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Diffstat (limited to 'doc/nasmdoc.src')
| -rw-r--r-- | doc/nasmdoc.src | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/doc/nasmdoc.src b/doc/nasmdoc.src index d6771cf5..4928253f 100644 --- a/doc/nasmdoc.src +++ b/doc/nasmdoc.src @@ -3397,6 +3397,44 @@ top context on the stack. Of course, after a subsequent \c{%push}, it can then still be accessed by the name \c{%$$localmac}. +\S{ctxfallthrough} \i{Context Fall-Through Lookup} + +By NASM version 2.10 context fall-through lookup for single macros +definition is officially deprecated and not supported. It was a bad +designed vague feature. + +A typical test case with context fall-through lookup is the following + +\c %macro ctxthru 0 +\c %push ctx1 +\c %assign %$external 1 +\c %push ctx2 +\c %assign %$internal 1 +\c mov eax, %$external +\c mov eax, %$internal +\c %pop +\c %pop +\c %endmacro + +As you may see \c{%$external} referred as being \c{ctx2} +context local macro but in real it is defined in external context. +This ugly trick will not work anymore. You have to declare that +\c{external} is defined in external context \c{ctx1} explicitly by +adding as many \c{$} as needed. For this case the correct code will +look like + +\c %macro ctxthru 0 +\c %push ctx1 +\c %assign %$external 1 +\c %push ctx2 +\c %assign %$internal 1 +\c mov eax, %$$external +\c mov eax, %$internal +\c %pop +\c %pop +\c %endmacro + + \S{ctxrepl} \i\c{%repl}: \I{renaming contexts}Renaming a Context If you need to change the name of the top context on the stack (in |