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.
################################################################################
