1 //===- DWARFDataExtractorTest.cpp -----------------------------------------===//
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/DebugInfo/DWARF/DWARFDataExtractor.h"
10 #include "llvm/Testing/Support/Error.h"
11 #include "gtest/gtest.h"
12 
13 using namespace llvm;
14 
15 namespace {
16 
17 TEST(DWARFDataExtractorTest, getInitialLength) {
18   auto GetWithError = [](ArrayRef<uint8_t> Bytes)
19       -> Expected<std::tuple<uint64_t, dwarf::DwarfFormat, uint64_t>> {
20     DWARFDataExtractor Data(Bytes, /*IsLittleEndian=*/false, /*AddressSize=*/8);
21     DWARFDataExtractor::Cursor C(0);
22     uint64_t Length;
23     dwarf::DwarfFormat Format;
24     std::tie(Length, Format) = Data.getInitialLength(C);
25     if (C)
26       return std::make_tuple(Length, Format, C.tell());
27 
28     EXPECT_EQ(Length, 0u);
29     EXPECT_EQ(Format, dwarf::DWARF32);
30     EXPECT_EQ(C.tell(), 0u);
31     return C.takeError();
32   };
33   auto GetWithoutError = [](ArrayRef<uint8_t> Bytes) {
34     DWARFDataExtractor Data(Bytes, /*IsLittleEndian=*/false, /*AddressSize=*/8);
35     uint64_t Offset = 0;
36     uint64_t Length;
37     dwarf::DwarfFormat Format;
38     std::tie(Length, Format) = Data.getInitialLength(&Offset);
39     return std::make_tuple(Length, Format, Offset);
40   };
41   auto ErrorResult = std::make_tuple(0, dwarf::DWARF32, 0);
42 
43   // Empty data.
44   EXPECT_THAT_EXPECTED(GetWithError({}),
45                        FailedWithMessage("unexpected end of data"));
46   EXPECT_EQ(GetWithoutError({}), ErrorResult);
47 
48   // Not long enough for the U32 field.
49   EXPECT_THAT_EXPECTED(GetWithError({0x00, 0x01, 0x02}),
50                        FailedWithMessage("unexpected end of data"));
51   EXPECT_EQ(GetWithoutError({0x00, 0x01, 0x02}), ErrorResult);
52 
53   EXPECT_THAT_EXPECTED(
54       GetWithError({0x00, 0x01, 0x02, 0x03}),
55       HasValue(std::make_tuple(0x00010203, dwarf::DWARF32, 4)));
56   EXPECT_EQ(GetWithoutError({0x00, 0x01, 0x02, 0x03}),
57             std::make_tuple(0x00010203, dwarf::DWARF32, 4));
58 
59   // Zeroes are not an error, but without the Error object it is hard to tell
60   // them apart from a failed read.
61   EXPECT_THAT_EXPECTED(
62       GetWithError({0x00, 0x00, 0x00, 0x00}),
63       HasValue(std::make_tuple(0x00000000, dwarf::DWARF32, 4)));
64   EXPECT_EQ(GetWithoutError({0x00, 0x00, 0x00, 0x00}),
65             std::make_tuple(0x00000000, dwarf::DWARF32, 4));
66 
67   // Smallest invalid value.
68   EXPECT_THAT_EXPECTED(
69       GetWithError({0xff, 0xff, 0xff, 0xf0}),
70       FailedWithMessage(
71           "unsupported reserved unit length of value 0xfffffff0"));
72   EXPECT_EQ(GetWithoutError({0xff, 0xff, 0xff, 0xf0}), ErrorResult);
73 
74   // DWARF64 marker without the subsequent length field.
75   EXPECT_THAT_EXPECTED(GetWithError({0xff, 0xff, 0xff, 0xff}),
76                        FailedWithMessage("unexpected end of data"));
77   EXPECT_EQ(GetWithoutError({0xff, 0xff, 0xff, 0xff}), ErrorResult);
78 
79   // Not enough data for the U64 length.
80   EXPECT_THAT_EXPECTED(
81       GetWithError({0xff, 0xff, 0xff, 0xff, 0x00, 0x01, 0x02, 0x03}),
82       FailedWithMessage("unexpected end of data"));
83   EXPECT_EQ(GetWithoutError({0xff, 0xff, 0xff, 0xff, 0x00, 0x01, 0x02, 0x03}),
84             ErrorResult);
85 
86   EXPECT_THAT_EXPECTED(
87       GetWithError({0xff, 0xff, 0xff, 0xff, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05,
88                     0x06, 0x07}),
89       HasValue(std::make_tuple(0x0001020304050607, dwarf::DWARF64, 12)));
90   EXPECT_EQ(GetWithoutError({0xff, 0xff, 0xff, 0xff, 0x00, 0x01, 0x02, 0x03,
91                              0x04, 0x05, 0x06, 0x07}),
92             std::make_tuple(0x0001020304050607, dwarf::DWARF64, 12));
93 }
94 
95 } // namespace
96