Fix 2004/vik2 for Linux

Unfortunately this fix required heavy modification to the original file
and inclusion of a file that was once generated by the Makefile but now
it works for both macOS and Linux. It unfortunately will generate a lot
of warnings in Linux (or at least some - in Rocky Linux and Fedora Linux
it generates a lot of warnings about GCC extensions and with clang it
also generates warning(s?) about reserved keywords for a total of 45131
(!!) warnings) but still it now works with Linux and macOS (clean
compilation).

See the thanks-for-fixes.md file for example warnings and what this fix
entailed.

2004/vik2/.gitignore

@@ -1,6 +1,4 @@
 cat-killing-curiosity
 vik2
-vik2_1.c
-vik2_2.c
 vik2.possible.cat.death_1.c
 vik2.possible.cat.death_2.c

2004/vik2/Makefile

@@ -38,7 +38,7 @@ include ../../var.mk
 
 # Common C compiler warnings to silence
 #
-CSILENCE= -Wno-strict-prototypes
+CSILENCE= -Wno-strict-prototypes -Wno-implicit-function-declaration
 
 # Common C compiler warning flags
 #
@@ -127,11 +127,7 @@ all: data ${TARGET}
 	supernova deep_magic magic charon pluto
 
 ${PROG}: ${PROG}.c
-	${RM} -f ${PROG}_1.c
-	${CC} -E '-DSTOP=_5' '-DFNAME="${PROG}_1.c"' ${PROG}.c > ${PROG}_1.c
-	${RM} -f ${PROG}_2.c
-	${CC} -E ${PROG}_1.c > ${PROG}_2.c
-	${CC} ${CFLAGS} ${PROG}_2.c -o ${PROG}
+	${CC} ${CFLAGS} -DFNAME='"${PROG}.c"' '-DSTOP=_5' ${PROG}.c -o ${PROG}
 
 # alternative executable
 #
@@ -153,12 +149,12 @@ everything: all alt
 # On some systems such as Linux, this source either fails
 # to finish compiling or takes a super-long time generating
 # a huge number of compiler errors.  As such, we do not
-# recommend compiling this code.  However for some the
+# recommend compiling this code.  However for ailurophiles the
 # curiosity factor, even though it may have the effect of:
 #
 #	kill -9 cat
 #
-# may too strong for some not try to compile the original
+# may be too strong to not try and compile the original
 # vik2 source code.  Therefore we offer this special
 # Makefile rule for those who do not wish curtail their curiosity.
 #
@@ -184,14 +180,13 @@ clean:
 	    ${RM} -f indent.c; \
 	fi
 vik2_clean:
-	${RM} -f vik2_1.c vik2_2.c vik2.o
+	${RM} -f vik2.o
 
 vik2_clobber: vik2_clean
 	${RM} -f vik2
 
 clobber: clean
 	${RM} -f ${TARGET} ${ALT_TARGET}
-	${RM} -f ${PROG}_1.c ${PROG}_2.c
 	${RM} -f ${PROG}.possible.cat.death_1.c ${PROG}.possible.cat.death_2.c cat-killing-curiosity
 	@-if [ -e sandwich ]; then \
 	    ${RM} -f sandwich; \

thanks-for-fixes.md

@@ -958,7 +958,7 @@ int and the rest must be a `char **`.
 
 ## [2004/gavin](2004/gavin/gavin.c) ([README.md](2004/gavin/README.md]))
 
-Yusuke  provided the `kernel` and `fs.tar`
+Yusuke provided the `kernel` and `fs.tar`
 files which can be used if you cannot normally use this entry. Instead of
 generating the files just use the files provided, found under the
 [img/](2004/gavin/img/)
@@ -982,6 +982,78 @@ second arg to main, which clang requires to be a `char **`, to be not the same
 name as a function defined earlier in the code and to use that variable which
 `main()` used.
 
+## [2004/vik2](2004/vik2/vik2.c) ([README.md](2004/vik2/README.md))
+
+Cody fixed this to compile in Linux. Although it compiled cleanly in macOS (and
+BSD?) the code failed to compile at all in Linux due to:
+
+```c
+cc -E vik2_1.c > vik2_2.c
+In file included from vik2.c:945,
+                 from vik2.c:959,
+                 from vik2.c:972,
+                 from vik2.c:1025:
+vik2.c:383:8: error: no macro name given in #ifdef directive
+  383 | O  \
+      |        ^
+In file included from vik2.c:946:
+vik2.c:383:8: error: no macro name given in #ifdef directive
+  383 | O  \
+      |        ^
+In file included from vik2.c:947:
+vik2.c:383:8: error: no macro name given in #ifdef directive
+  383 | O  \
+      |        ^
+In file included from vik2.c:948:
+vik2.c:383:8: error: no macro name given in #ifdef directive
+  383 | O  \
+      |        ^
+
+...
+
+In file included from vik2.c:182:
+
+vik2.c:992:85: error: #include nested depth 201 exceeds maximum of 200 (use -fmax-include-depth=DEPTH to increase the maximum)
+  992 | I
+      |                                                                                     ^
+vik2.c:1497:21: error: #include nested depth 200 exceeds maximum of 200 (use -fmax-include-depth=DEPTH to increase the maximum)
+vik2.c:1498:21: error: #include nested depth 200 exceeds maximum of 200 (use -fmax-include-depth=DEPTH to increase the maximum)
+vik2.c:1499:21: error: #include nested depth 200 exceeds maximum of 200 (use -fmax-include-depth=DEPTH to increase the maximum)
+vik2.c:1500:21: error: #include nested depth 200 exceeds maximum of 200 (use -fmax-include-depth=DEPTH to increase the maximum)
+vik2.c:1501:21: error: #include nested depth 200 exceeds maximum of 200 (use -fmax-include-depth=DEPTH to increase the maximum)
+vik2.c:1504:21: error: #include nested depth 200 exceeds maximum of 200 (use -fmax-include-depth=DEPTH to increase the maximum)
+make: *** [Makefile:133: vik2] Error 1
+
+```
+
+Unfortunately the fix required heavy modification to the original file (see
+below) and also inclusion of what used to be generated by the
+[Makefile](2004/vik2/Makefile) and will, in Linux, give many warnings like:
+
+```c
+cc -std=gnu99 -Wall -Wextra -pedantic -Wno-strict-prototypes -Wno-implicit-function-declaration    -O3 -DFNAME='"vik2.c"' '-DSTOP=_5' vik2.c -o vik2
+In file included from vik2.c:1002:
+vik2_1.c: In function 'main':
+vik2_1.c:1:3: warning: style of line directive is a GCC extension
+    1 | # 1 "vik2.c"
+      |   ^
+
+...
+
+```
+
+(which does not show up in macOS) but now it at least works for both Linux and
+macOS.
+
+As for the fix itself it required changing the C pre-processor macros that
+resulted in macros themselves like `#ifdef`, `#else` etc. to be `#ifdef`,
+`#else` etc. and also the inclusion of the file [vik2_1.c](2004/vik2/vik2_1.c)
+which used to be generated by the Makefile via `cc -E`. As one can see that file
+has references to macOS things but this is not harmful in Linux. It might be
+that those lines can be removed but there is no harm and since there are a lot
+of it this has not been done (`vik2.c` has 1009 lines and `vik2_1.c` has 1555
+lines!).
+
 
 ## [2005/aidan](2005/aidan/aidan.c) ([README.md](2005/aidan/README.md]))