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* [Bug symtab/27036] New: An address is mapping to more than one source line of code
@ 2020-12-09 1:05 yangyibiao at outlook dot com
2020-12-27 6:02 ` [Bug symtab/27036] " yangyibiao at outlook dot com
0 siblings, 1 reply; 2+ messages in thread
From: yangyibiao at outlook dot com @ 2020-12-09 1:05 UTC (permalink / raw)
To: gdb-prs
https://sourceware.org/bugzilla/show_bug.cgi?id=27036
Bug ID: 27036
Summary: An address is mapping to more than one source line of
code
Product: gdb
Version: 10.1
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: symtab
Assignee: unassigned at sourceware dot org
Reporter: yangyibiao at outlook dot com
Target Milestone: ---
Created attachment 13027
--> https://sourceware.org/bugzilla/attachment.cgi?id=13027&action=edit
the binary
$ gcc -O1 -g small.c
$ gdb a.out
(gdb) b main
Breakpoint 1 at 0x68e: file small.c, line 13.
(gdb) r
Starting program: /root/DeVIL/a.out
Breakpoint 1, main (argc=1, argv=0x7fffffffe588) at small.c:13
13 {
(gdb) s
18 pa = &a;
(gdb) s
19 pb = &b;
(gdb) s
20 pc = &c;
(gdb) s
22 access (pb);
(gdb) where -frame-info location-and-address
#0 0x00005555555546c6 in main (argc=1, argv=0x7fffffffe588) at small.c:22
(gdb) s
access (ptr=0x7fffffffe496 "") at small.c:9
9 *ptr = 'x';
(gdb) where -frame-info location-and-address
#0 0x00005555555546c6 in access (ptr=0x7fffffffe496 "") at small.c:9
#1 0x00005555555546c6 in main (argc=1, argv=0x7fffffffe588) at small.c:22
############################################################
We can found that 0x00005555555546c6 not only belongs to source line
"small.c:22" but also belongs to "small.c:9"
If compiling small.c without optimization, there is no such problem.
############################################################
$ cat small.c
/* { dg-do run } */
char *pa;
char *pb;
char *pc;
void access (volatile char *ptr)
{
*ptr = 'x';
}
int main (int argc, char **argv)
{
char a;
char b;
char c;
pa = &a;
pb = &b;
pc = &c;
access (pb);
access (pc);
// access 'b' here
access (pa + 32);
return 0;
}
$ gcc --version; gdb --version
gcc-10 (Ubuntu 10.1.0-2ubuntu1~18.04) 10.1.0
Copyright (C) 2020 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
GNU gdb (GDB) 10.1
Copyright (C) 2020 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
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* [Bug symtab/27036] An address is mapping to more than one source line of code
2020-12-09 1:05 [Bug symtab/27036] New: An address is mapping to more than one source line of code yangyibiao at outlook dot com
@ 2020-12-27 6:02 ` yangyibiao at outlook dot com
0 siblings, 0 replies; 2+ messages in thread
From: yangyibiao at outlook dot com @ 2020-12-27 6:02 UTC (permalink / raw)
To: gdb-prs
https://sourceware.org/bugzilla/show_bug.cgi?id=27036
Yibiao Yang <yangyibiao at outlook dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Resolution|--- |INVALID
Status|UNCONFIRMED |RESOLVED
--- Comment #1 from Yibiao Yang <yangyibiao at outlook dot com> ---
Sorry. Invalid bug report.
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^ permalink raw reply [flat|nested] 2+ messages in thread
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2020-12-09 1:05 [Bug symtab/27036] New: An address is mapping to more than one source line of code yangyibiao at outlook dot com
2020-12-27 6:02 ` [Bug symtab/27036] " yangyibiao at outlook dot com
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