c - nasm, macro print not working -

i'm calling function written in assembly c file. c code passes 2 pointers assembly function. i'm using print macro assembly check value of addresses , of elements pointed them.

here c code:

extern int nn_from_set(float *q, float *t, int q_length, int *s, int s_length);  int main() {     float *matrix_dyn = malloc(6*4*sizeof(float));     int *s = malloc( 3 * sizeof(int))     //the vectors filled here     //print address, no problem here     printf("t: %p, s: %p, sizeof int*: %u\n", matrix_dyn, s,  sizeof(matrix_dyn));     //assembly function called     printf("prova: %d\n", nn_from_set(matrix_dyn, matrix_dyn, 3, s, 3));     return 0; } 

here assembly code, it's bit long.

extern printf  %macro pabc 1           ; "simple" print macro section .data        .strm db %1,0            ; %1 first actual macro call  section .text      ; push onto stack bacwards     push dword [nnfs_int]                ; int     push dword .strm     push dword nnfs_fmt_int              ; users string     call printf                          ; call c function     add esp, 12                           ; pop stack 3 * 4 bytes  %endmacro      section .data fmt: db "%s, dist: %e",10,0         ; format string printf nnfs_fmt: db "%s",10,0              ; format string printf nnfs_fmt_int:   db "%s %p",10,0     ; format string int debug       section .bss  nnfs_dst:   resd 1                  ; reserve 32-bit word nnfs_tmp:   resd 1                  ; int tmp; nnfs_index: resd 1                  ; reserve 32-bit, int index;   nnfs_int:   resd 1      section .text  ; function translated  ; int nearest_neighbor_from_set(float* q, float* t, int q_length, int* s, int s_length)  global nn_from_set  nnfs_q           equ     8 nnfs_t           equ     12 nnfs_q_length    equ     16 nnfs_s           equ     20 nnfs_s_length    equ     24  nn_from_set:             ; -------------------------------------------             ; entrace sequence             ; -------------------------------------------             push    ebp         ; save base pointer             mov     ebp, esp    ; point current stack frame             push    ebx         ; save general registers             push    esi                      push    edi              mov ecx, [ebp + nnfs_t]     ; t             mov edx, [ebp + nnfs_s]     ; s              mov [nnfs_int], ecx         ; print t             pabc "ecx, t: "               mov [nnfs_int], edx        ; print s              ;pabc "edx, s: "              mov esi, [edx]              ; *s              mov [nnfs_int], esi         ; print *s             ;pabc "edx"              add edx, 4             mov esi, [edx]              mov [nnfs_int], esi             ;pabc "esi"              ; fine di nn_from_set             mov eax, 50         ; test purpose              ; ------------------------------------------             ; exit sequence             ; ------------------------------------------              pop     edi             pop     esi             pop     ebx             mov     esp, ebp             pop     ebp             ret 

i have 2 problems, version of code, when try compile, says .strm defined, each time try call macro after first call.

second problem. change macro this:

 %macro pabc 1           ; "simple" print macro  section .text      ; push onto stack bacwards     push dword [nnfs_int]                ; int     push dword nnfs_fmt_int              ; users string     call printf                          ; call c function     add esp, 8                           ; pop stack 2 * 4 bytes  %endmacro 

i've removed .strm argument. format string now:

nnfs_fmt_int:   db " reg %p",10,0 

with version, first call of macro prints correctly, second goes wrong. example, call macro print addresses of 2 pointers:

mov [nnfs_int], ecx         ; print t pabc "ecx, t: "   mov [nnfs_int], edx        ; print s  pabc "edx, s: " 

here output (the first line printed c file):

t: 0x8500008, s: 0x8500070, sizeof int*: 4  reg 0x8500008  reg 0xf7778898 

address of t printed correctly, s's one, not. if invert 2 calls.

mov [nnfs_int], edx         ; print s pabc "ecx, t: "   mov [nnfs_int], ecx        ; print t pabc "edx, s: " 

this output (the first line printed c file):

t: 0x93a0008, s: 0x93a0070, sizeof int*: 4  reg 0x93a0070  reg (nil) 

s printed right, t isn't.

i have no idea going wrong, have used same macro pattern , hasn't created me problem until now. examples tha used create macro here: http://www.csee.umbc.edu/portal/help/nasm/sample.shtml

sorry long question, , thank in advance help.

according standard calling convention, registers caller-saved, namely eax, ecx , edx. such, shouldn't expect value retained through call printf. that's presumably why wrong value printed. push second 1 on stack before printing first one, pop print too. since on stack, can reload there:

mov ecx, [ebp + nnfs_t]     ; t mov [nnfs_int], ecx         ; print t pabc "ecx, t: "   mov edx, [ebp + nnfs_s]     ; s mov [nnfs_int], edx         ; print s  pabc "edx, s: "  ; reload since printing changed ecx , edx mov ecx, [ebp + nnfs_t]     ; t mov edx, [ebp + nnfs_s]     ; s