I’m teaching myself Intel x64 assembler with the assistance of a really good textbook: “The Art of 64-Bit Assembly” by Randall Hyde. I’ve run into a snag trying to call the C/C++ printf function from a MASM program. (I’m running MASM Version 14.39.33523.0 in Visual Studio 2022 (64-bit) Version 17.9.6 on a Windows 10 64-bit platform.) The program assembles successfully, but generates a link error on the CALL PRINTF instruction. Here’s the program:

;   Test Call C++ Function printf()
;       testPrintf.asm

option casemap:none     ; Establish case sensitivity for compatibility with C/C++
includelib kernel32.lib
nl  =   10      ; ASCII code for newline
.data
    prtStr  byte    "Hello, World!", nl, 0
.code
externdef printf:proc           ; External declaration for C/C++ printf() function

public asmMain
asmMain proc
    sub rsp, 56             ; Set aside space for shadow registers, etc.
    lea rcx, prtStr
    call printf
    add rsp, 56             ; Pop off space for shadow registers, etc.
    ret
asmMain endp
end

From VS Command Line after running vcvars64.bat:
ml64 testPrintf.asm /link /subsystem:console /entry:asmMain

Link Errors:
testPrintf.obj : error LNK2019: unresolved external symbol printf referenced in function asmMain
testPrintf.exe : fatal error LNK1120: 1 unresolved externals

I’ve tried a few other ways to perform the call that I found on this forum (and others), but I haven’t found a solution that doesn’t produce these link errors. I think I may need to add an INCLUDELIB statement, but I also can’t find the name of the library that contains the printf function.

It’s a bit maddening because it seems like a problem that should be relatively easy to fix, but the solution eludes me despite several hours of research and trial-and-error. If you see the problem, your assistance would be greatly appreciated. Thank you.

Tried:

1. Using extern instead of externdef.
2. Declaring and linking to __imp_printf instead of printf. This worked for a couple of other C/C++ functions, but not for printf.
3. Searching for and reading questions that matched with terms like “MASM”, “LINK ERROR”, “Call C/C++ PRINTF”, etc.
4. Searching the Visual Studio user forums.
5. Guessing at INCLUDELIB names likely to contain printf (couldn’t find that, either)
6. Pleading, groveling, crying, begging, conniving, promising, threatening, doodling exploding heads, binge-eating hot pockets. Nothing worked.