cc1plus error -fsanitize-coverage=4

[ghost]

Describe the bug

-fsanitize-coverage=4 throws an error using

./configure --with-curl=/usr --with-lmdb=/usr --enable-afl-fuzz --enable-parser-generation --enable-mutex-on-pm

after running command export CXX=afl-clang-fast++ and finally make.

Logs and dumps

Specfically:
cc1plus: error: unrecognized argument to ‘-fsanitize-coverage=’ option: ‘4’

Generally:

libtool: compile:  g++ -DHAVE_CONFIG_H -I. -I../../src -std=c++11 -I../.. -I../../headers -I../../others -std=c++11 -I.. -g -fPIC -O3 -DWITH_GEOIP -I/usr/include/ -fsanitize=address -fsanitize-coverage=4 -DWITH_YAJL -I/usr/include/yajl -DWITH_LMDB -I/usr/include -DPCRE_HAVE_JIT -I/usr/include/libxml2 -DWITH_LIBXML2 -g -O2 -MT libmodsec_parser_la-seclang-parser.lo -MD -MP -MF .deps/libmodsec_parser_la-seclang-parser.Tpo -c seclang-parser.cc  -fPIC -DPIC -o .libs/libmodsec_parser_la-seclang-parser.o

cc1plus: error: unrecognized argument to ‘-fsanitize-coverage=’ option: ‘4’
make[4]: *** [Makefile:588: libmodsec_parser_la-seclang-parser.lo] Error 1
make[4]: Leaving directory '/opt/ModSecurity/src/parser'
make[3]: *** [Makefile:499: all] Error 2
make[3]: Leaving directory '/opt/ModSecurity/src/parser'
make[2]: *** [Makefile:3464: all-recursive] Error 1
make[2]: Leaving directory '/opt/ModSecurity/src'
make[1]: *** [Makefile:1219: all] Error 2
make[1]: Leaving directory '/opt/ModSecurity/src'
make: *** [Makefile:1030: all-recursive] Error 1

To Reproduce

Tell me how to reproduce it

Expected behavior

I don't know what I should be expecting.

Server (please complete the following information):

• ModSecurity version: 3.0.4
• OS (and distro): Ubuntu 20.04

Rule Set (please complete the following information):
N/A

Additional context

I have found this resource explaining what -fsanitize-coverage=4 means from
clang cpp flags:

Original semantics of -fsanitize-coverage flag is preserved:
  * -fsanitize-coverage=0 disables the coverage
  * -fsanitize-coverage=1 is a synonym for -fsanitize-coverage=func
  * -fsanitize-coverage=2 is a synonym for -fsanitize-coverage=bb
  * -fsanitize-coverage=3 is a synonym for -fsanitize-coverage=edge
  * -fsanitize-coverage=4 is a synonym for -fsanitize-coverage=edge,indirect-calls

I am not sure what -fsanitize-coverage=edge,indirect-calls is used for.

Also, here is my Configuration Output:

 Mandatory dependencies
   + libInjection                                  ....v3.9.2-30-gbf234eb
   + SecLang tests                                 ....d03f4c1

 Optional dependencies
   + GeoIP/MaxMind                                 ....found
      * (MaxMind) v1.4.2
         -lmaxminddb, -DWITH_MAXMIND -I/usr/include/x86_64-linux-gnu
      * (GeoIP) v1.6.12
         -lGeoIP, -I/usr/include/
   + LibCURL                                       ....found v7.68.0
      -lcurl,  -DWITH_CURL_SSLVERSION_TLSv1_2 -DWITH_CURL
   + YAJL                                          ....found v2.1.0
      -lyajl, -DWITH_YAJL -I/usr/include/yajl
   + LMDB                                          ....found
      -llmdb, -DWITH_LMDB -I/usr/include
   + LibXML2                                       ....found v2.9.10
      -lxml2, -I/usr/include/libxml2 -DWITH_LIBXML2
   + SSDEEP                                        ....found
      -lfuzzy -L/usr/lib/x86_64-linux-gnu/, -DWITH_SSDEEP -I/usr/include
   + LUA                                           ....found v503
      -llua5.3 -L/usr/lib/x86_64-linux-gnu/, -DWITH_LUA -DWITH_LUA_5_3 -I/usr/include/lua5.3

 Other Options
   + Test Utilities                                ....enabled
   + SecDebugLog                                   ....enabled
   + afl fuzzer                                    ....enabled
    (-fsanitize=address -fsanitize-coverage=4 )
   + library examples                              ....enabled
   + Building parser                               ....enabled
   + Treating pm operations as critical section    ....enabled

WARNING: afl fuzzer was enabled. Make sure you are using the
 'afl-clang-fast' as the compiler, otherwise the compilation
  will fail.

 You can set the compiler using:

  $ export CXX=afl-clang-fast++
  $ export CC=afl-clang-fast

[zimmerle]

Those flags are dependent on your infrastructure/clang are you really interested in run afl on ModSec?

[ghost]

To be honest, I don't know what I'm getting myself into.

I don't know why I would need afl (or any other options for that matter).

It sounds like afl isn't essential, so the answer to your question is: no, I'm not that interested and thus, will run ModSec without it.

However, that leaves me wondering what the use of afl on ModSec is.

[zimmerle]

afl is something to test ModSecurity is not something to run ModSecurity with. For further info on AFL - https://github.com/google/AFL