Print Page - Create a ASM Library and use it in an ASM Program

Title: Create a ASM Library and use it in an ASM Program
Post by: riversr54 on August 12, 2018, 04:34:35 AM

I'm trying to create a very small and simple library in ASM. This is just a learning exercise so please don't ask me why :biggrin:. I've been throught the process of creating the library and then calling it from the other ASM program but I can't seem to get past identifying the process in the calling program. No matter what I've done, I always get "unresolved external symbol". I need two things:

1. Simple instructions on creating the library and using it in a calling ASM program.
2. A way to view the available procedures in a .lib file. I've tried dumpbin with no luck.

The code in the library(StaticLib03):
.386 ; force 32 bit code
.model flat, stdcall ; memory model & calling convention
option casemap :none ; case sensitive

.code
testproc proc
   mov eax, 1
   inc eax
   ret
testproc endp
end

The code in my calling program(TestLib):

.386
.model flat, stdcall
.stack 4096
ExitProcess proto, dwExitCode:dword

INCLUDE StaticLib03.inc
INCLUDELIB StaticLib03.lib

.data

.code
main proc
call testproc

invoke ExitProcess, 0
main endp
end main

Title: Re: Create a ASM Library and use it in an ASM Program
Post by: Vortex on August 12, 2018, 05:13:06 AM

Hi riversr54,

Here is a quick example.

Code Select

include     \masm32\include\masm32rt.inc

sum     PROTO :DWORD,:DWORD
mult    PROTO :DWORD,:DWORD

.data

string  db '%u',13,10,'%u',0

.data?

var dd ?

.code

start:

    invoke  sum,10,20
    mov     var,eax
    
    invoke  mult,30,40
    invoke  crt_printf,ADDR string,var,eax
    invoke  ExitProcess,0

END start

Title: Re: Create a ASM Library and use it in an ASM Program
Post by: riversr54 on August 12, 2018, 05:53:52 AM

Thanks for the example. I do have a couple follow up questions.

I don't see anywhere that you included any reference to the library file. Is it enough that it just be in the same folder and the linker will find it using the procedure names?

Do you know a way to list procedures in the library?

Thanks very much.

Title: Re: Create a ASM Library and use it in an ASM Program
Post by: Vortex on August 12, 2018, 06:39:12 AM

Hello,

Code Select

sum     PROTO :DWORD,:DWORD
mult    PROTO :DWORD,:DWORD

The function prototypes are declaring the external functions. The linker will find and extract the procedures examining the static library.

Code Select

\masm32\bin\polink /SUBSYSTEM:CONSOLE Test.obj testlib.lib

The static library could be located in another folder :

Code Select

\masm32\bin\polink /SUBSYSTEM:CONSOLE Test.obj D:\libraries\testlib.lib

Listing the procedures :

Code Select

\masm32\bin\polib.exe /list testlib.lib
mult.obj
sum.obj

You can also use the MS linker to list the procedures :

Code Select

\masm32\bin\link.exe -lib -list testlib.lib
Microsoft (R) Library Manager Version 5.12.8078
Copyright (C) Microsoft Corp 1992-1998. All rights reserved.

sum.obj
mult.obj

Title: Re: Create a ASM Library and use it in an ASM Program
Post by: riversr54 on August 12, 2018, 07:53:34 AM

Thank you very much. Part of my problem was that I've been trying to do some of this in Visual Studio. I think I'm learning quickly that it may not be the best way.

The MASM Forum

General => The Campus => Topic started by: riversr54 on August 12, 2018, 04:34:35 AM