This is a preliminary announcement regarding the rewrite/revamp of the NASM preprocessor.
This rewrite addresses issues with implementing recursive macros (%rmacro/%irmacro) as previously attempted, %exitmacro and also makes room for new directives.
New NASM Directives:
This rewrite also attempts to address heavy/nested macro invocation efficiency issues.
This rewrite is currently a branch [in GIT] called preprocessor-rewrite, and tentatively labeled as version 2.10rc1. Please note that NASM 2.09rc (official/main/master) is still going and NASM 2.09 should be released fairly soon.
This rewrite has been known to accurately build all NASMX demos, along with a variety of other code snippets by various people.
As positive/successful as this rewrite has been thus far, it is still a major change and we would like to catch as many bugs as possible before merging it into the main/master NASM code base.
Please help us test this rewrite further by downloading/compiling the preprocessor-rewrite branch of the NASM source code, and testing it against your NASM code/snippets.
Windows (Win32/MinGW) Binaries: http://www.nasm.us/downloads/preproc-rewrite.zip (these binaries will be updated when new preproc-rewrite updates are made, along with a corresponding reply to this thread.)
Source Download via Browser: goto http://repo.or.cz/w/nasm.git/shortlog/refs/heads/preproc-rewrite and click on the top-most tar.gz or zip "snapshot" link, decompress/unarchive accordingly.
Source Download via GIT:
Compiling on MacOSX/FreeBSD/Linux/et al.: (assumes you are in the preproc-rewrite directory of the downloaded source)
Shell Script for GIT Download + Compiling on MacOSX/FreeBSD/Linux/etc al.:
If you are comfortable enough with making this branch of NASM your primary binary on MacOSX/FreeBSD/Linux/et al., follow the above compile instructions with: sudo make install
If there are any questions/comments/corrections/concerns, please reply to this thread.
Thanks. -SpooK
This rewrite addresses issues with implementing recursive macros (%rmacro/%irmacro) as previously attempted, %exitmacro and also makes room for new directives.
New NASM Directives:
- %rmacro: Recursive Macro, can be called arbitrarily deep (really high limit [2^20] set to catch infinite loops.)
- %irmacro: Same as above, except case-insensitive like %imacro.
- %exitmacro: Terminates the current macro invocation, much like %exitrep; can be nested in other preprocessor directives (e.g. %if/%endif) within the macro, with exception of another macro, of course.
- %while/%endwhile/%exitwhile: A fusion between %rep and %if.
- %comment/%endcomment: Comment block for long/multi-line comments. A little syntactic sugar, if you will.
- %final: Causes rest of line after %final to be preprocessed after all other "normal" preprocessing is complete. Multiple %final directives work like the x86 stack, LIFO/FILO.
This rewrite also attempts to address heavy/nested macro invocation efficiency issues.
This rewrite is currently a branch [in GIT] called preprocessor-rewrite, and tentatively labeled as version 2.10rc1. Please note that NASM 2.09rc (official/main/master) is still going and NASM 2.09 should be released fairly soon.
This rewrite has been known to accurately build all NASMX demos, along with a variety of other code snippets by various people.
As positive/successful as this rewrite has been thus far, it is still a major change and we would like to catch as many bugs as possible before merging it into the main/master NASM code base.
Please help us test this rewrite further by downloading/compiling the preprocessor-rewrite branch of the NASM source code, and testing it against your NASM code/snippets.
Windows (Win32/MinGW) Binaries: http://www.nasm.us/downloads/preproc-rewrite.zip (these binaries will be updated when new preproc-rewrite updates are made, along with a corresponding reply to this thread.)
Source Download via Browser: goto http://repo.or.cz/w/nasm.git/shortlog/refs/heads/preproc-rewrite and click on the top-most tar.gz or zip "snapshot" link, decompress/unarchive accordingly.
Source Download via GIT:
git clone git://repo.or.cz/nasm.git preproc-rewrite
cd ./preproc-rewrite
git checkout origin/preproc-rewrite
Compiling on MacOSX/FreeBSD/Linux/et al.: (assumes you are in the preproc-rewrite directory of the downloaded source)
autoheader
autoconf
./configure
make
Shell Script for GIT Download + Compiling on MacOSX/FreeBSD/Linux/etc al.:
#!/bin/sh
git clone git://repo.or.cz/nasm.git preproc-rewrite
cd ./preproc-rewrite
git checkout origin/preproc-rewrite
autoheader
autoconf
./configure
make
If you are comfortable enough with making this branch of NASM your primary binary on MacOSX/FreeBSD/Linux/et al., follow the above compile instructions with: sudo make install
If there are any questions/comments/corrections/concerns, please reply to this thread.
Thanks. -SpooK
MASM has a recursion depth limit somewhere around 20 deep, saying I am interested is a gross understatement.
With recursive macros, and nested structure definitions, NASM is finally ready for a full-blown object oriented buildtime assembly environment.
Just wondering why recursive macros need a different directive to single-depth ones.
With recursive macros, and nested structure definitions, NASM is finally ready for a full-blown object oriented buildtime assembly environment.
Just wondering why recursive macros need a different directive to single-depth ones.
Just wondering why recursive macros need a different directive to single-depth ones.
I can think of two immediate reasons.
1.) So macros (syntax and all) doesn't break existing code because...
2.) Macros can be used to overload instructions, a situation where you would want recursion, e.g (a simplistic example)
%imacro call 1
call _GENERIC_SYMBOL_SCHEME_%1
%endmacro
;...
call PRETTY_FUNCTION_NAME
#2 is (was?) fundamental to NASMX and a few other projects.
wraps them both under the mantle of a common directive which sets a per-macro-name buildtime switch that triggers nested macro references to use the new macro directive
Update: Fixed a bug regarding the emission of labels that immediately precede macro invocations. The new source/binaries are available, and can be found as instructed in the initial post.
Note: The latest x264 source successfully builds and passes checkasm with this preprocessor rewrite of NASM.
Note: The latest x264 source successfully builds and passes checkasm with this preprocessor rewrite of NASM.
Update: Fixed line number handling.
Update: Fixed macro-relative line number handling for %warning/%error/%fatal/etc. This update, combined with the general preprocessor redesign, now allows for %warning/%error/%fatal lines within %rep blocks, that are nested within macros, to correctly emit the exact macro-relative line number.
Update: Context-local labels will no longer implicitly search upper/outer contexts in the case of undefined labels. This feature was added in NASM 0.98.03, and is now being removed due to its unintuitive and error-prone design. There will be a deprecation warning for "usage" of this feature in the NASM 2.09. For NASM 2.10 and beyond, relying on this context-local label fallthrough will simply generate an expression syntax error. If you rely on this soon-to-be deprecated feature, please take this time to adjust your code, accordingly.
Note: The Win32 Binaries link has changed: http://www.nasm.us/downloads/preproc-rewrite.zip
Update: Context-local labels will no longer implicitly search upper/outer contexts in the case of undefined labels. This feature was added in NASM 0.98.03, and is now being removed due to its unintuitive and error-prone design. There will be a deprecation warning for "usage" of this feature in the NASM 2.09. For NASM 2.10 and beyond, relying on this context-local label fallthrough will simply generate an expression syntax error. If you rely on this soon-to-be deprecated feature, please take this time to adjust your code, accordingly.
Note: The Win32 Binaries link has changed: http://www.nasm.us/downloads/preproc-rewrite.zip