Print Page - Using rv macro

Title: Using rv macro
Post by: Matthew on April 25, 2012, 07:58:47 PM

Hello all, this is my first post here :dance:

Is there a way to specify the parameters when using macros over multiple lines.

i.e

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mov hWnd, rv(CreateWindowEx, NULL, addr szWindowClassName, addr szAppName, WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, NULL, NULL, hInst, NULL)

to something like;

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mov hWnd, rv(CreateWindowEx,\
    NULL,\
    addr szWindowClassName,\
    addr szAppName,\
    WS_OVERLAPPEDWINDOW,\
    CW_USEDEFAULT,\
    CW_USEDEFAULT,\
    CW_USEDEFAULT,\
    CW_USEDEFAULT,\
    NULL,\
    NULL,\
    hInst,\
    NULL)

I tried this but I get the following; error A2157: missing right parenthesis

I know I can do it by using the following but was just wondering if im missing something obvious.

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fn CreateWindowEx,\
    NULL,\
    addr szWindowClassName,\
    addr szAppName,\
    WS_OVERLAPPEDWINDOW,\
    CW_USEDEFAULT,\
    CW_USEDEFAULT,\
    CW_USEDEFAULT,\
    CW_USEDEFAULT,\
    NULL,\
    NULL,\
    hInst,\
    NULL)
mov hWnd, eax

Thanks for your time.

Title: Re: Using rv macro
Post by: jj2007 on April 25, 2012, 08:12:19 PM

The first one works with JWasm but not with any version of ML.EXE:
   mov ecx, rv(GetStdHandle,\
   STD_OUTPUT_HANDLE)

This one works in any case:
   invoke GetStdHandle,\
   STD_OUTPUT_HANDLE
   xchg eax, ebx ; assuming you need the result in a protected register

Title: Re: Using rv macro
Post by: qWord on April 25, 2012, 08:24:38 PM

hi,
unfortunately, continuation of the line can't be used for function-like macros. However, you can also use the fnx macro that allows a syntax, which is similar to mov x,rv(...):

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fnx hWnd=CreateWindowEx,\
    NULL,\
    addr szWindowClassName,\
    addr szAppName,\
    WS_OVERLAPPEDWINDOW,\
    CW_USEDEFAULT,\
    CW_USEDEFAULT,\
    CW_USEDEFAULT,\
    CW_USEDEFAULT,\
    NULL,\
    NULL,\
    hInst,\
    NULL

if you are not happy with the name fnx, you can redeclare the fn-macro:

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fn macro args:VARARG
	fnx args
endm

Title: Re: Using rv macro
Post by: jj2007 on April 25, 2012, 08:50:22 PM

Strangely enough,

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	Let esi="Hello \
	World"+CrLf$
	Print esi

outputs Hello World, in spite of the tab before World. Apparently whitespace gets ignored.
Works with Masm but JWasm says Error A2090: Line too long after expansion

Caution with labels, by the way:

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include \masm32\include\masm32rt.inc
.code
mystart:	mov ebx, rv(GetTickCount)
	sub ebx, rv(GetTickCount)
	inkey str$(ebx), " for ebx"
	exit
end mystart

Should be roughly zero, right? Test it... and see what Olly has to say :wink

Title: Re: Using rv macro
Post by: Matthew on April 25, 2012, 09:06:07 PM

Thanks to both :U

Title: Re: Using rv macro
Post by: hutch-- on April 27, 2012, 07:27:41 AM

Matthew,

You hit it right the first time, the macro parser in MASM is a bit "agricultural" in that it expects brackets to be matched on the line where the first one occurs. using either the "fn" or "fnx" macros does the job fine but you must write EAX to the memory operand you want it stored in as in fact you have done.

The MASM Forum Archive 2004 to 2012

General Forums => The Campus => Topic started by: Matthew on April 25, 2012, 07:58:47 PM