[PATCH] variable size arrays in nested functions

[Jakub Jelinek]

Hi!

The testcase below causes in ICE in expand_expr in gcc-2.96-RH. The issue is
that any SAVE_EXPR's generated from grokdeclarator for the function
arguments get context of the containing function, not the function they
belong to (or 0 if the function is not nested).
With current CVS head, the wrong SAVE_EXPR's are generated as well but for
some reason don't make it into expand_expr in this case so the ICE does not
happen (the abort() is because SAVE_EXPR corresponding to variable size
array argument's size doesn't have SAVE_EXPR_RTL attached yet and has non-NULL
context which is different from current function).
Does a patch like this look ok? It causes all SAVE_EXPRs for parameters
to have NULL context meaning they can be used in current function (ie.
nested one in this case).
Bootstrapped on i386-redhat-linux, no regressions.

2001-02-09  Jakub Jelinek  <jakub@redhat.com>

	* c-decl.c (push_parm_decl): Call grokdeclarator always with
	current_function_decl == 0, even for nested functions.

	* gcc.c-torture/execute/20010209-1.c: New test.

--- gcc/c-decl.c.jj	Mon Feb  5 14:50:26 2001
+++ gcc/c-decl.c	Fri Feb  9 00:50:29 2001
@@ -3768,15 +3768,22 @@ void
 push_parm_decl (parm)
      tree parm;
 {
-  tree decl;
+  tree decl, fn;
   int old_immediate_size_expand = immediate_size_expand;
   /* Don't try computing parm sizes now -- wait till fn is called.  */
   immediate_size_expand = 0;
 
+  /* Make sure any save_expr are not created in the context of the containing
+     function for nested functions.  */
+  fn = current_function_decl;
+  current_function_decl = 0;
+
   decl = grokdeclarator (TREE_VALUE (TREE_PURPOSE (parm)),
 			 TREE_PURPOSE (TREE_PURPOSE (parm)), PARM, 0);
   decl_attributes (decl, TREE_VALUE (TREE_VALUE (parm)),
 		   TREE_PURPOSE (TREE_VALUE (parm)));
+
+  current_function_decl = fn;
 
 #if 0
   if (DECL_NAME (decl))
--- gcc/testsuite/gcc.c-torture/execute/20010209-1.c.jj	Fri Feb  9 01:13:27 2001
+++ gcc/testsuite/gcc.c-torture/execute/20010209-1.c	Fri Feb  9 01:13:18 2001
@@ -0,0 +1,21 @@
+int b;
+int foo (void)
+{
+  int x[b];
+  int bar (int t[b])
+  {
+    int i;
+    for (i = 0; i < b; i++)
+      t[i] = i + (i > 0 ? t[i-1] : 0);
+    return t[b-1];
+  }
+  return bar (x);
+}
+
+int main ()
+{
+  b = 6;
+  if (foo () != 15)
+    abort ();
+  exit (0);
+}

	Jakub