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<base href="https://bugs.llvm.org/">
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<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Wrong variable value shown during debugging at Og"
href="https://bugs.llvm.org/show_bug.cgi?id=45923">45923</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>Wrong variable value shown during debugging at Og
</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>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>-New Bugs
</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>ditaliano@apple.com, htmldeveloper@gmail.com, llvm-bugs@lists.llvm.org, neeilans@live.com, richard-llvm@metafoo.co.uk
</td>
</tr></table>
<p>
<div>
<pre>At line 13 value 1 should be assigned to variable f while -1 is shown in lldb
and gdb.
$ cat a.c
typedef unsigned uint32_t;
int(a)(b) { return b; }
char c;
uint32_t d;
static int func_5(uint32_t p_6) {
for (; c; c = 5)
p_6 || d;
}
int e;
int main() {
int f;
e = a(8);
f = e && 9;
func_5(f);
}
$ 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 -O3 -g -o opt a.c
$ lldb opt
(lldb) target create "opt"
Current executable set to 'opt' (x86_64).
(lldb) b main
Breakpoint 1: where = opt`main at a.c:12:5, address = 0x0000000000400490
(lldb) r
Process 117 launched: 'opt' (x86_64)
Process 117 stopped
* thread #1, name = 'opt', stop reason = breakpoint 1.1
frame #0: 0x0000000000400490 opt`main at a.c:12:5
9 int e;
10 int main() {
11 int f;
-> 12 e = a(8);
13 f = e && 9;
14 func_5(f);
15 }
(lldb) n
Process 117 stopped
* thread #1, name = 'opt', stop reason = step over
frame #0: 0x000000000040049a opt`main at a.c:14
11 int f;
12 e = a(8);
13 f = e && 9;
-> 14 func_5(f);
15 }
(lldb) p f
(int) $0 = -1
(lldb) p e
(int) $1 = 8
(lldb) expr e && 8
(bool) $2 = true
$ gdb opt
(gdb) b main
Breakpoint 1 at 0x400490: file a.c, line 12.
(gdb) r
Starting program: opt
Breakpoint 1, main () at a.c:12
12 e = a(8);
(gdb) s
14 func_5(f);
(gdb) p f
$1 = -1
(gdb)</pre>
</div>
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