preproc: add %i... variants, evaluated macro parameters, cleanupsevalmacro

All directives which create single-line macros now have %i... variants
to define case-insensitive versions. Case insensitive rather sucks,
but at least this way it is consistent.

Single-line macro parameters can now be evaluated as a number, as done
by %assign. To do so, declare a parameter starting with =, for
example:

%define foo(x,=y) mov [x],macro_array_y

... would evaluate y as a number but leave x as a string.

NOTE: it would arguably be better to have this as a per-instance
basis, but it is easily handled by having a secondary macro called
with the same argument twice.

Finally, add a more consistent method for defining "magic" macros,
which need to be evaluated at runtime. For now, it is only used by the
special macros __FILE__, __LINE__, __BITS__, __PTR__, and __PASS__.

__PTR__ is a new macro which evaluates to word, dword or qword
matching the value of __BITS__.

The magic macro framework, however, provides a natural hook for a
future plug-in infrastructure to hook into a scripting language.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/test/evalmacro.asm b/test/evalmacro.asm
new file mode 100644
index 00000000..0dd668dd
--- /dev/null
+++ b/test/evalmacro.asm
@@ -0,0 +1,4 @@
+%define tonum(=x) x
+
+	dd tonum(1+3)
+	dd tonum(5*7)