[Bug debug/95431] inconsistent behaviors at -O2
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95431 Yibiao Yang changed: What|Removed |Added CC||yangyibiao at hust dot edu.cn --- Comment #1 from Yibiao Yang --- Created attachment 48640 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48640=edit a.out
[Bug debug/95432] inconsistent behaviors at -O2
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95432 Yibiao Yang changed: What|Removed |Added CC||yangyibiao at hust dot edu.cn --- Comment #1 from Yibiao Yang --- Created attachment 48639 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48639=edit a.out
[Bug debug/95432] New: inconsistent behaviors at -O2
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95432
Bug ID: 95432
Summary: inconsistent behaviors at -O2
Product: gcc
Version: 10.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: debug
Assignee: unassigned at gcc dot gnu.org
Reporter: yangyibiao at hust dot edu.cn
Target Milestone: ---
Consider test case:
...
$ cat small.c
__attribute__ ((noinline, noclone))
int foo (char *c)
{
asm volatile ("" : : "r" (c) : "memory");
return 1;
}
int main ()
{
char tpl1[20] = "/tmp/test.XXX";
char tpl2[20] = "/tmp/test.XXX";
int fd1 = foo (tpl1);
int fd2 = foo (tpl2);
if (fd1 == -1) {
return 1;
}
return 0;
}
...
When stepping with step, line 13 is not hit by gdb.
...
$ gcc -O2 -g small.c; gdb -q a.out
Reading symbols from a.out...
(gdb) b main
Breakpoint 1 at 0x401020: file small.c, line 10.
(gdb) r
Starting program: /home/yibiao/Debugger/a.out
Breakpoint 1, main () at small.c:10
10char tpl1[20] = "/tmp/test.XXX";
(gdb) step
11char tpl2[20] = "/tmp/test.XXX";
(gdb)
12int fd1 = foo (tpl1);
(gdb)
foo (c=c@entry=0x7fffdea0 "/tmp/test.XXX") at small.c:5
5 return 1;
(gdb)
foo (c=c@entry=0x7fffdec0 "/tmp/test.XXX") at small.c:5
5 return 1;
(gdb)
main () at small.c:14
14if (fd1 == -1) {
(gdb)
0x77df4023 in __libc_start_main () from /usr/lib/libc.so.6
(gdb)
Single stepping until exit from function __libc_start_main,
which has no line number information.
[Inferior 1 (process 1852557) exited normally]
...
When stepping with stepi, line 13 is hit by gdb as follow.
...
$ gcc -O2 -g small.c; gdb -q a.out
Reading symbols from a.out...
(gdb) b main
Breakpoint 1 at 0x401020: file small.c, line 10.
(gdb) r
Starting program: /home/yibiao/Debugger/a.out
Breakpoint 1, main () at small.c:10
10char tpl1[20] = "/tmp/test.XXX";
(gdb) stepi
0x00401024 10char tpl1[20] = "/tmp/test.XXX";
(gdb)
0x0040102c 12int fd1 = foo (tpl1);
(gdb)
0x0040102f 10char tpl1[20] = "/tmp/test.XXX";
(gdb)
11char tpl2[20] = "/tmp/test.XXX";
(gdb)
12int fd1 = foo (tpl1);
(gdb)
0x00401043 11char tpl2[20] = "/tmp/test.XXX";
(gdb)
0x00401048 12int fd1 = foo (tpl1);
(gdb)
foo (c=c@entry=0x7fffdea0 "/tmp/test.XXX") at small.c:5
5 return 1;
(gdb)
0x00401165 5 return 1;
(gdb)
0x0040104d in main () at small.c:13
13int fd2 = foo (tpl2);
(gdb)
...
$ gcc --version
gcc (GCC) 10.0.1 20200419 (experimental)
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.
$ gdb --version
GNU gdb (GDB) 10.0.50.20200517-git
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.
[Bug debug/95431] New: inconsistent behaviors at -O2
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95431
Bug ID: 95431
Summary: inconsistent behaviors at -O2
Product: gcc
Version: 10.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: debug
Assignee: unassigned at gcc dot gnu.org
Reporter: yangyibiao at hust dot edu.cn
Target Milestone: ---
Consider test case:
...
$ cat small.c
#include
volatile int one = 1;
int main() {
char a1[] = {(char)one, 2, 3, 4};
char a2[] = {1, (char)(2*one), 3, 4};
int res = memcmp (a1, a2, 5 + one);
return res;
}
...
When stepping using step Line 7 is not hit by gdb.
...
$ gcc -O2 -g small.c; gdb -q a.out
Reading symbols from a.out...
(gdb) b main
Breakpoint 1 at 0x401040: file small.c, line 6.
(gdb) r
Starting program: /home/yibiao/Debugger/a.out
Breakpoint 1, main () at small.c:6
6 char a1[] = {(char)one, 2, 3, 4};
(gdb) step
8 int res = memcmp (a1, a2, 5 + one);
(gdb)
...
When stepping using stepi, Line 7 is hit after Line 6 by gdb.
...
$ gcc -O2 -g small.c; gdb -q a.out
Reading symbols from a.out...
(gdb) b main
Breakpoint 1 at 0x401040: file small.c, line 6.
(gdb) si
The program is not being run.
(gdb) r
Starting program: /home/yibiao/Debugger/a.out
Breakpoint 1, main () at small.c:6
6 char a1[] = {(char)one, 2, 3, 4};
(gdb) si
0x00401044 6 char a1[] = {(char)one, 2, 3, 4};
(gdb) si
0x0040104a 7 char a2[] = {1, (char)(2*one), 3, 4};
(gdb)
$ gcc --version
gcc (GCC) 10.0.1 20200419 (experimental)
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.
$ gdb --version
GNU gdb (GDB) 10.0.50.20200517-git
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.
[Bug debug/95414] New: Wrong debug info for argc at -O2
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95414
Bug ID: 95414
Summary: Wrong debug info for argc at -O2
Product: gcc
Version: 10.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: debug
Assignee: unassigned at gcc dot gnu.org
Reporter: yangyibiao at hust dot edu.cn
Target Milestone: ---
Created attachment 48633
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48633=edit
a.out
$ gcc --version
gcc (GCC) 10.0.1 20200419 (experimental)
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.
yibiao:~/Debugger$ gdb --version
GNU gdb (GDB) 10.0.50.20200517-git
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.
Consider test-case:
...
$ cat small.c
#include
int main(int argc, char **argv) {
char buf[6];
char c[] = "abc";
sprintf(buf, (char *)c, 1);
return 0;
}
...
$ gcc -O2 -g small.c; gdb -q a.out
Reading symbols from a.out...
(gdb) b main
Breakpoint 1 at 0x401040: file small.c, line 5.
(gdb) r
Starting program: /home/yibiao/Debugger/a.out
Breakpoint 1, main (argc=1, argv=0x7fffdff8) at small.c:5
5 char c[] = "abc";
(gdb) info args argc
argc = 1
(gdb) step
6 sprintf(buf, (char *)c, 1);
(gdb) info args argc
argc = -8454
(gdb)
/**
We can find that at line 5, the value of argc is 1. When stepping to line 6,
the value of argc is changed to -8454. When stepping with stepi, the value of
argc is correct.
[Bug debug/95387] New: inconsistent behaviors at -Os
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95387
Bug ID: 95387
Summary: inconsistent behaviors at -Os
Product: gcc
Version: 10.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: debug
Assignee: unassigned at gcc dot gnu.org
Reporter: yangyibiao at hust dot edu.cn
Target Milestone: ---
Created attachment 48628
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48628=edit
a.out
$ gdb --version
GNU gdb (GDB) 10.0.50.20200517-git
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.
$ gcc --version
gcc (GCC) 10.0.1 20200419 (experimental)
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.
Consider test case:
$ cat small.c
#include
int main () {
char a1[4] = {1, 2, 3, 4};
char a2[4] = {1, 2, 3, 4};
int res = memcmp(a1, a2, 4);
return res;
}
/**when using stepping using stepi, Line 5 is hit after line 6. /
$ gcc -Os -g small.c; gdb -q a.out
Reading symbols from a.out...
(gdb) b main
Breakpoint 1 at 0x401040: file small.c, line 4.
(gdb) r
Starting program: /home/yibiao/Debugger/a.out
Breakpoint 1, main () at small.c:4
4 char a1[4] = {1, 2, 3, 4};
(gdb) si
0x00401044 6 int res = memcmp(a1, a2, 4);
(gdb) si
0x00401049 6 int res = memcmp(a1, a2, 4);
(gdb) si
0x0040104e 6 int res = memcmp(a1, a2, 4);
(gdb) si
0x00401053 4 char a1[4] = {1, 2, 3, 4};
(gdb) si
5 char a2[4] = {1, 2, 3, 4};
(gdb) si
6 int res = memcmp(a1, a2, 4);
(gdb)
/** when setting breakpoint, we can found that line 5 is hit before line 6
***/
$ gcc -Os -g small.c; gdb -q a.out
Reading symbols from a.out...
(gdb) b 5
Breakpoint 1 at 0x40105b: file small.c, line 5.
(gdb) b 6
Breakpoint 2 at 0x401063: file small.c, line 6.
(gdb) r
Starting program: /home/yibiao/Debugger/a.out
Breakpoint 1, main () at small.c:5
5 char a2[4] = {1, 2, 3, 4};
(gdb) c
Continuing.
Breakpoint 2, main () at small.c:6
6 int res = memcmp(a1, a2, 4);
(gdb)
[Bug debug/95377] New: inconsistent behaviors at -O1
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95377
Bug ID: 95377
Summary: inconsistent behaviors at -O1
Product: gcc
Version: 10.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: debug
Assignee: unassigned at gcc dot gnu.org
Reporter: yangyibiao at hust dot edu.cn
Target Milestone: ---
Created attachment 48622
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48622=edit
a.out
$ gcc --version
gcc (GCC) 10.0.1 20200419 (experimental)
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.
$ gdb --version
GNU gdb (GDB) 10.0.50.20200517-git
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.
Consider test-case:
...
$ cat small.c
char *pa;
void access (volatile char *ptr) {
*ptr = 'x';
}
int main () {
char a;
pa =
access (pa);
return 0;
}
...
When stepping through the program by using "stepi"
...
$ gcc -O1 -g small.c; gdb -q a.out
Reading symbols from a.out...
(gdb) b main
Breakpoint 1 at 0x401106: file small.c, line 9.
(gdb) r
Starting program: /home/yibiao/Debugger/a.out
Breakpoint 1, main () at small.c:9
9 pa =
(gdb) stepi
0x0040110b 9 pa =
(gdb)
access (ptr=0x7fffdf07 "") at small.c:4
4 *ptr = 'x';
(gdb)
main () at small.c:11
11return 0;
(gdb)
...
/**
As showed, when stepping with stepi, Line 10 is skipping over. While using
step, Line 10 is hit by gdb as follow:
***/
When stepping through the program by using step:
...
$ gcc -O1 -g small.c
$ gdb -q a.out
Reading symbols from a.out...
(gdb) b main
Breakpoint 1 at 0x401106: file small.c, line 9.
(gdb) r
Starting program: /home/yibiao/Debugger/a.out
Breakpoint 1, main () at small.c:9
9 pa =
(gdb) step
10access (pa);
(gdb)
access (ptr=0x7fffdf07 "") at small.c:4
4 *ptr = 'x';
(gdb)
main () at small.c:11
11return 0;
(gdb)
Considering that this might be caused by gdb, I also submit a bug report to gdb
as inspired by Tom de Vries :
https://sourceware.org/bugzilla/show_bug.cgi?id=26057
[Bug debug/95360] inconsistent behaviors at -O0
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95360 --- Comment #6 from Yibiao Yang --- (In reply to Jonathan Wakely from comment #2) > (In reply to Yibiao Yang from comment #0) > > As showed, Line 6 is hit first and then hit Line 7 with stepi. > > However, when using step, gdb is first hit Line 7 and then hit Line 6. > > This is an inconsistent behaviors between stepi and step > > Why is that a bug? Why is it a GCC bug? To be honest, I am not sure whether this is a gcc bug or a gdb bug. I am very sorry for that. I report it here as I doubt that the line table is generated incorrectly by compilers.
[Bug debug/95360] inconsistent behaviors at -O0
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95360 --- Comment #5 from Yibiao Yang --- (In reply to Tom de Vries from comment #3) > (In reply to Yibiao Yang from comment #0) > > Breakpoint 1, main () at small.c:5 > > 5 for (; d<1; d++) > > (gdb) stepi > > 0x00401154 5 for (; d<1; d++) > > (gdb) stepi > > 0x0040115a 5 for (; d<1; d++) > > (gdb) stepi > > 0x0040115c 5 for (; d<1; d++) > > (gdb) stepi > > 0x0040113b 6 for (; b<1; b++) > > (gdb) stepi > > 0x00401141 6 for (; b<1; b++) > > (gdb) stepi > > 0x00401143 6 for (; b<1; b++) > > (gdb) stepi > > 7 c[b][d+1] = 0; > > (gdb) > > > > > > /* > > As showed, Line 6 is hit first and then hit Line 7 with stepi. > > However, when using step, gdb is first hit Line 7 and then hit Line 6. > > This is an inconsistent behaviors between stepi and step > > */ > > Gdb is behaving consistently in the following sense: > - when gdb is at a "recommended breakpoint location" it shows the source line > only with line number prefix. > - otherwise, it shows the source line with both address and line number > prefix. > > So, what the stepi sequence shows it that the next "recommended breakpoint > location" after line 5 is line 7, which is consistent with a step from line > 5 to line 7. I agree that at some time it will step to line 7 after executing line 6 and at other times it will step to line 6 after executing line7 as they both at the same iteration. However, my concern is that for the "first iteration or first time" line 6 should be hit ahead of line 7 no matter on whether we using step or using stepi. That's to say, the first hit of Line 6 or Line 7 should be consistent between step and stepi.
[Bug debug/95360] inconsistent behaviors at -O0
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95360 --- Comment #1 from Yibiao Yang --- Created attachment 48616 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48616=edit the binary
[Bug debug/95360] New: inconsistent behaviors at -O0
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95360
Bug ID: 95360
Summary: inconsistent behaviors at -O0
Product: gcc
Version: 10.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: debug
Assignee: unassigned at gcc dot gnu.org
Reporter: yangyibiao at hust dot edu.cn
Target Milestone: ---
$ gcc --version
gcc (GCC) 10.0.1 20200419 (experimental)
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.
$ gdb --version
GNU gdb (GDB) 10.0.50.20200517-git
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.
$ cat small.c
unsigned int b,d;
static int c[1][2] = {{0, 1}};
int main() {
for (; d<1; d++)
for (; b<1; b++)
c[b][d+1] = 0;
return 0;
}
$ gcc -O0 -g small.c
$ gdb -q a.out
Reading symbols from a.out...
(gdb) b 5
Breakpoint 1 at 0x401106: file small.c, line 5.
(gdb) r
Starting program: /home/yibiao/Debugger/a.out
Breakpoint 1, main () at small.c:5
5 for (; d<1; d++)
(gdb) stepi
0x00401154 5 for (; d<1; d++)
(gdb) stepi
0x0040115a 5 for (; d<1; d++)
(gdb) stepi
0x0040115c 5 for (; d<1; d++)
(gdb) stepi
0x0040113b 6 for (; b<1; b++)
(gdb) stepi
0x00401141 6 for (; b<1; b++)
(gdb) stepi
0x00401143 6 for (; b<1; b++)
(gdb) stepi
7 c[b][d+1] = 0;
(gdb)
/*
As showed, Line 6 is hit first and then hit Line 7 with stepi.
However, when using step, gdb is first hit Line 7 and then hit Line 6.
This is an inconsistent behaviors between stepi and step
*/
$ gdb -q a.out
Reading symbols from a.out...
(gdb) b main
Breakpoint 1 at 0x401106: file small.c, line 5.
(gdb) r
Starting program: /home/yibiao/Debugger/a.out
Breakpoint 1, main () at small.c:5
5 for (; d<1; d++)
(gdb) step
7 c[b][d+1] = 0;
(gdb)
6 for (; b<1; b++)
(gdb)
Breakpoint 1, main () at small.c:6
6 for (; b<1; b++)
(gdb)
[Bug gcov-profile/93726] [GCOV] unexecuted functions lead to incorrect code coverage when it calls a function with a variable argument
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93726 --- Comment #2 from Yibiao Yang --- (In reply to Martin Liška from comment #1) > How is that different from PR93725? Of this one, it wrongly marked a (executed) statement as not executed. For Bug PR93725, the frequencies is incorrect: A statement is in fact executed one time but wrongly marked as executed two times.
[Bug gcov-profile/93766] New: [GCOV] incorrect coverage when compiled with option '-fsanitize=undefined' for struct assignment statement
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93766
Bug ID: 93766
Summary: [GCOV] incorrect coverage when compiled with option
'-fsanitize=undefined' for struct assignment statement
Product: gcc
Version: 9.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: gcov-profile
Assignee: unassigned at gcc dot gnu.org
Reporter: yangyibiao at hust dot edu.cn
CC: marxin at gcc dot gnu.org
Target Milestone: ---
$ gcov -v
gcov (GCC) 9.2.0
Copyright (C) 2019 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.
$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/9.2.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /build/gcc/src/gcc/configure --prefix=/usr --libdir=/usr/lib
--libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info
--with-bugurl=https://bugs.archlinux.org/
--enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++,d --enable-shared
--enable-threads=posix --with-system-zlib --with-isl --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-clocale=gnu --disable-libstdcxx-pch
--disable-libssp --enable-gnu-unique-object --enable-linker-build-id
--enable-lto --enable-plugin --enable-install-libiberty
--with-linker-hash-style=gnu --enable-gnu-indirect-function --enable-multilib
--disable-werror --enable-checking=release --enable-default-pie
--enable-default-ssp --enable-cet=auto gdc_include_dir=/usr/include/dlang/gdc
Thread model: posix
gcc version 9.2.0 (GCC)
$ cat small.c
#include
typedef struct
{
int e;
} S;
inline __attribute__ ((always_inline)) void foo (S *y)
{
S c = *y;
}
void main (void)
{
S y;
memset (, 0, sizeof (y));
foo();
}
$ gcc -O0 --coverage -fsanitize=undefined small.c; ./a.out; gcov small.c; cat
small.c.gcov
File 'small.c'
Lines executed:100.00% of 5
Creating 'small.c.gcov'
-:0:Source:small.c
-:0:Graph:small.gcno
-:0:Data:small.gcda
-:0:Runs:1
-:1:#include
-:2:
-:3:typedef struct
-:4:{
-:5: int e;
-:6:} S;
-:7:
-:8:inline __attribute__ ((always_inline)) void foo (S *y)
-:9:{
2: 10: S c = *y;
1: 11:}
-: 12:
1: 13:void main (void)
-: 14:{
-: 15: S y;
1: 16: memset (, 0, sizeof (y));
-: 17: foo();
1: 18:}
We can find that Line #10 is wrongly marked as executed twice.
When compiling without "-fsanitize=undefined", the coverage will be correct.
[Bug gcov-profile/93757] New: [GCOV] incorrect coverage for inline function with "a?b:c" expression
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93757
Bug ID: 93757
Summary: [GCOV] incorrect coverage for inline function with
"a?b:c" expression
Product: gcc
Version: 9.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: gcov-profile
Assignee: unassigned at gcc dot gnu.org
Reporter: yangyibiao at hust dot edu.cn
CC: marxin at gcc dot gnu.org
Target Milestone: ---
$ gcov -v
gcov (GCC) 9.2.0
Copyright (C) 2019 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.
$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/9.2.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /build/gcc/src/gcc/configure --prefix=/usr --libdir=/usr/lib
--libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info
--with-bugurl=https://bugs.archlinux.org/
--enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++,d --enable-shared
--enable-threads=posix --with-system-zlib --with-isl --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-clocale=gnu --disable-libstdcxx-pch
--disable-libssp --enable-gnu-unique-object --enable-linker-build-id
--enable-lto --enable-plugin --enable-install-libiberty
--with-linker-hash-style=gnu --enable-gnu-indirect-function --enable-multilib
--disable-werror --enable-checking=release --enable-default-pie
--enable-default-ssp --enable-cet=auto gdc_include_dir=/usr/include/dlang/gdc
Thread model: posix
gcc version 9.2.0 (GCC)
$ cat small.c
static unsigned int oq[10];
static struct us { unsigned int irq; } sp[10];
static __inline__ __attribute__((always_inline)) int bar(int irq)
{
return ((irq == 2) ? 9 : irq);
}
int main(void)
{
int i = 0;
struct us *s = sp;
for (; i < 10; i++, s++)
s->irq = bar(oq[i]);
return 0;
}
$ gcc -O0 --coverage small.c; ./a.out; gcov small.c; cat small.c.gcov
File 'small.c'
Lines executed:100.00% of 7
Creating 'small.c.gcov'
-:0:Source:small.c
-:0:Graph:small.gcno
-:0:Data:small.gcda
-:0:Runs:1
-:1:static unsigned int oq[10];
-:2:
-:3:static struct us { unsigned int irq; } sp[10];
-:4:
-:5:static __inline__ __attribute__((always_inline)) int bar(int irq)
-:6:{
10*:7: return ((irq == 2) ? 9 : irq);
-:8:}
-:9:
1: 10:int main(void)
-: 11:{
1: 12: int i = 0;
1: 13: struct us *s = sp;
-: 14:
11: 15: for (; i < 10; i++, s++)
20: 16: s->irq = bar(oq[i]);
-: 17:
1: 18: return 0;
-: 19:}
###
We can find that Line #16 is wrongly marked as executed 20 times.
When inline attribute is removed for function 'bar', the coverage is correct.
[Bug gcov-profile/93754] New: [GCOV] incorrect coverage for user-defined "free" function
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93754
Bug ID: 93754
Summary: [GCOV] incorrect coverage for user-defined "free"
function
Product: gcc
Version: 9.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: gcov-profile
Assignee: unassigned at gcc dot gnu.org
Reporter: yangyibiao at hust dot edu.cn
CC: marxin at gcc dot gnu.org
Target Milestone: ---
$ gcov -v
gcov (GCC) 9.2.0
Copyright (C) 2019 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.
$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/9.2.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /build/gcc/src/gcc/configure --prefix=/usr --libdir=/usr/lib
--libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info
--with-bugurl=https://bugs.archlinux.org/
--enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++,d --enable-shared
--enable-threads=posix --with-system-zlib --with-isl --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-clocale=gnu --disable-libstdcxx-pch
--disable-libssp --enable-gnu-unique-object --enable-linker-build-id
--enable-lto --enable-plugin --enable-install-libiberty
--with-linker-hash-style=gnu --enable-gnu-indirect-function --enable-multilib
--disable-werror --enable-checking=release --enable-default-pie
--enable-default-ssp --enable-cet=auto gdc_include_dir=/usr/include/dlang/gdc
Thread model: posix
gcc version 9.2.0 (GCC)
code for small.c
$ cat small.c
void free(void *ptr)
{
return;
}
void *foo()
{
return 0;
}
void main()
{
void *p = foo();
free(p);
}
coverage generated by gcov
$ gcc -O0 --coverage small.c; ./a.out; gcov small.c; cat small.c.gcov
File 'small.c'
Lines executed:100.00% of 8
Creating 'small.c.gcov'
-:0:Source:small.c
-:0:Graph:small.gcno
-:0:Data:small.gcda
-:0:Runs:1
2:1:void free(void *ptr)
-:2:{
2:3: return;
-:4:}
-:5:
1:6:void *foo()
-:7:{
1:8: return 0;
-:9:}
-: 10:
1: 11:void main()
-: 12:{
1: 13: void *p = foo();
1: 14: free(p);
1: 15:}
#
Function "free" is called only once in Line #14.
However, we can find that Line #1 and #3 are wrongly marked as executed twice.
[Bug gcov-profile/93735] New: [GCOV] incorrect coverage for calling variable arguments function with incremental expression in its parameter list
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93735
Bug ID: 93735
Summary: [GCOV] incorrect coverage for calling variable
arguments function with incremental expression in its
parameter list
Product: gcc
Version: 9.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: gcov-profile
Assignee: unassigned at gcc dot gnu.org
Reporter: yangyibiao at hust dot edu.cn
CC: marxin at gcc dot gnu.org
Target Milestone: ---
$ gcov -v
gcov (GCC) 9.2.0
Copyright (C) 2019 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.
$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/9.2.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /build/gcc/src/gcc/configure --prefix=/usr --libdir=/usr/lib
--libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info
--with-bugurl=https://bugs.archlinux.org/
--enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++,d --enable-shared
--enable-threads=posix --with-system-zlib --with-isl --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-clocale=gnu --disable-libstdcxx-pch
--disable-libssp --enable-gnu-unique-object --enable-linker-build-id
--enable-lto --enable-plugin --enable-install-libiberty
--with-linker-hash-style=gnu --enable-gnu-indirect-function --enable-multilib
--disable-werror --enable-checking=release --enable-default-pie
--enable-default-ssp --enable-cet=auto gdc_include_dir=/usr/include/dlang/gdc
Thread model: posix
gcc version 9.2.0 (GCC)
$ cat small.c
int v = 8;
__attribute__((noinline)) int foo(int x, int y, ...) { return x; }
inline __attribute__((always_inline, gnu_inline)) int bar(int x, ...) { return
foo(x, 1, 2); }
int main(void)
{
bar(0, ++v, 1);
if (bar(0, ++v, 1) != 0)
return 1;
return 0;
}
$ gcc -O0 -g --coverage small.c; ./a.out; gcov small.c; cat small.c.gcov
File 'small.c'
Lines executed:71.43% of 7
Creating 'small.c.gcov'
-:0:Source:small.c
-:0:Graph:small.gcno
-:0:Data:small.gcda
-:0:Runs:1
-:1:int v = 8;
-:2:
2:3:__attribute__((noinline)) int foo(int x, int y, ...) { return x; }
-:4:
#:5:inline __attribute__((always_inline, gnu_inline)) int bar(int x,
...) { return foo(x, 1, 2); }
-:6:
1:7:int main(void)
-:8:{
1:9: bar(0, ++v, 1);
2: 10: if (bar(0, ++v, 1) != 0)
#: 11:return 1;
1: 12: return 0;
-: 13:}
### We can find that: Line #9 is marked as executed one time.
### However, Line #10 is wrongly marked as executed two times.
### when removing ++v in its parameter list, the coverage will be correct.
[Bug gcov-profile/93726] New: [GCOV] unexecuted functions lead to incorrect code coverage when it calls a function with a variable argument
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93726
Bug ID: 93726
Summary: [GCOV] unexecuted functions lead to incorrect code
coverage when it calls a function with a variable
argument
Product: gcc
Version: 9.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: gcov-profile
Assignee: unassigned at gcc dot gnu.org
Reporter: yangyibiao at hust dot edu.cn
CC: marxin at gcc dot gnu.org
Target Milestone: ---
$ gcov -v
gcov (GCC) 9.2.0
Copyright (C) 2019 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.
$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/9.2.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /build/gcc/src/gcc/configure --prefix=/usr --libdir=/usr/lib
--libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info
--with-bugurl=https://bugs.archlinux.org/
--enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++,d --enable-shared
--enable-threads=posix --with-system-zlib --with-isl --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-clocale=gnu --disable-libstdcxx-pch
--disable-libssp --enable-gnu-unique-object --enable-linker-build-id
--enable-lto --enable-plugin --enable-install-libiberty
--with-linker-hash-style=gnu --enable-gnu-indirect-function --enable-multilib
--disable-werror --enable-checking=release --enable-default-pie
--enable-default-ssp --enable-cet=auto gdc_include_dir=/usr/include/dlang/gdc
Thread model: posix
gcc version 9.2.0 (GCC)
$ cat small.c
#include
long x, y;
inline void __attribute__((always_inline)) f1(va_list ap)
{
x = va_arg(ap, double);
x += va_arg(ap, long);
x += va_arg(ap, double);
}
void foo(int i, ...)
{
va_list ap;
va_start(ap, i);
f1(ap);
va_end(ap);
}
void bar(int i, ...)
{
va_list ap;
va_start(ap, i);
switch (i)
{
case 0:
y = va_arg(ap, double);
break;
default:
break;
}
f1(ap);
va_end(ap);
}
void main(void) { foo(3, 16.0); }
$ gcc -O0 --coverage small.c; ./a.out; gcov small.c; cat small.c.gcov
File 'small.c'
Lines executed:42.11% of 19
Creating 'small.c.gcov'
-:0:Source:small.c
-:0:Graph:small.gcno
-:0:Data:small.gcda
-:0:Runs:1
-:1:#include
-:2:
-:3:long x, y;
-:4:
-:5:inline void __attribute__((always_inline)) f1(va_list ap)
-:6:{
#:7: x = va_arg(ap, double);
1*:8: x += va_arg(ap, long);
1*:9: x += va_arg(ap, double);
1*: 10:}
-: 11:
1: 12:void foo(int i, ...)
-: 13:{
-: 14: va_list ap;
1: 15: va_start(ap, i);
-: 16: f1(ap);
1: 17: va_end(ap);
1: 18:}
-: 19:
#: 20:void bar(int i, ...)
-: 21:{
-: 22: va_list ap;
#: 23: va_start(ap, i);
#: 24: switch (i)
-: 25: {
#: 26: case 0:
#: 27:y = va_arg(ap, double);
#: 28:break;
#: 29: default:
#: 30:break;
-: 31: }
-: 32: f1(ap);
#: 33: va_end(ap);
#: 34:}
-: 35:
1: 36:void main(void) { foo(3, 16.0); }
### We can find that: Line #7 is not executed.
### when the definition of function "bar" is removed from the source code, the
coverage will be different.
[Bug gcov-profile/93725] New: [GCOV] inline attribute leads to incorrect code coverage for calling variable argument function
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93725
Bug ID: 93725
Summary: [GCOV] inline attribute leads to incorrect code
coverage for calling variable argument function
Product: gcc
Version: 9.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: gcov-profile
Assignee: unassigned at gcc dot gnu.org
Reporter: yangyibiao at hust dot edu.cn
CC: marxin at gcc dot gnu.org
Target Milestone: ---
$ gcov -v
gcov (GCC) 9.2.0
Copyright (C) 2019 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.
$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/9.2.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /build/gcc/src/gcc/configure --prefix=/usr --libdir=/usr/lib
--libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info
--with-bugurl=https://bugs.archlinux.org/
--enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++,d --enable-shared
--enable-threads=posix --with-system-zlib --with-isl --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-clocale=gnu --disable-libstdcxx-pch
--disable-libssp --enable-gnu-unique-object --enable-linker-build-id
--enable-lto --enable-plugin --enable-install-libiberty
--with-linker-hash-style=gnu --enable-gnu-indirect-function --enable-multilib
--disable-werror --enable-checking=release --enable-default-pie
--enable-default-ssp --enable-cet=auto gdc_include_dir=/usr/include/dlang/gdc
Thread model: posix
gcc version 9.2.0 (GCC)
$ cat small.c
#include
long x;
inline void __attribute__((always_inline)) f1(va_list ap)
{
x = va_arg(ap, double);
x += va_arg(ap, long);
x += va_arg(ap, double);
}
void f(int i, ...)
{
va_list ap;
va_start(ap, i);
f1(ap);
va_end(ap);
}
int main(void) { f(3, 16.0); return 0; }
$ gcc -O0 --coverage small.c; ./a.out; gcov small.c; cat small.c.gcov
File 'small.c'
Lines executed:100.00% of 9
Creating 'small.c.gcov'
-:0:Source:small.c
-:0:Graph:small.gcno
-:0:Data:small.gcda
-:0:Runs:1
-:1:#include
-:2:
-:3:long x;
-:4:
-:5:inline void __attribute__((always_inline)) f1(va_list ap)
-:6:{
2:7: x = va_arg(ap, double);
1:8: x += va_arg(ap, long);
1:9: x += va_arg(ap, double);
1: 10:}
-: 11:
1: 12:void f(int i, ...)
-: 13:{
-: 14: va_list ap;
1: 15: va_start(ap, i);
-: 16: f1(ap);
1: 17: va_end(ap);
1: 18:}
-: 19:
1: 20:int main(void) { f(3, 16.0); return 0; }
### We can find that: Line #7 is calling an function with variable argument
which is wrongly marked as executed 2 times
### When the "__attribute__ ((always_inline))" is removed for function "f1",
the code coverage is correct
[Bug gcov-profile/93706] New: [GCOV] function with inline attribute leads to incorrect code coverage
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93706
Bug ID: 93706
Summary: [GCOV] function with inline attribute leads to
incorrect code coverage
Product: gcc
Version: 9.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: gcov-profile
Assignee: unassigned at gcc dot gnu.org
Reporter: yangyibiao at hust dot edu.cn
CC: marxin at gcc dot gnu.org
Target Milestone: ---
$ gcov -v
gcov (GCC) 9.2.0
Copyright (C) 2019 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.
$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/9.2.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /build/gcc/src/gcc/configure --prefix=/usr --libdir=/usr/lib
--libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info
--with-bugurl=https://bugs.archlinux.org/
--enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++,d --enable-shared
--enable-threads=posix --with-system-zlib --with-isl --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-clocale=gnu --disable-libstdcxx-pch
--disable-libssp --enable-gnu-unique-object --enable-linker-build-id
--enable-lto --enable-plugin --enable-install-libiberty
--with-linker-hash-style=gnu --enable-gnu-indirect-function --enable-multilib
--disable-werror --enable-checking=release --enable-default-pie
--enable-default-ssp --enable-cet=auto gdc_include_dir=/usr/include/dlang/gdc
Thread model: posix
gcc version 9.2.0 (GCC)
$ cat small.c
static inline __attribute__ ((always_inline)) int foo (unsigned short v)
{
return (v << 8) | (v >> 8);
}
int main ()
{
unsigned short b = 0;
return foo(b);
}
$ gcc -O0 --coverage small.c; ./a.out; gcov small.c; cat small.c.gcov
File 'small.c'
Lines executed:100.00% of 4
Creating 'small.c.gcov'
-:0:Source:small.c
-:0:Graph:small.gcno
-:0:Data:small.gcda
-:0:Runs:1
-:1:static inline __attribute__ ((always_inline)) int foo (unsigned short
v)
-:2:{
1:3: return (v << 8) | (v >> 8);
-:4:}
-:5:
1:6:int main ()
-:7:{
1:8: unsigned short b = 0;
2:9: return foo(b);
-: 10:}
### We can find that: Line #9 is wrongly marked as executed 2 times
### When the "__attribute__ ((always_inline))" is removed for the definition of
function "foo", the code coverage is correct
[Bug gcov-profile/93626] [GCOV] incorrect coverage when compiled with option '-fsanitize=undefined' for typedef struct
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93626 --- Comment #2 from Yibiao Yang --- (In reply to Martin Liška from comment #1) > I would not recommend combining --coverage and a sanitizer. Thanks for the suggestion. Yes, this is an abnormal combination.
[Bug gcov-profile/93693] New: [GCOV] incorrect coverage when compiled with option '-fsanitize=undefined' for function defined inside other function
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93693
Bug ID: 93693
Summary: [GCOV] incorrect coverage when compiled with option
'-fsanitize=undefined' for function defined inside
other function
Product: gcc
Version: 9.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: gcov-profile
Assignee: unassigned at gcc dot gnu.org
Reporter: yangyibiao at hust dot edu.cn
CC: marxin at gcc dot gnu.org
Target Milestone: ---
$ gdb -v
GNU gdb (GDB) 9.0.50.20191210-git
Copyright (C) 2019 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.
$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/9.2.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /build/gcc/src/gcc/configure --prefix=/usr --libdir=/usr/lib
--libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info
--with-bugurl=https://bugs.archlinux.org/
--enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++,d --enable-shared
--enable-threads=posix --with-system-zlib --with-isl --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-clocale=gnu --disable-libstdcxx-pch
--disable-libssp --enable-gnu-unique-object --enable-linker-build-id
--enable-lto --enable-plugin --enable-install-libiberty
--with-linker-hash-style=gnu --enable-gnu-indirect-function --enable-multilib
--disable-werror --enable-checking=release --enable-default-pie
--enable-default-ssp --enable-cet=auto gdc_include_dir=/usr/include/dlang/gdc
Thread model: posix
gcc version 9.2.0 (GCC)
$ cat small.c
int N1 = 0;
int foo(char a[2][++N1])
{
N1 += 4; return sizeof(a[0]);
}
int bar(int N2)
{
int foo1(char a[2][++N2])
{
N2 += 4; return sizeof(a[0]);
}
foo1(0);
}
int main()
{
foo(0); bar(0);
}
$ gcc -O0 --coverage -fsanitize=undefined small.c; ./a.out; gcov small.c; cat
small.c.gcov
File 'small.c'
Lines executed:100.00% of 9
Creating 'small.c.gcov'
-:0:Source:small.c
-:0:Graph:small.gcno
-:0:Data:small.gcda
-:0:Runs:1
-:1:int N1 = 0;
-:2:
1:3:int foo(char a[2][++N1])
-:4:{
1:5: N1 += 4; return sizeof(a[0]);
-:6:}
-:7:
1:8:int bar(int N2)
-:9:{
2: 10: int foo1(char a[2][++N2])
-: 11: {
1: 12:N2 += 4; return sizeof(a[0]);
-: 13: }
-: 14:
1: 15: foo1(0);
1: 16:}
-: 17:
1: 18:int main()
-: 19:{
1: 20: foo(0); bar(0);
-: 21:}
### We can find that: Line #3 is executed 1 times. foo is executed one time.
### When function foo is defined inside other function, the coverage is
incorrect with compilation option "-fsanitize=undefined". (Line #10 is executed
2 times.)
### While removing compilation option "-fsanitize=undefined", the coverage will
be correct.
[Bug gcov-profile/93680] New: [GCOV] "do-while" structure in case statement leads to incorrect code coverage
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93680
Bug ID: 93680
Summary: [GCOV] "do-while" structure in case statement leads to
incorrect code coverage
Product: gcc
Version: 9.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: gcov-profile
Assignee: unassigned at gcc dot gnu.org
Reporter: yangyibiao at hust dot edu.cn
CC: marxin at gcc dot gnu.org
Target Milestone: ---
$ gcov -v
gcov (GCC) 9.2.0
Copyright (C) 2019 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.
$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/9.2.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /build/gcc/src/gcc/configure --prefix=/usr --libdir=/usr/lib
--libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info
--with-bugurl=https://bugs.archlinux.org/
--enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++,d --enable-shared
--enable-threads=posix --with-system-zlib --with-isl --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-clocale=gnu --disable-libstdcxx-pch
--disable-libssp --enable-gnu-unique-object --enable-linker-build-id
--enable-lto --enable-plugin --enable-install-libiberty
--with-linker-hash-style=gnu --enable-gnu-indirect-function --enable-multilib
--disable-werror --enable-checking=release --enable-default-pie
--enable-default-ssp --enable-cet=auto gdc_include_dir=/usr/include/dlang/gdc
Thread model: posix
gcc version 9.2.0 (GCC)
$ cat small.c
int f(int s, int n)
{
int p = 0;
switch (s)
{
case 0:
do { p++; } while (--n);
return p;
case 1:
do { p++; } while (--n);
return p;
}
return 0;
}
void main() { f(0, 5); f(1, 5); }
$ gcc -O0 --coverage small.c; ./a.out; gcov small.c; cat small.c.gcov
File 'small.c'
Lines executed:90.91% of 11
Creating 'small.c.gcov'
-:0:Source:small.c
-:0:Graph:small.gcno
-:0:Data:small.gcda
-:0:Runs:1
2:1:int f(int s, int n)
-:2:{
2:3: int p = 0;
-:4:
2:5: switch (s)
-:6: {
5:7:case 0:
5:8:do { p++; } while (--n);
1:9:return p;
-: 10:
4: 11:case 1:
5: 12:do { p++; } while (--n);
1: 13:return p;
-: 14: }
-: 15:
#: 16: return 0;
-: 17:}
-: 18:
1: 19:void main() { f(0, 5); f(1, 5); }
###
### We can find that: Line #7 is executed 5 times, Line #11 is executed 4
times.
### In my opinion, both of these two statements (Line #7 and Line #11) should
only executed once.
### OR AT LEAST, they should with same coverage statistics: both executed are 4
or 5 times.
### When we replace the "do-while" statement to "while" structure, the coverage
is correct
###
[Bug gcov-profile/93626] New: [GCOV] incorrect coverage when compiled with option '-fsanitize=undefined' for typedef struct
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93626
Bug ID: 93626
Summary: [GCOV] incorrect coverage when compiled with option
'-fsanitize=undefined' for typedef struct
Product: gcc
Version: 9.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: gcov-profile
Assignee: unassigned at gcc dot gnu.org
Reporter: yangyibiao at hust dot edu.cn
CC: marxin at gcc dot gnu.org
Target Milestone: ---
$ gcov -v
gcov (GCC) 9.2.0
Copyright (C) 2019 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.
$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/9.2.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /build/gcc/src/gcc/configure --prefix=/usr --libdir=/usr/lib
--libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info
--with-bugurl=https://bugs.archlinux.org/
--enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++,d --enable-shared
--enable-threads=posix --with-system-zlib --with-isl --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-clocale=gnu --disable-libstdcxx-pch
--disable-libssp --enable-gnu-unique-object --enable-linker-build-id
--enable-lto --enable-plugin --enable-install-libiberty
--with-linker-hash-style=gnu --enable-gnu-indirect-function --enable-multilib
--disable-werror --enable-checking=release --enable-default-pie
--enable-default-ssp --enable-cet=auto gdc_include_dir=/usr/include/dlang/gdc
Thread model: posix
gcc version 9.2.0 (GCC)
$ cat small.c
void main()
{
int t = 2;
typedef struct
{
char v[t];
} B;
B b;
for (int i = 0; i < 2; i++)
b.v[i] = 0;
}
$ gcc --coverage -O0 -fsanitize=undefined small.c; ./a.out; gcov small.c; cat
small.c.gcov
File 'small.c'
Lines executed:100.00% of 9
Creating 'small.c.gcov'
-:0:Source:small.c
-:0:Graph:small.gcno
-:0:Data:small.gcda
-:0:Runs:1
1:1:void main()
1:2:{
1:3: int t = 2;
1:4: typedef struct
-:5: {
3:6:char v[t];
-:7: } B;
1:8: B b;
3:9: for (int i = 0; i < 2; i++)
2: 10:b.v[i] = 0;
1: 11:}
Line #6 is wrongly marked as executed three times. When compiled without option
'-fsanitize=undefined', the coverage report is correct.
[Bug debug/93000] [gdb] gdb failed to break on an executed address
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93000 --- Comment #1 from Yibiao Yang --- the compilation command is as follows: $ gcc -w -g -O0 small.c -o small.obj
[Bug debug/93000] New: [gdb] gdb failed to break on an executed address
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93000
Bug ID: 93000
Summary: [gdb] gdb failed to break on an executed address
Product: gcc
Version: 8.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: debug
Assignee: unassigned at gcc dot gnu.org
Reporter: yangyibiao at hust dot edu.cn
Target Milestone: ---
$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/8/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu
8.3.0-6ubuntu1~18.04.1' --with-bugurl=file:///usr/share/doc/gcc-8/README.Bugs
--enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++ --prefix=/usr
--with-gcc-major-version-only --program-suffix=-8
--program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id
--libexecdir=/usr/lib --without-included-gettext --enable-threads=posix
--libdir=/usr/lib --enable-nls --enable-bootstrap --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes
--with-default-libstdcxx-abi=new --enable-gnu-unique-object
--disable-vtable-verify --enable-libmpx --enable-plugin --enable-default-pie
--with-system-zlib --with-target-system-zlib --enable-objc-gc=auto
--enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64
--with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic
--enable-offload-targets=nvptx-none --without-cuda-driver
--enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu
--target=x86_64-linux-gnu
Thread model: posix
gcc version 8.3.0 (Ubuntu 8.3.0-6ubuntu1~18.04.1)
test program
$ cat small.c
/* { dg-do run } */
/* { dg-options "-fsanitize=undefined -fsanitize-undefined-trap-on-error" } */
int __attribute__((noinline,noclone))
h(int a)
{
return 2 * (a * (__INT_MAX__/2 + 1));
}
int __attribute__((noinline,noclone))
i(int a)
{
return (2 * a) * (__INT_MAX__/2 + 1);
}
int __attribute__((noinline,noclone))
j(int a, int b)
{
return (b * a) * (__INT_MAX__/2 + 1);
}
int __attribute__((noinline,noclone))
k(int a, int b)
{
return (2 * a) * b;
}
int main()
{
volatile int tem = h(-1);
tem = i(-1);
tem = j(-1, 2);
tem = k(-1, __INT_MAX__/2 + 1);
return 0;
}
gdb commands
$ cat cmds1
break *i+0x0
run
kill
q
$ cat cmds2
break *j+0x0
run
kill
q
execute commands
$ gdb -batch -x cmds1 ./small.obj
Breakpoint 1 at 0x5e6: file small.c, line 11.
[7]+ Stopped gdb -batch -x cmds ./small.obj
$ gdb -batch -x cmds2 ./small.obj
Breakpoint 1 at 0x5f7: file small.c, line 16.
Breakpoint 1, j (a=-1, b=0) at small.c:16
16 {
Kill the program being debugged? (y or n) [answered Y; input not from terminal]
[Inferior 1 (process 15108) killed]
problem
gdb failed to break at address "*i+0x0" while it breaks at address "*j+0x0"
function "i" and "j" are both executed functions called by "main" function in
the test program.
