Writing Hello World in MASM [duplicate] - windows

Question

Having such a simple assembly Win 32 program:
.386
.model flat, stdcall
option casemap :none
EXTERN printf :PROC ; declare printf
.data
HelloWorld db "Hello Wolrd!:-)", 0
.code
start:
sub esp, 4
push offset HelloWorld
call printf
add esp, 4
ret
end start
I can successfully compile it by just:
ml.exe /c HelloWorld.asm
BUT have a problem linking it. When I use:
link HelloWorld.obj libcmt.lib
I'm getting an error:
unresolved external symbol _main called in _mainCRTStartup
What have I change/correct to to successfully link the program to run it?
P.S.
Please don't tell me to use just nasm. I'd like to use ml & link from my MSVC.

Answer 1

With some minor tweaks this now builds correctly.
.386
.model flat, c
option casemap :none
includelib libcmt.lib
includelib legacy_stdio_definitions.lib
EXTERN printf :PROC ; declare printf
.data
HelloWorld db "Hello World!:-)", 0
.code
main PROC
push offset HelloWorld
call printf
add esp, 4
ret
main ENDP
END
The main edits are
.model flat, c sets the calling conventions for procedures to C.
If you decide to keep .model flat, stdcall it'll require these changes.
Replace
EXTERN printf :PROC
main PROC
with
printf PROTO NEAR C,:DWORD
main PROC NEAR C
Included libcmt.lib and legacy_stdio_definitions.lib which statically links the native C-Runtime startup into your code.
Changed entry point from start to main. There's an entry point (_mainCRTStartup) within the C-Runtime library (CRT) libcmt.lib, which does some initialization tasks, and then hands off control to the entry point for your application main. You can change the default entry point, but usually you want the convenience of the initialization the CRT entry point does for you automatically.
Removed the first sub esp,4 so the remaining one push is balanced by the add esp,4, so ESP is pointing at the return address when ret runs.
To build, open a Windows command prompt and run:
"C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\VC\Auxiliary\Build\vcvars32.bat"
to set the MSVC Environment initialized for: 'x86'
Next, run these MASM commands
ml.exe /c /coff HelloWorld.asm
link.exe /SUBSYSTEM:console HelloWorld.obj
The program displays
Hello World!:-)

Answer 2

Your error message says that it can't find the exported symbol (i.e. function) "_main". I expect renaming your start function to _main would get it to compile.