1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
|
// Copyright 2018 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "absl/debugging/internal/demangle.h"
#include <cstdlib>
#include <string>
#include "gtest/gtest.h"
#include "absl/base/internal/raw_logging.h"
#include "absl/debugging/internal/stack_consumption.h"
#include "absl/memory/memory.h"
namespace absl {
namespace debugging_internal {
namespace {
// A wrapper function for Demangle() to make the unit test simple.
static const char *DemangleIt(const char * const mangled) {
static char demangled[4096];
if (Demangle(mangled, demangled, sizeof(demangled))) {
return demangled;
} else {
return mangled;
}
}
// Test corner cases of bounary conditions.
TEST(Demangle, CornerCases) {
char tmp[10];
EXPECT_TRUE(Demangle("_Z6foobarv", tmp, sizeof(tmp)));
// sizeof("foobar()") == 9
EXPECT_STREQ("foobar()", tmp);
EXPECT_TRUE(Demangle("_Z6foobarv", tmp, 9));
EXPECT_STREQ("foobar()", tmp);
EXPECT_FALSE(Demangle("_Z6foobarv", tmp, 8)); // Not enough.
EXPECT_FALSE(Demangle("_Z6foobarv", tmp, 1));
EXPECT_FALSE(Demangle("_Z6foobarv", tmp, 0));
EXPECT_FALSE(Demangle("_Z6foobarv", nullptr, 0)); // Should not cause SEGV.
EXPECT_FALSE(Demangle("_Z1000000", tmp, 9));
}
// Test handling of functions suffixed with .clone.N, which is used
// by GCC 4.5.x (and our locally-modified version of GCC 4.4.x), and
// .constprop.N and .isra.N, which are used by GCC 4.6.x. These
// suffixes are used to indicate functions which have been cloned
// during optimization. We ignore these suffixes.
TEST(Demangle, Clones) {
char tmp[20];
EXPECT_TRUE(Demangle("_ZL3Foov", tmp, sizeof(tmp)));
EXPECT_STREQ("Foo()", tmp);
EXPECT_TRUE(Demangle("_ZL3Foov.clone.3", tmp, sizeof(tmp)));
EXPECT_STREQ("Foo()", tmp);
EXPECT_TRUE(Demangle("_ZL3Foov.constprop.80", tmp, sizeof(tmp)));
EXPECT_STREQ("Foo()", tmp);
EXPECT_TRUE(Demangle("_ZL3Foov.isra.18", tmp, sizeof(tmp)));
EXPECT_STREQ("Foo()", tmp);
EXPECT_TRUE(Demangle("_ZL3Foov.isra.2.constprop.18", tmp, sizeof(tmp)));
EXPECT_STREQ("Foo()", tmp);
// Invalid (truncated), should not demangle.
EXPECT_FALSE(Demangle("_ZL3Foov.clo", tmp, sizeof(tmp)));
// Invalid (.clone. not followed by number), should not demangle.
EXPECT_FALSE(Demangle("_ZL3Foov.clone.", tmp, sizeof(tmp)));
// Invalid (.clone. followed by non-number), should not demangle.
EXPECT_FALSE(Demangle("_ZL3Foov.clone.foo", tmp, sizeof(tmp)));
// Invalid (.constprop. not followed by number), should not demangle.
EXPECT_FALSE(Demangle("_ZL3Foov.isra.2.constprop.", tmp, sizeof(tmp)));
}
// Tests that verify that Demangle footprint is within some limit.
// They are not to be run under sanitizers as the sanitizers increase
// stack consumption by about 4x.
#if defined(ABSL_INTERNAL_HAVE_DEBUGGING_STACK_CONSUMPTION) && \
!defined(ADDRESS_SANITIZER) && !defined(MEMORY_SANITIZER) && \
!defined(THREAD_SANITIZER)
static const char *g_mangled;
static char g_demangle_buffer[4096];
static char *g_demangle_result;
static void DemangleSignalHandler(int signo) {
if (Demangle(g_mangled, g_demangle_buffer, sizeof(g_demangle_buffer))) {
g_demangle_result = g_demangle_buffer;
} else {
g_demangle_result = nullptr;
}
}
// Call Demangle and figure out the stack footprint of this call.
static const char *DemangleStackConsumption(const char *mangled,
int *stack_consumed) {
g_mangled = mangled;
*stack_consumed = GetSignalHandlerStackConsumption(DemangleSignalHandler);
ABSL_RAW_LOG(INFO, "Stack consumption of Demangle: %d", *stack_consumed);
return g_demangle_result;
}
// Demangle stack consumption should be within 8kB for simple mangled names
// with some level of nesting. With alternate signal stack we have 64K,
// but some signal handlers run on thread stack, and could have arbitrarily
// little space left (so we don't want to make this number too large).
const int kStackConsumptionUpperLimit = 8192;
// Returns a mangled name nested to the given depth.
static std::string NestedMangledName(int depth) {
std::string mangled_name = "_Z1a";
if (depth > 0) {
mangled_name += "IXL";
mangled_name += NestedMangledName(depth - 1);
mangled_name += "EEE";
}
return mangled_name;
}
TEST(Demangle, DemangleStackConsumption) {
// Measure stack consumption of Demangle for nested mangled names of varying
// depth. Since Demangle is implemented as a recursive descent parser,
// stack consumption will grow as the nesting depth increases. By measuring
// the stack consumption for increasing depths, we can see the growing
// impact of any stack-saving changes made to the code for Demangle.
int stack_consumed = 0;
const char *demangled =
DemangleStackConsumption("_Z6foobarv", &stack_consumed);
EXPECT_STREQ("foobar()", demangled);
EXPECT_GT(stack_consumed, 0);
EXPECT_LT(stack_consumed, kStackConsumptionUpperLimit);
const std::string nested_mangled_name0 = NestedMangledName(0);
demangled = DemangleStackConsumption(nested_mangled_name0.c_str(),
&stack_consumed);
EXPECT_STREQ("a", demangled);
EXPECT_GT(stack_consumed, 0);
EXPECT_LT(stack_consumed, kStackConsumptionUpperLimit);
const std::string nested_mangled_name1 = NestedMangledName(1);
demangled = DemangleStackConsumption(nested_mangled_name1.c_str(),
&stack_consumed);
EXPECT_STREQ("a<>", demangled);
EXPECT_GT(stack_consumed, 0);
EXPECT_LT(stack_consumed, kStackConsumptionUpperLimit);
const std::string nested_mangled_name2 = NestedMangledName(2);
demangled = DemangleStackConsumption(nested_mangled_name2.c_str(),
&stack_consumed);
EXPECT_STREQ("a<>", demangled);
EXPECT_GT(stack_consumed, 0);
EXPECT_LT(stack_consumed, kStackConsumptionUpperLimit);
const std::string nested_mangled_name3 = NestedMangledName(3);
demangled = DemangleStackConsumption(nested_mangled_name3.c_str(),
&stack_consumed);
EXPECT_STREQ("a<>", demangled);
EXPECT_GT(stack_consumed, 0);
EXPECT_LT(stack_consumed, kStackConsumptionUpperLimit);
}
#endif // Stack consumption tests
static void TestOnInput(const char* input) {
static const int kOutSize = 1048576;
auto out = absl::make_unique<char[]>(kOutSize);
Demangle(input, out.get(), kOutSize);
}
TEST(DemangleRegression, NegativeLength) {
TestOnInput("_ZZn4");
}
TEST(DemangleRegression, DeeplyNestedArrayType) {
const int depth = 100000;
std::string data = "_ZStI";
data.reserve(data.size() + 3 * depth + 1);
for (int i = 0; i < depth; i++) {
data += "A1_";
}
TestOnInput(data.c_str());
}
} // namespace
} // namespace debugging_internal
} // namespace absl
|
