[llvm-bugs] [Bug 45060] New: Wrong debug info generated at -O3 (-O0 is correct)

[via llvm-bugs]

https://bugs.llvm.org/show_bug.cgi?id=45060

            Bug ID: 45060
           Summary: Wrong debug info generated at -O3 (-O0 is correct)
           Product: clang
           Version: trunk
          Hardware: PC
                OS: Linux
            Status: NEW
          Severity: enhancement
          Priority: P
         Component: LLVM Codegen
          Assignee: unassignedclangbugs at nondot.org
          Reporter: shuo.d at outlook.com
                CC: llvm-bugs at lists.llvm.org, neeilans at live.com,
                    richard-llvm at metafoo.co.uk

The expected output from lldb should be -1. However, compiled with "-O3", lldb
outputs 15.




$ clang-trunk -v
clang version 11.0.0 (https://github.com/llvm/llvm-project.git
c3595d1069277b4ab0df49d7139b6f1bbc94f21c)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/local/bin
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/8
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/9
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.4
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.4.7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.6
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.6.4
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.8
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.8.5
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5.5.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6.5.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7.4.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/8
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/9
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/9
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Candidate multilib: x32;@mx32
Selected multilib: .;@m64




$ clang-trunk -g abc.c -O3
$ lldb-trunk -s cmds -b a.out 
(lldb) target create "a.out"
Current executable set to '/home/sding/LLDB-testing/reduce/24519/report2/a.out'
(x86_64).
(lldb) command source -s 0 'cmds'
Executing commands in '/home/sding/LLDB-testing/reduce/24519/report2/cmds'.
(lldb) b 3 
Breakpoint 1: where = a.out`main at abc.c:4:1, address = 0x0000000000400480
(lldb) r
Process 18302 stopped
* thread #1, name = 'a.out', stop reason = breakpoint 1.1
    frame #0: 0x0000000000400480 a.out`main at abc.c:4:1
   1    int main() {
   2      int a = -1;
   3      a = 15; // optimize_me_not0
-> 4    }

Process 18302 launched: '/home/sding/LLDB-testing/reduce/24519/report2/a.out'
(x86_64)
(lldb) p a
(int) $0 = 15
(lldb) kill
Process 18302 exited with status = 9 (0x00000009) 
(lldb) q




$ clang-trunk -g abc.c -O0
$ lldb-trunk -s cmds -b a.out 
(lldb) target create "a.out"
Current executable set to '/home/sding/LLDB-testing/reduce/24519/report2/a.out'
(x86_64).
(lldb) command source -s 0 'cmds'
Executing commands in '/home/sding/LLDB-testing/reduce/24519/report2/cmds'.
(lldb) b 3 
Breakpoint 1: where = a.out`main + 13 at abc.c:3:5, address =
0x000000000040048d
(lldb) r
Process 19728 stopped
* thread #1, name = 'a.out', stop reason = breakpoint 1.1
    frame #0: 0x000000000040048d a.out`main at abc.c:3:5
   1    int main() {
   2      int a = -1;
-> 3      a = 15; // optimize_me_not0
   4    }

Process 19728 launched: '/home/sding/LLDB-testing/reduce/24519/report2/a.out'
(x86_64)
(lldb) p a
(int) $0 = -1
(lldb) kill
Process 19728 exited with status = 9 (0x00000009) 
(lldb) q




$ cat abc.c 
int main() {
  int a = -1;
  a = 15; // optimize_me_not0
}




$ cat cmds
b 3 
r
p a
kill
q

-- 
You are receiving this mail because:
You are on the CC list for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-bugs/attachments/20200228/56578514/attachment-0001.html>