1//===-------------------------------------------------------------- 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#include "llvm/Frontend/Directive/Spelling.h"
10
11#include "llvm/ADT/StringRef.h"
12#include "llvm/Support/MathExtras.h"
13
14#include <cassert>
15
16using namespace llvm;
17
18static bool Contains(directive::VersionRange V, int P) {
19 return V.Min <= P && P <= V.Max;
20}
21
22llvm::StringRef llvm::directive::FindName(
23 llvm::iterator_range<const directive::Spelling *> Range, unsigned Version) {
24 assert(llvm::isInt<8 * sizeof(int)>(Version) && "Version value out of range");
25
26 int V = Version;
27 // Do a linear search to find the first Spelling that contains Version.
28 // The condition "contains(S, Version)" does not partition the list of
29 // spellings, so std::[lower|upper]_bound cannot be used.
30 // In practice the list of spellings is expected to be very short, so
31 // linear search seems appropriate. In general, an interval tree may be
32 // a better choice, but in this case it may be an overkill.
33 for (auto &S : Range) {
34 if (Contains(V: S.Versions, P: V))
35 return S.Name;
36 }
37 return StringRef();
38}
39