Compile error at Ubuntu 20.04

[tshrinivasan]

Getting below error on compiling.

lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 20.04.3 LTS
Release: 20.04
Codename: focal

shrini@shrini-laptop:~/dev/dev/autocrop$ make CXXFLAGS=-DWRITE_DEBUG_IMAGES
g++ -DWRITE_DEBUG_IMAGES -ansi -Werror -D_BSD_SOURCE -DANSI -fPIC -O3 -DL_LITTLE_ENDIAN -Ileptonica-1.68/src -c autoCropScribe.c -o autoCropScribe.o
In file included from /usr/include/x86_64-linux-gnu/bits/libc-header-start.h:33,
from /usr/include/stdio.h:27,
from autoCropScribe.c:13:
/usr/include/features.h:187:3: error: #warning "_BSD_SOURCE and _SVID_SOURCE are deprecated, use _DEFAULT_SOURCE" [-Werror=cpp]
187 | # warning "_BSD_SOURCE and _SVID_SOURCE are deprecated, use _DEFAULT_SOURCE"
| ^~~~~~~
autoCropScribe.c: In function ‘double CalculateFullPageSADrow(PIX*, l_uint32, l_uint32, l_uint32, l_uint32)’:
autoCropScribe.c:243:28: error: call of overloaded ‘abs(l_uint32)’ is ambiguous
243 | acc += (abs(a-b));
| ^
In file included from /usr/include/c++/9/cstdlib:75,
from /usr/include/c++/9/stdlib.h:36,
from autoCropScribe.c:14:
/usr/include/stdlib.h:840:12: note: candidate: ‘int abs(int)’
840 | extern int abs (int __x) __THROW attribute ((const)) __wur;
| ^~~
In file included from /usr/include/c++/9/cstdlib:77,
from /usr/include/c++/9/stdlib.h:36,
from autoCropScribe.c:14:
/usr/include/c++/9/bits/std_abs.h:79:3: note: candidate: ‘long double std::abs(long double)’
79 | abs(long double __x)
| ^~~
/usr/include/c++/9/bits/std_abs.h:75:3: note: candidate: ‘float std::abs(float)’
75 | abs(float __x)
| ^~~
/usr/include/c++/9/bits/std_abs.h:71:3: note: candidate: ‘double std::abs(double)’
71 | abs(double __x)
| ^~~
/usr/include/c++/9/bits/std_abs.h:61:3: note: candidate: ‘long long int std::abs(long long int)’
61 | abs(long long __x) { return __builtin_llabs (__x); }
| ^~~
/usr/include/c++/9/bits/std_abs.h:56:3: note: candidate: ‘long int std::abs(long int)’
56 | abs(long __i) { return __builtin_labs(__i); }
| ^~~
autoCropScribe.c: In function ‘int AdjustCropBoxByVariance(PIX*, l_int32*, l_int32*, l_int32*, l_int32*, l_int32, double)’:
autoCropScribe.c:1229:1: error: no return statement in function returning non-void [-Werror=return-type]
1229 | }
| ^
autoCropScribe.c: In function ‘int AdjustCropBox(PIX*, l_int32*, l_int32*, l_int32*, l_int32*, l_int32)’:
autoCropScribe.c:1129:12: error: control reaches end of non-void function [-Werror=return-type]
1129 | *cropB = newB;
| ~~~~~~~^~~~~~
cc1plus: all warnings being treated as errors
make: *** [Makefile:36: autoCropScribe.o] Error 1