https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97910
Bug ID: 97910
Summary: [GCOV]"&&" lead to incorrect code coverage when
multiple expressions of a single statement fall in
different lines
Product: gcc
Version: 10.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: gcov-profile
Assignee: unassigned at gcc dot gnu.org
Reporter: yangyibiao at outlook dot com
CC: marxin at gcc dot gnu.org
Target Milestone: ---
$ cat test.c
struct hx {
int a, b, c;
} __attribute__ ((aligned));
static struct hx x = {0xc11f, 0xc22f, ~1};
static struct hx y = {0xfd10, 0xfe20, ~2};
int f()
{
return ((x.a & 0x3ff0) == (y.a & 0x03ff) &&
(x.b & 0x3ff0) == (y.b & 0x03ff));
}
int main() { f(); }
$ gcc -O0 --coverage test.c; ./a.out; gcov test.c; cat test.c.gcov
File 'test.c'
Lines executed:100.00% of 4
Creating 'test.c.gcov'
-: 0:Source:test.c
-: 0:Graph:test.gcno
-: 0:Data:test.gcda
-: 0:Runs:1
-: 1:struct hx {
-: 2: int a, b, c;
-: 3:} __attribute__ ((aligned));
-: 4:
-: 5:static struct hx x = {0xc11f, 0xc22f, ~1};
-: 6:static struct hx y = {0xfd10, 0xfe20, ~2};
-: 7:
1: 8:int f()
-: 9:{
2*: 10: return ((x.a & 0x3ff0) == (y.a & 0x03ff) &&
1: 11: (x.b & 0x3ff0) == (y.b & 0x03ff));
-: 12:}
-: 13:
1: 14:int main() { f(); }
################################
We can found that Line #10 is wrongly marked as executed twice.
When debug this program in debugger, Line 10 is only hit once.
Note that: When Line 10 and Line 11 in the same line, the result will be
correct.
$ gcc --version; gcov --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.
gcov (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.
