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

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>

asm/pptok.dat

@@ -1,6 +1,6 @@
 ## --------------------------------------------------------------------------
 ##   
-##   Copyright 1996-2016 The NASM Authors - All Rights Reserved
+##   Copyright 1996-2019 The NASM Authors - All Rights Reserved
 ##   See the file AUTHORS included with the NASM distribution for
 ##   the specific copyright holders.
 ##
@@ -70,8 +70,12 @@
 %ideftok
 %if*
 %imacro
-%irmacro
 %include
+%ipathsearch
+%irmacro
+%istrcat
+%istrlen
+%isubstr
 %ixdefine
 %line
 %local

asm/quote.c

@@ -216,6 +216,14 @@ static char *emit_utf8(char *q, int32_t v)
     return q;
 }
 
+/*
+ * Quote a C string
+ */
+char *nasm_quote_cstr(const char *str)
+{
+    return nasm_quote(str, strlen(str));
+}
+
 /*
  * Do an *in-place* dequoting of the specified string, returning the
  * resulting length (which may be containing embedded nulls.)

asm/quote.h

@@ -37,6 +37,7 @@
 #include "compiler.h"
 
 char *nasm_quote(const char *str, size_t len);
+char *nasm_quote_cstr(const char *str);
 size_t nasm_unquote(char *str, char **endptr);
 char *nasm_skip_string(char *str);
 

macros/standard.mac

@@ -1,6 +1,6 @@
 ;; --------------------------------------------------------------------------
 ;;   
-;;   Copyright 1996-2016 The NASM Authors - All Rights Reserved
+;;   Copyright 1996-2019 The NASM Authors - All Rights Reserved
 ;;   See the file AUTHORS included with the NASM distribution for
 ;;   the specific copyright holders.
 ;;
@@ -49,12 +49,6 @@ STD: nasm
 ; here, not all of them are: the user-level form of a format-specific
 ; directive should be defined in the module for that directive.
 
-; These three need to be defined, though the actual definitions will
-; be constantly updated during preprocessing.
-%define __FILE__
-%define __LINE__
-%define __BITS__
-
 %define __SECT__            ; it ought to be defined, even if as nothing
 
 %imacro section 1+.nolist

test/evalmacro.asm

@@ -0,0 +1,4 @@
+%define tonum(=x) x
+
+	dd tonum(1+3)
+	dd tonum(5*7)