1//===- VersionTuple.cpp - Version Number Handling ---------------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file implements the VersionTuple class, which represents a version in
11// the form major[.minor[.subminor]].
12//
13//===----------------------------------------------------------------------===//
14#include "clang/Basic/VersionTuple.h"
15#include "llvm/Support/raw_ostream.h"
16
17using namespace clang;
18
19std::string VersionTuple::getAsString() const {
20  std::string Result;
21  {
22    llvm::raw_string_ostream Out(Result);
23    Out << *this;
24  }
25  return Result;
26}
27
28raw_ostream& clang::operator<<(raw_ostream &Out,
29                                     const VersionTuple &V) {
30  Out << V.getMajor();
31  if (Optional<unsigned> Minor = V.getMinor())
32    Out << '.' << *Minor;
33  if (Optional<unsigned> Subminor = V.getSubminor())
34    Out << '.' << *Subminor;
35  return Out;
36}
37
38static bool parseInt(StringRef &input, unsigned &value) {
39  assert(value == 0);
40  if (input.empty()) return true;
41
42  char next = input[0];
43  input = input.substr(1);
44  if (next < '0' || next > '9') return true;
45  value = (unsigned) (next - '0');
46
47  while (!input.empty()) {
48    next = input[0];
49    if (next < '0' || next > '9') return false;
50    input = input.substr(1);
51    value = value * 10 + (unsigned) (next - '0');
52  }
53
54  return false;
55}
56
57bool VersionTuple::tryParse(StringRef input) {
58  unsigned major = 0, minor = 0, micro = 0;
59
60  // Parse the major version, [0-9]+
61  if (parseInt(input, major)) return true;
62
63  if (input.empty()) {
64    *this = VersionTuple(major);
65    return false;
66  }
67
68  // If we're not done, parse the minor version, \.[0-9]+
69  if (input[0] != '.') return true;
70  input = input.substr(1);
71  if (parseInt(input, minor)) return true;
72
73  if (input.empty()) {
74    *this = VersionTuple(major, minor);
75    return false;
76  }
77
78  // If we're not done, parse the micro version, \.[0-9]+
79  if (input[0] != '.') return true;
80  input = input.substr(1);
81  if (parseInt(input, micro)) return true;
82
83  // If we have characters left over, it's an error.
84  if (!input.empty()) return true;
85
86  *this = VersionTuple(major, minor, micro);
87  return false;
88}
89