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 16 using namespace llvm; 17 18 static bool Contains(directive::VersionRange V, int P) { 19 return V.Min <= P && P <= V.Max; 20 } 21 22 llvm::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(S.Versions, V)) 35 return S.Name; 36 } 37 return StringRef(); 38 } 39