re PR fortran/13082 (Function entries and entries with alternate returns not implemented)

2004-08-17  Paul Brook  <paul@codesourcery.com>
	Tobias Schlueter  <tobias.schlueter@physik.uni-muenchen.de>

	PR fortran/13082
	* decl.c (get_proc_name): Update mystery comment.
	(gfc_match_entry): Check for errors earlier.  Add entry point to list.
	* dump-parse-tree.c (gfc_show_code_node): Print EXEC_ENTRY nodes.
	* gfortran.h (symbol_attribute): Add entry_master.  Document entry.
	(struct gfc_entry_list): Define.
	(gfc_get_entry_list): Define.
	(struct gfc_namespace): Add refs and entries.
	(enum gfc_exec_op): Add EXEC_ENTRY.
	(struct gfc_code): Add ext.entry.
	* module.c (ab_attribute, attr_bits): Remove AB_ENTRY.
	(mio_symbol_attribute): Don't save/reture addr->entry.
	(mio_namespace_ref): Refcount namespaces.
	* parse.c (accept_statement): Handle ST_ENTRY.
	(gfc_fixup_sibling_symbols): Mark symbol as referenced.
	(parse_contained): Fixup sibling references to entry points
	after parsing the procedure body.
	* resolve.c (resolve_contained_fntype): New function.
	(merge_argument_lists, resolve_entries): New functions.
	(resolve_contained_functions): Use them.
	(resolve_code): Handle EXEC_ENTRY.
	(gfc_resolve): Call resolve_entries.
	* st.c (gfc_free_statement): Handle EXEC_ENTRY.
	* symbol.c (gfc_get_namespace): Refcount namespaces.
	(gfc_free_namespace): Ditto.
	* trans-array.c (gfc_trans_dummy_array_bias): Treat all args as
	optional when multiple entry points are present.
	* trans-decl.c (gfc_get_symbol_decl): Remove incorrect check.
	(gfc_get_extern_function_decl): Add assertion.  Fix coment.
	(create_function_arglist, trans_function_start, build_entry_thunks):
	New functions.
	(gfc_build_function_decl): Rename ...
	(build_function_decl): ... to this.
	(gfc_create_function_decl): New function.
	(gfc_generate_contained_functions): Use it.
	(gfc_trans_entry_master_switch): New function.
	(gfc_generate_function_code): Use new functions.
	* trans-stmt.c (gfc_trans_entry): New function.
	* trans-stmt.h (gfc_trans_entry): Add prototype.
	* trans-types.c (gfc_get_function_type): Add entry point argument.
	* trans.c (gfc_trans_code): Handle EXEC_ENTRY.
	(gfc_generate_module_code): Call gfc_create_function_decl.
	* trans.h (gfc_build_function_decl): Remove.
	(gfc_create_function_decl): Add prototype.
testsuite/
	* gfortran.dg/entry_1.f90: New test.

Co-Authored-By: Tobias Schlüter <tobias.schlueter@physik.uni-muenchen.de>

From-SVN: r86128

1 files changed, 41 insertions, 3 deletions

diff --git a/gcc/fortran/gfortran.h b/gcc/fortran/gfortran.h
index 80cdbbe..4585161 100644
--- a/gcc/fortran/gfortran.h
+++ b/gcc/fortran/gfortran.h
@@ -386,7 +386,7 @@ typedef struct
   /* Variable attributes.  */
   unsigned allocatable:1, dimension:1, external:1, intrinsic:1,
     optional:1, pointer:1, save:1, target:1,
-    dummy:1, result:1, entry:1, assign:1;
+    dummy:1, result:1, assign:1;
 
   unsigned data:1,		/* Symbol is named in a DATA statement.  */
     use_assoc:1;		/* Symbol has been use-associated.  */
@@ -399,6 +399,14 @@ typedef struct
   unsigned sequence:1, elemental:1, pure:1, recursive:1;
   unsigned unmaskable:1, masked:1, contained:1;
 
+  /* Set if this procedure is an alternate entry point.  These procedures
+     don't have any code associated, and the backend will turn them into
+     thunks to the master function.  */
+  unsigned entry:1;
+  /* Set if this is the master function for a procedure with multiple
+     entry points.  */
+  unsigned entry_master:1;
+
   /* Set if a function must always be referenced by an explicit interface.  */
   unsigned always_explicit:1;
 
@@ -668,7 +676,6 @@ typedef struct gfc_symbol
   struct gfc_namespace *ns;	/* namespace containing this symbol */
 
   tree backend_decl;
-
 }
 gfc_symbol;
 
@@ -687,6 +694,23 @@ gfc_common_head;
 #define gfc_get_common_head() gfc_getmem(sizeof(gfc_common_head))
 
 
+/* A list of all the alternate entry points for a procedure.  */
+
+typedef struct gfc_entry_list
+{
+  /* The symbol for this entry point.  */
+  gfc_symbol *sym;
+  /* The zero-based id of this entry point.  */
+  int id;
+  /* The LABEL_EXPR marking this entry point.  */
+  tree label;
+  /* The nest item in the list.  */
+  struct gfc_entry_list *next;
+}
+gfc_entry_list;
+
+#define gfc_get_entry_list() \
+  (gfc_entry_list *) gfc_getmem(sizeof(gfc_entry_list))
 
 /* Within a namespace, symbols are pointed to by symtree nodes that
    are linked together in a balanced binary tree.  There can be
@@ -712,6 +736,10 @@ typedef struct gfc_symtree
 gfc_symtree;
 
 
+/* A namespace describes the contents of procedure, module or
+   interface block.  */
+/* ??? Anything else use these?  */
+
 typedef struct gfc_namespace
 {
   /* Tree containing all the symbols in this namespace.  */
@@ -755,6 +783,14 @@ typedef struct gfc_namespace
   gfc_charlen *cl_list;
 
   int save_all, seen_save;
+
+  /* Normally we don't need to refcount namespaces.  However when we read
+     a module containing a function with multiple entry points, this
+     will appear as several functions with the same formal namespace.  */
+  int refs;
+
+  /* A list of all alternate entry points to this procedure (or NULL).  */
+  gfc_entry_list *entries;
 }
 gfc_namespace;
 
@@ -1204,7 +1240,8 @@ gfc_forall_iterator;
 typedef enum
 {
   EXEC_NOP = 1, EXEC_ASSIGN, EXEC_LABEL_ASSIGN, EXEC_POINTER_ASSIGN,
-  EXEC_GOTO, EXEC_CALL, EXEC_RETURN, EXEC_PAUSE, EXEC_STOP, EXEC_CONTINUE,
+  EXEC_GOTO, EXEC_CALL, EXEC_RETURN, EXEC_ENTRY,
+  EXEC_PAUSE, EXEC_STOP, EXEC_CONTINUE,
   EXEC_IF, EXEC_ARITHMETIC_IF, EXEC_DO, EXEC_DO_WHILE, EXEC_SELECT,
   EXEC_FORALL, EXEC_WHERE, EXEC_CYCLE, EXEC_EXIT,
   EXEC_ALLOCATE, EXEC_DEALLOCATE,
@@ -1243,6 +1280,7 @@ typedef struct gfc_code
     gfc_forall_iterator *forall_iterator;
     struct gfc_code *whichloop;
     int stop_code;
+    gfc_entry_list *entry;
   }
   ext;		/* Points to additional structures required by statement */