187 lines
4.8 KiB
PHP
187 lines
4.8 KiB
PHP
; Platform-specific procedures for Linux.
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; Reallocate memory at pointer [start.buf] and size [start.allocated],
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; new size is in eax.
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realloc:
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push ebx esi edi
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mov ecx, eax
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push ebp
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kercall __NR_mmap2, 0, , PROT_READ+PROT_WRITE, MAP_PRIVATE+MAP_ANONYMOUS, -1, 0
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pop ebp
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cmp eax, 0xFFFFF000
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ja nomemory
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add [start.free], ecx
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xchg ecx, [start.allocated]
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sub [start.free], ecx
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mov edi, eax
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xchg eax, [start.buf]
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shr ecx, 2
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jz .nothing
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push ecx
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mov esi, eax
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rep movsd
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pop ecx
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shl ecx, 2
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call free_eax_ecx
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.nothing:
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pop edi esi ebx
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ret
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; Read the next portion of input data to [start.buf].
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read:
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mov ecx, [start.buf]
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add ecx, [start.allocated]
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mov edx, [start.free]
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sub ecx, edx
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kercall __NR_read, [start.in], ,
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test eax, eax
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js readerr
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ret
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; Write output data: eax=pointer, edi=size.
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write:
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mov ecx, eax
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kercall __NR_write, [start.out], , edi
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cmp eax, edi
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jnz writeerr
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ret
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; Parse command line, open input and output files.
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get_params:
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; 1. Initialize default streams: 0 for stdin, 1 for stdout.
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inc [start.out]
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; 2. Prepare for scanning, skipping argv[0].
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mov ebx, [start.argc]
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cmp ebx, 1
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jbe .noargs
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dec ebx
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lea esi, [start.argv+4] ; skip argv[0]
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xor edi, edi ; no args parsed yet
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; 3. Parse loop.
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.parse:
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; 3a. Get the next argument.
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lodsd
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; 3b. Check whether it is a known option.
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cmp word [eax], '-e'
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jnz @f
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cmp byte [eax+2], 0
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jnz @f
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; 3c. If it is, modify flags and continue the loop.
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mov [start.flags], 1 ; '-e' is given
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jmp .nextarg
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@@:
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; 3d. Otherwise, it is a name of input or output file.
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; edi keeps the count of names encountered before;
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; edi = 0 means this is input file, edi = 1 - output file,
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; otherwise this is third arg, which is an error
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cmp edi, 1
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ja information
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; 3e. Some parameters of __NR_open differ for input and output. Setup them.
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mov ecx, O_WRONLY+O_CREAT+O_TRUNC
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mov edx, 0644o
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jz @f
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mov ecx, O_RDONLY
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@@:
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; 3f. Open/create the file, save the handle.
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push ebx
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mov ebx, eax
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kercall __NR_open
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pop ebx
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test eax, eax
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js .fileerr
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mov [start.in+edi*4], eax
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inc edi
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.nextarg:
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dec ebx
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jnz .parse
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.noargs:
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; 4. End of command line reached. Return.
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ret
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.fileerr:
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test edi, edi
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jz in_openerr
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jmp out_openerr
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; Exit, return code is in al.
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exit:
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movzx ebx, al
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push ebx
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mov eax, [start.buf]
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test eax, eax
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jz @f
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mov ecx, [start.allocated]
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call free_eax_ecx
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@@:
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kercall __NR_close, [start.in]
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kercall __NR_close, [start.out]
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pop ebx
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kercall __NR_exit
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; Helper procedure for realloc and exit.
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free_eax_ecx:
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mov ebx, eax
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kercall __NR_munmap
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ret
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; Output the message given in esi to stderr.
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sayerr:
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movzx edx, byte [esi-1]
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kercall __NR_write, 2, esi,
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ret
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; Get environment variable esi (ebx-relative pointer) to the buffer,
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; expanding it if needed.
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get_environment_variable:
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mov ecx, [start.argc]
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lea ecx, [start.argv+ecx*4+4]
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.findvar:
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mov edx, [ecx]
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add ecx, 4
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test edx, edx
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jz .notfound
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push esi
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add esi, ebx
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.comparename:
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lodsb
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cmp al, [edx]
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jnz @f
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inc edx
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jmp .comparename
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@@:
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pop esi
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test al, al
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jnz .findvar
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cmp byte [edx], '='
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jnz .findvar
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inc edx
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xor eax, eax
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@@:
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inc eax
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cmp byte [edx+eax-1], 0
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jnz @b
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stdcall alloc_in_buf, eax
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@@:
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mov al, [edx]
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inc edx
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mov [edi+ebx], al
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inc edi
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test al, al
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jnz @b
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ret
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.notfound:
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stdcall alloc_in_buf, 1
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mov byte [edi+ebx], 0
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inc edi
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ret
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; Test whether a file with name [.testname] exists.
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; Returns eax<0 if not, nonzero otherwise.
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test_file_exists:
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push ebx
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add ebx, [start.testname]
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sub esp, 800h
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kercall __NR_stat, , esp
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add esp, 800h
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pop ebx
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ret
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