Start build system and add error types

.gitignore

@@ -31,3 +31,4 @@
 # Debug files
 *.dSYM/
 *.su
+.depend

Makefile

@@ -0,0 +1,45 @@
+CC = gcc
+RM = rm -f
+CFLAGS = -fPIC -g -O2 -std=c99 \
+	-Wall -Wextra -pedantic -Werror \
+	-Wdeclaration-after-statement \
+	-Wno-format-zero-length \
+	-Wold-style-definition \
+	-Woverflow \
+	-Wpointer-arith \
+	-Wstrict-prototypes \
+	-Wunused \
+	-Wvla
+
+LDFLAGS = -g -shared
+LDLIBS =
+
+TARGET_LIB = mulithash.so
+
+SRCS = errors.c
+OBJS = $(subst .c,.o,$(SRCS))
+
+all: ${TARGET_LIB} 
+
+$(TARGET_LIB): $(OBJS)
+	$(CC) ${LDFLAGS} -o $@ $^
+
+test: test.o pid.o
+	$(C) $(LDFLAGS) -o test test.o pid.o $(LDLIBS) 
+
+depend: .depend
+
+.depend: $(SRCS)
+	rm -f ./.depend
+	$(CC) $(CFLAGS) -MM $^>>./.depend;
+
+clean:
+	$(RM) $(OBJS)
+	$(RM) $(TARGET_LIB)
+
+dist-clean: clean
+	$(RM) *~ .depend
+
+.PHONY: all depend clean dist-clean
+
+include .depend

errors.c

@@ -0,0 +1,18 @@
+/* vim: set ts=8 sw=8 noexpandtab: */
+#include "errors.h"
+
+static const struct mh_error_desc {
+	int code;
+	char *message;
+} mh_errordesc[] = {
+	{ MH_E_UNKNOWN_CODE, "unknown multihash code" },
+	{ MH_E_TOO_SHORT, "multihash too short. must be > 3 bytes" },
+	{ MH_E_TOO_LONG, "multihash too long. must be < 129 bytes" },
+	{ MH_E_LEN_NOT_SUPPORTED, "multihash does not yet support"
+		" digests longer than 127 bytes" }
+};
+
+const char *mh_error_string(mh_error code) {
+	code += 1;
+	return "";
+}

errors.h

@@ -0,0 +1,14 @@
+/* vim: set ts=8 sw=8 noexpandtab: */
+#ifndef ERROR_H
+#define ERROR_H
+
+typedef enum {
+	MH_E_UNKNOWN_CODE = -1,
+	MH_E_TOO_SHORT = -2,
+	MH_E_TOO_LONG = -3,
+	MH_E_LEN_NOT_SUPPORTED = -4
+} mh_error;
+
+const char *mh_error_string(mh_error code);
+
+#endif /* end of include guard */