1//===- FormatCommon.h - Formatters for common LLVM types --------*- 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#ifndef LLVM_SUPPORT_FORMATCOMMON_H
10#define LLVM_SUPPORT_FORMATCOMMON_H
11
12#include "llvm/ADT/SmallString.h"
13#include "llvm/Support/FormatVariadicDetails.h"
14#include "llvm/Support/raw_ostream.h"
15
16namespace llvm {
17enum class AlignStyle { Left, Center, Right };
18
19struct FmtAlign {
20  detail::format_adapter &Adapter;
21  AlignStyle Where;
22  size_t Amount;
23  char Fill;
24
25  FmtAlign(detail::format_adapter &Adapter, AlignStyle Where, size_t Amount,
26           char Fill = ' ')
27      : Adapter(Adapter), Where(Where), Amount(Amount), Fill(Fill) {}
28
29  void format(raw_ostream &S, StringRef Options) {
30    // If we don't need to align, we can format straight into the underlying
31    // stream.  Otherwise we have to go through an intermediate stream first
32    // in order to calculate how long the output is so we can align it.
33    // TODO: Make the format method return the number of bytes written, that
34    // way we can also skip the intermediate stream for left-aligned output.
35    if (Amount == 0) {
36      Adapter.format(S, Options);
37      return;
38    }
39    SmallString<64> Item;
40    raw_svector_ostream Stream(Item);
41
42    Adapter.format(Stream, Options);
43    if (Amount <= Item.size()) {
44      S << Item;
45      return;
46    }
47
48    size_t PadAmount = Amount - Item.size();
49    switch (Where) {
50    case AlignStyle::Left:
51      S << Item;
52      fill(S, PadAmount);
53      break;
54    case AlignStyle::Center: {
55      size_t X = PadAmount / 2;
56      fill(S, X);
57      S << Item;
58      fill(S, PadAmount - X);
59      break;
60    }
61    default:
62      fill(S, PadAmount);
63      S << Item;
64      break;
65    }
66  }
67
68private:
69  void fill(llvm::raw_ostream &S, size_t Count) {
70    for (size_t I = 0; I < Count; ++I)
71      S << Fill;
72  }
73};
74}
75
76#endif
77