c-common.c (c_expand_start_cond): Expect the IF_STMT node to be passed in, do not build it.

        * c-common.c (c_expand_start_cond): Expect the IF_STMT node to
        be passed in, do not build it.
        (c_begin_if_stmt): New function.
        (c_begin_while_stmt, c_finish_while_stmt_cond): Likewise.
        * c-common.h (c_expand_start_cond): Update prototype.
        (c_begin_if_stmt): Prototype new function.
        (c_begin_while_stmt, c_finish_while_stmt_cond): Likewise.
        * c-parse.in (if_prefix): Use c_begin_if_stmt,
        c_begin_while_stmt and c_finish_while_stmt_cond.

From-SVN: r48539

gcc/ChangeLog

+Fri Jan  4 11:45:05 2002  Jeffrey A Law  (law@redhat.com)
+
+        * c-common.c (c_expand_start_cond): Expect the IF_STMT node to
+        be passed in, do not build it.
+        (c_begin_if_stmt): New function.
+        (c_begin_while_stmt, c_finish_while_stmt_cond): Likewise.
+        * c-common.h (c_expand_start_cond): Update prototype.
+        (c_begin_if_stmt): Prototype new function.
+        (c_begin_while_stmt, c_finish_while_stmt_cond): Likewise.
+        * c-parse.in (if_prefix): Use c_begin_if_stmt,
+        c_begin_while_stmt and c_finish_while_stmt_cond.
+
 2002-01-04  William Cohen  <wcohen@redhat.com>
 
 	* config/pa/elf.h (ASM_FILE_START): Reverted to profile_flag.

gcc/c-common.c

@@ -268,15 +268,20 @@ static int if_stack_space = 0;
 static int if_stack_pointer = 0;
 
 /* Record the start of an if-then, and record the start of it
-   for ambiguous else detection.  */
+   for ambiguous else detection.
+
+   COND is the condition for the if-then statement.
+
+   IF_STMT is the statement node that has already been created for
+   this if-then statement.  It is created before parsing the
+   condition to keep line number information accurate.  */
 
 void
-c_expand_start_cond (cond, compstmt_count)
+c_expand_start_cond (cond, compstmt_count, if_stmt)
      tree cond;
      int compstmt_count;
+     tree if_stmt;
 {
-  tree if_stmt;
-
   /* Make sure there is enough space on the stack.  */
   if (if_stack_space == 0)
     {
@@ -289,7 +294,6 @@ c_expand_start_cond (cond, 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);
 
@@ -355,6 +359,46 @@ c_finish_else ()
   RECHAIN_STMTS (if_stmt, ELSE_CLAUSE (if_stmt));
 }
 
+/* Begin an if-statement.  Returns a newly created IF_STMT if
+   appropriate.
+
+   Unlike the C++ front-end, we do not call add_stmt here; it is
+   probably safe to do so, but I am not very familiar with this
+   code so I am being extra careful not to change its behavior
+   beyond what is strictly necessary for correctness.  */
+
+tree
+c_begin_if_stmt ()
+{
+  tree r;
+  r = build_stmt (IF_STMT, NULL_TREE, NULL_TREE, NULL_TREE);
+  return r;
+}
+
+/* Begin a while statement.  Returns a newly created WHILE_STMT if
+   appropriate.
+
+   Unlike the C++ front-end, we do not call add_stmt here; it is
+   probably safe to do so, but I am not very familiar with this
+   code so I am being extra careful not to change its behavior
+   beyond what is strictly necessary for correctness.  */
+
+tree
+c_begin_while_stmt ()
+{
+  tree r;
+  r = build_stmt (WHILE_STMT, NULL_TREE, NULL_TREE);
+  return r;
+}
+
+void
+c_finish_while_stmt_cond (cond, while_stmt)
+     tree while_stmt;
+     tree cond;
+{
+  WHILE_COND (while_stmt) = cond;
+}
+
 /* Push current bindings for the function name VAR_DECLS.  */
 
 void

gcc/c-common.h

@@ -337,6 +337,10 @@ extern void expand_stmt                         PARAMS ((tree));
 extern void mark_stmt_tree                      PARAMS ((void *));
 extern void shadow_warning			PARAMS ((const char *,
 							 tree, tree));
+extern tree c_begin_if_stmt			PARAMS ((void));
+extern tree c_begin_while_stmt			PARAMS ((void));
+extern void c_finish_while_stmt_cond		PARAMS ((tree, tree));
+
 
 /* Extra information associated with a DECL.  Other C dialects extend
    this structure in various ways.  The C front-end only uses this
@@ -505,7 +509,7 @@ extern tree c_alignof_expr			PARAMS ((tree));
    NOP_EXPR is used as a special case (see truthvalue_conversion).  */
 extern void binary_op_error			PARAMS ((enum tree_code));
 extern tree c_expand_expr_stmt			PARAMS ((tree));
-extern void c_expand_start_cond			PARAMS ((tree, int));
+extern void c_expand_start_cond			PARAMS ((tree, int, tree));
 extern void c_finish_then                       PARAMS ((void));
 extern void c_expand_start_else			PARAMS ((void));
 extern void c_finish_else                   PARAMS ((void));

gcc/c-parse.in

@@ -2186,13 +2186,23 @@ simple_if:
 	;
 
 if_prefix:
-	  IF '(' expr ')'
-		{ c_expand_start_cond (truthvalue_conversion ($3), 
-				       compstmt_count);
+	  /* We must build the IF_STMT node before parsing its
+	     condition so that STMT_LINENO refers to the line
+	     containing the "if", and not the line containing
+	     the close-parenthesis.
+
+	     c_begin_if_stmt returns the IF_STMT node, which
+	     we later pass to c_expand_start_cond to fill
+	     in the condition and other tidbits.  */
+          IF
+                { $<ttype>$ = c_begin_if_stmt (); }
+            '(' expr ')'
+		{ c_expand_start_cond (truthvalue_conversion ($4), 
+				       compstmt_count,$<ttype>2);
 		  $<itype>$ = stmt_count;
 		  if_stmt_file = $<filename>-2;
 		  if_stmt_line = $<lineno>-1; }
-	;
+        ;
 
 /* This is a subroutine of stmt.
    It is used twice, once for valid DO statements
@@ -2287,12 +2297,22 @@ select_or_iter_stmt:
    Otherwise a crash is likely.  */
 	| simple_if ELSE error
 		{ c_expand_end_cond (); }
+       /* We must build the WHILE_STMT node before parsing its
+	  condition so that STMT_LINENO refers to the line
+	  containing the "while", and not the line containing
+	  the close-parenthesis.
+
+	  c_begin_while_stmt returns the WHILE_STMT node, which
+	  we later pass to c_finish_while_stmt_cond to fill
+	  in the condition and other tidbits.  */
 	| WHILE
-                { stmt_count++; }
+                { stmt_count++; 
+		  $<ttype>$ = c_begin_while_stmt (); }
 	  '(' expr ')'
                 { $4 = truthvalue_conversion ($4);
-		  $<ttype>$ 
-		    = add_stmt (build_stmt (WHILE_STMT, $4, NULL_TREE)); }
+		  c_finish_while_stmt_cond (truthvalue_conversion ($4),
+					    $<ttype>2);
+		  $<ttype>$ = add_stmt ($<ttype>2); }
 	  c99_block_lineno_labeled_stmt
 		{ RECHAIN_STMTS ($<ttype>6, WHILE_BODY ($<ttype>6)); }
 	| do_stmt_start