[gfortran] PR13910 Old-style initialization of LOGICAL variables

[Tobias Schlüter]

This adds a very restricted language extension.

Bud reported that it is commonplace in some codes to initialize LOGICALs 
as follows:
LOGICAL L / .TRUE. /

This patch allows this, if we're compiling with STD_GNU. Compile 
testcase attached.

Bootstrapped and regtested. This has been in my tree for a while and 
caused no problems.

- Tobi

2004-05-11  Tobias Schlüter <tobias.schlueter@physik.uni-muenchen.de>

	PR fortran/13910
	* decl.c: Update copyright years. Include system.h and flags.h.
	Reorder includes to match other files.
	(variable_decl): Allow old-style initialization of LOGICALS.

Index: decl.c
===================================================================
RCS file: /cvsroot/gcc/gcc/gcc/fortran/Attic/decl.c,v
retrieving revision 1.1.2.2
diff -u -p -r1.1.2.2 decl.c
--- decl.c      2 Aug 2003 00:26:48 -0000       1.1.2.2
+++ decl.c      11 May 2004 19:36:42 -0000
@@ -1,5 +1,5 @@
  /* Declaration statement matcher
-   Copyright (C) 2002 Free Software Foundation, Inc.
+   Copyright (C) 2002, 2004 Free Software Foundation, Inc.
     Contributed by Andy Vaught

  This file is part of GNU G95.
@@ -21,10 +21,14 @@ Boston, MA 02111-1307, USA.  */


  #include "config.h"
+#include "system.h"
+#include "flags.h"
+
+#include <string.h>
+
  #include "gfortran.h"
  #include "match.h"
  #include "parse.h"
-#include <string.h>


  /* This flag is set if a an old-style length selector is matched
@@ -556,9 +569,52 @@ variable_decl (void)
        goto cleanup;
      }

+  /* Allow non-standard old style initialization of the form:
+        LOGICAL l /.TRUE./
+     In order to not introduce an overly complex extension, this is
+     fairly restricted: we only allow this for non-pointer variables,
+     and only if no colon has been seen, i.e.
+        LOGICAL :: l /.TRUE./
+     is not allowed.  */
+  if (!colon_seen)
+    {
+      if (gfc_match (" /") == MATCH_YES)
+       {
+         if (current_attr.pointer)
+           {
+             gfc_error("Pointer initialization at %C requires '=>'");
+             m = MATCH_ERROR;
+             goto cleanup;
+           }
+
+         m = gfc_match_init_expr (&initializer);
+         if (m == MATCH_NO)
+           {
+             gfc_error ("Expected an initialization expression at %C");
+             m = MATCH_ERROR;
+           }
+
+         if (current_attr.flavor != FL_PARAMETER && gfc_pure (NULL))
+           {
+             gfc_error
+               ("Initialization of variable at %C is not allowed in a "
+                "PURE procedure");
+             m = MATCH_ERROR;
+           }
+
+         m = gfc_match(" /");
+         if (m == MATCH_YES && pedantic)
+           if (gfc_notify_std (GFC_STD_GNU, "Extension: Old-style "
+                               "initialization of LOGICAL at %C") == 
FAILURE)
+             m = MATCH_NO;
+
+         if (m != MATCH_YES)
+           goto cleanup;
+       }
+    }
    /* The double colon must be present in order to have initializers.
       Otherwise the statement is ambiguous with an assignment 
statement.  */
-  if (colon_seen)
+  else
      {
        if (gfc_match (" =>") == MATCH_YES)
         {