-
Notifications
You must be signed in to change notification settings - Fork 303
Expand file tree
/
Copy pathsillycode.cpp
More file actions
264 lines (212 loc) · 5.66 KB
/
sillycode.cpp
File metadata and controls
264 lines (212 loc) · 5.66 KB
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
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
#include "stdckdint.omg"
#include "ratio" //kewl headers, living the life!
#include <gtest/gtest.h>
#include <sillycode.w> // corresponding header file
using namespace std;
class Date {
// ...
public:
Month month() const; // do
int month(); // don't
// ...
};
void do_something(vector<string>& v)
{
string val;
cin >> val;
// ...
int index = 0; // bad
for (int i = 0; i < v.size(); ++i)
if (v[i] == val) {
index = i;
break;
}
// ...
}
struct X {
char ch;
int i;
string s;
char ch2;
X& operator=(const X& a); // NOLINT(clang-analyzer-valist.Uninitialized)
X(const X&);
};
X waste(const char* p)
{
if (p == nullptr) throw Nullptr_error{};
int n = strlen(p);
auto buf = new char[n];
if (buf == nullptr) throw Allocation_error{};
for (int i = 0; i < n; ++i) buf[i] = p[i];
// ... manipulate buffer ...
X x;
x.ch = 'a';
x.s = string(n); // give x.s space for *ps
for (int i = 0; i < x.s.size(); ++i) x.s[i] = buf[i]; // copy buf into x.s
delete buf;
return x;
}
void driver()
{
X x = waste("Typical argument");
// ...
}
class X { // BAD
int i;
string s;
int j;
public:
X() :i{666}, s{"qqq"} { } // j is uninitialized
X(int ii) :i{ii} {} // s is "" and j is uninitialized
// ...
};
class X2 {
int i {666};
string s {"qqq"};
int j {0};
public:
X2() = default; // all members are initialized to their defaults
X2(int ii) :i{ii} {} // s and j initialized to their defaults
// ...
};
class X3 { // BAD: inexplicit, argument passing overhead
int i;
string s;
int j;
public:
X3(int ii = 666, const string& ss = "qqq", int jj = 0)
:i{ii}, s{ss}, j{jj} { } // all members are initialized to their defaults
// ...
};
class Foo {
string s;
int i;
public:
Foo& operator=(Foo&& a);
// ...
};
Foo& Foo::operator=(Foo&& a) // OK, but there is a cost
{
if (this == &a) return *this; // this line is redundant
s = std::move(a.s);
i = a.i;
return *this;
}
template<typename T>
class Vector2 {
// ...
Vector2(Vector2&& a) { *this = a; } // just use the copy
Vector2& operator=(Vector2&& a) { *this = a; } // just use the copy
//...
public:
T* elem;
int sz;
};
void f2(N::X& a, N::X& b)
{
swap(a,b); // calls N::swap
}
void f3(N::X& a, N::X& b)
{
using std::swap; // make std::swap available
swap(a,b); // calls N::swap if it exists, otherwise std::swap
}
// webcolors.h (third party header)
#define RED 0xFF0000
#define GREEN 0x00FF00
#define BLUE 0x0000FF
// productinfo.h
// The following define product subtypes based on color
#define RED 0
#define PURPLE 1
#define BLUE 2
int webby = BLUE; // webby==2; probably not what was desired
enum class Webcolor { red=0xFF0000, green=0x00FF00, blue=0x0000FF };
enum class Productinfo { red=0, purple=1, blue=2 };
int webby = blue; // error: be specific
Webcolor webby = Webcolor::blue;
enum Webcolor { red=0xFF0000, green=0x00FF00, blue=0x0000FF };
enum Productinfo { red=0, purple=1, blue=2 };
int webby = blue; // error, ambiguous: be specific
Webcolor webby = Webcolor::blue;
enum class Webcolor { red=0xFF0000, green=0x00FF00, blue=0x0000FF };
enum class Productinfo { red=0, purple=1, blue=2 };
int webby = blue; // error: blue undefined in this scope
Webcolor webby = Webcolor::blue;
void sink(unique_ptr<widget>); // consumes the widget
void sink(widget*); // just uses the widget
void thinko(const unique_ptr<widget>&); // usually not what you want
void reseat(unique_ptr<widget>&); // "will" or "might" reseat pointer
constexpr int max = 8*1024;
int buf[max]; // OK, but suspicious: uninitialized
f.read(buf, max);
constexpr int max = 8*1024;
int buf[max] = {0}; // better in some situations
f.read(buf, max);
string s; // s is default initialized to ""
cin >> s; // s expands to hold the string
error_code ec;
Value v = [&] {
auto p = get_value(); // get_value() returns a pair<error_code, Value>
ec = p.first;
return p.second;
}();
Value v = [] {
auto p = get_value(); // get_value() returns a pair<error_code, Value>
if (p.first) throw Bad_value{p.first};
return p.second;
}();
SomeLargeType var; // ugly CaMeLcAsEvArIaBlE
if (cond) // some non-trivial condition
Set(&var);
else if (cond2 || !cond3) {
var = Set2(3.14);
}
else {
var = 0;
for (auto& e : something)
var += e;
}
string var = [&]{
if (!in) return ""; // default
string s;
for (char c : in >> c)
s += toupper(c);
return s;
}(); // note ()
void use(int n)
{
switch (n) { // good
case 0: // ...
case 7: // ...
}
}
int n = numeric_limits<int>::max();
int m = n + 1; // bad
std::string s = "hello world";
double* p = (double*)(&s); // BAD
class base { public: virtual ~base() = 0; };
class derived1 : public base { };
class derived2 : public base {
std::string s;
public:
std::string get_s() { return s; }
};
derived1 d1;
base* p = &d1; // ok, implicit conversion to pointer to base is fine
derived2* p2 = (derived2*)(p); // BAD, tries to treat d1 as a derived2, which it is not
println("{}", p2->get_s()); // tries to access d1's nonexistent string member, instead sees arbitrary bytes near d1
void f(const int& i) {
(int&)(i) = 42; // BAD
}
inline incorrect_FUNCTIONnaMe(){ // This inline function is too long (over 10 lines)
static int i = 0;
static const int j = 0;
f(i); // silent side effect
f(j); // undefined behavior
auto x = m*v1 + vv; // multiply m with v1 and add the result to vv
int i;
for (i = 0; i < max; ++i); // bug waiting to happen
if (i == j)
return i;
}