1 // RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s
2 
3 void a(int i);
4 int b();
5 int c();
6 
7 #define MACRO_A 0
8 
9 #define AND(x, y) ((x) && (y))
10 
11 void test1(int x, int y) {
12   while(true) {
13     if (x); // expected-warning {{if statement has empty body}} expected-note{{put the semicolon on a separate line to silence this warning}}
14 
15     // Check that we handle conditions that start or end with a macro
16     // correctly.
17     if (x == MACRO_A); // expected-warning {{if statement has empty body}} expected-note{{put the semicolon on a separate line to silence this warning}}
18     if (MACRO_A == x); // expected-warning {{if statement has empty body}} expected-note{{put the semicolon on a separate line to silence this warning}}
19 
20     // Check that we handle the case where the condition comes from a macro
21     // expansion over multiple lines.
22     if (AND(b(),
23             c())); // expected-warning {{if statement has empty body}} expected-note{{put the semicolon on a separate line to silence this warning}}
24 
25     while (AND(b(),
26                c())); // expected-warning{{while loop has empty body}} expected-note{{put the semicolon on a separate line to silence this warning}}
27       a(0);
28 
29     int i;
30     // PR11329
31     for (i = 0; i < x; i++); { // expected-warning{{for loop has empty body}} expected-note{{put the semicolon on a separate line to silence this warning}}
32       a(i);
33       b();
34     }
35 
36     for (i = 0; i < x; i++); // expected-warning{{for loop has empty body}} expected-note{{put the semicolon on a separate line to silence this warning}}
37     {
38       a(i);
39     }
40 
41     for (i = 0;
42          i < x;
43          i++); // expected-warning{{for loop has empty body}} expected-note{{put the semicolon on a separate line to silence this warning}}
44     {
45       a(i);
46     }
47 
48     int arr[3] = { 1, 2, 3 };
49     for (int j : arr); // expected-warning{{range-based for loop has empty body}} expected-note{{put the semicolon on a separate line to silence this warning}}
50       a(i);
51 
52     for (int j :
53          arr); // expected-warning{{range-based for loop has empty body}} expected-note{{put the semicolon on a separate line to silence this warning}}
54       a(i);
55 
56     while (b() == 0); // expected-warning{{while loop has empty body}} expected-note{{put the semicolon on a separate line to silence this warning}}
57       a(i);
58 
59     while (b() == 0); { // expected-warning{{while loop has empty body}} expected-note{{put the semicolon on a separate line to silence this warning}}
60       a(i);
61     }
62 
63     while (b() == 0); // expected-warning{{while loop has empty body}} expected-note{{put the semicolon on a separate line to silence this warning}}
64     {
65       a(i);
66     }
67 
68     while (b() == 0 ||
69            c() == 0); // expected-warning{{while loop has empty body}} expected-note{{put the semicolon on a separate line to silence this warning}}
70     {
71       a(i);
72     }
73 
74     do;          // expected-note{{to match this 'do'}}
75       b();       // expected-error{{expected 'while' in do/while loop}}
76     while (b()); // no-warning
77     c();
78 
79     do;          // expected-note{{to match this 'do'}}
80       b();       // expected-error{{expected 'while' in do/while loop}}
81     while (b()); // expected-warning{{while loop has empty body}} expected-note{{put the semicolon on a separate line to silence this warning}}
82       c();
83 
84     switch(x) // no-warning
85     {
86       switch(y); // expected-warning{{switch statement has empty body}} expected-note{{put the semicolon on a separate line to silence this warning}}
87       {
88         case 0:
89           a(10);
90           break;
91         default:
92           a(20);
93           break;
94       }
95     }
96   }
97 }
98 
99 /// There should be no warning  when null statement is placed on its own line.
100 void test2(int x, int y) {
101   if (x) // no-warning
102     ; // no-warning
103 
104   int i;
105   for (i = 0; i < x; i++) // no-warning
106     ; // no-warning
107 
108   for (i = 0;
109        i < x;
110        i++) // no-warning
111     ; // no-warning
112 
113   int arr[3] = { 1, 2, 3 };
114   for (int j : arr) // no-warning
115     ; // no-warning
116 
117   while (b() == 0) // no-warning
118     ; // no-warning
119 
120   while (b() == 0 ||
121          c() == 0) // no-warning
122     ; // no-warning
123 
124   switch(x)
125   {
126     switch(y) // no-warning
127       ; // no-warning
128   }
129 
130   // Last `for' or `while' statement in compound statement shouldn't warn.
131   while(b() == 0); // no-warning
132 }
133 
134 /// There should be no warning for a null statement resulting from an empty macro.
135 #define EMPTY(a)
136 void test3(int x, int y) {
137   if (x) EMPTY(x); // no-warning
138 
139   int i;
140   for (i = 0; i < x; i++) EMPTY(i); // no-warning
141 
142   for (i = 0;
143        i < x;
144        i++) EMPTY(i); // no-warning
145 
146   int arr[3] = { 1, 2, 3 };
147   for (int j : arr) EMPTY(j); // no-warning
148 
149   for (int j :
150        arr) EMPTY(j); // no-warning
151 
152   while (b() == 0) EMPTY(i); // no-warning
153 
154   while (b() == 0 ||
155          c() == 0) EMPTY(i); // no-warning
156 
157   switch (x) {
158     switch (y)
159       EMPTY(i); // no-warning
160   }
161 }
162 
163 void test4(int x)
164 {
165   // Idiom used in some metaprogramming constructs.
166   switch (x) default:; // no-warning
167 
168   // Frequent idiom used in macros.
169   do {} while (false); // no-warning
170 }
171 
172 /// There should be no warning for a common for/while idiom when it is obvious
173 /// from indentation that next statement wasn't meant to be a body.
174 void test5(int x, int y) {
175   int i;
176   for (i = 0; i < x; i++); // expected-warning{{for loop has empty body}} expected-note{{put the semicolon on a separate line to silence this warning}}
177     a(i);
178 
179   for (i = 0; i < x; i++); // no-warning
180   a(i);
181 
182   for (i = 0;
183        i < x;
184        i++); // expected-warning{{for loop has empty body}} expected-note{{put the semicolon on a separate line to silence this warning}}
185     a(i);
186 
187   for (i = 0;
188        i < x;
189        i++); // no-warning
190   a(i);
191 
192   while (b() == 0); // expected-warning{{while loop has empty body}} expected-note{{put the semicolon on a separate line to silence this warning}}
193     a(i);
194 
195   while (b() == 0); // no-warning
196   a(i);
197 
198   while (b() == 0 ||
199          c() == 0); // expected-warning{{while loop has empty body}} expected-note{{put the semicolon on a separate line to silence this warning}}
200     a(i);
201 
202   while (b() == 0 ||
203          c() == 0); // no-warning
204   a(i);
205 }
206 
207 /// There should be no warning for a statement with a non-null body.
208 void test6(int x, int y) {
209   if (x) {} // no-warning
210 
211   if (x)
212     a(x); // no-warning
213 
214   int i;
215   for (i = 0; i < x; i++) // no-warning
216     a(i); // no-warning
217 
218   for (i = 0; i < x; i++) { // no-warning
219     a(i); // no-warning
220   }
221 
222   for (i = 0;
223        i < x;
224        i++) // no-warning
225     a(i); // no-warning
226 
227   int arr[3] = { 1, 2, 3 };
228   for (int j : arr) // no-warning
229     a(j);
230 
231   for (int j : arr) {} // no-warning
232 
233   while (b() == 0) // no-warning
234     a(i); // no-warning
235 
236   while (b() == 0) {} // no-warning
237 
238   switch(x) // no-warning
239   {
240     switch(y) // no-warning
241     {
242       case 0:
243         a(10);
244         break;
245       default:
246         a(20);
247         break;
248     }
249   }
250 }
251 
252 void test_errors(int x) {
253   if (1)
254     aa; // expected-error{{use of undeclared identifier}}
255         // no empty body warning.
256 
257   int i;
258   for (i = 0; i < x; i++)
259     bb; // expected-error{{use of undeclared identifier}}
260 
261   int arr[3] = { 1, 2, 3 };
262   for (int j : arr)
263     cc; // expected-error{{use of undeclared identifier}}
264 
265   while (b() == 0)
266     dd; // expected-error{{use of undeclared identifier}}
267 }
268 
269 // Warnings for statements in templates shouldn't be duplicated for all
270 // instantiations.
271 template <typename T>
272 void test_template(int x) {
273   if (x); // expected-warning{{if statement has empty body}} expected-note{{put the semicolon on a separate line to silence this warning}}
274 
275   if (x)
276     EMPTY(x); // no-warning
277 
278   int arr[3] = { 1, 2, 3 };
279   for (int j : arr); // expected-warning{{range-based for loop has empty body}} expected-note{{put the semicolon on a separate line to silence this warning}}
280 
281   while (b() == 0); // expected-warning{{while loop has empty body}} expected-note{{put the semicolon on a separate line to silence this warning}}
282     a(x);
283 }
284 
285 void test_template_inst(int x) {
286   test_template<int>(x);
287   test_template<double>(x);
288 }
289 
290 #define IDENTITY(a) a
291 void test7(int x, int y) {
292   if (x) IDENTITY(); // no-warning
293 }
294 
295