[Bug gcov-profile/85338] New: [GCOV] Type conversion leads to incorrect coverage in printf

["yangyibiao at nju dot edu.cn" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85338

            Bug ID: 85338
           Summary: [GCOV] Type conversion leads to incorrect coverage in
                    printf
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: gcov-profile
          Assignee: unassigned at gcc dot gnu.org
          Reporter: yangyibiao at nju dot edu.cn
                CC: marxin at gcc dot gnu.org
  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
8-20170923-1ubuntu2' --with-bugurl=file:///usr/share/doc/gcc-8/README.Bugs
--enable-languages=c,c++,go,brig,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 --with-sysroot=/ --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 --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
--enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu
--target=x86_64-linux-gnu
Thread model: posix
gcc version 8.0.0 20170923 (experimental) [trunk revision 253118] (Ubuntu
8-20170923-1ubuntu2)

$ cat small.c
#include <stdio.h>

void Test(long long Val, int Amt)
{
  printf("  lshr: 0x%llx \t\t shl: 0x%llx\n", Val >> Amt, Val << Amt);
  printf("  lshr: 0x%llx\t\tshl: 0x%llx\n",
    Val >> Amt, Val << Amt);
  printf("  lshr: 0x%llx \t\t shl: 0x%llx\n",
    (unsigned long long)Val >> Amt, Val << Amt);
}

int main()
{
  Test(10, 4);

  return 0;
}

$ gcc --coverage small.c; ./a.out; gcov-8 small.c; cat small.c.gcov
  lshr: 0x0              shl: 0xa0
  lshr: 0x0             shl: 0xa0
  lshr: 0x0              shl: 0xa0
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
        -:    0:Programs:1
        -:    1:#include <stdio.h>
        -:    2:
        1:    3:void Test(long long Val, int Amt)
        -:    4:{
        1:    5:  printf("  lshr: 0x%llx \t\t shl: 0x%llx\n", Val >> Amt, Val
<< Amt);
        1:    6:  printf("  lshr: 0x%llx\t\tshl: 0x%llx\n",
        -:    7:    Val >> Amt, Val << Amt);
        2:    8:  printf("  lshr: 0x%llx \t\t shl: 0x%llx\n",
        1:    9:    (unsigned long long)Val >> Amt, Val << Amt);
        1:   10:}
        -:   11:
        1:   12:int main()
        -:   13:{
        1:   14:  Test(10, 4);
        -:   15:
        1:   16:  return 0;
        -:   17:}


Line #8 is wrongly marked as executed twice. 
As can be seen from Line #5 and Line #6, I think this incorrect coverage is
caused by type conversions.