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<base href="https://bugs.llvm.org/">
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - [LLVM-COV] wrong coverage for a label pointed by a static pointer in a static function"
href="https://bugs.llvm.org/show_bug.cgi?id=37083">37083</a>
</td>
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<tr>
<th>Summary</th>
<td>[LLVM-COV] wrong coverage for a label pointed by a static pointer in a static function
</td>
</tr>
<tr>
<th>Product</th>
<td>Runtime Libraries
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
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<th>OS</th>
<td>All
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>libprofile library
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>yangyibiao@nju.edu.cn
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>$ cat small.c
#include <stdio.h>
static int doit(int x){
__label__ lbl1;
__label__ lbl2;
static int jtab_init = 0;
static void *jtab[2];
if(!jtab_init) {
jtab[0] = &&lbl1;
jtab[1] = &&lbl2;
jtab_init = 1;
}
if (jtab[x]==(&&lbl1))
printf("call doit(%d) *jtab[x] at lbl1\n", x);
if (jtab[x]==(&&lbl2))
printf("call doit(%d) *jtab[x] at lbl2\n", x);
goto *jtab[x];
lbl1:
return 1;
lbl2:
return 2;
}
int main(void){
doit(0);
doit(1);
return 0;
}
$ clang -O0 -g -fcoverage-mapping -fprofile-instr-generate=small.profraw
small.c; ./a.out; llvm-profdata merge small.profraw -o small.profdata; llvm-cov
show a.out -instr-profile=small.profdata small.c > small.gcov; cat small.gcov
call doit(0) *jtab[x] at lbl1
call doit(1) *jtab[x] at lbl2
1| |#include <stdio.h>
2| |
3| 2|static int doit(int x){
4| 2| __label__ lbl1;
5| 2| __label__ lbl2;
6| 2| static int jtab_init = 0;
7| 2| static void *jtab[2];
8| 2|
9| 2| if(!jtab_init) {
10| 1| jtab[0] = &&lbl1;
11| 1| jtab[1] = &&lbl2;
12| 1| jtab_init = 1;
13| 1| }
14| 2|
15| 2| if (jtab[x]==(&&lbl1))
16| 1| printf("call doit(%d) *jtab[x] at lbl1\n", x);
17| 2| if (jtab[x]==(&&lbl2))
18| 1| printf("call doit(%d) *jtab[x] at lbl2\n", x);
19| 2|
20| 2| goto *jtab[x];
21| 2|
22| 2|lbl1:
23| 1| return 1;
24| 1|lbl2:
25| 1| return 2;
26| 0|}
27| |
28| 1|int main(void){
29| 1| doit(0);
30| 1| doit(1);
31| 1|
32| 1| return 0;
33| 1|}
*****
Line #22 is wrongly marked as executed twice. However, from the output of the
program, a the second call to doit function. *jtab[x] is equal to lbl2,
therefore, Line #22 should be only executed once.</pre>
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