Make the compiler options a bit more strict about C compliance (in other words I just learned about these flags and they seem to be ideal for this project).

Makefile

@@ -1,5 +1,5 @@
 CC = gcc
-CFLAGS=-g -Wall -DDEBUG -Wpedantic -Wextra
+CFLAGS=-g -Wall -DDEBUG -Wpedantic -Wextra -Wunused-result -std=c99 -pedantic-errors
 SRCDIR=src
 OBJDIR=obj
 SRCS=$(wildcard $(SRCDIR)/*.c)
@@ -11,7 +11,7 @@ BIN=$(BINDIR)/assm
 
 all: $(BIN)
 
-release: CFLAGS=-Wall -Wpedantic -O2
+release: CFLAGS=-Wall -Wpedantic -std=c99 -pedantic-errors -O2
 release: clean
 release: $(BIN)