[bug] Error with procedure definition macros in PROC64.INC

Index > Macroinstructions > [bug] Error with procedure definition macros in PROC64.INC

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Bird of Hermes

Joined: 02 Nov 2024
Posts: 4
Location: Russia

Bird of Hermes 02 Nov 2024, 09:19

Because the stdcall fix fastcall line is after the define@proc macro definition, if we define a procedure with the stdcall calling convention, it will be impossible to call functions using standard macros inside such a procedure. The reason for this is that in the define@proc macro, stdcall is not yet replaced with fastcall, so the macro looks for the stdcall convention, and when using the macro, the replacement of stdcall with fastcall is already performed, so the macro receives fastcall as a parameter and turns it into a procedure argument. Here is an example of code that can cause the error

Code:

proc proc1
        ret
endp

proc proc2 stdcall
        fastcall proc1
        ret
endp

To solve this problem, change the order of the definition in the standard distribution or make stdcall a macro.

02 Nov 2024, 09:19

macomics

Joined: 26 Jan 2021
Posts: 1043
Location: Russia

macomics 02 Nov 2024, 14:52

I can't reproduce this with the standard PROC64.INC file from fasmw17332.zip dated 21 Sep 2024 12:13:15 UTC.

Code:

~ $ cat test_proc.asm
use64
include 'PROC64.INC'

proc proc1
        ret
endp

proc proc2 stdcall
        fastcall proc1
        ret
endp
~ $ fasm test_proc.asm test_proc
flat assembler  version 1.73.30  (16384 kilobytes memory)
1 passes, 0 bytes.

02 Nov 2024, 14:52

Bird of Hermes

Joined: 02 Nov 2024
Posts: 4
Location: Russia

Bird of Hermes 02 Nov 2024, 18:59

macomics wrote:

I can't reproduce this with the standard PROC64.INC file from fasmw17332.zip dated 21 Sep 2024 12:13:15 UTC.

Code:

~ $ cat test_proc.asm
use64
include 'PROC64.INC'

proc proc1
        ret
endp

proc proc2 stdcall
        fastcall proc1
        ret
endp
~ $ fasm test_proc.asm test_proc
flat assembler  version 1.73.30  (16384 kilobytes memory)
1 passes, 0 bytes.

Aren't you confused by the fact that the output file contains 0 bytes? Try adding the line a = proc2 to the code.

_________________
If something can't be done with macros, then there were too few macros.

02 Nov 2024, 18:59

macomics

Joined: 26 Jan 2021
Posts: 1043
Location: Russia

macomics 02 Nov 2024, 19:50

Ok. Well

Code:

~ $ cat test_proc.asm
use64
include 'PROC64.INC'

proc proc1
        ret
endp

proc proc2 stdcall
        fastcall proc1
        ret
endp

a = proc2
~ $ fasm -m 102400 test_proc.asm test_proc
flat assembler  version 1.73.30  (102400 kilobytes memory)
test_proc.asm [9]:
        fastcall proc1
PROC64.INC [300] fastcall [292]:
    call proc
processed: ..arg?I proc1
error: illegal instruction.

But!

Code:

~ $ cat test_proc.asm
use64
include 'PROC64.INC'

proc proc1
        ret
endp

proc proc2 stdcall
        fastcall proc1
        ret
endp

        call proc2
~ $ fasm -m 102400 test_proc.asm test_proc
flat assembler  version 1.73.30  (102400 kilobytes memory)
test_proc.asm [13]:
        call proc2
processed: ..arg?I proc2
error: illegal instruction.

That is, the proc2 label was not even generated

02 Nov 2024, 19:50

Bird of Hermes

Joined: 02 Nov 2024
Posts: 4
Location: Russia

Bird of Hermes 03 Nov 2024, 07:59

macomics wrote:

Ok. Well

Code:

~ $ cat test_proc.asm
use64
include 'PROC64.INC'

proc proc1
        ret
endp

proc proc2 stdcall
        fastcall proc1
        ret
endp

a = proc2
~ $ fasm -m 102400 test_proc.asm test_proc
flat assembler  version 1.73.30  (102400 kilobytes memory)
test_proc.asm [9]:
        fastcall proc1
PROC64.INC [300] fastcall [292]:
    call proc
processed: ..arg?I proc1
error: illegal instruction.

But!

Code:

~ $ cat test_proc.asm
use64
include 'PROC64.INC'

proc proc1
        ret
endp

proc proc2 stdcall
        fastcall proc1
        ret
endp

        call proc2
~ $ fasm -m 102400 test_proc.asm test_proc
flat assembler  version 1.73.30  (102400 kilobytes memory)
test_proc.asm [13]:
        call proc2
processed: ..arg?I proc2
error: illegal instruction.

That is, the proc2 label was not even generated

Use jmp instead. Because the proc macro tried to convert fastcall to a local variable using equ, the fastcall macro was called instead and converted call to a local variable

_________________
If something can't be done with macros, then there were too few macros.

03 Nov 2024, 07:59

revolution
When all else fails, read the source

Joined: 24 Aug 2004
Posts: 20459
Location: In your JS exploiting you and your system

revolution 03 Nov 2024, 09:47

Replacing stdcall fix fastcall in proc64.inc with macro stdcall arg& { fastcall args } appears to fix the problem.

Code:

~ cat test.asm 
use64
include 'macro/proc64.inc'

proc proc1
        ret
endp

proc proc2 stdcall
        fastcall proc1
        ret
endp

jmp proc2
call proc2
a = proc2

~ fasm test.asm 
flat assembler  version 1.73.31  (16384 kilobytes memory)
4 passes, 32 bytes.

~

03 Nov 2024, 09:47

Bird of Hermes

Joined: 02 Nov 2024
Posts: 4
Location: Russia

Bird of Hermes 04 Nov 2024, 09:42

revolution wrote:

Replacing stdcall fix fastcall in proc64.inc with macro stdcall arg& { fastcall args } appears to fix the problem.

Code:

~ cat test.asm 
use64
include 'macro/proc64.inc'

proc proc1
        ret
endp

proc proc2 stdcall
        fastcall proc1
        ret
endp

jmp proc2
call proc2
a = proc2

~ fasm test.asm 
flat assembler  version 1.73.31  (16384 kilobytes memory)
4 passes, 32 bytes.

~

Yes, as I said at the very beginning, it works, but I would like this error be fixed in the official package

_________________
If something can't be done with macros, then there were too few macros.

04 Nov 2024, 09:42

revolution
When all else fails, read the source

Joined: 24 Aug 2004
Posts: 20459
Location: In your JS exploiting you and your system

revolution 04 Nov 2024, 10:20

This thread has been stickied and marked with [bug], so it has the best chance to get the attention of the author.

04 Nov 2024, 10:20

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