clang/unittests/Lex/HeaderMapTestUtils.h

   1 //===- unittests/Lex/HeaderMapTestUtils.h - HeaderMap utils -------===//
   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_CLANG_UNITTESTS_LEX_HEADERMAPTESTUTILS_H
  10 #define LLVM_CLANG_UNITTESTS_LEX_HEADERMAPTESTUTILS_H
  11
  12 #include "clang/Basic/CharInfo.h"
  13 #include "clang/Lex/HeaderMap.h"
  14 #include "clang/Lex/HeaderMapTypes.h"
  15 #include "llvm/Support/SwapByteOrder.h"
  16 #include <cassert>
  17
  18 namespace clang {
  19 namespace test {
  20
  21 // Lay out a header file for testing.
  22 template <unsigned NumBuckets, unsigned NumBytes> struct HMapFileMock {
  23   HMapHeader Header;
  24   HMapBucket Buckets[NumBuckets];
  25   unsigned char Bytes[NumBytes];
  26
  27   void init() {
  28     memset(this, 0, sizeof(HMapFileMock));
  29     Header.Magic = HMAP_HeaderMagicNumber;
  30     Header.Version = HMAP_HeaderVersion;
  31     Header.NumBuckets = NumBuckets;
  32     Header.StringsOffset = sizeof(Header) + sizeof(Buckets);
  33   }
  34
  35   void swapBytes() {
  36     Header.Magic = llvm::byteswap(Header.Magic);
  37     Header.Version = llvm::byteswap(Header.Version);
  38     Header.NumBuckets = llvm::byteswap(Header.NumBuckets);
  39     Header.StringsOffset = llvm::byteswap(Header.StringsOffset);
  40   }
  41
  42   std::unique_ptr<llvm::MemoryBuffer> getBuffer() {
  43     return llvm::MemoryBuffer::getMemBuffer(
  44         StringRef(reinterpret_cast<char *>(this), sizeof(HMapFileMock)),
  45         "header",
  46         /* RequresNullTerminator */ false);
  47   }
  48 };
  49
  50 template <class FileTy> struct HMapFileMockMaker {
  51   FileTy &File;
  52   unsigned SI = 1;
  53   unsigned BI = 0;
  54   HMapFileMockMaker(FileTy &File) : File(File) {}
  55
  56   unsigned addString(StringRef S) {
  57     assert(SI + S.size() + 1 <= sizeof(File.Bytes));
  58     std::copy(S.begin(), S.end(), File.Bytes + SI);
  59     auto OldSI = SI;
  60     SI += S.size() + 1;
  61     return OldSI;
  62   }
  63
  64   void addBucket(StringRef Str, unsigned Key, unsigned Prefix,
  65                  unsigned Suffix) {
  66     addBucket(getHash(Str), Key, Prefix, Suffix);
  67   }
  68
  69   void addBucket(unsigned Hash, unsigned Key, unsigned Prefix,
  70                  unsigned Suffix) {
  71     assert(!(File.Header.NumBuckets & (File.Header.NumBuckets - 1)));
  72     unsigned I = Hash & (File.Header.NumBuckets - 1);
  73     do {
  74       if (!File.Buckets[I].Key) {
  75         File.Buckets[I].Key = Key;
  76         File.Buckets[I].Prefix = Prefix;
  77         File.Buckets[I].Suffix = Suffix;
  78         ++File.Header.NumEntries;
  79         return;
  80       }
  81       ++I;
  82       I &= File.Header.NumBuckets - 1;
  83     } while (I != (Hash & (File.Header.NumBuckets - 1)));
  84     llvm_unreachable("no empty buckets");
  85   }
  86
  87   // The header map hash function.
  88   static unsigned getHash(StringRef Str) {
  89     unsigned Result = 0;
  90     for (char C : Str)
  91       Result += toLowercase(C) * 13;
  92     return Result;
  93   }
  94 };
  95
  96 } // namespace test
  97 } // namespace clang
  98
  99 #endif