`Werror` makes compilation fail on MinGW64

[FrostKiwi]

Initially reported as an issue libdatachannel in paullouisageneau/libdatachannel#1528

libsrtp 2.8.0 needs target_compile_options(srtp2 PRIVATE -Wno-error=format) in order to not fail building with toolchain CLANG + MinGW64 + UCRT as installed by https://scoop.sh/#/apps?q=mingw-mstorsjo-llvm-ucrt&id=4e35bf42629409cf7722249d1b574c84d2d19675

[16/402] Building C object _deps/libdatachannel-build/deps/libsrtp/CMakeFiles/srtp2.dir/srtp/srtp.c.obj
FAILED: [code=1] _deps/libdatachannel-build/deps/libsrtp/CMakeFiles/srtp2.dir/srtp/srtp.c.obj
C:\Users\artsimow\scoop\apps\mingw-mstorsjo-llvm-ucrt\current\bin\clang.exe -DHAVE_CONFIG_H -DWIN32_LEAN_AND_MEAN -D_CRT_SECURE_NO_WARNINGS -IC:/Users/artsimow/myMachineConnector/buildRel/_deps/libdatachannel-build/deps/libsrtp -IC:/Users/artsimow/myMachineConnector/buildRel/_deps/libdatachannel-src/deps/libsrtp/crypto/include -IC:/Users/artsimow/myMachineConnector/buildRel/_deps/libdatachannel-src/deps/libsrtp/include -IC:/Users/artsimow/myMachineConnector/buildRel/_deps/mbedtls-src/include -O3 -DNDEBUG -std=gnu99 -fansi-escape-codes -fcolor-diagnostics -Wall -Wextra -Wshadow -Wpedantic -Wunused -Wnull-dereference -Wdouble-promotion -Wcast-qual -Werror -MD -MT _deps/libdatachannel-build/deps/libsrtp/CMakeFiles/srtp2.dir/srtp/srtp.c.obj -MF _deps\libdatachannel-build\deps\libsrtp\CMakeFiles\srtp2.dir\srtp\srtp.c.obj.d -o _deps/libdatachannel-build/deps/libsrtp/CMakeFiles/srtp2.dir/srtp/srtp.c.obj -c C:/Users/artsimow/myMachineConnector/buildRel/_deps/libdatachannel-src/deps/libsrtp/srtp/srtp.c
C:/Users/artsimow/myMachineConnector/buildRel/_deps/libdatachannel-src/deps/libsrtp/srtp/srtp.c:667:60: error: format specifies type 'unsigned int' but the argument has type 'u_long' (aka 'unsigned long') [-Werror,-Wformat]
  667 |     debug_print(mod_srtp, "cloning stream (SSRC: 0x%08x)", ntohl(ssrc));
      |                                                    ~~~~    ^~~~~~~~~~~
      |                                                    %08lx
C:/Users/artsimow/myMachineConnector/buildRel/_deps/libdatachannel-src/deps/libsrtp/crypto/include/err.h:139:75: note: expanded from macro 'debug_print'
  139 |     srtp_err_report(srtp_err_level_debug, ("%s: " format "\n"), mod.name, arg)
      |                                                   ~~~~~~                  ^~~
C:/Users/artsimow/myMachineConnector/buildRel/_deps/libdatachannel-src/deps/libsrtp/srtp/srtp.c:2785:25: error: format specifies type 'unsigned int' but the argument has type 'u_long' (aka 'unsigned long') [-Werror,-Wformat]
 2784 |             debug_print(mod_srtp, "using provisional stream (SSRC: 0x%08x)",
      |                                                                      ~~~~
      |                                                                      %08lx
 2785 |                         ntohl(hdr->ssrc));
      |                         ^~~~~~~~~~~~~~~~
C:/Users/artsimow/myMachineConnector/buildRel/_deps/libdatachannel-src/deps/libsrtp/crypto/include/err.h:139:75: note: expanded from macro 'debug_print'
  139 |     srtp_err_report(srtp_err_level_debug, ("%s: " format "\n"), mod.name, arg)
      |                                                   ~~~~~~                  ^~~
C:/Users/artsimow/myMachineConnector/buildRel/_deps/libdatachannel-src/deps/libsrtp/srtp/srtp.c:4550:25: error: format specifies type 'unsigned int' but the argument has type 'u_long' (aka 'unsigned long') [-Werror,-Wformat]
 4549 |                         "srtcp using provisional stream (SSRC: 0x%08x)",
      |                                                                  ~~~~
      |                                                                  %08lx
 4550 |                         ntohl(hdr->ssrc));
      |                         ^~~~~~~~~~~~~~~~
C:/Users/artsimow/myMachineConnector/buildRel/_deps/libdatachannel-src/deps/libsrtp/crypto/include/err.h:139:75: note: expanded from macro 'debug_print'
  139 |     srtp_err_report(srtp_err_level_debug, ("%s: " format "\n"), mod.name, arg)
      |

[pabuhler]

Hi, I think this should have been fix in #806 . Not currently in a release but committed.