Module 1:
;******************************************************************************* ; A generic Linked List ADT for any datatype. ; ; Author: William .386 .MODEL flat, stdcall .STACK 4096 PUBLIC push_front, print_list ; Win32 function prototypes and synonyms GetProcessHeap PROTO HeapAlloc PROTO, hHeap:DWORD, dwFlags:DWORD, dwBytes:DWORD GetStdHandle PROTO, nStdHandle:DWORD WriteConsoleA PROTO, hConsoleOutput:DWORD, lpBuffer:PTR DWORD, nNumberofCharsToWrite:DWORD, lpNumberOfCharsWritten:PTR DWORD, lpReserved:DWORD STD_OUTPUT_HANDLE equ -11 HEAP_ZERO_MEMORY equ 00000008h .CODE ;------------------------------------------------------------------------------- ; print_list(hptr, fptr) ; ; Prints nodes of given linked list ; ; Entry: hptr EQU [ebp + 8] ;head ptr fptr EQU DWORD PTR[ebp + 12] ;std_call func ptr that ; prints list data type ;------------------------------------------------------------------------------- print_list: push ebp mov ebp, esp sub esp, 12 push eax push edx push ebx ; Locals variables arrow EQU [ebp - 4] ;string "-> " mov DWORD PTR arrow, ' >-' nstr EQU [ebp - 8] ;string "NULL" mov DWORD PTR nstr, 'LLUN' wrtn EQU [ebp - 12] ;num of chars written mov DWORD PTR wrtn, 0 ; loop while(node != NULL) mov ebx, hptr jmp endL3 L3: ; print (node->data) push [ebx] call fptr ; print "-> " INVOKE GetStdHandle, STD_OUTPUT_HANDLE mov edx, eax INVOKE WriteConsoleA, edx, ADDR arrow, 3, ADDR wrtn, 0 ;node = node -> next mov ebx, [ebx + 4] endL3: test ebx, ebx jnz L3 ;print "NULL" INVOKE GetStdHandle, STD_OUTPUT_HANDLE mov edx, eax INVOKE WriteConsoleA, edx, ADDR nstr, 4, ADDR wrtn, 0 pop ebx pop edx pop eax mov esp, ebp pop ebp ret 8 ;------------------------------------------------------------------------------- ; push_front(headptr, dataptr, dsiz) ; ; Adds a new linked list node to the front of a linked list. ; ; Entry: hptr EQU [ebp + 8] ;DW ptr to headptr dptr EQU [ebp + 12] ;DW data ptr dsiz EQU [ebp + 16] ;DW data size in bytes node_size EQU 00000008h ;------------------------------------------------------------------------------- push_front: ; set up stack save regs push ebp mov ebp, esp push eax push ebx push ecx push edx push esi ; allocate memory for new node call GetProcessHeap INVOKE HeapAlloc, eax, HEAP_ZERO_MEMORY, node_size mov ebx, eax ;save node in ebx ; allocate memory for new data call GetProcessHeap INVOKE HeapAlloc, eax, HEAP_ZERO_MEMORY, dsiz ; save into new node mov [ebx], eax ;node->data = new data mov eax, hptr mov eax, [eax] ;dereference hptr mov [ebx + 4], eax ;node->next = hptr ; loop copying data into newly allocated ; memory byte per byte mov edx, dsiz mov esi, dptr xor ecx, ecx ;loop counter jmp endL1 L1: mov al, [esi + ecx] mov [ebx + ecx], al inc ecx endL1: cmp ecx, edx jl L1 ; hptr = new node mov eax, hptr mov [eax], ebx ; restore regs clean up stack pop esi pop edx pop ecx pop ebx pop eax pop ebp ret 12 END Module 2
;******************************************************************************* ; LL_main.asm is the main module that demonstrates the Linked_List ADT ; ; Author: William .386 .MODEL flat, stdcall .STACK 4096 EXTERN push_front:near, print_list:near ; Win32 API function prototypes and synonyms ExitProcess PROTO, dwExitCode:DWORD GetStdHandle PROTO, nStdHandle:DWORD WriteConsoleA PROTO, hConsoleOutput:DWORD, lpBuffer:PTR DWORD, nNumberofCharsToWrite:DWORD, lpNumberOfCharsWritten:PTR DWORD, lpReserved:DWORD STD_OUTPUT_HANDLE EQU -11 NULL EQU 0 .CODE ;------------------------------------------------------------------------------- ; print_hex(num) ; ; prints a 32 bit unsigned hexadecimal number to the console ; ; Entry: num EQU [ebp + 8] ; DW unsigned hex number ;------------------------------------------------------------------------------- print_hex: ; set up stack frame, save regs push ebp mov ebp, esp sub esp, 4 push eax push ebx push edx push esi ; local variable for # of chars written by WriteConsoleA nWrtn EQU [ebp - 4] mov DWORD PTR nWrtn, 0 ; This loop repeatedly divides the number by 10h, converts the remainder ; to its corresponding ASCII code, and then saves the char to the stack mov eax, num mov ebx, 10h ; the divisor, 10h xor edx, edx ; clear edx xor esi, esi ; esi = num of chars L1: div ebx ; div num by 10h ;convert remainer to ASCII code ;if edx > 9, add 7 cmp edx, 9 jle endIf1 add edx, 7 endIf1: ;add char '0' to num add edx, '0' ;put char on stack dec esp ; allocate stack space mov [esp], dl ; save char to stack inc esi ; inc num of chars xor edx, edx ; clear edx ; end of loop L1 test eax, eax ; loop while num != 0 jnz L1 ; print out chars from the stack mov edx, esp INVOKE GetStdHandle, STD_OUTPUT_HANDLE mov ecx, eax INVOKE WriteConsoleA, ecx, edx, esi, ADDR nWrtn, NULL add esp, esi ; restore esp ; ;clean up stack, restore regs pop esi pop edx pop ebx pop eax mov esp, ebp pop ebp ret 4 ;------------------------------------------------------------------------------- ; main() ; ; creates a linked list of integers and prints them to the screen. ;------------------------------------------------------------------------------- main: mov ebp, esp sub esp, 8 ; local variables head_ptr EQU [ebp - 4] ; head of list mov DWORD PTR head_ptr, 0 hex_int EQU [ebp - 8] ; a starting int mov DWORD PTR hex_int, 10fd134h ; loop L2 adds 6 numbers to list xor esi, esi ; loop counter L2: ; add hex_int to front of the list push 4 lea eax, hex_int push eax lea eax, head_ptr push eax call push_front inc esi add DWORD PTR hex_int, 14768h ; end of L2 cmp esi, 6 ; while (esi < 6) jl L2 ; print out list push print_hex push head_ptr call print_list mov esp, ebp INVOKE ExitProcess, 0 END main Output:
116363C-> 114EED4-> 113A76C-> 1126004-> 111189C-> 10FD134-> NULL
This is a minimal implementation of a Linked List that took me a long time to figure out and get working. It only allows you to create a list, push to it, and print it out. There is no way to destroy the list, so the program leaks memory.
I'm looking for ALL criticism.
