Added lexer, implemented tests build system

tests/makefile

@@ -0,0 +1,74 @@
+#compiler settings
+CFLAGS=-g -Wall -Werror -Wno-unused-parameter -Wno-unused-function -Wno-unused-variable
+LIBS=-lm
+
+#directories
+TEST_SOURCEDIR=../$(TOY_SOURCEDIR)
+TEST_CASESDIR=cases
+
+TEST_OUTDIR=out
+TEST_OBJDIR=obj
+
+#file names
+TEST_SOURCEFILES=$(wildcard $(TEST_SOURCEDIR)/*.c)
+TEST_CASESFILES=$(wildcard $(TEST_CASESDIR)/*.c)
+
+#build the object files, compile the test cases, and run
+all: clean build-source build-cases $(addprefix $(TEST_OUTDIR)/,$(notdir $(TEST_CASESFILES:%.c=%.exe)))
+
+#targets for each set of source files
+.PHONY: build-source
+build-source: $(TEST_OUTDIR) $(TEST_OBJDIR) $(addprefix $(TEST_OBJDIR)/,$(notdir $(TEST_SOURCEFILES:.c=.o)))
+
+.PHONY: build-cases
+build-cases: $(TEST_OUTDIR) $(TEST_OBJDIR) $(addprefix $(TEST_OBJDIR)/,$(notdir $(TEST_CASESFILES:.c=.o))) 
+
+#util targets
+$(TEST_OUTDIR):
+	mkdir $(TEST_OUTDIR)
+
+$(TEST_OBJDIR):
+	mkdir $(TEST_OBJDIR)
+
+#compilation step
+$(TEST_OBJDIR)/%.o: $(TEST_SOURCEDIR)/%.c
+	$(CC) -c -o $@ $< $(addprefix -I,$(TEST_SOURCEDIR)) $(CFLAGS) -fdata-sections -ffunction-sections
+
+$(TEST_OBJDIR)/%.o: $(TEST_CASESDIR)/%.c
+	$(CC) -c -o $@ $< $(addprefix -I,$(TEST_SOURCEDIR) $(TEST_CASESDIR)) $(CFLAGS) -fdata-sections -ffunction-sections
+
+#final linking step (with extra flags to strip dead code)
+$(TEST_OUTDIR)/%.exe: $(TEST_OBJDIR)/%.o
+	@$(CC) -o $@ $(shell find $(TEST_OBJDIR) -name '*.o') $(CFLAGS) $(LIBS) -Wl,--gc-sections
+	$@
+
+#util commands
+.PHONY: clean
+clean:
+ifeq ($(shell uname),Linux)
+	find . -type f -name '*.o' -delete
+	find . -type f -name '*.a' -delete
+	find . -type f -name '*.exe' -delete
+	find . -type f -name '*.dll' -delete
+	find . -type f -name '*.lib' -delete
+	find . -type f -name '*.so' -delete
+	find . -type f -name '*.dylib' -delete
+	find . -type d -name 'out' -delete
+	find . -type d -name 'obj' -delete
+else ifeq ($(OS),Windows_NT)
+	del *.o *.a *.exe *.dll *.lib *.so *.dylib
+	del /s out
+	del /s obj
+else ifeq ($(shell uname),Darwin)
+	find . -type f -name '*.o' -delete
+	find . -type f -name '*.a' -delete
+	find . -type f -name '*.exe' -delete
+	find . -type f -name '*.dll' -delete
+	find . -type f -name '*.lib' -delete
+	find . -type f -name '*.so' -delete
+	find . -type f -name '*.dylib' -delete
+	find . -type d -name 'out' -delete
+	find . -type d -name 'obj' -delete
+else
+	@echo "Deletion failed - what platform is this?"
+endif