LLDB  mainline
UUID.cpp
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1 //===-- UUID.cpp ----------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "lldb/Utility/UUID.h"
10 
11 #include "lldb/Utility/Stream.h"
12 #include "llvm/ADT/StringRef.h"
13 #include "llvm/Support/Format.h"
14 
15 #include <ctype.h>
16 #include <stdio.h>
17 #include <string.h>
18 
19 using namespace lldb_private;
20 
21 // Whether to put a separator after count uuid bytes.
22 // For the first 16 bytes we follow the traditional UUID format. After that, we
23 // simply put a dash after every 6 bytes.
24 static inline bool separate(size_t count) {
25  if (count >= 10)
26  return (count - 10) % 6 == 0;
27 
28  switch (count) {
29  case 4:
30  case 6:
31  case 8:
32  return true;
33  default:
34  return false;
35  }
36 }
37 
38 std::string UUID::GetAsString(llvm::StringRef separator) const {
39  std::string result;
40  llvm::raw_string_ostream os(result);
41 
42  for (auto B : llvm::enumerate(GetBytes())) {
43  if (separate(B.index()))
44  os << separator;
45 
46  os << llvm::format_hex_no_prefix(B.value(), 2, true);
47  }
48  os.flush();
49 
50  return result;
51 }
52 
53 void UUID::Dump(Stream *s) const { s->PutCString(GetAsString()); }
54 
55 static inline int xdigit_to_int(char ch) {
56  ch = tolower(ch);
57  if (ch >= 'a' && ch <= 'f')
58  return 10 + ch - 'a';
59  return ch - '0';
60 }
61 
62 llvm::StringRef
64  llvm::SmallVectorImpl<uint8_t> &uuid_bytes) {
65  uuid_bytes.clear();
66  while (p.size() >= 2) {
67  if (isxdigit(p[0]) && isxdigit(p[1])) {
68  int hi_nibble = xdigit_to_int(p[0]);
69  int lo_nibble = xdigit_to_int(p[1]);
70  // Translate the two hex nibble characters into a byte
71  uuid_bytes.push_back((hi_nibble << 4) + lo_nibble);
72 
73  // Skip both hex digits
74  p = p.drop_front(2);
75  } else if (p.front() == '-') {
76  // Skip dashes
77  p = p.drop_front();
78  } else {
79  // UUID values can only consist of hex characters and '-' chars
80  break;
81  }
82  }
83  return p;
84 }
85 
86 bool UUID::SetFromStringRef(llvm::StringRef str) {
87  llvm::StringRef p = str;
88 
89  // Skip leading whitespace characters
90  p = p.ltrim();
91 
92  llvm::SmallVector<uint8_t, 20> bytes;
93  llvm::StringRef rest = UUID::DecodeUUIDBytesFromString(p, bytes);
94 
95  // Return false if we could not consume the entire string or if the parsed
96  // UUID is empty.
97  if (!rest.empty() || bytes.empty())
98  return false;
99 
100  *this = fromData(bytes);
101  return true;
102 }
103 
104 bool UUID::SetFromOptionalStringRef(llvm::StringRef str) {
105  bool result = SetFromStringRef(str);
106  if (result) {
107  if (llvm::all_of(m_bytes, [](uint8_t b) { return b == 0; }))
108  Clear();
109  }
110 
111  return result;
112 }
size_t PutCString(llvm::StringRef cstr)
Output a C string to the stream.
Definition: Stream.cpp:63
A class that represents a running process on the host machine.
A stream class that can stream formatted output to a file.
Definition: Stream.h:28
static int xdigit_to_int(char ch)
Definition: UUID.cpp:55
std::string GetAsString(llvm::StringRef separator="-") const
Definition: UUID.cpp:38
static bool separate(size_t count)
Definition: UUID.cpp:24
llvm::SmallVector< uint8_t, 20 > m_bytes
Definition: UUID.h:93
llvm::ArrayRef< uint8_t > GetBytes() const
Definition: UUID.h:59
static UUID fromData(const void *bytes, uint32_t num_bytes)
Creates a UUID from the data pointed to by the bytes argument.
Definition: UUID.h:28
void Clear()
Definition: UUID.h:55
bool SetFromOptionalStringRef(llvm::StringRef str)
Definition: UUID.cpp:104
void Dump(Stream *s) const
Definition: UUID.cpp:53
static llvm::StringRef DecodeUUIDBytesFromString(llvm::StringRef str, llvm::SmallVectorImpl< uint8_t > &uuid_bytes)
Decode as many UUID bytes as possible from the C string cstr.
Definition: UUID.cpp:63
bool SetFromStringRef(llvm::StringRef str)
Definition: UUID.cpp:86