Fix crash when source file is missing

HCF is now a successful exit
Fix crash when source file is missing or unreadable
Add fizzbuzz sample

Author: Phlarx

Makefile

@@ -1,6 +1,6 @@
 CC=gcc
-#CFLAGS= -Wall -Wextra -Wpedantic -O3 -std=c11
-CFLAGS= -Wall -Wextra -Wpedantic -O0 -std=c11 -g
+CFLAGS= -Wall -Wextra -Wpedantic -O3 -std=c11
+#CFLAGS= -Wall -Wextra -Wpedantic -O0 -std=c11 -g
 RM=rm -f
 
 OBJECTS=tis.o tis_io.o tis_node.o tis_ops.o

README.md

@@ -3,5 +3,8 @@ A TIS-100 emulator, for the wonderful Zachtronics game of the same name. Uses TI
 
 None of the others available did quite what I wanted, so I'm going to try my hand at making my own.
 
+This is all very WIP, so a bunch of things aren't implemented. However, the instruction set should be functional
+and complete. Also no documentation yet, sorry. It's on my short list.
+
 (useful links for dev'ment:)
 https://alandesmet.github.io/TIS-100-Hackers-Guide/

sample/fizzbuzz.tisasm

@@ -0,0 +1,68 @@
+@0
+## FizzBuzz
+# shuttle
+MOV RIGHT DOWN
+MOV DOWN RIGHT
+@1
+# div 3
+MOV RIGHT DOWN
+MOV DOWN NIL
+MOV RIGHT DOWN
+MOV DOWN NIL
+MOV RIGHT LEFT
+MOV LEFT DOWN
+MOV DOWN NIL
+@2
+# counter
+S: SUB 100
+JGZ Q
+ADD 101
+MOV ACC LEFT
+JMP S
+Q: HCF
+@3
+# shuttle
+MOV UP DOWN
+MOV DOWN UP
+@4
+# div 5
+MOV UP DOWN
+MOV NIL UP
+MOV UP DOWN
+MOV NIL UP
+MOV UP DOWN
+MOV NIL UP
+MOV UP DOWN
+MOV NIL UP
+MOV UP RIGHT
+MOV RIGHT DOWN
+MOV NIL UP
+@5
+# shuttle
+MOV LEFT DOWN
+MOV DOWN LEFT
+@6
+# print Fizz
+MOV UP NIL
+MOV 70 DOWN
+MOV 105 DOWN
+MOV 122 DOWN
+MOV 122 DOWN
+MOV NIL UP
+@7
+# print numbers
+MOV ANY ACC
+JEZ N
+MOV ACC DOWN
+N: MOV -1 RIGHT
+@8
+# print Buzz + \n
+S: MOV ANY ACC
+JLZ N
+MOV 66 DOWN
+MOV 117 DOWN
+MOV 122 DOWN
+MOV 122 DOWN
+MOV NIL UP
+JMP S
+N: MOV 10 DOWN

sample/fizzbuzz.tiscfg

@@ -0,0 +1,7 @@
+3 3
+CCC
+CCC
+CCC
+O0 ASCII -
+O1 NUMERIC -
+O2 ASCII -

sample/hello.tisasm

@@ -12,4 +12,5 @@ MOV 114 DOWN
 MOV 108 DOWN
 MOV 100 DOWN
 MOV 33 DOWN
-MOV 0 UP
+MOV 10 DOWN
+HCF

tis.c

@@ -259,6 +259,10 @@ int init_layout(tis_t* tis, char* layoutfile, int layoutmode) {
 
 int init_nodes(tis_t* tis, char* sourcefile) {
     FILE* source = fopen(sourcefile, "r");
+    if(source == NULL) {
+        error("Unable to open source file '%s' for reading\n", sourcefile);
+        return INIT_FAIL;
+    }
 
     char buf[BUFSIZE];
     int id = -1, preid = -1;

tis_ops.c

@@ -27,7 +27,7 @@ tis_op_result_t step(tis_t* tis, tis_node_t* node, tis_op_t* op) {
                 }
                 break;
             case TIS_OP_TYPE_HCF:
-                custom_abort();
+                halt();
                 break;
             case TIS_OP_TYPE_JEZ:
                 if(node->acc == 0) {

tis_types.h

@@ -252,6 +252,7 @@ extern tis_opt_t opts;
 #define error(...) do { if(opts.verbose >= -1) { fprintf(stderr, "ERROR:\t"__VA_ARGS__); } } while(0)
 
 #define custom_abort() exit(EXIT_FAILURE)
+#define halt() exit(EXIT_SUCCESS)
 
 /*
  * Begin inlines