A function template instantiation fix

[Kriang Lerdsuwanakij <lerdsuwa at scf-fs dot usc dot edu>]

Hi,

The patch below fix function template problems when some template
parameters does not appear in either function arguments or return type. 
They are not correctly instantiated.  Here is a simple test program that
fails during linking - f<long> and f<char> not instantiated and the f()
function calls in main() are not mangled.

#include <iostream.h>

template <class T> int f()
{
	return sizeof(T);
}

int main()
{
	cout << f<long>() << f<char>() << ' ' << f<long>() << endl;
}

*******************

Sun Oct 26 23:49:55 1997  Kriang Lerdsuwanakij <lerdsuwa@scf.usc.edu>

	* pt.c (tsubst): Instantiate template functions properly when 
	template parameter does not appear in function arguments and
	return type.
	(comp_template_args): Handle member templates required by 
	tsubst.

 
diff -u save/pt.c cp/pt.c
--- save/pt.c	Sun Oct 26 00:11:51 1997
+++ cp/pt.c	Sun Oct 26 23:49:55 1997
@@ -1157,7 +1157,13 @@
 	continue;
       if (TREE_CODE (nt) != TREE_CODE (ot))
 	return 0;
-      if (TREE_CODE_CLASS (TREE_CODE (ot)) == 't')
+      if (TREE_CODE (nt) == TREE_VEC)
+        {
+          /* For member templates */
+	  if (comp_template_args (nt, ot))
+	    continue;
+        }
+      else if (TREE_CODE_CLASS (TREE_CODE (ot)) == 't')
 	{
 	  if (comptypes (ot, nt, 1))
 	    continue;
@@ -2246,14 +2252,6 @@
 	    type = tsubst (type, args, nargs, in_decl);
 	  }
 
-	if (type == TREE_TYPE (t)
-	    && (! member || ctx == DECL_CLASS_CONTEXT (t)))
-	  {
-	    t = copy_node (t);
-	    copy_lang_decl (t);
-	    return t;
-	  }
-
 	/* Do we already have this instantiation?  */
 	if (DECL_TEMPLATE_INFO (t) != NULL_TREE)
 	  {
@@ -2262,7 +2260,8 @@
 
 	    for (; decls; decls = TREE_CHAIN (decls))
 	      if (TREE_TYPE (TREE_VALUE (decls)) == type
-		  && DECL_CLASS_CONTEXT (TREE_VALUE (decls)) == ctx)
+		  && DECL_CLASS_CONTEXT (TREE_VALUE (decls)) == ctx
+		  && comp_template_args (TREE_PURPOSE (decls), args))
 		return TREE_VALUE (decls);
 	  }