	statement-tree, rather than generating RTL after every statement.
	* c-semantics.c (lang_expand_decl_stmt): Define.
	(add_decl_stmt): New function.
	(add_scope_stmt): Likewise.
	(finish_stmt_tree): Tweak.
	(genrtl_expr_stmt): Likewise.
	(genrtl_decl_stmt): Handle local labels, and call
	lang_expand_decl_stmt if required.
	(genrtl_for_stmt): Fix line-number handling.
	(genrtl_case_label): Handle cleanups.
	(genrtl_asm_stmt): Don't call combine_strings.
	(genrtl_compound_stmt): Simplify.
	(expand_stmt): Handle SCOPE_STMTs.
	* c-tree.h (struct lang_decl): New structure.
	(C_DECLARED_LABEL_FLAG): Remove.
	(c_begin_compound_stmt): Declare.
	(c_expand_decl_stmt): Likewise.
	(c_expand_start_case): Rename to c_start_case.
	(c_finish_case): New function.
	* c-typeck.c (start_init): Tweak setting of
	constructor_incremental.
	(c_expand_asm_operands): Tweak error-handling.  Add to the
	statement-tree.
	(c_expand_return): Add to the statement-tree.
	(c_expand_start_case): Rename to ...
	(c_start_case): ... this.
	(struct c_switch): New type.
	(switch_stack): New variable.
	(do_case): Simplify.
	(c_finish_case): New function.
	* dependence.c: Include expr.h.
	(enum dependence_type): Change spelling of enumerals.
	(check_node_dependence): Adjust.
	* expr.h (lang_safe_from_p): Declare.
	(safe_from_p): Likewise.
	* expr.c (lang_safe_from_p): New variable.
	(safe_from_p): Give it external linkage.  Use lang_safe_from_p.
	* stmt.c (expand_expr_stmt): Avoid clobberring of last_expr_type.
	* toplev.c (rest_of_decl_compilation): Robustify.
	* tree.c (contains_placeholder_p): Likewise.
	* Makefile.in: Update dependencies.
	* objc/objc-act.h: Adjust calculation of value for dummy_tree_code.
	* objc/objc-act.c: Include rtl.h, expr.h, and c-common.h.
	(objc_expand_function_end): New function.
	(finish_method_def): Use it.
	(init_objc): Initialize more language-specific hooks.
	* objc/Make-lang.in: Update dependencies.

	* cp-tree.h (struct cp_language_function): Remove
	x_scope_stmt_stack and name_declared.
	(current_scope_stmt_stack): Remove.
	(function_name_declared_p): New macro.
	(struct lang_decl_flags): Use c_lang_decl as a base class.
	(context): Remove.
	(struct lang_decl): Replace saved_tree with context.
	(DECL_FRIEND_CONTEXT): Adjust accordingly.
	(SET_DECL_FRIEND_CONTEXT): Likewise.
	(DECL_VIRTUAL_CONTEXT): Likewise.
	(DECL_SAVED_TREE): Remove.
	(C_DECLARED_LABEL_FLAG): Likewise.
	(cplus_expand_expr_stmt): Don't declare.
	(add_decl_stmt): Likewise.
	(add_scope_stmt): Likewise.
	* decl.c (mark_stmt_tree): Remove.
	(case_compare): Likewise.
	(finish_case_label): Use c_add_case_label.
	(init_decl_processing): Set more language-specific hooks.
	(build_enumerator): Fix typo in comment.
	(cplus_expand_expr_stmt): Remove.
	(mark_lang_function): Use mark_c_language_function.
	(lang_mark_tree): Use c_mark_lang_decl.
	* decl2.c: Change order of inclusion.
	* except.c: Likewise.
	* expr.c (cplus_expand_expr): Remove handling of STMT_EXPR.  Fall
	back on c_expand_expr.
	* friend.c: Include expr.h.
	* init.c: Change order of inclusion.
	* Makefile.in: Update dependencies.
	* lex.h (free_lang_decl_chain): Remove.
	* optimize.c (maybe_clone_body): Use function_name_declared_p.
	* pt.c (build_template_decl): Don't copy DECL_VIRTUAL_CONTEXT if
	it doesn't exist.
	(instantiate_decl): Use function_name_declared_p.
	* semantics.c (lang_expand_expr_stmt): Remove.
	(set_current_function_name_declared): Likewise.
	(current_function_name_declared): Likewise.
	(begin_compound_stmt): Use function_name_declared_p.
	(add_decl_stmt): Remove.
	(setup_vtbl_ptr): Use function_name_declared_p.
	(add_scope_stmt): Remove.
	(current_scope_stmt_stack): New function.
	(cp_expand_stmt): Don't handle SCOPE_STMTs.
	(expand_body): Use function_name_declared_p.
	* tree.c (cp_statement_code_p): Don't include SCOPE_STMT.
	* typeck.c: Change order of includes.
	(convert_sequence): Remove.

From-SVN: r36464

1 files changed, 317 insertions, 10 deletions

diff --git a/gcc/c-common.c b/gcc/c-common.c
index 2f35541..54335dd 100644
--- a/gcc/c-common.c
+++ b/gcc/c-common.c
@@ -22,7 +22,6 @@ Boston, MA 02111-1307, USA.  */
 #include "config.h"
 #include "system.h"
 #include "tree.h"
-#include "c-common.h"
 #include "flags.h"
 #include "toplev.h"
 #include "output.h"
@@ -30,6 +29,7 @@ Boston, MA 02111-1307, USA.  */
 #include "rtl.h"
 #include "ggc.h"
 #include "expr.h"
+#include "c-common.h"
 #include "tm_p.h"
 #include "intl.h"
 
@@ -149,6 +149,10 @@ tree (*make_fname_decl)                PARAMS ((tree, const char *, int));
    returns 1 for language-specific statement codes.  */
 int (*lang_statement_code_p)           PARAMS ((enum tree_code));
 
+/* If non-NULL, the address of a language-specific function that takes
+   any action required right before expand_function_end is called.  */
+void (*lang_expand_function_end)       PARAMS ((void));
+
 /* Nonzero means the expression being parsed will never be evaluated.
    This is a count, since unevaluated expressions can nest.  */
 int skip_evaluation;
@@ -181,6 +185,7 @@ typedef struct
   int line;
   const char *file;
   int needs_warning;
+  tree if_stmt;
 } if_elt;
 static void tfaff			PARAMS ((void));
 
@@ -192,15 +197,16 @@ static int if_stack_space = 0;
 /* Stack pointer.  */
 static int if_stack_pointer = 0;
 
-/* Generate RTL for the start of an if-then, and record the start of it
+/* Record the start of an if-then, and record the start of it
    for ambiguous else detection.  */
 
 void
-c_expand_start_cond (cond, exitflag, compstmt_count)
+c_expand_start_cond (cond, compstmt_count)
      tree cond;
-     int exitflag;
      int compstmt_count;
 {
+  tree if_stmt;
+
   /* Make sure there is enough space on the stack.  */
   if (if_stack_space == 0)
     {
@@ -213,17 +219,29 @@ c_expand_start_cond (cond, exitflag, compstmt_count)
       if_stack = (if_elt *)xrealloc (if_stack, if_stack_space * sizeof (if_elt));
     }
 
+  if_stmt = build_stmt (IF_STMT, NULL_TREE, NULL_TREE, NULL_TREE);
+  IF_COND (if_stmt) = cond;
+  add_stmt (if_stmt);
+
   /* Record this if statement.  */
   if_stack[if_stack_pointer].compstmt_count = compstmt_count;
   if_stack[if_stack_pointer].file = input_filename;
   if_stack[if_stack_pointer].line = lineno;
   if_stack[if_stack_pointer].needs_warning = 0;
+  if_stack[if_stack_pointer].if_stmt = if_stmt;
   if_stack_pointer++;
+}
 
-  expand_start_cond (cond, exitflag);
+/* Called after the then-clause for an if-statement is processed.  */
+
+void
+c_finish_then ()
+{
+  tree if_stmt = if_stack[if_stack_pointer - 1].if_stmt;
+  RECHAIN_STMTS (if_stmt, THEN_CLAUSE (if_stmt));
 }
 
-/* Generate RTL for the end of an if-then.  Optionally warn if a nested
+/* Record the end of an if-then.  Optionally warn if a nested
    if statement had an ambiguous else clause.  */
 
 void
@@ -234,10 +252,10 @@ c_expand_end_cond ()
     warning_with_file_and_line (if_stack[if_stack_pointer].file,
 				if_stack[if_stack_pointer].line,
 				"suggest explicit braces to avoid ambiguous `else'");
-  expand_end_cond ();
+  last_expr_type = NULL_TREE;
 }
 
-/* Generate RTL between the then-clause and the else-clause
+/* Called between the then-clause and the else-clause
    of an if-then-else.  */
 
 void
@@ -256,8 +274,15 @@ c_expand_start_else ()
      case.  Also don't warn for any if statements nested in this else.  */
   if_stack[if_stack_pointer - 1].needs_warning = 0;
   if_stack[if_stack_pointer - 1].compstmt_count--;
+}
+
+/* Called after the else-clause for an if-statement is processed.  */
 
-  expand_start_else ();
+void
+c_finish_else ()
+{
+  tree if_stmt = if_stack[if_stack_pointer - 1].if_stmt;
+  RECHAIN_STMTS (if_stmt, ELSE_CLAUSE (if_stmt));
 }
 
 /* Make bindings for __FUNCTION__, __PRETTY_FUNCTION__, and __func__.  */
@@ -2770,7 +2795,8 @@ c_expand_expr_stmt (expr)
       && TREE_CODE (TREE_TYPE (expr)) != ARRAY_TYPE)
     error ("expression statement has incomplete type");
 
-  expand_expr_stmt (expr);
+  last_expr_type = TREE_TYPE (expr); 
+  add_stmt (build_stmt (EXPR_STMT, expr));
 }
 
 /* Validate the expression after `case' and apply default promotions.  */
@@ -4540,6 +4566,7 @@ statement_code_p (code)
     case RETURN_STMT:
     case BREAK_STMT:
     case CONTINUE_STMT:
+    case SCOPE_STMT:
     case SWITCH_STMT:
     case GOTO_STMT:
     case LABEL_STMT:
@@ -4627,6 +4654,286 @@ walk_stmt_tree (tp, func, data)
 #undef WALK_SUBTREE
 }
 
+/* Used to compare case labels.  K1 and K2 are actually tree nodes
+   representing case labels, or NULL_TREE for a `default' label.
+   Returns -1 if K1 is ordered before K2, -1 if K1 is ordered after
+   K2, and 0 if K1 and K2 are equal.  */
+
+int
+case_compare (k1, k2)
+     splay_tree_key k1;
+     splay_tree_key k2;
+{
+  /* Consider a NULL key (such as arises with a `default' label) to be
+     smaller than anything else.  */
+  if (!k1)
+    return k2 ? -1 : 0;
+  else if (!k2)
+    return k1 ? 1 : 0;
+
+  return tree_int_cst_compare ((tree) k1, (tree) k2);
+}
+
+/* Process a case label for the range LOW_VALUE ... HIGH_VALUE.  If
+   LOW_VALUE and HIGH_VALUE are both NULL_TREE then this case label is
+   actually a `default' label.  If only HIGH_VALUE is NULL_TREE, then
+   case label was declared using the usual C/C++ syntax, rather than
+   the GNU case range extension.  CASES is a tree containing all the
+   case ranges processed so far; COND is the condition for the
+   switch-statement itself.  Returns the CASE_LABEL created, or
+   ERROR_MARK_NODE if no CASE_LABEL is created.  */
+
+tree
+c_add_case_label (cases, cond, low_value, high_value)
+     splay_tree cases;
+     tree cond;
+     tree low_value;
+     tree high_value;
+{
+  tree type;
+  tree label;
+  tree case_label;
+  splay_tree_node node;
+
+  /* Create the LABEL_DECL itself.  */
+  label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
+  DECL_CONTEXT (label) = current_function_decl;
+
+  /* If there was an error processing the switch condition, bail now
+     before we get more confused.  */
+  if (!cond || cond == error_mark_node)
+    {
+      /* Add a label anyhow so that the back-end doesn't think that
+	 the beginning of the switch is unreachable.  */
+      if (!cases->root)
+	add_stmt (build_case_label (NULL_TREE, NULL_TREE, label));
+      return error_mark_node;
+    }
+
+  if ((low_value && TREE_TYPE (low_value) 
+       && POINTER_TYPE_P (TREE_TYPE (low_value))) 
+      || (high_value && TREE_TYPE (high_value)
+	  && POINTER_TYPE_P (TREE_TYPE (high_value))))
+    error ("pointers are not permitted as case values");
+
+  /* Case ranges are a GNU extension.  */
+  if (high_value && pedantic)
+    {
+      if (c_language == clk_cplusplus)
+	pedwarn ("ISO C++ forbids range expressions in switch statements");
+      else
+	pedwarn ("ISO C forbids range expressions in switch statements");
+    }
+
+  type = TREE_TYPE (cond);
+  if (low_value)
+    {
+      low_value = check_case_value (low_value);
+      low_value = convert_and_check (type, low_value);
+    }
+  if (high_value)
+    {
+      high_value = check_case_value (high_value);
+      high_value = convert_and_check (type, high_value);
+    }
+
+  /* If an error has occurred, bail out now.  */
+  if (low_value == error_mark_node || high_value == error_mark_node)
+    {
+      if (!cases->root)
+	add_stmt (build_case_label (NULL_TREE, NULL_TREE, label));
+      return error_mark_node;
+    }
+
+  /* If the LOW_VALUE and HIGH_VALUE are the same, then this isn't
+     really a case range, even though it was written that way.  Remove
+     the HIGH_VALUE to simplify later processing.  */
+  if (tree_int_cst_equal (low_value, high_value))
+    high_value = NULL_TREE;
+  if (low_value && high_value 
+      && !tree_int_cst_lt (low_value, high_value)) 
+    warning ("empty range specified");
+
+  /* Look up the LOW_VALUE in the table of case labels we already
+     have.  */
+  node = splay_tree_lookup (cases, (splay_tree_key) low_value);
+  /* If there was not an exact match, check for overlapping ranges.
+     There's no need to do this if there's no LOW_VALUE or HIGH_VALUE;
+     that's a `default' label and the only overlap is an exact match.  */
+  if (!node && (low_value || high_value))
+    {
+      splay_tree_node low_bound;
+      splay_tree_node high_bound;
+
+      /* Even though there wasn't an exact match, there might be an
+	 overlap between this case range and another case range.
+	 Since we've (inductively) not allowed any overlapping case
+	 ranges, we simply need to find the greatest low case label
+	 that is smaller that LOW_VALUE, and the smallest low case
+	 label that is greater than LOW_VALUE.  If there is an overlap
+	 it will occur in one of these two ranges.  */
+      low_bound = splay_tree_predecessor (cases,
+					  (splay_tree_key) low_value);
+      high_bound = splay_tree_successor (cases,
+					 (splay_tree_key) low_value);
+
+      /* Check to see if the LOW_BOUND overlaps.  It is smaller than
+	 the LOW_VALUE, so there is no need to check unless the
+	 LOW_BOUND is in fact itself a case range.  */
+      if (low_bound
+	  && CASE_HIGH ((tree) low_bound->value)
+	  && tree_int_cst_compare (CASE_HIGH ((tree) low_bound->value),
+				    low_value) >= 0)
+	node = low_bound;
+      /* Check to see if the HIGH_BOUND overlaps.  The low end of that
+	 range is bigger than the low end of the current range, so we
+	 are only interested if the current range is a real range, and
+	 not an ordinary case label.  */
+      else if (high_bound 
+	       && high_value
+	       && (tree_int_cst_compare ((tree) high_bound->key,
+					 high_value)
+		   <= 0))
+	node = high_bound;
+    }
+  /* If there was an overlap, issue an error.  */
+  if (node)
+    {
+      tree duplicate = CASE_LABEL_DECL ((tree) node->value);
+
+      if (high_value)
+	{
+	  error ("duplicate (or overlapping) case value");
+	  error_with_decl (duplicate, 
+			   "this is the first entry overlapping that value");
+	}
+      else if (low_value)
+	{
+	  error ("duplicate case value") ;
+	  error_with_decl (duplicate, "previously used here");
+	}
+      else
+	{
+	  error ("multiple default labels in one switch");
+	  error_with_decl (duplicate, "this is the first default label");
+	}
+      if (!cases->root)
+	add_stmt (build_case_label (NULL_TREE, NULL_TREE, label));
+    }
+
+  /* Add a CASE_LABEL to the statement-tree.  */
+  case_label = add_stmt (build_case_label (low_value, high_value, label));
+  /* Register this case label in the splay tree.  */
+  splay_tree_insert (cases, 
+		     (splay_tree_key) low_value,
+		     (splay_tree_value) case_label);
+
+  return case_label;
+}
+
+/* Mark P (a stmt_tree) for GC.  The use of a `void *' for the
+   parameter allows this function to be used as a GC-marking
+   function.  */
+
+void
+mark_stmt_tree (p)
+     void *p;
+{
+  stmt_tree st = (stmt_tree) p;
+
+  ggc_mark_tree (st->x_last_stmt);
+  ggc_mark_tree (st->x_last_expr_type);
+}
+
+/* Mark LD for GC.  */
+
+void
+c_mark_lang_decl (c)
+     struct c_lang_decl *c;
+{
+  ggc_mark_tree (c->saved_tree);
+}
+
+/* Mark F for GC.  */
+
+void
+mark_c_language_function (f)
+     struct language_function *f;
+{
+  if (!f)
+    return;
+
+  mark_stmt_tree (&f->x_stmt_tree);
+  ggc_mark_tree (f->x_scope_stmt_stack);
+}
+
+/* Hook used by expand_expr to expand language-specific tree codes.  */
+
+rtx
+c_expand_expr (exp, target, tmode, modifier)
+     tree exp;
+     rtx target;
+     enum machine_mode tmode;
+     enum expand_modifier modifier;
+{
+  switch (TREE_CODE (exp))
+    {
+    case STMT_EXPR:
+      {
+	tree rtl_expr;
+	rtx result;
+
+	/* Since expand_expr_stmt calls free_temp_slots after every
+	   expression statement, we must call push_temp_slots here.
+	   Otherwise, any temporaries in use now would be considered
+	   out-of-scope after the first EXPR_STMT from within the
+	   STMT_EXPR.  */
+	push_temp_slots ();
+	rtl_expr = expand_start_stmt_expr ();
+	expand_stmt (STMT_EXPR_STMT (exp));
+	expand_end_stmt_expr (rtl_expr);
+	result = expand_expr (rtl_expr, target, tmode, modifier);
+	pop_temp_slots ();
+	return result;
+      }
+      break;
+      
+    default:
+      abort ();
+    }
+
+  abort ();
+  return NULL;
+}
+
+/* Hook used by safe_from_p to handle language-specific tree codes.  */
+
+int
+c_safe_from_p (target, exp)
+     rtx target;
+     tree exp;
+{
+  /* We can see statements here when processing the body of a
+     statement-expression.  For a declaration statement declaring a
+     variable, look at the variable's initializer.  */
+  if (TREE_CODE (exp) == DECL_STMT) 
+    {
+      tree decl = DECL_STMT_DECL (exp);
+
+      if (TREE_CODE (decl) == VAR_DECL
+	  && DECL_INITIAL (decl)
+	  && !safe_from_p (target, DECL_INITIAL (decl), /*top_p=*/0))
+	return 0;
+    }
+
+  /* For any statement, we must follow the statement-chain.  */
+  if (statement_code_p (TREE_CODE (exp)) && TREE_CHAIN (exp))
+    return safe_from_p (target, TREE_CHAIN (exp), /*top_p=*/0);
+
+  /* Assume everything else is safe.  */
+  return 1;
+}
+
 /* Tree code classes. */
 
 #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) TYPE,