diff options
Diffstat (limited to 'doc/nasmdoc.src')
| -rw-r--r-- | doc/nasmdoc.src | 38 |
1 files changed, 25 insertions, 13 deletions
diff --git a/doc/nasmdoc.src b/doc/nasmdoc.src index 03ef92ef..fd8af522 100644 --- a/doc/nasmdoc.src +++ b/doc/nasmdoc.src @@ -1957,7 +1957,7 @@ You can \i{pre-define} single-line macros using the `-d' option on the NASM command line: see \k{opt-d}. -\S{xdefine} Enhancing %define: \I\c{%ixdefine}\i\c{%xdefine} +\S{xdefine} Enhancing \c{%define}: \I\c{%ixdefine}\i\c{%xdefine} To have a reference to an embedded single-line macro resolved at the time that it is embedded, as opposed to when the calling macro is @@ -2074,7 +2074,7 @@ instruction has been used as a label in older code. For example: \c %idefine pause $%? ; Hide the PAUSE instruction -\S{undef} Undefining macros: \i\c{%undef} +\S{undef} Undefining Macros: \i\c{%undef} Single-line macros can be removed with the \c{%undef} command. For example, the following sequence: @@ -2121,6 +2121,27 @@ a relocatable reference such as a code or data address, or anything involving a register). +\S{defstr} Defining Strings: \I\c{%idefstr}\i\c{%defstr} + +\c{%defstr}, and its case-insensitive counterpart \c{%idefstr}, define +or redefine a single-line macro without parameters but converts the +entire right-hand side, after macro expansion, to a quoted string +before definition. + +For example: + +\c %defstr test TEST + +is equivalent to + +\c %define test 'TEST' + +This can be used, for example, with the \c{%!} construct (see +\k{getenv}): + +\c %defstr PATH %!PATH ; The operating system PATH variable + + \H{strlen} \i{String Handling in Macros}: \i\c{%strlen} and \i\c{%substr} It's often useful to be able to handle strings in macros. NASM @@ -3637,18 +3658,9 @@ For example, suppose that you have an environment variable \c{FOO}, and you want the contents of \c{FOO} to be embedded in your program. You could do that as follows: -\c %define FOO %!FOO -\c %define quote ' -\c -\c tmpstr db quote FOO quote +\c %defstr FOO %!FOO -At the time of writing, this will generate an "unterminated string" -warning at the time of defining "quote", and it will add a space -before and after the string that is read in. I was unable to find -a simple workaround (although a workaround can be created using a -multi-line macro), so I believe that you will need to either learn how -to create more complex macros, or allow for the extra spaces if you -make use of this feature in that way. +See \k{defstr} for notes on the \c{%defstr} directive. \C{directive} \i{Assembler Directives} |