[patch,gfortran] PR 24245: ICE with -fdump-parse-tree

[Erik Edelmann]

On Sat, Oct 29, 2005 at 07:42:50PM +0200, Steven Bosscher wrote:
> When I wrote this (sorry I broke something with it too ;-) I had this code
> here because I knew that we would have parsed some statements already:
> 
> +  /* Set the location to the first line of code.  */
> +  if (ns->code)
> +    main_program->declared_at = ns->code->loc;
> +  ns->proc_name = main_program;
> 
> But in your case, I think ns->code is always NULL, so you're not getting
> the declared_at right here.  And I wasn't getting it right for an empty
> main program.  This code was only there because I had no other locus to
> work with ;-)
> 
> IIUC you add the symbol at parse time, so you can use gfc_current_locus
> instead of my hack.

Yes, you are right.

> Also, you seem to be calling main_program_symbol twice for the same main
> program: Once from accept_statement, and once from gfc_parse_file.  It
> would be better to only call it from gfc_parse_file.  One call can go in
> under "case ST_PROGRAM:" and the other one under "default:", which is
> where we end up for unnamed main programs.  The call from accept_statement
> should go away.

OK.

Attached is a patch to address these issues.  

One additional note:  The call to gfc_status() from
show_symtree(), where we got the ICE, is commented out right now.
This comes from the patch by Gaurav Gautam and Tobi, posted here:
http://gcc.gnu.org/ml/fortran/2005-10/msg00713.html, which
contains this part:

--- gcc/fortran/dump-parse-tree.c       (revision 106030)
+++ gcc/fortran/dump-parse-tree.c       (working copy)
@@ -756,7 +756,9 @@ show_symtree (gfc_symtree * st)
   gfc_status ("symtree: %s  Ambig %d", st->name, st->ambiguous);
 
   if (st->n.sym->ns != gfc_current_ns)
-    gfc_status (" from namespace %s", st->n.sym->ns->proc_name->name);
+    /* Do nothing
+       gfc_status (" from namespace %s", st->n.sym->ns->proc_name->name); */
+    ;
   else
     gfc_show_symbol (st->n.sym);
 }

Since this part wasn't mentioned in the Changelog entry of that
patch, I assume that it wasn't intentional (Tobi & Gaurav: is
this assumption correct?). My patch uncomments the call to
gfc_status() again.


        Erik


2005-11-01  Erik Edelmann  <eedelman@gcc.gnu.org>

	PR 24245
	* trans.c (gfc_generate_code): Move code to create a main
	program symbol from here ...
	* parse.c (main_program_symbol): ... to this new
	function, setting the locus from gfc_current_locus
	instead of ns->code->loc. 
	(gfc_parse_file):  Call main_program_symbol for main programs.
	* dump-parse-tree.c (show_symtree): Uncomment call to
	gfc_status.
-------------- next part --------------
Index: gcc/fortran/dump-parse-tree.c
===================================================================
--- gcc/fortran/dump-parse-tree.c	(revision 106328)
+++ gcc/fortran/dump-parse-tree.c	(working copy)
@@ -756,9 +756,7 @@
   gfc_status ("symtree: %s  Ambig %d", st->name, st->ambiguous);
 
   if (st->n.sym->ns != gfc_current_ns)
-    /* Do nothing
-       gfc_status (" from namespace %s", st->n.sym->ns->proc_name->name); */
-    ;
+    gfc_status (" from namespace %s", st->n.sym->ns->proc_name->name);
   else
     gfc_show_symbol (st->n.sym);
 }
Index: gcc/fortran/parse.c
===================================================================
--- gcc/fortran/parse.c	(revision 106328)
+++ gcc/fortran/parse.c	(working copy)
@@ -970,6 +970,28 @@
 }
 
 
+/* Create a symbol for the main program and assign it to ns->proc_name.  */
+ 
+static void 
+main_program_symbol (gfc_namespace * ns)
+{
+  gfc_symbol *main_program;
+  symbol_attribute attr;
+
+  gfc_get_symbol ("MAIN__", ns, &main_program);
+  gfc_clear_attr (&attr);
+  attr.flavor = FL_PROCEDURE;
+  attr.proc = PROC_UNKNOWN;
+  attr.subroutine = 1;
+  attr.access = ACCESS_PUBLIC;
+  attr.is_main_program = 1;
+  main_program->attr = attr;
+  main_program->declared_at = gfc_current_locus;
+  ns->proc_name = main_program;
+  gfc_commit_symbols ();
+}
+
+
 /* Do whatever is necessary to accept the last statement.  */
 
 static void
@@ -2590,6 +2612,7 @@
       prog_locus = gfc_current_locus;
 
       push_state (&s, COMP_PROGRAM, gfc_new_block);
+      main_program_symbol(gfc_current_ns);
       accept_statement (st);
       add_global_program ();
       parse_progunit (ST_NONE);
@@ -2631,6 +2654,7 @@
       prog_locus = gfc_current_locus;
 
       push_state (&s, COMP_PROGRAM, gfc_new_block);
+      main_program_symbol(gfc_current_ns);
       parse_progunit (st);
       break;
     }
Index: gcc/fortran/trans.c
===================================================================
--- gcc/fortran/trans.c	(revision 106328)
+++ gcc/fortran/trans.c	(working copy)
@@ -656,30 +656,6 @@
       return;
     }
 
-  /* Main program subroutine.  */
-  if (!ns->proc_name)
-    {
-      gfc_symbol *main_program;
-      symbol_attribute attr;
-
-      /* Lots of things get upset if a subroutine doesn't have a symbol, so we
-         make one now.  Hopefully we've set all the required fields.  */
-      gfc_get_symbol ("MAIN__", ns, &main_program);
-      gfc_clear_attr (&attr);
-      attr.flavor = FL_PROCEDURE;
-      attr.proc = PROC_UNKNOWN;
-      attr.subroutine = 1;
-      attr.access = ACCESS_PUBLIC;
-      attr.is_main_program = 1;
-      main_program->attr = attr;
-
-      /* Set the location to the first line of code.  */
-      if (ns->code)
-	main_program->declared_at = ns->code->loc;
-      ns->proc_name = main_program;
-      gfc_commit_symbols ();
-    }
-
   gfc_generate_function_code (ns);
 }