JWasm / Discussion / Open Discussion, Help: FASTPASS and prologue/epilogue generation

I’m playing a bit with the delayed expansion for the HLL functions, but the FASTPASS creates some problems for testing.

There are a two errors on compiling (v2.08) without FASTPASS: OPATTR2 and PROLOG2.

I think i have found a solution for this:

void DefineFlatGroup( void )
/**************************/
{
    if( ModuleInfo.flat_grp == NULL ) {
    /* can't fail because <FLAT> is a reserved word */
    ModuleInfo.flat_grp = CreateGroup( "FLAT" );
    ModuleInfo.flat_grp->sym.Ofssize = ModuleInfo.defOfssize;
    //ModuleInfo.flatgrp_idx = ModuleInfo.flat_grp->e.grpinfo->grp_idx;
#ifdef FASTPASS
    }
#else
    } else {
    ModuleInfo.flat_grp->sym.isdefined = TRUE;
    }
#endif
}
void ProcInit( void )
/*******************/
{
    ProcStack = NULL;
    CurrProc  = NULL;
    procidx = 1;
    DefineProc = FALSE;
#ifndef FASTPASS
    ModuleInfo.prologuemode = PEM_DEFAULT;
    ModuleInfo.epiloguemode = PEM_DEFAULT;
#endif
    /* v2.06: no forward references in INVOKE if -Zne is set */
    ModuleInfo.invoke_exprparm = ( Options.strict_masm_compat ? EXPF_NOLCREATE : 0 );
#if AMD64_SUPPORT
    unw_segs_defined = 0;
#endif
}

And now this fails:

.486
.model flat, stdcall
option casemap :none
include \masm32\include\windows.inc
include \masm32\macros\macros.asm

Error A2141: Statement not allowed inside structure definition

windows.inc:
NMHDR STRUCT
    hwndFrom    DWORD ?
    idFrom      DWORD ?
    code    DWORD ?
NMHDR ends
NMTTDISPINFOA STRUCT
  hdr           NMHDR  <>
  lpszText          DWORD  ?
  szText        BYTE 80 dup(?)
  union
    hInst           DWORD  ?
    hinst           DWORD  ?
  ends
  uFlags        DWORD  ?
  lParam        DWORD  ?
NMTTDISPINFOA ENDS
NMTTDISPINFOW STRUCT
  hdr           NMHDR  <>
  lpszText          DWORD  ?
  szText        WORD 80 dup(?)
  union
    hInst           DWORD  ?
    hinst           DWORD  ?
  ends
  uFlags        DWORD  ?
  lParam        DWORD  ?
NMTTDISPINFOW ENDS
macros.asm:
      szText MACRO Name, Text:VARARG
    LOCAL lbl
      jmp lbl
        Name db Text,0
      lbl:
    ENDM

japheth - 2012-11-06

> but the FASTPASS creates some problems for testing.

Perhaps you should explain what the problems are … in a bit more detail

> There are a two errors on compiling (v2.08) without FASTPASS: OPATTR2 and PROLOG2.

I have no idea what OPATTR2 and PROLOG2 are.

> I think i have found a solution for this:

Without knowing the problem I cannot judge your "solution".

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Hjort Nidudsson - 2012-11-06

OPATTR2.ASM is included in the Regress subdir in JWASM’s source code. It test different usage of .TYPE, and the type FLAT fails if not defined:

;--- test .TYPE .386 @what macro xx dw .TYPE xx endm _TEXT segment use32 'CODE' @what FLAT _TEXT ends end

This works in the first pass, but fails in the second because the ModuleInfo.flat_grp->sym.isdefined is cleared on init the second pass. When parsing start over, DefineFlatGroup(void) is called again, but fails to define FLAT.

The PROLOG2.ASM has the problem; works in pass one but fail in second pass:

;--- prologue generation ;--- first instruction after PROC contains a macro function! .386 .model flat, stdcall option casemap :none @prologue macro procname,flag,parmbyte,localbyte,reglist,userparms if flag if parmbyte + localbyte push ebp movzx ebp,sp endif if localbyte add esp,-localbyte endif endif for r,reglist push r endm exitm %localbyte endm CStr macro text local x .const x db text,0 .code exitm <offset x> endm .code x1 proc a1:dword ret x1 endp option prologue:@prologue p1 proc uses ebx esi x:dword ret p1 endp p2 proc uses ebx esi x:dword invoke x1, CStr("abc") ret p2 endp p3 proc uses ebx esi x:dword .if ( eax == 1 ) .endif ret p3 endp end

The problem with a delayed expansion of an <expression>is that it demands a rescan of the source code to work properly. This could be achieved with removing the FASTPASS code for testing.

The syntax of the while (<expression>) { <statement> }, <statement> is executed repeatedly as long as the value of <expression> remains non-zero. The test takes place before each execution of the <statement>. The implementation of this will be:

jmp expression statement: <expanded statement> expression: <expanded expression> jnz statement

A delayed expansion of <expression> will demand (among other things) a reset of global counters (counter = counter + 1), so the rescan of the source code is ideal for testing.

Using FASTPASS and expand delayed code seems to mess up a few other things as well. When a function call is expanded, the last expanded line is repeated after <expanded expression>. A test to determine if this happened:

p = LineStoreCurr->line; <expand expression> if (p != LineStoreCurr->line) LineStoreCurr->line[0] = ‘;’;

I see the FASTPASS code have been around for some time, so it is probably not a big priority to make it work without this. However, it could be a good thing (since it already there) to keep it for testing.
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japheth - 2012-11-06

> This works in the first pass, but fails in the second because the ModuleInfo.flat_grp->sym.isdefined is cleared on init the second pass.

What does "fails" mean? I used the jwasm debug version ( which allows to disable FASTPASS with -d7) and cannot see any problem with FLAT.

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Well,

#ifdef FASTPASS
    }
#else
    } else {
    ModuleInfo.flat_grp->sym.isdefined = TRUE;
    }
#endif

could be written

#ifdef DEBUG_OUT
#ifdef FASTPASS
    } else if ( Parse_Pass > PASS_1 && UseSavedState == FALSE ) {
    ModuleInfo.flat_grp->sym.isdefined = TRUE;
    }
#else
    }
#endif
#else
    }
#endif

if this should be tested with a debug switch.
But then you have to rewrite the runtest.cmd file to include the -d7 switch (maybe you have, I don't).

I was thinking of changing the

#ifndef FASTPASS
#define FASTPASS     1 /* don't scan full source if pass > 1  */
#endif

#ifndef FASTPASS
//#define FASTPASS     1 /* don't scan full source if pass > 1  */
#endif

and then runtest.cmd.

> I used the jwasm debug version ( which allows to disable FASTPASS with -d7)

jwasm -bin type.asm

00000000    20 00

jwasm -d7 -bin type.asm

00000000    00 00

jwasm -bin prolog2.asm

00000000    55 8B EC C9 C2 ..

jwasm -d7 -bin prolog2.asm

00000000    55 0F B7 EC C9 C2 ..

Ok, I see the FLAT problem now. This is kinda special case. Simplest "solution" probably is:

void DefineFlatGroup( void )
/**************************/
{
    if( ModuleInfo.flat_grp == NULL ) {
        /* can't fail because <FLAT> is a reserved word */
        ModuleInfo.flat_grp = CreateGroup( "FLAT" );
        ModuleInfo.flat_grp->sym.Ofssize = ModuleInfo.defOfssize;
    }
    ModuleInfo.flat_grp->sym.isdefined = TRUE; /* v2.09 */
}

Masm and jwasm don't behave identically here, but I don't know if I like what Masm does:

.386
_TEXT segment use32 'CODE'
xxx textequ %(.type FLAT)
%echo type FLAT: xxx
ifdef FLAT
echo FLAT defined
endif
_TEXT ends
end

After all, result 32 in .type means "defined", so why is there no "FLAT defined" message?

The GROUP DGROUP seems to work but FLAT behave different

.386
.model flat
.code
ifdef DGROUP
echo DGROUP defined
endif
end
...
.model small
.code
ifdef DGROUP
echo DGROUP defined
endif
ifdef FLAT
echo FLAT defined
endif
end
jwasm:
DGROUP defined
FLAT defined
masm:
DGROUP defined
type2.asm(6) : error A2085: instruction or register not accepted in current CPU mode
FLAT defined
type2.asm(8) : fatal error A1010: unmatched block nesting

japheth - 2012-11-08

> The GROUP DGROUP seems to work but FLAT behave different

Yes. DGROUP is just an automatically ( by the .MODEL directive ) generated symbol; FLAT is a reserved word, that exists from the very beginning.

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Before I forget (and mess up your tracking system again ;-), I inserted this in the coff section:

ret_code coff_write_header( struct module_info *modinfo )
...
    srcname = CurrFName[ASM];
#ifndef __FULLSRCPATH
    srcname += strlen( srcname );
    while ( srcname > CurrFName[ASM] &&
       *(srcname-1) != '/' &&
       *(srcname-1) != '\\') srcname--;
#endif

japheth - 2012-11-10

Ok, I also checked the "prolog2" thing - your fix is correct and needed.

And the COFF .file value fix is now also the default. This entry might vanish in a later version - Masm v8 does not write this symbol anymore.

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FASTPASS and prologue/epilogue generation

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FASTPASS and prologue/epilogue generation