| 1 | /* "True" vs "False" vs "Unknown". |
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| 2 | Copyright (C) 2019-2023 Free Software Foundation, Inc. |
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| 3 | Contributed by David Malcolm <dmalcolm@redhat.com>. |
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| 4 | |
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| 5 | This file is part of GCC. |
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| 6 | |
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| 7 | GCC is free software; you can redistribute it and/or modify it |
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| 8 | under the terms of the GNU General Public License as published by |
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| 9 | the Free Software Foundation; either version 3, or (at your option) |
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| 10 | any later version. |
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| 11 | |
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| 12 | GCC is distributed in the hope that it will be useful, but |
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| 13 | WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 15 | General Public License for more details. |
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| 16 | |
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| 17 | You should have received a copy of the GNU General Public License |
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| 18 | along with GCC; see the file COPYING3. If not see |
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| 19 | <http://www.gnu.org/licenses/>. */ |
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| 20 | |
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| 21 | #ifndef GCC_TRISTATE_H |
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| 22 | #define GCC_TRISTATE_H |
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| 23 | |
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| 24 | /* "True" vs "False" vs "Unknown". */ |
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| 25 | |
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| 26 | class tristate { |
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| 27 | public: |
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| 28 | enum value { |
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| 29 | TS_UNKNOWN, |
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| 30 | TS_TRUE, |
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| 31 | TS_FALSE |
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| 32 | }; |
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| 33 | |
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| 34 | tristate (enum value val) : m_value (val) {} |
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| 35 | tristate (bool val) : m_value (val ? TS_TRUE : TS_FALSE) {} |
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| 36 | static tristate unknown () { return tristate (TS_UNKNOWN); } |
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| 37 | |
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| 38 | const char *as_string () const; |
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| 39 | |
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| 40 | bool is_known () const { return m_value != TS_UNKNOWN; } |
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| 41 | bool is_unknown () const { return m_value == TS_UNKNOWN; } |
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| 42 | bool is_true () const { return m_value == TS_TRUE; } |
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| 43 | bool is_false () const { return m_value == TS_FALSE; } |
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| 44 | |
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| 45 | tristate not_ () const; |
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| 46 | tristate or_ (tristate other) const; |
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| 47 | tristate and_ (tristate other) const; |
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| 48 | |
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| 49 | bool operator== (const tristate &other) const |
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| 50 | { |
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| 51 | return m_value == other.m_value; |
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| 52 | } |
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| 53 | |
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| 54 | bool operator!= (const tristate &other) const |
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| 55 | { |
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| 56 | return m_value != other.m_value; |
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| 57 | } |
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| 58 | |
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| 59 | enum value get_value () const { return m_value; } |
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| 60 | |
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| 61 | private: |
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| 62 | enum value m_value; |
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| 63 | }; |
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| 64 | |
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| 65 | /* Overloaded boolean operators on tristates. */ |
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| 66 | |
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| 67 | inline tristate |
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| 68 | operator ! (tristate t) |
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| 69 | { |
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| 70 | return t.not_ (); |
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| 71 | } |
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| 72 | |
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| 73 | inline tristate |
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| 74 | operator || (tristate a, tristate b) |
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| 75 | { |
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| 76 | return a.or_ (other: b); |
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| 77 | } |
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| 78 | |
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| 79 | inline tristate |
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| 80 | operator && (tristate a, tristate b) |
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| 81 | { |
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| 82 | return a.and_ (other: b); |
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| 83 | } |
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| 84 | |
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| 85 | #endif /* GCC_TRISTATE_H */ |
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| 86 | |
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