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Diffstat (limited to 'changes.asm')
| -rw-r--r-- | changes.asm | 292 |
1 files changed, 292 insertions, 0 deletions
diff --git a/changes.asm b/changes.asm new file mode 100644 index 00000000..7b9dd491 --- /dev/null +++ b/changes.asm @@ -0,0 +1,292 @@ +;This file demonstrates many of the differences between NASM version X and NASM +;version 0.97 +; +; changes.asm is copyright (C) 1998 John S. Fine +; +; It may be redistributed under the same conditions as NASM as described in +; Licence file in the NASM archive +;_________________________________ +; +; nasm changes.asm -l changes.lst +; +; When assembled without any -d switches, it includes examples which: +; Work correctly in version X +; and Work incorrectly and/or display warnings in version 0.97 +; and Do not prevent the generation of output in version 0.97 +; +; Not all the differences can be seen in the .lst file. I suggest that you use +; "ndisasm changes" to examine the code actually generated. +;_________________________________ +; +; nasm changes.asm -l changes.lst -doldmsg +; +; When assembled with -doldmsg, it adds examples which: +; Work correctly in version X +; and Generate error messages in version 0.97 and do not generate output +;_________________________________ +; +; nasm changes.asm -l changes.lst -doldcrash +; +; When assembled with -doldcrash, it adds examples which: +; Work correctly in version X +; and Cause NASM to crash in version 0.97 +;_________________________________ +; +; nasm changes.asm -l changes.lst -dnewmsg +; +; When assembled with -dnewmsg, it adds examples which: +; Generate error messages in version X +; and Generate wrong output without warning or error message in version 0.97 +;----------------------------------------------------------------------------- + +; Please note that I have reported the name of the person who made the +; correction based on very limited information. In several cases, I am sure I +; will identify the wrong author. Please send me any corrections; I don't +; intend to insult or exclude anyone. + +;----------------------------------------------------------------------------- +; Bug fixed by Simon in assemble() +; +; The following generated "call next" / "call next-1" instead of +; two copies of "call next" +; + times 2 a16 call next +next: + +;----------------------------------------------------------------------------- +; Bug fixed by John in parse_line() (and other routines) +; +; This used to jmp to prior.1, when it should be here.1 +; +prior: +.1: +here: jmp .1 +.1: + +;----------------------------------------------------------------------------- +; Bug fixed by John in assemble() +; +; Strings used in dq and dt were not zero filled correctly +; + dq 'b' + + +;----------------------------------------------------------------------------- +; Bug fixed by Simon in isn_names[] +; +; Was not recognised as an instruction +; + int01 + +;----------------------------------------------------------------------------- +; Bug fixed by Jim Hague in ??? +; +; Forward references were instruction level rather than per operand +; + shr word [forwardref],1 +forwardref: + +;----------------------------------------------------------------------------- +; Bug fixed by John in preproc.c +; +; It used to silently discard id characters appended to a multi-line +; macro parameter (such as the x in %1x below). +; +%macro xxx 1 +%1: nop +%{1}x: jmp %1x +%endmacro +xxx yyy + +%ifdef oldmsg +;*************************************************************** +; +; The following examples will generate error messages in 0.97 and will generate +; correct output in the new version. + +;----------------------------------------------------------------------------- +; Bug fixed by Simon in isns.dat +; +; The optional "near" was not permitted on JMP and CALL +; + jmp near here + +;----------------------------------------------------------------------------- +; Feature added by Simon in stdscan() +; +; You can now use the numeric value of strings in %assign +; +%assign xxx 'ABCD' + dd xxx + +;----------------------------------------------------------------------------- +; Feature added by John in add_vectors() +; +; Stranger address expressions are now supported as long as they resolve to +; something valid. +; + mov ax, [eax + ebx + ecx - eax] + +;----------------------------------------------------------------------------- +; Bug fixed by Simon in ??? +; +; The EQU directive affected local labels in a way that was inconsistent +; between passes +; +.local: +neither equ $ + jmp .local + +;----------------------------------------------------------------------------- +; Feature added by Jules in parse_line +; +; You can override a size specifier +; +%define arg1 dword [bp+4] + cmp word arg1, 2 + +;----------------------------------------------------------------------------- +; Bug fixed by John in preproc.c +; +; You could not use a label on the same line with a macro invocation, if the +; macro definition began with a preprocessor directive. +; + struc mytype +.long resd 1 + endstruc + +lbl istruc mytype + at mytype.long, dd 'ABCD' + iend + +;----------------------------------------------------------------------------- +; Warning removed by John in preproc.c +; +; In order to allow macros that extend the definition of instructions, I +; disabled the warning on a multi-line macro referencing itself. +; +%endif ;NASM 0.97 doesn't handle %0 etc. inside false %if +%macro push 1-* ; +%rep %0 ; +push %1 ; +%rotate 1 ; +%endrep ; +%endmacro ; +%ifdef oldmsg ; + + push ax,bx + +;----------------------------------------------------------------------------- +; Warning removed by John in preproc.c +; +; To support other types of macros that extend the definition of instructions, +; I disabled the warning on a multi-line macro called with the wrong number of +; parameters. PUSH and POP can be extended equally well by either method, but +; other intruction extensions may need one method or the other, so I made both +; work. +; +; Note that neither of these warnings was really needed, because a later stage +; of NASM would almost always give an adequate error message if the macro use +; really was wrong. +; +%endif +%macro pop 2-* +%rep %0 +pop %1 +%rotate 1 +%endrep +%endmacro +%ifdef oldmsg + + pop ax,bx +%endif + + +%ifdef newmsg ;*************************************************************** + +;----------------------------------------------------------------------------- +; Bug fixed by John in parse_line() (and other routines) +; +; This invalid code used to assemble without errors +; +myself equ myself+1 + jmp myself + +;----------------------------------------------------------------------------- +; Change made by John in preproc.c +; +; In 0.97, an id that appears as a label on a macro invocation was always +; prepended to the first line of the macro expansion. That caused several +; bugs, but also could be used in tricks like the arg macro in c16.mac and +; c32.mac. +; +; In version X, an id that appears as a label on a macro invocation will +; normally be defined as a label for the address at which the macro is +; invoked, regardless of whether the first line of the macro expansion is +; something that can take a label. The new token %00 may be used for any +; of the situations in which the old prepend behavior was doing something +; tricky but useful. %00 can also be used more than once and in places +; other than the start of the expansion. +; +%endif +%assign arg_off 0 + +%imacro arg 0-1 2 ;arg defined the old way + equ arg_off +%assign arg_off %1+arg_off +%endmacro + +%ifdef newmsg +arg_example arg +%endif + +%imacro arg2 0-1 2 ;arg defined the new way +%00 equ arg_off +%assign arg_off %1+arg_off +%endmacro + +%ifdef oldmsg +arg_example2 arg2 + +;----------------------------------------------------------------------------- +; Change made by Jules and John in INSNS.DAT +; +; Various instruction in which the size of an immediate is built-in to the +; instruction set, now allow you to redundantly specify that size as long +; as you specify it correctly +; + AAD byte 5 + AAM byte 5 + BT bx, byte 3 + BTC cx, byte 4 + BTR dx, byte 5 + BTS si, byte 6 + IN eax, byte 0x40 + INT byte 21h + OUT byte 70h, ax + RET word 2 + RETN word 2 + RETF word 4 + +; note "ENTER" has not been changed yet. + +%endif + +%ifdef oldcrash ;************************************************************* + +This_label_is_256_characters_long__There_used_to_be_a_bug_in_stdscan_which_made_it_crash_when_it_did_a_keyword_search_on_any_label_longer_than_255_characters__Now_anything_longer_than_MAX_KEYWORD_is_always_a_symbol__It_will_not_even_try_a_keyword_search___ + +;----------------------------------------------------------------------------- +; Bug fixed by John in preproc.c +; +; Builds of NASM that prohibit dereferencing a NULL pointer used to crash if a +; macro that started with a blank line was invoked with a label +; +%macro empty_macro 0 + +%endm + +emlabel empty_macro + jmp emlabel + +%endif |