re PR fortran/18082 (Infinite loop with automatic length character objects)

2005-10-12  Paul Thomas  <pault@gcc.gnu.org>

	PR fortran/18082
	* decl.c (variable_decl): Make a new copy of the character
	length for each variable, when the expression is not a
	constant.

2005-10-12  Paul Thomas  <pault@gcc.gnu.org>

	PR fortran/18082
	gfortran.dg/automatic_char_len_1.f90: New test.

From-SVN: r105329

gcc/fortran/ChangeLog

+2005-10-12  Paul Thomas  <pault@gcc.gnu.org>
+
+	PR fortran/18082
+	* decl.c (variable_decl): Make a new copy of the character
+	length for each variable, when the expression is not a
+	constant.
+
 2005-10-12  Francois-Xavier Coudert  <coudert@clipper.ens.fr>
 
 	* gfortran.h: Add bitmasks for different FPE traps. Add fpe

gcc/fortran/decl.c

@@ -900,7 +900,7 @@ gfc_match_null (gfc_expr ** result)
    symbol table or the current interface.  */
 
 static match
-variable_decl (void)
+variable_decl (int elem)
 {
   char name[GFC_MAX_SYMBOL_LEN + 1];
   gfc_expr *initializer, *char_len;
@@ -944,8 +944,20 @@ variable_decl (void)
 	  cl->length = char_len;
 	  break;
 
+	/* Non-constant lengths need to be copied after the first
+	   element.  */
 	case MATCH_NO:
-	  cl = current_ts.cl;
+	  if (elem > 1 && current_ts.cl->length
+		&& current_ts.cl->length->expr_type != EXPR_CONSTANT)
+	    {
+	      cl = gfc_get_charlen ();
+	      cl->next = gfc_current_ns->cl_list;
+	      gfc_current_ns->cl_list = cl;
+	      cl->length = gfc_copy_expr (current_ts.cl->length);
+	    }
+	  else
+	    cl = current_ts.cl;
+
 	  break;
 
 	case MATCH_ERROR:
@@ -1944,6 +1956,7 @@ gfc_match_data_decl (void)
 {
   gfc_symbol *sym;
   match m;
+  int elem;
 
   m = match_type_spec (&current_ts, 0);
   if (m != MATCH_YES)
@@ -1995,10 +2008,12 @@ ok:
   if (m == MATCH_NO && current_ts.type == BT_CHARACTER && old_char_selector)
     gfc_match_char (',');
 
-  /* Give the types/attributes to symbols that follow.  */
+  /* Give the types/attributes to symbols that follow. Give the element
+     a number so that repeat character length expressions can be copied.  */
+  elem = 1;
   for (;;)
     {
-      m = variable_decl ();
+      m = variable_decl (elem++);
       if (m == MATCH_ERROR)
 	goto cleanup;
       if (m == MATCH_NO)

gcc/testsuite/ChangeLog

 2005-10-12  Paul Thomas  <pault@gcc.gnu.org>
 
+	PR fortran/18082
+	gfortran.dg/automatic_char_len_1.f90: New test.
+
+2005-10-12  Paul Thomas  <pault@gcc.gnu.org>
+
 	PR fortran/20847
 	gfortran.dg/save_common.f90: New test.
 

gcc/testsuite/gfortran.dg/automatic_char_len_1.f90

+! { dg-do compile }
+! PR18082 - Compiler would get stuck in loop, whilst treating
+! the assignments.
+! Test is one of PR cases.
+subroutine snafu (i)
+character*(i) :: c1, c2
+c1 = ""
+c2 = ""
+end subroutine snafu
+
+