Reintroduced example fib.c via examples/ folder

Makefile

@@ -23,19 +23,24 @@ VM_DIST=$(DIST)/vm
 VM_SRC=vm
 VM_CODE:=$(addprefix $(VM_SRC)/, inst.c runtime.c)
 VM_OBJECTS:=$(VM_CODE:$(VM_SRC)/%.c=$(VM_DIST)/%.o)
-VM_DEPS:=$(VM_OBJECTS:%.o=%.d) $(VM_DIST)/fib.d $(VM_DIST)/main.d
+VM_DEPS:=$(VM_OBJECTS:%.o=%.d) $(VM_DIST)/main.d
 VM_VERBOSE=0
 VM_CFLAGS:=$(CFLAGS) -D VERBOSE=$(VM_VERBOSE)
 VM_OUT=$(DIST)/ovm.out
 
 
+## EXAMPLES setup
+EXAMPLES_DIST=$(DIST)/examples
+EXAMPLES_SRC=examples
+EXAMPLES_CFLAGS=$(CFLAGS)
+EXAMPLES=$(DIST)/fib.out
+
 # Things you want to build on `make`
 all: $(DIST) lib vm examples
 
 lib: $(LIB_DIST) $(LIB_OBJECTS)
 vm: $(VM_DIST) $(VM_OUT)
-examples: vm-examples
+examples: $(EXAMPLES_DIST) $(EXAMPLES)
-vm-examples: $(VM_DIST) $(VM_DIST)/fib.out
 
 # Recipes
 ## LIB Recipes
@@ -56,6 +61,15 @@ $(VM_DIST)/%.o: $(VM_SRC)/%.c
 	@$(CC) $(VM_CFLAGS) -MMD -c $< -o $@ $(LIBS)
 	@echo -e "$(TERM_GREEN)$@$(TERM_RESET)"
 
+## EXAMPLES recipes
+$(DIST)/fib.out: $(LIB_OBJECTS) $(VM_OBJECTS) $(ASM_OBJECTS) $(EXAMPLES_DIST)/fib.o
+	@$(CC) $(EXAMPLES_CFLAGS) $^ -o $@ $(LIBS)
+	@echo -e "$(TERM_GREEN)$@$(TERM_RESET)"
+
+$(EXAMPLES_DIST)/%.o: $(EXAMPLES_SRC)/%.c
+	@$(CC) $(EXAMPLES_CFLAGS) -MMD -c $< -o $@ $(LIBS)
+	@echo -e "$(TERM_GREEN)$@$(TERM_RESET)"
+
 OUT=
 ARGS=
 .PHONY: run
@@ -75,3 +89,6 @@ $(LIB_DIST):
 
 $(VM_DIST):
 	mkdir -p $(VM_DIST)
+
+$(EXAMPLES_DIST):
+	mkdir -p $(EXAMPLES_DIST)

examples/fib.c

@@ -0,0 +1,79 @@
+/* Copyright (C) 2023 Aryadev Chavali
+
+ * You may distribute and modify this code under the terms of the GPLv2
+ * license.  You should have received a copy of the GPLv2 license with
+ * this file.  If not, please write to: aryadev@aryadevchavali.com.
+
+ * Created: 2023-10-23
+ * Author: Aryadev Chavali
+ * Description: An example virtual machine program which computes and
+ * prints fibonacci numbers.  Note that by default the virtual machine
+ * just rolls overflows over, so this program will never terminate.
+ */
+
+#include <assert.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "../vm/inst.h"
+#include "../vm/runtime.h"
+
+int main(void)
+{
+  inst_t instructions[] = {
+      // MOV the values 1 and 1 to REG[0] and REG[1] respectively
+      INST_PUSH(WORD, 1),
+      INST_MOV(WORD, 0),
+      INST_PUSH(WORD, 1),
+      INST_MOV(WORD, 1),
+
+      // Print value at register 0 with newline.
+      INST_PUSH_REG(WORD, 0), // <-- #
+      INST_PRINT(WORD),
+      INST_PUSH(BYTE, '\n'),
+      INST_PRINT(CHAR),
+
+      // Print value at register 1 with newline
+      INST_PUSH_REG(WORD, 1),
+      INST_PRINT(WORD),
+      INST_PUSH(BYTE, '\n'),
+      INST_PRINT(CHAR),
+
+      /* Compute the next pair of fibonacci numbers */
+      // REG[0] + REG[1]
+      INST_PUSH_REG(WORD, 0),
+      INST_PUSH_REG(WORD, 1),
+      INST_PLUS(WORD),
+
+      // Mov REG[0] + REG[1] to REG[0]
+      INST_MOV(WORD, 0),
+
+      // REG[0] + REG[1]
+      INST_PUSH_REG(WORD, 0),
+      INST_PUSH_REG(WORD, 1),
+      INST_PLUS(WORD),
+
+      // Mov REG[0] + REG[1] to REG[1]
+      INST_MOV(WORD, 1),
+
+      // Jump to the point #
+      INST_JUMP_ABS(4),
+      INST_HALT,
+  };
+
+  byte stack[256];
+  vm_t vm = {0};
+  vm_load_stack(&vm, stack, ARR_SIZE(stack));
+  vm_load_program(&vm, instructions, ARR_SIZE(instructions));
+  err_t err = vm_execute_all(&vm);
+
+  if (err)
+  {
+    const char *error_str = err_as_cstr(err);
+    fprintf(stderr, "[ERROR]: %s\n", error_str);
+    fprintf(stderr, "[ERROR]: VM Trace:\n");
+    vm_print_all(&vm, stderr);
+    return 255 - err;
+  }
+  return 0;
+}