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<head>
<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 - Lifetime of a variable too short at Og"
href="https://bugs.llvm.org/show_bug.cgi?id=49580">49580</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>Lifetime of a variable too short at Og
</td>
</tr>
<tr>
<th>Product</th>
<td>libraries
</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>DebugInfo
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>cristianassaiante@outlook.com
</td>
</tr>
<tr>
<th>CC</th>
<td>jdevlieghere@apple.com, keith.walker@arm.com, llvm-bugs@lists.llvm.org, paul_robinson@playstation.sony.com
</td>
</tr></table>
<p>
<div>
<pre>Upon calling a function from an external module, the variables previously
used by for loops which are passed to it, are not visible from frame var.
$ cat a.c
void test_nop();
void test_support_3002(int i, int j, int k);
static int func_1(void)
{
int l_6[4][1][1];
int i, j, k;
for (i = 0; i < 4; i++)
{
for (j = 0; j < 1; j++)
{
for (k = 0; k < 1; k++)
l_6[i][j][k] = 0xE6BACD79;
}
}
test_nop();
test_support_3002(i, j, k);
return l_6[0][0][0];
}
int main (void)
{
func_1();
return 0;
}
$ cat lib/test.c
#include <stdio.h>
#include <stdint.h>
#include "test.h"
void test_nop() {
printf("\n");
}
void test_support_3002(int i, int j, int k) {
printf("%d %d %d", i, j, k);
}
$ cat lib/test.h
#pragma once
void test_nop();
void test_support_3002(int i, int j, int k);
$ clang -v
clang version 13.0.0
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
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7.5.0
Candidate multilib: .;@m64
Selected multilib: .;@m64
$ lldb -v
lldb version 13.0.0
clang revision c2c977ce50597b0e5186afc342c5784bd0aa6973
lldb revision c2c977ce50597b0e5186afc342c5784bd0aa6973
$ clang -c -o lib/test.o -I lib lib/test.c
$ clang -g -Og -o opt -I lib/ lib/test.o a.co
$ lldb opt
(lldb) target create "opt"
Current executable set to
'/home/stepping/debuginfo-analysis/bug_submission/opt' (x86_64).
(lldb) b func_1
Breakpoint 1: where = opt`main + 1 [inlined] func_1 at a.c:25, address =
0x0000000000400531
(lldb) r
Process 57 launched: '/home/stepping/debuginfo-analysis/bug_submission/opt'
(x86_64)
Process 57 stopped
* thread #1, name = 'opt', stop reason = breakpoint 1.1
frame #0: 0x0000000000400531 opt`main [inlined] func_1 at a.c:18:1
15 l_6[i][j][k] = 0xE6BACD79;
16 }
17 }
-> 18 test_nop();
19 test_support_3002(i, j, k);
20 return l_6[0][0][0];
21 }
(lldb) n
Process 57 stopped
* thread #1, name = 'opt', stop reason = step over
frame #0: 0x0000000000400538 opt`main [inlined] func_1 at a.c:19:1
16 }
17 }
18 test_nop();
-> 19 test_support_3002(i, j, k);
20 return l_6[0][0][0];
21 }
22
(lldb) frame var
(lldb) frame var i
error: no variable named 'i' found in this frame
(lldb) frame var j
error: no variable named 'j' found in this frame
(lldb) frame var k
error: no variable named 'k' found in this frame</pre>
</div>
</p>
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