1// RUN: %check_clang_tidy -std=c++11-or-later %s google-readability-casting %t -- -- -fexceptions
2
3bool g() { return false; }
4
5enum Enum { Enum1 };
6struct X {};
7struct Y : public X {};
8
9void f(int a, double b, const char *cpc, const void *cpv, X *pX) {
10 const char *cpc2 = (const char*)cpc;
11 // CHECK-MESSAGES: :[[@LINE-1]]:22: warning: redundant cast to the same type [google-readability-casting]
12 // CHECK-FIXES: const char *cpc2 = cpc;
13
14 typedef const char *Typedef1;
15 typedef const char *Typedef2;
16 Typedef1 t1;
17 (Typedef2)t1;
18 // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: C-style casts are discouraged; use static_cast (if needed, the cast may be redundant) [google-readability-casting]
19 // CHECK-FIXES: {{^}} static_cast<Typedef2>(t1);
20 (const char*)t1;
21 // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: {{.*}}; use static_cast (if needed
22 // CHECK-FIXES: {{^}} static_cast<const char*>(t1);
23 (Typedef1)cpc;
24 // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: {{.*}}; use static_cast (if needed
25 // CHECK-FIXES: {{^}} static_cast<Typedef1>(cpc);
26 (Typedef1)t1;
27 // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: redundant cast to the same type
28 // CHECK-FIXES: {{^}} t1;
29
30 char *pc = (char*)cpc;
31 // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: C-style casts are discouraged; use const_cast [google-readability-casting]
32 // CHECK-FIXES: char *pc = const_cast<char*>(cpc);
33 typedef char Char;
34 Char *pChar = (Char*)pc;
35 // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: {{.*}}; use static_cast (if needed
36 // CHECK-FIXES: {{^}} Char *pChar = static_cast<Char*>(pc);
37
38 (Char)*cpc;
39 // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: {{.*}}; use static_cast (if needed
40 // CHECK-FIXES: {{^}} static_cast<Char>(*cpc);
41
42 (char)*pChar;
43 // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: {{.*}}; use static_cast (if needed
44 // CHECK-FIXES: {{^}} static_cast<char>(*pChar);
45
46 (const char*)cpv;
47 // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: {{.*}}; use static_cast [
48 // CHECK-FIXES: static_cast<const char*>(cpv);
49
50 char *pc2 = (char*)(cpc + 33);
51 // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: {{.*}}; use const_cast [
52 // CHECK-FIXES: char *pc2 = const_cast<char*>(cpc + 33);
53
54 const char &crc = *cpc;
55 char &rc = (char&)crc;
56 // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: {{.*}}; use const_cast [
57 // CHECK-FIXES: char &rc = const_cast<char&>(crc);
58
59 char &rc2 = (char&)*cpc;
60 // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: {{.*}}; use const_cast [
61 // CHECK-FIXES: char &rc2 = const_cast<char&>(*cpc);
62
63 char ** const* const* ppcpcpc;
64 char ****ppppc = (char****)ppcpcpc;
65 // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: {{.*}}; use const_cast [
66 // CHECK-FIXES: char ****ppppc = const_cast<char****>(ppcpcpc);
67
68 char ***pppc = (char***)*(ppcpcpc);
69 // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: {{.*}}; use const_cast [
70 // CHECK-FIXES: char ***pppc = const_cast<char***>(*(ppcpcpc));
71
72 char ***pppc2 = (char***)(*ppcpcpc);
73 // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: {{.*}}; use const_cast [
74 // CHECK-FIXES: char ***pppc2 = const_cast<char***>(*ppcpcpc);
75
76 char *pc5 = (char*)(const char*)(cpv);
77 // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: {{.*}}; use const_cast [
78 // CHECK-MESSAGES: :[[@LINE-2]]:22: warning: {{.*}}; use static_cast [
79 // CHECK-FIXES: char *pc5 = const_cast<char*>(static_cast<const char*>(cpv));
80
81 int b1 = (int)b;
82 // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: {{.*}}; use static_cast [
83 // CHECK-FIXES: int b1 = static_cast<int>(b);
84 b1 = (const int&)b;
85 // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: {{.*}}; use static_cast/const_cast/reinterpret_cast [
86 // CHECK-FIXES: b1 = (const int&)b;
87
88 b1 = (int) b;
89 // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: {{.*}}; use static_cast {{.*}}
90 // CHECK-FIXES: b1 = static_cast<int>(b);
91
92 b1 = (int) b;
93 // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: {{.*}}; use static_cast {{.*}}
94 // CHECK-FIXES: b1 = static_cast<int>(b);
95
96 b1 = (int) (b);
97 // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: {{.*}}; use static_cast {{.*}}
98 // CHECK-FIXES: b1 = static_cast<int>(b);
99
100 b1 = (int) (b);
101 // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: {{.*}}; use static_cast {{.*}}
102 // CHECK-FIXES: b1 = static_cast<int>(b);
103
104 Y *pB = (Y*)pX;
105 // CHECK-MESSAGES: :[[@LINE-1]]:11: warning: {{.*}}; use static_cast/const_cast/reinterpret_cast [
106 Y &rB = (Y&)*pX;
107 // CHECK-MESSAGES: :[[@LINE-1]]:11: warning: {{.*}}; use static_cast/const_cast/reinterpret_cast [
108
109 const char *pc3 = (const char*)cpv;
110 // CHECK-MESSAGES: :[[@LINE-1]]:21: warning: {{.*}}; use static_cast [
111 // CHECK-FIXES: const char *pc3 = static_cast<const char*>(cpv);
112
113 char *pc4 = (char*)cpv;
114 // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: {{.*}}; use static_cast/const_cast/reinterpret_cast [
115 // CHECK-FIXES: char *pc4 = (char*)cpv;
116
117 b1 = (int)Enum1;
118 // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: {{.*}}; use static_cast [
119 // CHECK-FIXES: b1 = static_cast<int>(Enum1);
120
121 Enum e = (Enum)b1;
122 // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: {{.*}}; use static_cast [
123 // CHECK-FIXES: Enum e = static_cast<Enum>(b1);
124
125 e = (Enum)Enum1;
126 // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: redundant cast to the same type
127 // CHECK-FIXES: {{^}} e = Enum1;
128
129 e = (Enum)e;
130 // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: redundant cast to the same type
131 // CHECK-FIXES: {{^}} e = e;
132
133 e = (Enum) e;
134 // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: redundant cast to the same type
135 // CHECK-FIXES: {{^}} e = e;
136
137 e = (Enum) (e);
138 // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: redundant cast to the same type
139 // CHECK-FIXES: {{^}} e = (e);
140
141 static const int kZero = 0;
142 (int)kZero;
143 // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: redundant cast to the same type
144 // CHECK-FIXES: {{^}} kZero;
145
146 int b2 = static_cast<double>(b);
147 int b3 = b;
148 double aa = a;
149 (void)aa;
150 return (void)g();
151}
152
153template <typename T>
154void template_function(T t, int n) {
155 int i = (int)t;
156 // CHECK-MESSAGES: :[[@LINE-1]]:11: warning: {{.*}}; use static_cast/const_cast/reinterpret_cast [
157 // CHECK-FIXES: int i = (int)t;
158 int j = (int)n;
159 // CHECK-MESSAGES: :[[@LINE-1]]:11: warning: redundant cast to the same type
160 // CHECK-FIXES: int j = n;
161}
162
163template <typename T>
164struct TemplateStruct {
165 void f(T t, int n) {
166 int k = (int)t;
167 // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: {{.*}}; use static_cast/const_cast/reinterpret_cast
168 // CHECK-FIXES: int k = (int)t;
169 int l = (int)n;
170 // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: redundant cast to the same type
171 // CHECK-FIXES: int l = n;
172 }
173};
174
175void test_templates() {
176 template_function(t: 1, n: 42);
177 template_function(t: 1.0, n: 42);
178 TemplateStruct<int>().f(t: 1, n: 42);
179 TemplateStruct<double>().f(t: 1.0, n: 42);
180}
181
182extern "C" {
183void extern_c_code(const char *cpc) {
184 const char *cpc2 = (const char*)cpc;
185 // CHECK-MESSAGES: :[[@LINE-1]]:22: warning: redundant cast to the same type
186 // CHECK-FIXES: const char *cpc2 = cpc;
187 char *pc = (char*)cpc;
188}
189}
190
191#define CAST(type, value) (type)(value)
192void macros(double d) {
193 int i = CAST(int, d);
194}
195
196enum E { E1 = 1 };
197template <E e>
198struct A {
199 // Usage of template argument e = E1 is represented as (E)1 in the AST for
200 // some reason. We have a special treatment of this case to avoid warnings
201 // here.
202 static const E ee = e;
203};
204struct B : public A<E1> {};
205
206
207void overloaded_function();
208void overloaded_function(int);
209
210template<typename Fn>
211void g(Fn fn) {
212 fn();
213}
214
215void function_casts() {
216 typedef void (*FnPtrVoid)();
217 typedef void (&FnRefVoid)();
218 typedef void (&FnRefInt)(int);
219
220 g(fn: (void (*)())overloaded_function);
221 // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: C-style casts are discouraged; use static_cast [
222 // CHECK-FIXES: g(static_cast<void (*)()>(overloaded_function));
223 g(fn: (void (*)())&overloaded_function);
224 // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: C-style casts are discouraged; use static_cast [
225 // CHECK-FIXES: g(static_cast<void (*)()>(&overloaded_function));
226 g(fn: (void (&)())overloaded_function);
227 // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: C-style casts are discouraged; use static_cast [
228 // CHECK-FIXES: g(static_cast<void (&)()>(overloaded_function));
229
230 g(fn: (FnPtrVoid)overloaded_function);
231 // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: C-style casts are discouraged; use static_cast [
232 // CHECK-FIXES: g(static_cast<FnPtrVoid>(overloaded_function));
233 g(fn: (FnPtrVoid)&overloaded_function);
234 // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: C-style casts are discouraged; use static_cast [
235 // CHECK-FIXES: g(static_cast<FnPtrVoid>(&overloaded_function));
236 g(fn: (FnRefVoid)overloaded_function);
237 // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: C-style casts are discouraged; use static_cast [
238 // CHECK-FIXES: g(static_cast<FnRefVoid>(overloaded_function));
239
240 FnPtrVoid fn0 = (void (*)())&overloaded_function;
241 // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: C-style casts are discouraged; use static_cast [
242 // CHECK-FIXES: FnPtrVoid fn0 = static_cast<void (*)()>(&overloaded_function);
243 FnPtrVoid fn1 = (void (*)())overloaded_function;
244 // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: C-style casts are discouraged; use static_cast [
245 // CHECK-FIXES: FnPtrVoid fn1 = static_cast<void (*)()>(overloaded_function);
246 FnPtrVoid fn1a = (FnPtrVoid)overloaded_function;
247 // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: C-style casts are discouraged; use static_cast [
248 // CHECK-FIXES: FnPtrVoid fn1a = static_cast<FnPtrVoid>(overloaded_function);
249 FnRefInt fn2 = (void (&)(int))overloaded_function;
250 // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: C-style casts are discouraged; use static_cast [
251 // CHECK-FIXES: FnRefInt fn2 = static_cast<void (&)(int)>(overloaded_function);
252 auto fn3 = (void (*)())&overloaded_function;
253 // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: C-style casts are discouraged; use static_cast [
254 // CHECK-FIXES: auto fn3 = static_cast<void (*)()>(&overloaded_function);
255 auto fn4 = (void (*)())overloaded_function;
256 // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: C-style casts are discouraged; use static_cast [
257 // CHECK-FIXES: auto fn4 = static_cast<void (*)()>(overloaded_function);
258 auto fn5 = (void (&)(int))overloaded_function;
259 // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: C-style casts are discouraged; use static_cast [
260 // CHECK-FIXES: auto fn5 = static_cast<void (&)(int)>(overloaded_function);
261
262 void (*fn6)() = (void (*)())&overloaded_function;
263 // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: C-style casts are discouraged; use static_cast [
264 // CHECK-FIXES: void (*fn6)() = static_cast<void (*)()>(&overloaded_function);
265 void (*fn7)() = (void (*)())overloaded_function;
266 // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: C-style casts are discouraged; use static_cast [
267 // CHECK-FIXES: void (*fn7)() = static_cast<void (*)()>(overloaded_function);
268 void (*fn8)() = (FnPtrVoid)overloaded_function;
269 // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: C-style casts are discouraged; use static_cast [
270 // CHECK-FIXES: void (*fn8)() = static_cast<FnPtrVoid>(overloaded_function);
271 void (&fn9)(int) = (void (&)(int))overloaded_function;
272 // CHECK-MESSAGES: :[[@LINE-1]]:22: warning: C-style casts are discouraged; use static_cast [
273 // CHECK-FIXES: void (&fn9)(int) = static_cast<void (&)(int)>(overloaded_function);
274
275 void (*correct1)() = static_cast<void (*)()>(overloaded_function);
276 FnPtrVoid correct2 = static_cast<void (*)()>(&overloaded_function);
277 FnRefInt correct3 = static_cast<void (&)(int)>(overloaded_function);
278}
279
280struct S {
281 S(const char *);
282};
283struct ConvertibleToS {
284 operator S() const;
285};
286struct ConvertibleToSRef {
287 operator const S&() const;
288};
289
290void conversions() {
291 //auto s1 = (const S&)"";
292 // C HECK-MESSAGES: :[[@LINE-1]]:10: warning: C-style casts are discouraged; use static_cast [
293 // C HECK-FIXES: S s1 = static_cast<const S&>("");
294 auto s2 = (S)"";
295 // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: C-style casts are discouraged; use constructor call syntax [
296 // CHECK-FIXES: auto s2 = S("");
297 auto s2a = (struct S)"";
298 // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: C-style casts are discouraged; use static_cast [
299 // CHECK-FIXES: auto s2a = static_cast<struct S>("");
300 auto s2b = (const S)"";
301 // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: C-style casts are discouraged; use static_cast [
302 // FIXME: This should be constructor call syntax: S("").
303 // CHECK-FIXES: auto s2b = static_cast<const S>("");
304 ConvertibleToS c;
305 auto s3 = (const S&)c;
306 // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: C-style casts are discouraged; use static_cast/const_cast/reinterpret_cast [
307 // CHECK-FIXES: auto s3 = (const S&)c;
308 // FIXME: This should be a static_cast.
309 // C HECK-FIXES: auto s3 = static_cast<const S&>(c);
310 auto s4 = (S)c;
311 // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: C-style casts are discouraged; use constructor call syntax [
312 // CHECK-FIXES: auto s4 = S(c);
313 ConvertibleToSRef cr;
314 auto s5 = (const S&)cr;
315 // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: C-style casts are discouraged; use static_cast/const_cast/reinterpret_cast [
316 // CHECK-FIXES: auto s5 = (const S&)cr;
317 // FIXME: This should be a static_cast.
318 // C HECK-FIXES: auto s5 = static_cast<const S&>(cr);
319 auto s6 = (S)cr;
320 // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: C-style casts are discouraged; use constructor call syntax [
321 // CHECK-FIXES: auto s6 = S(cr);
322}
323
324template <class T>
325T functional_cast_template(float i) {
326 return T(i);
327}
328
329struct S2 {
330 S2(float);
331};
332using T = S2;
333using U = S2 &;
334
335void functional_casts() {
336 float x = 1.5F;
337 auto y = int(x);
338 // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: C-style casts are discouraged; use static_cast
339 // CHECK-FIXES: auto y = static_cast<int>(x);
340
341#pragma clang diagnostic push
342#pragma clang diagnostic ignored "-Wc++11-narrowing"
343 // This if fine, compiler will warn about implicit conversions with brace initialization
344 auto z = int{x};
345#pragma clang diagnostic pop
346
347 // Functional casts are allowed if S is of class type
348 const char *str = "foo";
349 auto s = S(str);
350
351 // Functional casts in template functions
352 functional_cast_template<S2>(i: x);
353 functional_cast_template<int>(i: x);
354
355 // New expressions are not functional casts
356 auto w = new int(x);
357
358 // Typedefs
359 S2 t = T(x); // OK, constructor call
360 S2 u = U(x); // NOK, it's a reinterpret_cast in disguise
361 // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: C-style casts are discouraged; use static_cast/const_cast/reinterpret_cast
362
363 throw S2(5.0f);
364}
365

source code of clang-tools-extra/test/clang-tidy/checkers/google/readability-casting.cpp