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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 - Wrong Debug Information for Oz. Stepping on dead code."
href="https://bugs.llvm.org/show_bug.cgi?id=45934">45934</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>Wrong Debug Information for Oz. Stepping on dead code.
</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>Keywords</th>
<td>wrong-debug
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>C
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>massarelli@diag.uniroma1.it
</td>
</tr>
<tr>
<th>CC</th>
<td>blitzrakete@gmail.com, dgregor@apple.com, ditaliano@apple.com, erik.pilkington@gmail.com, llvm-bugs@lists.llvm.org, richard-llvm@metafoo.co.uk
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<pre>The debugger shows that line 2 is executed while it shouldn't be.
$ cat a.c
int add(int ui1, int ui2) {
return ui1 + ui2;
}
int g_8 ;
int a = 4 ;
int c
;
int main() {
for (g_8 = 0; (g_8 < 49); g_8 = add(g_8, 9)) {
for (; c ; c++)
;
if (a)
break;
}
}
$ clang -v
clang version 11.0.0 (<a href="https://github.com/llvm/llvm-project.git">https://github.com/llvm/llvm-project.git</a>
c25b20c0f6c13d68dbc2e185764082d61ae4a132)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/local/bin
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7.5.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/8
Found candidate GCC installation:
/usr/local/bin/../lib/gcc/x86_64-pc-linux-gnu/11.0.0
Selected GCC installation: /usr/local/bin/../lib/gcc/x86_64-pc-linux-gnu/11.0.0
Candidate multilib: .;@m64
Selected multilib: .;@m64
$ lldb -v
lldb version 11.0.0
clang revision c25b20c0f6c13d68dbc2e185764082d61ae4a132
llvm revision c25b20c0f6c13d68dbc2e185764082d61ae4a132
$ gdb -v
GNU gdb (Ubuntu 8.1-0ubuntu3.2) 8.1.0.20180409-git
$ clang -Oz -g -o opt a.c
$ lldb opt
(lldb) target create "opt"
Current executable set to 'opt' (x86_64).
(lldb) b -l 2
Breakpoint 1: 2 locations.
(lldb) r
Process 145 launched: 'opt' (x86_64)
Process 145 stopped
* thread #1, name = 'opt', stop reason = breakpoint 1.2
frame #0: 0x000000000040049d opt`main [inlined] add(ui1=0, ui2=9) at
a.c:2:14
1 int add(int ui1, int ui2) {
-> 2 return ui1 + ui2;
3 }
4 int g_8 ;
5 int a = 4 ;
6 int c
7 ;
(lldb)
$ gdb opt
(gdb) b -l 2
Breakpoint 1 at 0x400474: -source a.c -line 2. (2 locations)
(gdb) r
Starting program: opt
Breakpoint 1, main () at a.c:9
9 for (g_8 = 0; (g_8 < 49); g_8 = add(g_8, 9)) {
(gdb) s
add (ui1=0, ui2=9) at a.c:2
2 return ui1 + ui2;
(gdb)</pre>
</div>
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