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ReC98/libs/BorlandC/fseek.asm

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[Reduction] #442-444: fseek and ftell
2014-09-02 18:41:48 +00:00
; static int pascal near Displacement (FILE *fp)
Displacement proc near
@@P = dword ptr -6
@@disp = word ptr -2
@@fp = DPTR_ 4
if LDATA
[JWasm move] Use unique global names for local labels where it matters From the TASM manual: "NEAR labels defined with the colon directive (:) are considered block-scoped if they are located inside a procedure, and you've selected a language interfacing convention with the MODEL statement. However, these symbols are not truly block-scoped; they can't be defined as anything other than a near label elsewhere in the program." MASM's own local label syntax - declaring labels using @@ and then jumping to the next and previous @@ using @F and @B - is obviously too limiting for any longer function, and is not even supported by TASM unless we switch it to MASM mode completely. While this is indeed ugly, it only affected 16 files, which is way less than what we would get in a TASM build without LOCALS. In comparison to having a modern, cross-platform assembler, that really is a small price to pay.
2014-11-21 07:22:03 +00:00
@@local_stack = 6
[Reduction] #442-444: fseek and ftell
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else
[JWasm move] Use unique global names for local labels where it matters From the TASM manual: "NEAR labels defined with the colon directive (:) are considered block-scoped if they are located inside a procedure, and you've selected a language interfacing convention with the MODEL statement. However, these symbols are not truly block-scoped; they can't be defined as anything other than a near label elsewhere in the program." MASM's own local label syntax - declaring labels using @@ and then jumping to the next and previous @@ using @F and @B - is obviously too limiting for any longer function, and is not even supported by TASM unless we switch it to MASM mode completely. While this is indeed ugly, it only affected 16 files, which is way less than what we would get in a TASM build without LOCALS. In comparison to having a modern, cross-platform assembler, that really is a small price to pay.
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@@local_stack = 2
[Reduction] #442-444: fseek and ftell
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endif
push bp
mov bp, sp
sub sp, @@local_stack
push si
push di
LES_ bx, [bp+@@fp]
cmp ES_[bx+FILE.level], 0
jge short @@absLevel
if LDATA
mov cx, ES_[bx+FILE._bsize]
add cx, ES_[bx+FILE.level]
inc cx
mov ax, cx
else
mov dx, ES_[bx+FILE._bsize]
add dx, ES_[bx+FILE.level]
inc dx
mov ax, dx
endif
jmp short @@bin?
@@absLevel:
LES_ bx, [bp+@@fp]
mov ax, ES_[bx+FILE.level]
cwd
xor ax, dx
sub ax, dx
if LDATA
mov cx, ax
else
mov dx, ax
endif
@@bin?:
mov [bp+@@disp], ax
LES_ bx, [bp+@@fp]
test byte ptr ES_[bx+FILE.flags], 40h
jnz short @@ret
LES_ bx, [bp+@@fp]
if LDATA
[JWasm move] Fix improper structure declarations Really, Borland? You considered it necessary to add directives for object- oriented programming (in Assembly!) and convenience features like bitfield records or PUSHSTATE/POPSTATE, yet you never came up with the actually *helpful* idea of just adding a simple basic pointer data type that depends on the current memory model's data size? Like, something like DP... oh wait, that's already taken, as an alias for DF, the 48-bit 80386 far pointer type. And this, exactly, is the problem with assemblers. The language itself is undefined beyond the instructions themselves, but it's obviously very uncomfortable to program anything with just that, so your assembler needs to add custom directives on top of that, and of course everyone has different ideas of the features and use cases that should (and should not) be covered by syntax. (I'm looking especially at you, NASM.) And then one of those developers sells their compiler division to a different company, which then subsequently discontinues all products without ever releasing the source code, trapping their nice extensions in a single executable for a single platform that is not even legally available anymore. tl;dr: http://xkcd.com/927/
2014-11-20 03:55:57 +00:00
mov dx, word ptr ES_[bx+FILE.curp+2]
mov ax, word ptr ES_[bx+FILE.curp]
[Reduction] #442-444: fseek and ftell
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mov word ptr [bp+@@P+2], dx
mov word ptr [bp+@@P], ax
else
[JWasm move] Fix improper structure declarations Really, Borland? You considered it necessary to add directives for object- oriented programming (in Assembly!) and convenience features like bitfield records or PUSHSTATE/POPSTATE, yet you never came up with the actually *helpful* idea of just adding a simple basic pointer data type that depends on the current memory model's data size? Like, something like DP... oh wait, that's already taken, as an alias for DF, the 48-bit 80386 far pointer type. And this, exactly, is the problem with assemblers. The language itself is undefined beyond the instructions themselves, but it's obviously very uncomfortable to program anything with just that, so your assembler needs to add custom directives on top of that, and of course everyone has different ideas of the features and use cases that should (and should not) be covered by syntax. (I'm looking especially at you, NASM.) And then one of those developers sells their compiler division to a different company, which then subsequently discontinues all products without ever releasing the source code, trapping their nice extensions in a single executable for a single platform that is not even legally available anymore. tl;dr: http://xkcd.com/927/
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mov cx, [bx+FILE.curp]
[Reduction] #442-444: fseek and ftell
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endif
cmp ES_[bx+FILE.level], 0
jge short @@readLoop
jmp short @@writeLoop
@@write:
if LDATA
dec word ptr [bp+@@P]
LES_ bx, [bp+@@P]
else
dec cx
mov bx, cx
endif
cmp byte ptr ES_[bx], 0Ah
jnz short @@writeLoop
inc [bp+@@disp]
@@writeLoop:
if LDATA
mov ax, cx
dec cx
else
mov ax, dx
dec dx
endif
or ax, ax
jnz short @@write
jmp short @@ret
@@read:
if LDATA
les bx, [bp+@@P]
inc word ptr [bp+@@P]
else
mov bx, cx
inc cx
endif
cmp byte ptr ES_[bx], 0Ah
jnz short @@readLoop
inc [bp+@@disp]
@@readLoop:
if LDATA
mov ax, cx
dec cx
else
mov ax, dx
dec dx
endif
or ax, ax
jnz short @@read
@@ret:
mov ax, [bp+@@disp]
pop di
pop si
mov sp, bp
pop bp
ret dPtrSize
Displacement endp
; int __cdecl fseek(FILE *fp, __int32 ofs, int whence)
[JWasm move] Don't use the DIST/CALLMODEL constants for procedures and labels Once you've actually found the right syntax that makes the assembler just use the default call type of the current memory model for both procedures (where it's just "PROC" without anything else) and labels (where it's "LABEL PROC"), these constants become completely unneccessary, even with TASM.
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_fseek proc
[Reduction] #442-444: fseek and ftell
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@@fp = DPTR_ 2 + dPtrSize
@@ofs = dword ptr 2 + dPtrSize + dPtrSize
@@whence = word ptr 2 + dPtrSize + dPtrSize + 4
push bp
mov bp, sp
push si
push di
if LDATA
push word ptr [bp+@@fp+2]
endif
push word ptr [bp+@@fp]
nopcall _fflush
[JWasm move] Fix improper structure declarations Really, Borland? You considered it necessary to add directives for object- oriented programming (in Assembly!) and convenience features like bitfield records or PUSHSTATE/POPSTATE, yet you never came up with the actually *helpful* idea of just adding a simple basic pointer data type that depends on the current memory model's data size? Like, something like DP... oh wait, that's already taken, as an alias for DF, the 48-bit 80386 far pointer type. And this, exactly, is the problem with assemblers. The language itself is undefined beyond the instructions themselves, but it's obviously very uncomfortable to program anything with just that, so your assembler needs to add custom directives on top of that, and of course everyone has different ideas of the features and use cases that should (and should not) be covered by syntax. (I'm looking especially at you, NASM.) And then one of those developers sells their compiler division to a different company, which then subsequently discontinues all products without ever releasing the source code, trapping their nice extensions in a single executable for a single platform that is not even legally available anymore. tl;dr: http://xkcd.com/927/
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popCX_
[Reduction] #442-444: fseek and ftell
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pop cx
or ax, ax
jz short @@fromCur?
mov ax, 0FFFFh
jmp short @@ret
@@fromCur?:
cmp [bp+@@whence], 1
jnz short @@set
LES_ bx, [bp+@@fp]
cmp ES_[bx+FILE.level], 0
jle short @@set
if LDATA
push word ptr [bp+@@fp+2]
endif
push bx
call Displacement
cwd
sub word ptr [bp+@@ofs], ax
sbb word ptr [bp+@@ofs+2], dx
@@set:
LES_ bx, [bp+@@fp]
and ES_[bx+FILE.flags], 0FE5Fh
mov ES_[bx+FILE.level], 0
if LDATA
[JWasm move] Fix improper structure declarations Really, Borland? You considered it necessary to add directives for object- oriented programming (in Assembly!) and convenience features like bitfield records or PUSHSTATE/POPSTATE, yet you never came up with the actually *helpful* idea of just adding a simple basic pointer data type that depends on the current memory model's data size? Like, something like DP... oh wait, that's already taken, as an alias for DF, the 48-bit 80386 far pointer type. And this, exactly, is the problem with assemblers. The language itself is undefined beyond the instructions themselves, but it's obviously very uncomfortable to program anything with just that, so your assembler needs to add custom directives on top of that, and of course everyone has different ideas of the features and use cases that should (and should not) be covered by syntax. (I'm looking especially at you, NASM.) And then one of those developers sells their compiler division to a different company, which then subsequently discontinues all products without ever releasing the source code, trapping their nice extensions in a single executable for a single platform that is not even legally available anymore. tl;dr: http://xkcd.com/927/
2014-11-20 03:55:57 +00:00
mov dx, word ptr ES_[bx+FILE.buffer+2]
[Reduction] #442-444: fseek and ftell
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endif
[JWasm move] Fix improper structure declarations Really, Borland? You considered it necessary to add directives for object- oriented programming (in Assembly!) and convenience features like bitfield records or PUSHSTATE/POPSTATE, yet you never came up with the actually *helpful* idea of just adding a simple basic pointer data type that depends on the current memory model's data size? Like, something like DP... oh wait, that's already taken, as an alias for DF, the 48-bit 80386 far pointer type. And this, exactly, is the problem with assemblers. The language itself is undefined beyond the instructions themselves, but it's obviously very uncomfortable to program anything with just that, so your assembler needs to add custom directives on top of that, and of course everyone has different ideas of the features and use cases that should (and should not) be covered by syntax. (I'm looking especially at you, NASM.) And then one of those developers sells their compiler division to a different company, which then subsequently discontinues all products without ever releasing the source code, trapping their nice extensions in a single executable for a single platform that is not even legally available anymore. tl;dr: http://xkcd.com/927/
2014-11-20 03:55:57 +00:00
mov ax, word ptr ES_[bx+FILE.buffer]
[Reduction] #442-444: fseek and ftell
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if LDATA
[JWasm move] Fix improper structure declarations Really, Borland? You considered it necessary to add directives for object- oriented programming (in Assembly!) and convenience features like bitfield records or PUSHSTATE/POPSTATE, yet you never came up with the actually *helpful* idea of just adding a simple basic pointer data type that depends on the current memory model's data size? Like, something like DP... oh wait, that's already taken, as an alias for DF, the 48-bit 80386 far pointer type. And this, exactly, is the problem with assemblers. The language itself is undefined beyond the instructions themselves, but it's obviously very uncomfortable to program anything with just that, so your assembler needs to add custom directives on top of that, and of course everyone has different ideas of the features and use cases that should (and should not) be covered by syntax. (I'm looking especially at you, NASM.) And then one of those developers sells their compiler division to a different company, which then subsequently discontinues all products without ever releasing the source code, trapping their nice extensions in a single executable for a single platform that is not even legally available anymore. tl;dr: http://xkcd.com/927/
2014-11-20 03:55:57 +00:00
mov word ptr ES_[bx+FILE.curp+2], dx
[Reduction] #442-444: fseek and ftell
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endif
[JWasm move] Fix improper structure declarations Really, Borland? You considered it necessary to add directives for object- oriented programming (in Assembly!) and convenience features like bitfield records or PUSHSTATE/POPSTATE, yet you never came up with the actually *helpful* idea of just adding a simple basic pointer data type that depends on the current memory model's data size? Like, something like DP... oh wait, that's already taken, as an alias for DF, the 48-bit 80386 far pointer type. And this, exactly, is the problem with assemblers. The language itself is undefined beyond the instructions themselves, but it's obviously very uncomfortable to program anything with just that, so your assembler needs to add custom directives on top of that, and of course everyone has different ideas of the features and use cases that should (and should not) be covered by syntax. (I'm looking especially at you, NASM.) And then one of those developers sells their compiler division to a different company, which then subsequently discontinues all products without ever releasing the source code, trapping their nice extensions in a single executable for a single platform that is not even legally available anymore. tl;dr: http://xkcd.com/927/
2014-11-20 03:55:57 +00:00
mov word ptr ES_[bx+FILE.curp], ax
[Reduction] #442-444: fseek and ftell
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push [bp+@@whence]
push word ptr [bp+@@ofs+2]
push word ptr [bp+@@ofs]
mov al, ES_[bx+FILE.fd]
cbw
push ax
nopcall _lseek
add sp, 8
cmp dx, -1
jnz short @@ret0
cmp ax, -1
jnz short @@ret0
mov ax, 0FFFFh
jmp short @@ret
@@ret0:
xor ax, ax
@@ret:
pop di
pop si
pop bp
ret
_fseek endp
; __int32 __cdecl ftell(FILE *fp)
[JWasm move] Don't use the DIST/CALLMODEL constants for procedures and labels Once you've actually found the right syntax that makes the assembler just use the default call type of the current memory model for both procedures (where it's just "PROC" without anything else) and labels (where it's "LABEL PROC"), these constants become completely unneccessary, even with TASM.
2014-11-05 17:20:02 +00:00
_ftell proc
[Reduction] #442-444: fseek and ftell
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@@l = dword ptr -8
@@a = dword ptr -4
@@fp = DPTR_ 2 + dPtrSize
push bp
mov bp, sp
sub sp, 8
push si
push di
mov ax, 1
push ax
xor ax, ax
push ax
push ax
LES_ bx, [bp+@@fp]
mov al, ES_[bx+FILE.fd]
cbw
push ax
nopcall _lseek
add sp, 8
mov word ptr [bp+@@a+2], dx
mov word ptr [bp+@@a], ax
cmp dx, -1
jnz short @@writing?
cmp ax, -1
jnz short @@writing?
jmp @@retA
@@writing?:
LES_ bx, [bp+@@fp]
cmp ES_[bx+FILE.level], 0
if LDATA
jl short @@appending?
jmp @@subDisplacement
else
jge short @@subDisplacement
endif
@@appending?:
mov al, ES_[bx+FILE.fd]
cbw
add ax, ax
mov bx, ax
test byte ptr (_openfd+1)[bx], 8
jz short @@addDisplacement
mov ax, 2
push ax
xor ax, ax
push ax
push ax
mov bx, word ptr [bp+@@fp]
mov al, ES_[bx+FILE.fd]
cbw
push ax
nopcall _lseek
add sp, 8
mov word ptr [bp+@@l+2], dx
mov word ptr [bp+@@l], ax
cmp dx, -1
jnz short @@restore
cmp ax, -1
jnz short @@restore
jmp short @@ret
@@restore:
xor ax, ax
push ax
push word ptr [bp+@@a+2]
push word ptr [bp+@@a]
LES_ bx, [bp+@@fp]
mov al, ES_[bx+FILE.fd]
cbw
push ax
nopcall _lseek
add sp, 8
cmp dx, -1
jnz short @@setAToL
cmp ax, -1
jnz short @@setAToL
mov dx, -1
mov ax, -1
jmp short @@ret
@@setAToL:
mov dx, word ptr [bp+@@l+2]
mov ax, word ptr [bp+@@l]
mov word ptr [bp+@@a+2], dx
mov word ptr [bp+@@a], ax
@@addDisplacement:
if LDATA
push word ptr [bp+@@fp+2]
endif
push word ptr [bp+@@fp]
call Displacement
cwd
add word ptr [bp+@@a], ax
adc word ptr [bp+@@a+2], dx
jmp short @@retA
@@subDisplacement:
if LDATA
push word ptr [bp+@@fp+2]
endif
push word ptr [bp+@@fp]
call Displacement
cwd
sub word ptr [bp+@@a], ax
sbb word ptr [bp+@@a+2], dx
@@retA:
mov dx, word ptr [bp+@@a+2]
mov ax, word ptr [bp+@@a]
@@ret:
pop di
pop si
mov sp, bp
pop bp
ret
_ftell endp