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+/* Language-level data type conversion for GNU C.
+ Copyright (C) 1987, 1988, 1991, 1998, 2002 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 2, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING. If not, write to the Free
+Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+02111-1307, USA. */
+
+
+/* This file contains the functions for converting C expressions
+ to different data types. The only entry point is `convert'.
+ Every language front end must have a `convert' function
+ but what kind of conversions it does will depend on the language. */
+
+/* copied from the f77 frontend I think */
+
+/* copied from c-convert.c without significant modification*/
+/* Change of width--truncation and extension of integers or reals--
+ is represented with NOP_EXPR. Proper functioning of many things
+ assumes that no other conversions can be NOP_EXPRs.
+*/
+
+/* I've added support for WITH_RECORD_EXPR. */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tree.h"
+#include "flags.h"
+#include "convert.h"
+#include "toplev.h"
+#include "gfortran.h"
+#include "trans.h"
+
+/*
+ Conversion between integer and pointer is represented with CONVERT_EXPR.
+ Converting integer to real uses FLOAT_EXPR
+ and real to integer uses FIX_TRUNC_EXPR.
+
+ Here is a list of all the functions that assume that widening and
+ narrowing is always done with a NOP_EXPR:
+ In convert.c, convert_to_integer.
+ In c-typeck.c, build_binary_op (boolean ops), and
+ c_common_truthvalue_conversion.
+ In expr.c: expand_expr, for operands of a MULT_EXPR.
+ In fold-const.c: fold.
+ In tree.c: get_narrower and get_unwidened. */
+
+/* Subroutines of `convert'. */
+
+
+
+/* Create an expression whose value is that of EXPR,
+ converted to type TYPE. The TREE_TYPE of the value
+ is always TYPE. This function implements all reasonable
+ conversions; callers should filter out those that are
+ not permitted by the language being compiled. */
+/* We are assuming that given a SIMPLE val, the result will be a SIMPLE rhs.
+ If this is not the case, we will abort with an internal error. */
+tree
+convert (tree type, tree expr)
+{
+ tree e = expr;
+ enum tree_code code = TREE_CODE (type);
+
+ if (type == TREE_TYPE (expr)
+ || TREE_CODE (expr) == ERROR_MARK
+ || code == ERROR_MARK || TREE_CODE (TREE_TYPE (expr)) == ERROR_MARK)
+ return expr;
+
+ if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (expr)))
+ return fold (build1 (NOP_EXPR, type, expr));
+ if (TREE_CODE (TREE_TYPE (expr)) == ERROR_MARK)
+ return error_mark_node;
+ if (TREE_CODE (TREE_TYPE (expr)) == VOID_TYPE)
+ {
+ error ("void value not ignored as it ought to be");
+ return error_mark_node;
+ }
+ if (code == VOID_TYPE)
+ return build1 (CONVERT_EXPR, type, e);
+#if 0
+ /* This is incorrect. A truncation can't be stripped this way.
+ Extensions will be stripped by the use of get_unwidened. */
+ if (TREE_CODE (expr) == NOP_EXPR)
+ return convert (type, TREE_OPERAND (expr, 0));
+#endif
+ if (code == INTEGER_TYPE || code == ENUMERAL_TYPE)
+ return fold (convert_to_integer (type, e));
+ if (code == BOOLEAN_TYPE)
+ {
+ e = gfc_truthvalue_conversion (e);
+
+ /* If we have a NOP_EXPR, we must fold it here to avoid
+ infinite recursion between fold () and convert (). */
+ if (TREE_CODE (e) == NOP_EXPR)
+ return fold (build1 (NOP_EXPR, type, TREE_OPERAND (e, 0)));
+ else
+ return fold (build1 (NOP_EXPR, type, e));
+ }
+ if (code == POINTER_TYPE || code == REFERENCE_TYPE)
+ return fold (convert_to_pointer (type, e));
+ if (code == REAL_TYPE)
+ return fold (convert_to_real (type, e));
+ if (code == COMPLEX_TYPE)
+ return fold (convert_to_complex (type, e));
+ if (code == VECTOR_TYPE)
+ return fold (convert_to_vector (type, e));
+
+ error ("conversion to non-scalar type requested");
+ return error_mark_node;
+}