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| Rev | Author | Line No. | Line |
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| 14 | pmbaty | 1 | //===--- StringView.h ----------------*- mode:c++;eval:(read-only-mode) -*-===// |
| 2 | // Do not edit! See README.txt. |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | // |
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| 9 | // FIXME: Use std::string_view instead when we support C++17. |
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| 10 | // There are two copies of this file in the source tree. The one under |
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| 11 | // libcxxabi is the original and the one under llvm is the copy. Use |
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| 12 | // cp-to-llvm.sh to update the copy. See README.txt for more details. |
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| 13 | // |
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| 14 | //===----------------------------------------------------------------------===// |
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| 15 | |||
| 16 | #ifndef DEMANGLE_STRINGVIEW_H |
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| 17 | #define DEMANGLE_STRINGVIEW_H |
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| 18 | |||
| 19 | #include "DemangleConfig.h" |
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| 20 | #include <cassert> |
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| 21 | #include <cstring> |
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| 22 | |||
| 23 | DEMANGLE_NAMESPACE_BEGIN |
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| 24 | |||
| 25 | class StringView { |
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| 26 | const char *First; |
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| 27 | const char *Last; |
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| 28 | |||
| 29 | public: |
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| 30 | static const size_t npos = ~size_t(0); |
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| 31 | |||
| 32 | template <size_t N> |
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| 33 | StringView(const char (&Str)[N]) : First(Str), Last(Str + N - 1) {} |
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| 34 | StringView(const char *First_, const char *Last_) |
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| 35 | : First(First_), Last(Last_) {} |
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| 36 | StringView(const char *First_, size_t Len) |
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| 37 | : First(First_), Last(First_ + Len) {} |
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| 38 | StringView(const char *Str) : First(Str), Last(Str + std::strlen(Str)) {} |
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| 39 | StringView() : First(nullptr), Last(nullptr) {} |
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| 40 | |||
| 41 | StringView substr(size_t Pos, size_t Len = npos) const { |
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| 42 | assert(Pos <= size()); |
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| 43 | if (Len > size() - Pos) |
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| 44 | Len = size() - Pos; |
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| 45 | return StringView(begin() + Pos, Len); |
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| 46 | } |
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| 47 | |||
| 48 | size_t find(char C, size_t From = 0) const { |
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| 49 | // Avoid calling memchr with nullptr. |
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| 50 | if (From < size()) { |
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| 51 | // Just forward to memchr, which is faster than a hand-rolled loop. |
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| 52 | if (const void *P = ::memchr(First + From, C, size() - From)) |
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| 53 | return size_t(static_cast<const char *>(P) - First); |
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| 54 | } |
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| 55 | return npos; |
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| 56 | } |
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| 57 | |||
| 58 | StringView dropFront(size_t N = 1) const { |
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| 59 | if (N >= size()) |
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| 60 | N = size(); |
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| 61 | return StringView(First + N, Last); |
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| 62 | } |
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| 63 | |||
| 64 | StringView dropBack(size_t N = 1) const { |
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| 65 | if (N >= size()) |
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| 66 | N = size(); |
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| 67 | return StringView(First, Last - N); |
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| 68 | } |
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| 69 | |||
| 70 | char front() const { |
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| 71 | assert(!empty()); |
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| 72 | return *begin(); |
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| 73 | } |
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| 74 | |||
| 75 | char back() const { |
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| 76 | assert(!empty()); |
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| 77 | return *(end() - 1); |
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| 78 | } |
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| 79 | |||
| 80 | char popFront() { |
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| 81 | assert(!empty()); |
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| 82 | return *First++; |
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| 83 | } |
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| 84 | |||
| 85 | bool consumeFront(char C) { |
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| 86 | if (!startsWith(C)) |
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| 87 | return false; |
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| 88 | *this = dropFront(1); |
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| 89 | return true; |
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| 90 | } |
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| 91 | |||
| 92 | bool consumeFront(StringView S) { |
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| 93 | if (!startsWith(S)) |
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| 94 | return false; |
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| 95 | *this = dropFront(S.size()); |
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| 96 | return true; |
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| 97 | } |
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| 98 | |||
| 99 | bool startsWith(char C) const { return !empty() && *begin() == C; } |
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| 100 | |||
| 101 | bool startsWith(StringView Str) const { |
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| 102 | if (Str.size() > size()) |
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| 103 | return false; |
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| 104 | return std::strncmp(Str.begin(), begin(), Str.size()) == 0; |
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| 105 | } |
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| 106 | |||
| 107 | const char &operator[](size_t Idx) const { return *(begin() + Idx); } |
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| 108 | |||
| 109 | const char *begin() const { return First; } |
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| 110 | const char *end() const { return Last; } |
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| 111 | size_t size() const { return static_cast<size_t>(Last - First); } |
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| 112 | bool empty() const { return First == Last; } |
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| 113 | }; |
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| 114 | |||
| 115 | inline bool operator==(const StringView &LHS, const StringView &RHS) { |
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| 116 | return LHS.size() == RHS.size() && |
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| 117 | std::strncmp(LHS.begin(), RHS.begin(), LHS.size()) == 0; |
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| 118 | } |
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| 119 | |||
| 120 | DEMANGLE_NAMESPACE_END |
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| 121 | |||
| 122 | #endif |