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0e48b5a2 | 1 | /* Language-level data type conversion for GNU C. |
23a5b65a | 2 | Copyright (C) 1987-2014 Free Software Foundation, Inc. |
0e48b5a2 | 3 | |
1322177d | 4 | This file is part of GCC. |
0e48b5a2 | 5 | |
1322177d LB |
6 | GCC is free software; you can redistribute it and/or modify it under |
7 | the terms of the GNU General Public License as published by the Free | |
9dcd6f09 | 8 | Software Foundation; either version 3, or (at your option) any later |
1322177d | 9 | version. |
0e48b5a2 | 10 | |
1322177d LB |
11 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
12 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
13 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
14 | for more details. | |
0e48b5a2 RS |
15 | |
16 | You should have received a copy of the GNU General Public License | |
9dcd6f09 NC |
17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ | |
0e48b5a2 RS |
19 | |
20 | ||
21 | /* This file contains the functions for converting C expressions | |
22 | to different data types. The only entry point is `convert'. | |
23 | Every language front end must have a `convert' function | |
24 | but what kind of conversions it does will depend on the language. */ | |
25 | ||
26 | #include "config.h" | |
c5c76735 | 27 | #include "system.h" |
4977bab6 ZW |
28 | #include "coretypes.h" |
29 | #include "tm.h" | |
0e48b5a2 RS |
30 | #include "tree.h" |
31 | #include "flags.h" | |
10055ae2 | 32 | #include "convert.h" |
39dabefd | 33 | #include "c-family/c-common.h" |
85498824 | 34 | #include "c-tree.h" |
e57e265b | 35 | #include "langhooks.h" |
4de67c26 | 36 | #include "target.h" |
0e48b5a2 RS |
37 | |
38 | /* Change of width--truncation and extension of integers or reals-- | |
39 | is represented with NOP_EXPR. Proper functioning of many things | |
40 | assumes that no other conversions can be NOP_EXPRs. | |
41 | ||
42 | Conversion between integer and pointer is represented with CONVERT_EXPR. | |
43 | Converting integer to real uses FLOAT_EXPR | |
44 | and real to integer uses FIX_TRUNC_EXPR. | |
45 | ||
46 | Here is a list of all the functions that assume that widening and | |
47 | narrowing is always done with a NOP_EXPR: | |
10055ae2 | 48 | In convert.c, convert_to_integer. |
78ef5b89 NB |
49 | In c-typeck.c, build_binary_op (boolean ops), and |
50 | c_common_truthvalue_conversion. | |
0e48b5a2 RS |
51 | In expr.c: expand_expr, for operands of a MULT_EXPR. |
52 | In fold-const.c: fold. | |
53 | In tree.c: get_narrower and get_unwidened. */ | |
54 | \f | |
55 | /* Subroutines of `convert'. */ | |
56 | ||
0e48b5a2 | 57 | |
0e48b5a2 RS |
58 | \f |
59 | /* Create an expression whose value is that of EXPR, | |
60 | converted to type TYPE. The TREE_TYPE of the value | |
61 | is always TYPE. This function implements all reasonable | |
62 | conversions; callers should filter out those that are | |
63 | not permitted by the language being compiled. */ | |
64 | ||
65 | tree | |
35b1a6fa | 66 | convert (tree type, tree expr) |
0e48b5a2 | 67 | { |
b3694847 SS |
68 | tree e = expr; |
69 | enum tree_code code = TREE_CODE (type); | |
4de67c26 | 70 | const char *invalid_conv_diag; |
4d84fe7c | 71 | tree ret; |
db3927fb | 72 | location_t loc = EXPR_LOCATION (expr); |
0e48b5a2 | 73 | |
4de67c26 JM |
74 | if (type == error_mark_node |
75 | || expr == error_mark_node | |
76 | || TREE_TYPE (expr) == error_mark_node) | |
77 | return error_mark_node; | |
78 | ||
79 | if ((invalid_conv_diag | |
80 | = targetm.invalid_conversion (TREE_TYPE (expr), type))) | |
81 | { | |
82 | error (invalid_conv_diag); | |
83 | return error_mark_node; | |
84 | } | |
85 | ||
86 | if (type == TREE_TYPE (expr)) | |
0e48b5a2 | 87 | return expr; |
40449a90 SL |
88 | ret = targetm.convert_to_type (type, expr); |
89 | if (ret) | |
90 | return ret; | |
17aec3eb | 91 | |
928c19bb JM |
92 | STRIP_TYPE_NOPS (e); |
93 | ||
d409320c JJ |
94 | if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (expr)) |
95 | && (TREE_CODE (TREE_TYPE (expr)) != COMPLEX_TYPE | |
96 | || TREE_CODE (e) == COMPLEX_EXPR)) | |
db3927fb | 97 | return fold_convert_loc (loc, type, expr); |
0e48b5a2 RS |
98 | if (TREE_CODE (TREE_TYPE (expr)) == ERROR_MARK) |
99 | return error_mark_node; | |
100 | if (TREE_CODE (TREE_TYPE (expr)) == VOID_TYPE) | |
101 | { | |
102 | error ("void value not ignored as it ought to be"); | |
103 | return error_mark_node; | |
104 | } | |
4d84fe7c JM |
105 | |
106 | switch (code) | |
107 | { | |
108 | case VOID_TYPE: | |
db3927fb | 109 | return fold_convert_loc (loc, type, e); |
4d84fe7c JM |
110 | |
111 | case INTEGER_TYPE: | |
112 | case ENUMERAL_TYPE: | |
113 | ret = convert_to_integer (type, e); | |
114 | goto maybe_fold; | |
115 | ||
116 | case BOOLEAN_TYPE: | |
db3927fb AH |
117 | return fold_convert_loc |
118 | (loc, type, c_objc_common_truthvalue_conversion (input_location, expr)); | |
4d84fe7c JM |
119 | |
120 | case POINTER_TYPE: | |
121 | case REFERENCE_TYPE: | |
122 | ret = convert_to_pointer (type, e); | |
123 | goto maybe_fold; | |
124 | ||
125 | case REAL_TYPE: | |
126 | ret = convert_to_real (type, e); | |
127 | goto maybe_fold; | |
128 | ||
129 | case FIXED_POINT_TYPE: | |
130 | ret = convert_to_fixed (type, e); | |
131 | goto maybe_fold; | |
132 | ||
133 | case COMPLEX_TYPE: | |
dfe776dd JJ |
134 | /* If converting from COMPLEX_TYPE to a different COMPLEX_TYPE |
135 | and e is not COMPLEX_EXPR, convert_to_complex uses save_expr, | |
136 | but for the C FE c_save_expr needs to be called instead. */ | |
137 | if (TREE_CODE (TREE_TYPE (e)) == COMPLEX_TYPE) | |
138 | { | |
d409320c | 139 | if (TREE_CODE (e) != COMPLEX_EXPR) |
dfe776dd | 140 | { |
d409320c JJ |
141 | tree subtype = TREE_TYPE (type); |
142 | tree elt_type = TREE_TYPE (TREE_TYPE (e)); | |
143 | ||
dfe776dd JJ |
144 | if (in_late_binary_op) |
145 | e = save_expr (e); | |
146 | else | |
147 | e = c_save_expr (e); | |
148 | ret | |
d409320c JJ |
149 | = fold_build2_loc (loc, COMPLEX_EXPR, type, |
150 | convert (subtype, | |
151 | fold_build1 (REALPART_EXPR, | |
152 | elt_type, e)), | |
153 | convert (subtype, | |
154 | fold_build1 (IMAGPART_EXPR, | |
155 | elt_type, e))); | |
dfe776dd JJ |
156 | goto maybe_fold; |
157 | } | |
158 | } | |
4d84fe7c JM |
159 | ret = convert_to_complex (type, e); |
160 | goto maybe_fold; | |
161 | ||
162 | case VECTOR_TYPE: | |
163 | ret = convert_to_vector (type, e); | |
164 | goto maybe_fold; | |
165 | ||
166 | case RECORD_TYPE: | |
167 | case UNION_TYPE: | |
168 | if (lang_hooks.types_compatible_p (type, TREE_TYPE (expr))) | |
169 | return e; | |
170 | break; | |
171 | ||
172 | default: | |
173 | break; | |
174 | ||
175 | maybe_fold: | |
176 | if (TREE_CODE (ret) != C_MAYBE_CONST_EXPR) | |
177 | ret = fold (ret); | |
178 | return ret; | |
179 | } | |
0e48b5a2 RS |
180 | |
181 | error ("conversion to non-scalar type requested"); | |
182 | return error_mark_node; | |
183 | } |