james kim

After compiling .cpp files with
"bcc -c -v -ml -1 test.cpp"
"bcc -c -v -ml -1 main.cpp"
where test.cpp contains nothing but an empty constructor
and main.cpp is main() function with no contents

the following linking error occurs on
"tlink /m /v /s /c test.obj main.obj, my_main.exe, my_main.map"


Please help me!

James
email: wonderfuljames@hotmail.com

james kim

Thanks Ed for your help.

I, however, was not successful in linking. The following is the result:

C:\BC45\BIN>tlink /m/v/s/c c0l test main,my_main,,cl
Turbo Link Version 7.00 Copyright (c) 1987, 1994 Borland International
Error: Undefined symbol _main in module c0.asm

As a matter of fact, I have my own startup code and I have tried linking with
it before.
The result was same


I know that it can not be this much difficult just to complie and link a very
simple program.
I am guessing that there is something that I am doing wrong.
I'd like to provide you more detail information regarding my environment.
Would you please please help me?

* I pasted all my files at the bottom of this email

1) I have Borland 4.52 installed in my C drive ==> C:\BC45\
2) I have my startup code named 'startup.obj' in C:\BC\45\BIN
'startup.asm' is located in C:\BC45\BIN\Chapter3
I am 99.99% sure that the startup code is okay.(I could tlink with C
source files).
3) I have two source files: led.cpp & blink.cpp
led.cpp: constructor and one public function with no contents
blink.cpp: main function with no contents but '#include "led.h"

Compiling/linking works perfectly fine with all the source files implemented
in C instead of C++.
I am guessing that the reason for error has to do with linking C++ source
files!

The following is the linking error message:
C:\BC45\BIN>tlink /m /v /s /c startup led blink, blink.exe, blink.map
Turbo Link Version 7.00 Copyright (c) 1987, 1994 Borland International
Error: Undefined symbol _main in module chapter3\startup.asm
Error: Undefined symbol operator new(unsigned int) in module led.cpp

I'd really appreciate it if you'd help me on this.
Thank you so much.

James
------------------------------------------------------------------------------------------------------------------------

The error told you part of what is wrong. The linker was not told to use
the compiler's runtime library or the compiler's startup code.

Instead of this
tlink /m /v /s /c test.obj main.obj, my_main.exe, my_main.map

try this:
tlink /m/v/s/c c0l test main,my_main,,cl

Where the '0' in c0l is a zero, not the letter 'o'.

. Ed
------------------------------------------------------------------------------------------------------------------------

1) blink.cpp

/************************************************** *************************
*
* Filename: blink.c
*
************************************************** ********************/

#include "led.h"

/************************************************** ********************
*
* Function: main()
*
* Description: Blink the green LED once a second.
*
************************************************** ********************/

void main(void)
{

} /* main() */
-----------------------------------------------------------------------------------------------------------------------

2) led.cpp

/************************************************** ********************
*
* Filename: led.cpp
*
************************************************** ********************/

#include "led.h"

/************************************************** ********************
*
* Function: constructor()
*
* Description: Toggle the state of one or both LED's.
*
************************************************** ********************/

led::led()
{
// To be implemented

} /* constructor */

/************************************************** ********************
*
* Function: toggleLed()
*
* Description: Toggle the state of one or both LED's.
*
************************************************** ********************/

void led::toggleLed(void)
{
// To be implemented

} /* toggleLed() */

-----------------------------------------------------------------------------------------------------------------------

3) led.h

/************************************************** ********************
*
* Filename: led.h
*
************************************************** ********************/

#ifndef _LED_H
#define _LED_H

class led
{
public:
led();
void toggleLed(void);
};


#endif /* _LED_H */

-----------------------------------------------------------------------------------------------------------------------

3) startup.asm

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;
;
; Filename: startup.asm
;
; Description: Startup code for Borland C/C++.
;
; Notes: This module should be specified first during linking.
;
; Warnings: The order of the segments within this file matters.
;
;
; Copyright (c) 1998 by Michael Barr. This software is placed into
; the public domain and may be used for any purpose. However, this
; notice must not be changed or removed and no warranty is either
; expressed or implied by its publication or distribution.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;

NAME startup

;
; Global Variables
;
PUBLIC _errno ; Required by the Borland libraries.
PUBLIC __psp ; Required for dynamic memory allocation.
PUBLIC __brklvl ; Required for dynamic memory allocation.
PUBLIC __heapbase ; Required for dynamic memory allocation.
PUBLIC __heaptop ; Required for dynamic memory allocation.

;
; Functions Defined Externally
;
EXTRN _main : FAR

;
; Constants
;
stack_size EQU 1024 ; By default, create a 1-kbyte stack.
ram_size EQU 2000h ; The Arcom board has 2000h pages of RAM.

PCB EQU 0ff00h ; Base of the Peripheral Control Block.
GCS0ST EQU PCB + 80h ; General-purpose chip select 0 start.
GCS0SP EQU PCB + 82h ; General-purpose chip select 0 stop.
GCS1ST EQU PCB + 84h ; General-purpose chip select 1 start.
GCS1SP EQU PCB + 86h ; General-purpose chip select 1 stop.

;
; Initializer/Terminator Structure Format (used by C++ modules)
;
Initializer STRUC

ctype DB ? ; Code Segment Type (0 = near, 1 = far)
priority DB ? ; Priority (0 = highest, 0xff = lowest)
foffset DW ? ; Function Pointer (Offset)
fsegment DW ? ; Function Pointer (Segment)

Initializer ENDS


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;
;
; Segment: _text
;
; Description: The following segment contains the startup code.
;
; Notes: If desired, this segment can be located in ROM.
;
; Warnings: The terminators are not executed, since embedded
; applications are not expected to complete and exit.
; However, an _exit_ segment must still be declared
; here, for compatibility with existing C++ libraries.
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;

_text SEGMENT PARA PUBLIC 'CODE'

ASSUME CS:_text

_startup PROC FAR
;
; Disable interrupts and set the direction flag.
;
cli
cld

;
; Perform hardware initializations that may not have been
; done by the hardware initialization code in EEPROM.
;
mov dx, GCS0ST
mov ax, 7000h
out dx, ax

mov dx, GCS0SP
mov ax, 710Ah
out dx, ax

mov dx, GCS1ST
mov ax, 7100h
out dx, ax

mov dx, GCS1SP
mov ax, 720Ah
out dx, ax

;
; Initialize the segment registers.
;
mov ax, dgroup
mov ds, ax
mov es, ax
ASSUME ds:dgroup, es:dgroup

initData:
;
; Zero the uninitialized data segment.
;
xor ax, ax
mov di, offset dgroup:bss_start
mov cx, offset dgroup:data_end
sub cx, di
shr cx, 1
jcxz initStack
rep stosw

initStack:
;
; Initialize the stack.
;
mov ax, _stack
mov ss, ax
mov sp, offset stack_top
ASSUME ss:_stack

initHeap:
;
; Initialize the heap.
;
mov ax, _farheap ; heapBase
inc ax

mov [__brklvl + 2], ax
mov [__brklvl], 0000h
mov [__heapbase + 2], ax
mov [__heapbase], 0000h
mov [__psp], ax

mov bx, ram_size ; heapEnd
mov [__heaptop + 2], bx
mov [__heaptop], 0000h

mov dx, _farheap
mov ds, dx
ASSUME ds:_farheap

mov [id], 'Z'
mov [owner], 0
sub bx, ax
mov [npages], bx

initModules:
;
; Call any static initializers found in the _init_ segment.
; The C++ language guarantees that these functions are called
; before main().
;
; The following registers are used.
; SI - offset of the next initializer
; DI - offset of the last initializer
; CX - number of initializers remaining
; BX - current initializer
; AH - current priority
;
mov si, offset igroup:init_start
mov di, offset igroup:init_end
mov ax, dgroup
mov ds, ax
mov ax, igroup
mov es, ax
ASSUME ds:dgroup, es:nothing

mov ax, di
sub ax, si
sub dx, dx
mov cx, SIZE Initializer
idiv cx
mov cx, ax ; CX has total number of initializers.
jcxz callMain
sub ah, ah ; AH has current priority (start at 0).

firstInitializer:
mov bx, si ; Restart, from the top of the table.

nextInitializer:
cmp bx, di ; Are there initializers left to check?
jae nextPriority ; If not, try the next priority.
cmp es:[bx.priority], ah ; Check this initializer's priority.
jne tryNextInitializer ; If it's not a match, try the next.

push es
push ax
push bx
push cx
push si
push di

call dword ptr es:[bx.foffset] ; Call the initializer

pop di
pop si
pop cx
pop bx
pop ax
pop es

dec cx ; Decrement number of initializers.
jz callMain ; If zero left, continue.

tryNextInitializer:
add bx, SIZE Initializer
jmp nextInitializer

nextPriority:
inc ah ; Process the next priority.
jmp firstInitializer

callMain:
;
; Enable interrupts and transfer control to C/C++.
;
sti
call _main

;
; A return from main() is unexpected. Halt the processor.
;
hlt

_startup endp

_text ENDS


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;
;
; Segments: _init_, _initend_, _exit_, _exitend_
;
; Description: The following segments are used for C++ initializers
; and terminators.
;
; Notes: If possible, these segments should be located in ROM.
;
; Warnings: The terminators are not executed, since embedded
; applications are not expected to complete and exit.
; However, an _exit_ segment must still be declared
; here, for compatibility with existing libraries.
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;

_init_ SEGMENT PARA PUBLIC 'INITDATA'

init_start LABEL DWORD

_init_ ENDS

igroup GROUP _init_


_initend_ SEGMENT BYTE PUBLIC 'INITDATA'

init_end LABEL DWORD

_initend_ ENDS

igroup GROUP _initend_


_exit_ SEGMENT DWORD PUBLIC 'EXITDATA'

exit_start LABEL DWORD

_exit_ ENDS

igroup GROUP _exit_


_exitend_ SEGMENT BYTE PUBLIC 'EXITDATA'

exit_end LABEL DWORD

DB 16 DUP (?) ; Force the next segment to a new paragraph

_exitend_ ENDS

igroup GROUP _exitend_


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;
;
; Segments: _data, _bss, _bssend, _stack, _farheap
;
; Description: The following segments are used for the initialized
; and uninitialized data, stack, and heap, respectively.
;
; Notes: These segments must be located in RAM. In fact, the
; _farheap segment will contain whatever RAM is left over
; after the others are allocated space.
;
; Warnings: For compatibility with Borland C/C++, the order of
; these segments must not be changed.
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;

_data SEGMENT PARA PUBLIC 'DATA'

data_start LABEL BYTE ; Mark the start of the initialized data.

_data ENDS

dgroup GROUP _data


_bss SEGMENT WORD PUBLIC 'BSS'

bss_start LABEL BYTE ; Mark the start of the uninitialized data.

_errno DW ?
__psp DW ?
__brklvl DW ?
DW ?
__heapbase DW ?
DW ?
__heaptop DW ?
DW ?

_bss ENDS

dgroup GROUP _bss


_bssend SEGMENT WORD PUBLIC 'BSSEND'

DW ? ; Give a fixed size for proper alignment.
data_end LABEL WORD ; Mark the end of the uninitialized data.

_bssend ENDS

dgroup GROUP _bssend


_stack SEGMENT PARA STACK 'STACK'

DB stack_size DUP (?) ; Reserve space for the stack.

EVEN
stack_top DW ?

_stack ENDS


_farheap SEGMENT PARA PUBLIC 'FARHEAP'

id DB ?
owner DW ?
npages DW ?

DB 11 DUP (?) ; Round the segment up to a full page.

_farheap ENDS


END _startup ; End module and declare _startup as entry point.

-----------------------------------------------------------------------------------------------------------------------

bob gonder

_main is in blink.cpp I don't see where you linked it.

ed mulroy [teamb]

You said "and main.cpp is main() function with no contents"

If so then you have a function named main (public name _main). My guess is
that you did not include the object file from that source file in the link.

If you want to use your own startup code then you are on your own. I will
not debug it for you.

.. Ed

james kim

Sorry for my lacking knowledge, but
what do you mean by 'I don't see where you linked it'?
Maybe that's what I am missing!

James

bob gonder

You are linking c0l, test and main. bit not blink.