How do I define a DllMain function in rust cdylib? - c++

Question

Is there a specific way to define a DllMain function in Rust? I have tried this:
use winapi::shared::ntdef::*;
use winapi::um::winnt::DLL_PROCESS_ATTACH;
use winapi::shared::minwindef::*;
use std::*;
#[no_mangle]
extern "stdcall" fn DllMain(hInstDll: HINSTANCE, fdwReason: DWORD, lpvReserved: LPVOID){
if fdwReason == DLL_PROCESS_ATTACH {
}
}
But windows doesn't seem to call the function when the dll is attached to a process?
Edit: Renaming function to _DllMainCRTStartup is recognized as an entry point by the compiler, but rust is unable to find the c-runtime libraries
`error: linking with 'link.exe' failed: exit code: 1120
|
= note: "C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.26.28801\bin\HostX64\x64\link.exe" "/NOLOGO" "/NXCOMPAT" "/LIBPATH:C:\Users\Admin\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\x86_64-pc-windows-msvc\lib" "C:\Users\Admin\source\repos\dandra_but_rust\target\debug\deps\dandra_but_rust.2zwdumngih9wy4mr.rcgu.o" "/OUT:C:\Users\Admin\source\repos\dandra_but_rust\target\debug\deps\dandra_but_rust.dll" "/DEF:C:\Users\Admin\AppData\Local\Temp\rustc7Q6l64\lib.def" "C:\Users\Admin\source\repos\dandra_but_rust\target\debug\deps\dandra_but_rust.2ir3c20pqmwv4eun.rcgu.o" "/OPT:REF,NOICF" "/DLL" "/IMPLIB:C:\Users\Admin\source\repos\dandra_but_rust\target\debug\deps\dandra_but_rust.dll.lib" "/DEBUG" "/NATVIS:C:\Users\Admin\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\etc\intrinsic.natvis" "/NATVIS:C:\Users\Admin\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\etc\liballoc.natvis" "/NATVIS:C:\Users\Admin\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\etc\libcore.natvis" "/NATVIS:C:\Users\Admin\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\etc\libstd.natvis" "/LIBPATH:C:\Users\Admin\source\repos\dandra_but_rust\target\debug\deps" "/LIBPATH:C:\Users\Admin\source\repos\dandra_but_rust\target\debug\build\minhook-sys-148df4753bb64a28\out" "/LIBPATH:C:\Users\Admin\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\x86_64-pc-windows-msvc\lib" "C:\Users\Admin\source\repos\dandra_but_rust\target\debug\deps\libwinapi-1d830746c941a966.rlib" "C:\Users\Admin\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\x86_64-pc-windows-msvc\lib\libstd-e5130808ccb074ce.rlib" "C:\Users\Admin\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\x86_64-pc-windows-msvc\lib\libpanic_unwind-580326a9fdffe4b1.rlib" "C:\Users\Admin\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\x86_64-pc-windows-msvc\lib\librustc_demangle-a76d77b5d9ed4759.rlib" "C:\Users\Admin\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\x86_64-pc-windows-msvc\lib\libhashbrown-d5a5b7aa7eeea0b8.rlib" "C:\Users\Admin\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\x86_64-pc-windows-msvc\lib\librustc_std_workspace_alloc-4b74b4985b95e6c8.rlib" "C:\Users\Admin\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\x86_64-pc-windows-msvc\lib\libunwind-b2d5eb0d27518d1c.rlib" "C:\Users\Admin\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\x86_64-pc-windows-msvc\lib\libcfg_if-8a162ec37e71ea47.rlib" "C:\Users\Admin\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\x86_64-pc-windows-msvc\lib\liblibc-45fb7c94b612099e.rlib" "C:\Users\Admin\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\x86_64-pc-windows-msvc\lib\liballoc-3c0db88c6c3c2080.rlib" "C:\Users\Admin\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\x86_64-pc-windows-msvc\lib\librustc_std_workspace_core-ae8fea3b9ef7193c.rlib" "C:\Users\Admin\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\x86_64-pc-windows-msvc\lib\libcore-44bd5dbe4e29964c.rlib" "C:\Users\Admin\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\x86_64-pc-windows-msvc\lib\libcompiler_builtins-2e1363d96f00dd60.rlib" "advapi32.lib" "cfgmgr32.lib" "credui.lib" "gdi32.lib" "kernel32.lib" "msimg32.lib" "ole32.lib" "opengl32.lib" "secur32.lib" "shell32.lib" "user32.lib" "winspool.lib" "advapi32.lib" "ws2_32.lib" "userenv.lib" "msvcrt.lib"
= note: LINK : warning LNK4216: Exported entry point _DllMainCRTStartup
Creating library C:\Users\Admin\source\repos\dandra_but_rust\target\debug\deps\dandra_but_rust.dll.lib and object C:\Users\Admin\source\repos\dandra_but_rust\target\debug\deps\dandra_but_rust.dll.exp
libstd-e5130808ccb074ce.rlib(std-e5130808ccb074ce.std.cergmp4c-cgu.0.rcgu.o) : error LNK2001: unresolved external symbol __CxxFrameHandler3
libpanic_unwind-580326a9fdffe4b1.rlib(panic_unwind-580326a9fdffe4b1.panic_unwind.c9nntgss-cgu.0.rcgu.o) : error LNK2001: unresolved external symbol __CxxFrameHandler3
liballoc-3c0db88c6c3c2080.rlib(alloc-3c0db88c6c3c2080.alloc.3pxpxezw-cgu.0.rcgu.o) : error LNK2001: unresolved external symbol __CxxFrameHandler3
libstd-e5130808ccb074ce.rlib(std-e5130808ccb074ce.std.cergmp4c-cgu.0.rcgu.o) : error LNK2019: unresolved external symbol memcpy referenced in function _ZN4core3fmt5Write10write_char17h1ad50f755d81c59eE
liballoc-3c0db88c6c3c2080.rlib(alloc-3c0db88c6c3c2080.alloc.3pxpxezw-cgu.0.rcgu.o) : error LNK2001: unresolved external symbol memcpy
libcore-44bd5dbe4e29964c.rlib(core-44bd5dbe4e29964c.core.7rmb18uk-cgu.0.rcgu.o) : error LNK2001: unresolved external symbol memcpy
libstd-e5130808ccb074ce.rlib(std-e5130808ccb074ce.std.cergmp4c-cgu.0.rcgu.o) : error LNK2019: unresolved external symbol memset referenced in function _ZN4core3ops8function6FnOnce40call_once$u7b$$u7b$vtable.shim$u7d$$u7d$17h79aa7d690a3d5e88E
librustc_demangle-a76d77b5d9ed4759.rlib(rustc_demangle-a76d77b5d9ed4759.rustc_demangle.bwbqjk7y-cgu.0.rcgu.o) : error LNK2001: unresolved external symbol memset
libcore-44bd5dbe4e29964c.rlib(core-44bd5dbe4e29964c.core.7rmb18uk-cgu.0.rcgu.o) : error LNK2001: unresolved external symbol memset
libstd-e5130808ccb074ce.rlib(std-e5130808ccb074ce.std.cergmp4c-cgu.0.rcgu.o) : error LNK2019: unresolved external symbol memmove referenced in function _ZN4core3ptr90drop_in_place$LT$std..io..buffered..bufwriter..BufWriter$LT$W$GT$..flush_buf..BufGuard$GT$17hedcaf5acf9e62584E
liballoc-3c0db88c6c3c2080.rlib(alloc-3c0db88c6c3c2080.alloc.3pxpxezw-cgu.0.rcgu.o) : error LNK2001: unresolved external symbol memmove
libstd-e5130808ccb074ce.rlib(std-e5130808ccb074ce.std.cergmp4c-cgu.0.rcgu.o) : error LNK2019: unresolved external symbol memcmp referenced in function _ZN5alloc11collections5btree3map21BTreeMap$LT$K$C$V$GT$6insert17hc358a9b81795c956E
librustc_demangle-a76d77b5d9ed4759.rlib(rustc_demangle-a76d77b5d9ed4759.rustc_demangle.bwbqjk7y-cgu.0.rcgu.o) : error LNK2001: unresolved external symbol memcmp
libcore-44bd5dbe4e29964c.rlib(core-44bd5dbe4e29964c.core.7rmb18uk-cgu.0.rcgu.o) : error LNK2001: unresolved external symbol memcmp
libstd-e5130808ccb074ce.rlib(std-e5130808ccb074ce.std.cergmp4c-cgu.0.rcgu.o) : error LNK2019: unresolved external symbol strlen referenced in function _ZN3std3ffi5c_str7CString8from_raw17h67ae0c016f9720bbE
libpanic_unwind-580326a9fdffe4b1.rlib(panic_unwind-580326a9fdffe4b1.panic_unwind.c9nntgss-cgu.0.rcgu.o) : error LNK2019: unresolved external symbol _CxxThrowException referenced in function _ZN12panic_unwind8real_imp5panic17hd7ecf9c6caff3a53E
msvcrt.lib(delete_scalar.obj) : error LNK2019: unresolved external symbol free referenced in function "void __cdecl operator delete(void *)" (??3#YAXPEAX#Z)
C:\Users\Admin\source\repos\dandra_but_rust\target\debug\deps\dandra_but_rust.dll : fatal error LNK1120: 8 unresolved externals
error: aborting due to previous error
error: could not compile 'dandra_but_rust'`