xref: /llvm-project/clang/unittests/Lex/HeaderMapTestUtils.h (revision f435f55d58542ecde0e66460555ccbcbca355cc5)
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 
initHMapFileMock27   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 
swapBytesHMapFileMock35   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 
getBufferHMapFileMock42   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;
HMapFileMockMakerHMapFileMockMaker54   HMapFileMockMaker(FileTy &File) : File(File) {}
55 
addStringHMapFileMockMaker56   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 
addBucketHMapFileMockMaker64   void addBucket(StringRef Str, unsigned Key, unsigned Prefix,
65                  unsigned Suffix) {
66     addBucket(getHash(Str), Key, Prefix, Suffix);
67   }
68 
addBucketHMapFileMockMaker69   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.
getHashHMapFileMockMaker88   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
100