Local variables

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Maggot

Joined: 31 Jul 2005
Posts: 1

Maggot 13 Sep 2005, 18:22

when i try this:

Code:

proc proc1
    local   var1:stuct1
    invoke  proc2,var1
endp

fasm returns me an error:
invalid value: pushd ..var?00006FC

Is it macro or compiler error? How to correct this mistake?

13 Sep 2005, 18:22

kidscracker

Joined: 29 Oct 2004
Posts: 46

kidscracker 13 Sep 2005, 18:47

When you create a local variable it use the stack, so the variable itselfi isn't an address, it is a poiter relative to EBP , something like EBP-4, etc. To poit to that variable you must use:

Code:

proc proc1
   local var1:struct1

lea eax,[var1]   ; < eax contains the address of var1
invoke proc2,eax  ;< send eax as a parameter

endp

13 Sep 2005, 18:47

Madis731

Joined: 25 Sep 2003
Posts: 2139
Location: Estonia

Madis731 20 Sep 2005, 12:48

You could also use:

Code:

proc proc1
  local var1:struct1
  invoke proc2,[var1]
endp

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20 Sep 2005, 12:48

Tomasz Grysztar

Joined: 16 Jun 2003
Posts: 8353
Location: Kraków, Poland

Tomasz Grysztar 20 Sep 2005, 12:55

Perhaps you mean

Code:

proc proc1
  local var1:struct1
  invoke proc2,addr var1
endp

it's the address of local variable, not the contents of it that he wants to pass to the procedure. The "addr" will work only with extended Win32 headers and will generate the code with LEA similar to the one kidscracker posted.

20 Sep 2005, 12:55

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