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Diffstat (limited to 'gcc-4.8.3/gcc/c/c-convert.c')
| -rw-r--r-- | gcc-4.8.3/gcc/c/c-convert.c | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/gcc-4.8.3/gcc/c/c-convert.c b/gcc-4.8.3/gcc/c/c-convert.c new file mode 100644 index 000000000..3951ef549 --- /dev/null +++ b/gcc-4.8.3/gcc/c/c-convert.c @@ -0,0 +1,183 @@ +/* Language-level data type conversion for GNU C. + Copyright (C) 1987-2013 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 3, 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 COPYING3. If not see +<http://www.gnu.org/licenses/>. */ + + +/* 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. */ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "tm.h" +#include "tree.h" +#include "flags.h" +#include "convert.h" +#include "c-family/c-common.h" +#include "c-tree.h" +#include "langhooks.h" +#include "target.h" + +/* 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. + + 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. */ + +tree +convert (tree type, tree expr) +{ + tree e = expr; + enum tree_code code = TREE_CODE (type); + const char *invalid_conv_diag; + tree ret; + location_t loc = EXPR_LOCATION (expr); + + if (type == error_mark_node + || expr == error_mark_node + || TREE_TYPE (expr) == error_mark_node) + return error_mark_node; + + if ((invalid_conv_diag + = targetm.invalid_conversion (TREE_TYPE (expr), type))) + { + error (invalid_conv_diag); + return error_mark_node; + } + + if (type == TREE_TYPE (expr)) + return expr; + ret = targetm.convert_to_type (type, expr); + if (ret) + return ret; + + STRIP_TYPE_NOPS (e); + + if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (expr)) + && (TREE_CODE (TREE_TYPE (expr)) != COMPLEX_TYPE + || TREE_CODE (e) == COMPLEX_EXPR)) + return fold_convert_loc (loc, 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; + } + + switch (code) + { + case VOID_TYPE: + return fold_convert_loc (loc, type, e); + + case INTEGER_TYPE: + case ENUMERAL_TYPE: + ret = convert_to_integer (type, e); + goto maybe_fold; + + case BOOLEAN_TYPE: + return fold_convert_loc + (loc, type, c_objc_common_truthvalue_conversion (input_location, expr)); + + case POINTER_TYPE: + case REFERENCE_TYPE: + ret = convert_to_pointer (type, e); + goto maybe_fold; + + case REAL_TYPE: + ret = convert_to_real (type, e); + goto maybe_fold; + + case FIXED_POINT_TYPE: + ret = convert_to_fixed (type, e); + goto maybe_fold; + + case COMPLEX_TYPE: + /* If converting from COMPLEX_TYPE to a different COMPLEX_TYPE + and e is not COMPLEX_EXPR, convert_to_complex uses save_expr, + but for the C FE c_save_expr needs to be called instead. */ + if (TREE_CODE (TREE_TYPE (e)) == COMPLEX_TYPE) + { + if (TREE_CODE (e) != COMPLEX_EXPR) + { + tree subtype = TREE_TYPE (type); + tree elt_type = TREE_TYPE (TREE_TYPE (e)); + + if (in_late_binary_op) + e = save_expr (e); + else + e = c_save_expr (e); + ret + = fold_build2_loc (loc, COMPLEX_EXPR, type, + convert (subtype, + fold_build1 (REALPART_EXPR, + elt_type, e)), + convert (subtype, + fold_build1 (IMAGPART_EXPR, + elt_type, e))); + goto maybe_fold; + } + } + ret = convert_to_complex (type, e); + goto maybe_fold; + + case VECTOR_TYPE: + ret = convert_to_vector (type, e); + goto maybe_fold; + + case RECORD_TYPE: + case UNION_TYPE: + if (lang_hooks.types_compatible_p (type, TREE_TYPE (expr))) + return e; + break; + + default: + break; + + maybe_fold: + if (TREE_CODE (ret) != C_MAYBE_CONST_EXPR) + ret = fold (ret); + return ret; + } + + error ("conversion to non-scalar type requested"); + return error_mark_node; +} |