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<base href="http://llvm.org/bugs/" />
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - False positive with containers & loop initialized value, container excluding assumptions with empty() with size()"
href="http://llvm.org/bugs/show_bug.cgi?id=17489">17489</a>
</td>
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<th>Summary</th>
<td>False positive with containers & loop initialized value, container excluding assumptions with empty() with size()
</td>
</tr>
<tr>
<th>Product</th>
<td>clang
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
<tr>
<th>OS</th>
<td>Linux
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
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<th>Component</th>
<td>Static Analyzer
</td>
</tr>
<tr>
<th>Assignee</th>
<td>kremenek@apple.com
</td>
</tr>
<tr>
<th>Reporter</th>
<td>artur@ebasoft.com.pl
</td>
</tr>
<tr>
<th>CC</th>
<td>llvmbugs@cs.uiuc.edu
</td>
</tr>
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<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>For this code below analyzer assumes !empty() and size()==0 as a possible case
clang version 3.4 (191810)
#include <iostream>
#include <vector>
struct foo_t{ int value; void prt(){ std::cout << "Hello, world!"<< value <<
std::endl;}};
using foo_list_t =std::vector<foo_t>;
void func( foo_list_t & foo_list )
{
if( !foo_list.empty() )
{
foo_t * first_foo = nullptr;
for( size_t i=0; i<foo_list.size(); ++i)
{
if( i == 0 )
first_foo = &foo_list[i];
std::cout << ".";
}
first_foo->prt();
}
}
int main(int argc, char **argv)
{
foo_list_t foo_list{ {0},{1},{2}};
func(foo_list);
return 0;
}
-----------------------------------------------
9 if( !foo_list.empty() )
2
←Taking true branch→
10 {
11 foo_t * first_foo = nullptr;
3
←'first_foo' initialized to a null pointer value
→
12 for( size_t i=0; i<foo_list.size(); ++i)
4
←Loop condition is false. Execution continues on line 18
→
13 {
14 if( i == 0 )
15 first_foo = &foo_list[i];
16 std::cout << ".";
17 }
18 first_foo->prt();
5
←Called C++ object pointer is null
19 }</pre>
</div>
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