read_f{4,8}{be,le}(): fix violations of strict aliasing rules

[generalmimon]

Solves kismetwireless/kismet#518

[GreyCat]

Makes sense to add this one. Thanks for thorough research and implementation!

[ZeroChaos-]

Kismet just pulled this update and it's still not working. Any chance you could take a look?

x86_64-pc-linux-gnu-g++ -std=gnu++20 -mtune=core2 -pipe -O3 -flto -frecord-gcc-switches -Wstringop-overread -Wformat -Wformat-security -D_FORTIFY_SOURCE=3 -D_GLIBCXX_ASSERTIONS -ftrivial-auto-var-init=zero -Wl,-z,relro,-z,now -fstack-protector-strong -fstack-clash-protection -fcf-protection=full  -Werror=odr -Werror=lto-type-mismatch -Werror=stringop-overread -Werror=format-security -march=alderlake -mabm -mno-cldemote -mno-kl -mno-sgx -mno-widekl -mshstk --param=l1-cache-line-size=64 --param=l1-cache-size=32 --param=l2-cache-size=36864 -fPIE -pie -ggdb3  -Wall -Wno-deprecated-declarations -Wno-format-truncation -Wno-unused-local-typedefs -Wno-unused-function -Wno-infinite-recursion -g -I. -fPIE -mtune=core2 -pipe  -flto -frecord-gcc-switches -Wstringop-overread -Wformat -Wformat-security -D_FORTIFY_SOURCE=3 -D_GLIBCXX_ASSERTIONS -ftrivial-auto-var-init=zero -Wl,-z,relro,-z,now -fstack-protector-strong -fstack-clash-protection -fcf-protection=full -Werror=odr -Werror=lto-type-mismatch -Werror=stringop-overread -Werror=format-security -march=alderlake -mabm -mno-cldemote -mno-kl -mno-sgx -mno-widekl -mshstk --param=l1-cache-line-size=64 --param=l1-cache-size=32 --param=l2-cache-size=36864 -fPIE -pie -ggdb3 -Werror=strict-aliasing  -DKS_STR_ENCODING_NONE -I/usr/include/dbus-1.0 -I/usr/lib64/dbus-1.0/include -I/usr/include/elogind   -c kaitaistream.cc -o kaitaistream.cc.o
kaitaistream.cc: In member function ‘float kaitai::kstream::read_f4be()’:
kaitaistream.cc:266:38: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing]
  266 |     return reinterpret_cast<float &>(t);
      |                                      ^
kaitaistream.cc: In member function ‘double kaitai::kstream::read_f8be()’:
kaitaistream.cc:275:39: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing]
  275 |     return reinterpret_cast<double &>(t);
      |                                       ^
kaitaistream.cc: In member function ‘float kaitai::kstream::read_f4le()’:
kaitaistream.cc:288:38: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing]
  288 |     return reinterpret_cast<float &>(t);
      |                                      ^
kaitaistream.cc: In member function ‘double kaitai::kstream::read_f8le()’:
kaitaistream.cc:297:39: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing]
  297 |     return reinterpret_cast<double &>(t);
      |

[ZeroChaos-]

Nevermind, apologies for the noise. There was an issue on import which is fixed now. Thanks for the fix!