1//===- VersionTuple.cpp - Version Number Handling ---------------*- C++ -*-===//
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// This file implements the VersionTuple class, which represents a version in
10// the form major[.minor[.subminor]].
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/Support/VersionTuple.h"
15#include "llvm/ADT/StringRef.h"
16#include "llvm/Support/raw_ostream.h"
17#include <cassert>
18
19using namespace llvm;
20
21std::string VersionTuple::getAsString() const {
22  std::string Result;
23  {
24    llvm::raw_string_ostream Out(Result);
25    Out << *this;
26  }
27  return Result;
28}
29
30raw_ostream &llvm::operator<<(raw_ostream &Out, const VersionTuple &V) {
31  Out << V.getMajor();
32  if (Optional<unsigned> Minor = V.getMinor())
33    Out << '.' << *Minor;
34  if (Optional<unsigned> Subminor = V.getSubminor())
35    Out << '.' << *Subminor;
36  if (Optional<unsigned> Build = V.getBuild())
37    Out << '.' << *Build;
38  return Out;
39}
40
41static bool parseInt(StringRef &input, unsigned &value) {
42  assert(value == 0);
43  if (input.empty())
44    return true;
45
46  char next = input[0];
47  input = input.substr(1);
48  if (next < '0' || next > '9')
49    return true;
50  value = (unsigned)(next - '0');
51
52  while (!input.empty()) {
53    next = input[0];
54    if (next < '0' || next > '9')
55      return false;
56    input = input.substr(1);
57    value = value * 10 + (unsigned)(next - '0');
58  }
59
60  return false;
61}
62
63bool VersionTuple::tryParse(StringRef input) {
64  unsigned major = 0, minor = 0, micro = 0, build = 0;
65
66  // Parse the major version, [0-9]+
67  if (parseInt(input, major))
68    return true;
69
70  if (input.empty()) {
71    *this = VersionTuple(major);
72    return false;
73  }
74
75  // If we're not done, parse the minor version, \.[0-9]+
76  if (input[0] != '.')
77    return true;
78  input = input.substr(1);
79  if (parseInt(input, minor))
80    return true;
81
82  if (input.empty()) {
83    *this = VersionTuple(major, minor);
84    return false;
85  }
86
87  // If we're not done, parse the micro version, \.[0-9]+
88  if (input[0] != '.')
89    return true;
90  input = input.substr(1);
91  if (parseInt(input, micro))
92    return true;
93
94  if (input.empty()) {
95    *this = VersionTuple(major, minor, micro);
96    return false;
97  }
98
99  // If we're not done, parse the micro version, \.[0-9]+
100  if (input[0] != '.')
101    return true;
102  input = input.substr(1);
103  if (parseInt(input, build))
104    return true;
105
106  // If we have characters left over, it's an error.
107  if (!input.empty())
108    return true;
109
110  *this = VersionTuple(major, minor, micro, build);
111  return false;
112}
113