llvm-project/lldb/source/Utility/UUID.cpp

124 lines
3.3 KiB
C++

//===-- UUID.cpp ------------------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "lldb/Utility/UUID.h"
#include "lldb/Utility/Stream.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Format.h"
#include <ctype.h>
#include <stdio.h>
#include <string.h>
using namespace lldb_private;
// Whether to put a separator after count uuid bytes.
// For the first 16 bytes we follow the traditional UUID format. After that, we
// simply put a dash after every 6 bytes.
static inline bool separate(size_t count) {
if (count >= 10)
return (count - 10) % 6 == 0;
switch (count) {
case 4:
case 6:
case 8:
return true;
default:
return false;
}
}
std::string UUID::GetAsString(llvm::StringRef separator) const {
std::string result;
llvm::raw_string_ostream os(result);
for (auto B : llvm::enumerate(GetBytes())) {
if (separate(B.index()))
os << separator;
os << llvm::format_hex_no_prefix(B.value(), 2, true);
}
os.flush();
return result;
}
void UUID::Dump(Stream *s) const { s->PutCString(GetAsString()); }
static inline int xdigit_to_int(char ch) {
ch = tolower(ch);
if (ch >= 'a' && ch <= 'f')
return 10 + ch - 'a';
return ch - '0';
}
llvm::StringRef
UUID::DecodeUUIDBytesFromString(llvm::StringRef p,
llvm::SmallVectorImpl<uint8_t> &uuid_bytes,
uint32_t num_uuid_bytes) {
uuid_bytes.clear();
while (!p.empty()) {
if (isxdigit(p[0]) && isxdigit(p[1])) {
int hi_nibble = xdigit_to_int(p[0]);
int lo_nibble = xdigit_to_int(p[1]);
// Translate the two hex nibble characters into a byte
uuid_bytes.push_back((hi_nibble << 4) + lo_nibble);
// Skip both hex digits
p = p.drop_front(2);
// Increment the byte that we are decoding within the UUID value and
// break out if we are done
if (uuid_bytes.size() == num_uuid_bytes)
break;
} else if (p.front() == '-') {
// Skip dashes
p = p.drop_front();
} else {
// UUID values can only consist of hex characters and '-' chars
break;
}
}
return p;
}
size_t UUID::SetFromStringRef(llvm::StringRef str, uint32_t num_uuid_bytes) {
llvm::StringRef p = str;
// Skip leading whitespace characters
p = p.ltrim();
llvm::SmallVector<uint8_t, 20> bytes;
llvm::StringRef rest =
UUID::DecodeUUIDBytesFromString(p, bytes, num_uuid_bytes);
// If we successfully decoded a UUID, return the amount of characters that
// were consumed
if (bytes.size() == num_uuid_bytes) {
*this = fromData(bytes);
return str.size() - rest.size();
}
// Else return zero to indicate we were not able to parse a UUID value
return 0;
}
size_t UUID::SetFromOptionalStringRef(llvm::StringRef str,
uint32_t num_uuid_bytes) {
size_t num_chars_consumed = SetFromStringRef(str, num_uuid_bytes);
if (num_chars_consumed) {
if (llvm::all_of(m_bytes, [](uint8_t b) { return b == 0; }))
Clear();
}
return num_chars_consumed;
}