thodg/libgit2

diff --git a/.gitignore b/.gitignore
index f5e3dd7..a6a1a6f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,4 @@
 /include/git/config.h
 *.o
 *.a
+*.exe
diff --git a/Makefile b/Makefile
index 51fcd3c..8c7af5e 100644
--- a/Makefile
+++ b/Makefile
@@ -16,11 +16,19 @@ OBJS += src/os/$(OS).o
 HDRS += include/git/config.h
 HDRS += include/git/os/$(OS).h
 
+GIT_LIB = libgit2.a
 
-all:: libgit2.a
+TEST_OBJ = $(patsubst %.c,%.o,\
+           $(wildcard tests/t[0-9][0-9][0-9][0-9]-*.c))
+TEST_EXE = $(patsubst %.o,%.exe,$(TEST_OBJ))
+TEST_RUN = $(patsubst %.exe,%.run,$(TEST_EXE))
+
+all:: $(GIT_LIB)
 
 clean:
-	rm -f libgit2.a src/*.o
+	rm -f $(GIT_LIB)
+	rm -f src/*.o
+	rm -f tests/*.o tests/*.exe
 	rm -f include/git/config.h
 	rm -rf apidocs
 
@@ -28,6 +36,8 @@ apidocs:
 	$(DOXYGEN) api.doxygen
 	cp CONVENTIONS apidocs/
 
+test: $(TEST_RUN)
+
 .c.o:
 	$(CC) $(BASIC_CFLAGS) $(CFLAGS) -c $< -o $@
 
@@ -36,10 +46,28 @@ include/git/config.h: include/git/config.h.in
 	mv $@+ $@
 
 $(OBJS): $(HDRS)
-libgit2.a: $(OBJS)
-	rm -f libgit2.a
-	$(AR) cr libgit2.a $(OBJS)
+$(GIT_LIB): $(OBJS)
+	rm -f $(LIB)
+	$(AR) cr $(GIT_LIB) $(OBJS)
+
+T_HDR    = tests/test_lib.h
+T_LIB    = tests/test_lib.o
+T_MAIN_C  = tests/test_main.c
+T_MAIN_O = tests/test_main.o
+
+$(T_LIB): tests/test_lib.h $(HDRS)
+$(TEST_EXE): $(T_LIB) $(T_HDR) $(T_MAIN_C) $(HDRS) $(GIT_LIB)
+
+tests/%.exe: tests/%.o
+	grep BEGIN_TEST $(patsubst %.o,%.c,$<) >tests/test_contents
+	$(CC) $(CFLAGS) -Iinclude -c $(T_MAIN_C) -o $(T_MAIN_O)
+	$(CC) -o $@ $(T_MAIN_O) $< $(T_LIB) -L. -lgit2
+	rm -f $(T_MAIN_O) tests/test_contents
+
+$(TEST_RUN): $(TEST_EXE)
+	$<
 
 .PHONY: all
 .PHONY: clean
+.PHONY: test $(TEST_RUN)
 .PHONY: apidocs
diff --git a/include/git/common.h b/include/git/common.h
index 45bb348..9882255 100644
--- a/include/git/common.h
+++ b/include/git/common.h
@@ -43,6 +43,20 @@
 # define GIT_EXTERN(type) type
 #endif
 
+/** Declare a function never returns to the caller. */
+#ifdef __GNUC__
+# define GIT_NORETURN __attribute__((__noreturn__))
+#else
+# define GIT_NORETURN /* empty */
+#endif
+
+/** Declare a function's takes printf style arguments. */
+#ifdef __GNUC__
+# define GIT_FORMAT_PRINTF(a,b) __attribute__((format (printf, a, b)))
+#else
+# define GIT_FORMAT_PRINTF(a,b) /* empty */
+#endif
+
 /**
  * @file git/common.h
  * @brief Git common platform definitions
diff --git a/tests/t0000-oid.c b/tests/t0000-oid.c
new file mode 100644
index 0000000..b0a3077
--- /dev/null
+++ b/tests/t0000-oid.c
@@ -0,0 +1,46 @@
+#include "test_lib.h"
+#include <git/oid.h>
+
+BEGIN_TEST(empty_string)
+	git_oid out;
+	must_fail(git_oid_mkstr(&out, ""));
+END_TEST
+
+BEGIN_TEST(invalid_string_moo)
+	git_oid out;
+	must_fail(git_oid_mkstr(&out, "moo"));
+END_TEST
+
+BEGIN_TEST(invalid_string_16a67770b7d8d72317c4b775213c23a8bd74f5ez)
+	git_oid out;
+	must_fail(git_oid_mkstr(&out, "16a67770b7d8d72317c4b775213c23a8bd74f5ez"));
+END_TEST
+
+BEGIN_TEST(valid_string_16a67770b7d8d72317c4b775213c23a8bd74f5e0)
+	git_oid out;
+	unsigned char exp[] = {
+		0x16, 0xa6, 0x77, 0x70, 0xb7,
+		0xd8, 0xd7, 0x23, 0x17, 0xc4,
+		0xb7, 0x75, 0x21, 0x3c, 0x23,
+		0xa8, 0xbd, 0x74, 0xf5, 0xe0,
+	};
+
+	must_pass(git_oid_mkstr(&out, "16a67770b7d8d72317c4b775213c23a8bd74f5e0"));
+	must_pass(memcmp(out.id, exp, sizeof(out.id)));
+
+	must_pass(git_oid_mkstr(&out, "16A67770B7D8D72317C4b775213C23A8BD74F5E0"));
+	must_pass(memcmp(out.id, exp, sizeof(out.id)));
+END_TEST
+
+BEGIN_TEST(valid_raw)
+	git_oid out;
+	unsigned char exp[] = {
+		0x16, 0xa6, 0x77, 0x70, 0xb7,
+		0xd8, 0xd7, 0x23, 0x17, 0xc4,
+		0xb7, 0x75, 0x21, 0x3c, 0x23,
+		0xa8, 0xbd, 0x74, 0xf5, 0xe0,
+	};
+
+	git_oid_mkraw(&out, exp);
+	must_pass(memcmp(out.id, exp, sizeof(out.id)));
+END_TEST
diff --git a/tests/test_lib.c b/tests/test_lib.c
new file mode 100644
index 0000000..06a1c29
--- /dev/null
+++ b/tests/test_lib.c
@@ -0,0 +1,99 @@
+/*
+ * This file is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2,
+ * as published by the Free Software Foundation.
+ *
+ * In addition to the permissions in the GNU General Public License,
+ * the authors give you unlimited permission to link the compiled
+ * version of this file into combinations with other programs,
+ * and to distribute those combinations without any restriction
+ * coming from the use of this file.  (The General Public License
+ * restrictions do apply in other respects; for example, they cover
+ * modification of the file, and distribution when not linked into
+ * a combined executable.)
+ *
+ * This file is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+#include "test_lib.h"
+
+struct test_info
+{
+	struct test_info *next;
+	const char *test_name;
+	const char *file_name;
+	int line_no;
+};
+
+static int first_test = 1;
+static struct test_info *current_test;
+
+static void show_test_result(const char *status)
+{
+	fprintf(stderr, "* %-6s %5d: %s\n",
+	        status,
+			current_test->line_no,
+			current_test->test_name);
+}
+
+void test_die(const char *fmt, ...)
+{
+	va_list p;
+
+	if (current_test)
+		show_test_result("FAILED");
+
+	va_start(p, fmt);
+	vfprintf(stderr, fmt, p);
+	va_end(p);
+	fputc('\n', stderr);
+	fflush(stderr);
+	exit(128);
+}
+
+void test_begin(
+	const char *test_name,
+	const char *file_name,
+	int line_no)
+{
+	struct test_info *i = malloc(sizeof(*i));
+	if (!i)
+		test_die("cannot malloc memory");
+
+	i->test_name = test_name;
+	i->file_name = file_name;
+	i->line_no = line_no;
+	current_test = i;
+
+	if (first_test) {
+		const char *name = strrchr(i->file_name, '/');
+		if (name)
+			name = name + 1;
+		else
+			name = i->file_name;
+		fprintf(stderr, "*** %s ***\n", name);
+		first_test = 0;
+	}
+}
+
+void test_end(void)
+{
+	if (!current_test)
+		test_die("BEGIN_TEST() not used before END_TEST");
+
+	show_test_result("ok");
+	free(current_test);
+	current_test = NULL;
+}
diff --git a/tests/test_lib.h b/tests/test_lib.h
new file mode 100644
index 0000000..7e7c393
--- /dev/null
+++ b/tests/test_lib.h
@@ -0,0 +1,85 @@
+/*
+ * This file is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2,
+ * as published by the Free Software Foundation.
+ *
+ * In addition to the permissions in the GNU General Public License,
+ * the authors give you unlimited permission to link the compiled
+ * version of this file into combinations with other programs,
+ * and to distribute those combinations without any restriction
+ * coming from the use of this file.  (The General Public License
+ * restrictions do apply in other respects; for example, they cover
+ * modification of the file, and distribution when not linked into
+ * a combined executable.)
+ *
+ * This file is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include <stdio.h>
+#include <git/common.h>
+
+/**
+ * Declares a new test block starting, with the specified name.
+ * @param name C symbol to assign to this test's function.
+ */
+#define BEGIN_TEST(name) \
+	void testfunc__##name (void) \
+	{ \
+		test_begin(#name, __FILE__, __LINE__); \
+	{
+
+/** Denote the end of a test. */
+#define END_TEST \
+	} \
+		test_end(); \
+	}
+
+/* These are internal functions for BEGIN_TEST, END_TEST. */
+extern void test_begin(const char *, const char *, int);
+extern void test_end(void);
+
+/**
+ * Abort the current test suite.
+ *
+ * This function terminates the current test suite
+ * and does not return to the caller.
+ *
+ * @param fmt printf style format string.
+ */
+extern void test_die(const char *fmt, ...)
+	GIT_NORETURN
+	GIT_FORMAT_PRINTF(1, 2);
+
+/**
+ * Evaluate a library function which must return success.
+ *
+ * The definition of "success" is the classical 0 return value.
+ * This macro makes the test suite fail if the expression evaluates
+ * to a non-zero result.  It is suitable for testing most API
+ * functions in the library.
+ *
+ * @param expr the expression to evaluate, and test the result of.
+ */
+#define must_pass(expr) \
+	if (expr) test_die("line %d: %s", __LINE__, #expr)
+
+/**
+ * Evaluate a library function which must return an error.
+ *
+ * The definition of "failure" is the classical non-0 return value.
+ * This macro makes the test suite fail if the expression evaluates
+ * to 0 (aka success).  It is suitable for testing most API
+ * functions in the library.
+ *
+ * @param expr the expression to evaluate, and test the result of.
+ */
+#define must_fail(expr) \
+	if (!(expr)) test_die("line %d: %s", __LINE__, #expr)
diff --git a/tests/test_main.c b/tests/test_main.c
new file mode 100644
index 0000000..a870abd
--- /dev/null
+++ b/tests/test_main.c
@@ -0,0 +1,39 @@
+/*
+ * This file is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2,
+ * as published by the Free Software Foundation.
+ *
+ * In addition to the permissions in the GNU General Public License,
+ * the authors give you unlimited permission to link the compiled
+ * version of this file into combinations with other programs,
+ * and to distribute those combinations without any restriction
+ * coming from the use of this file.  (The General Public License
+ * restrictions do apply in other respects; for example, they cover
+ * modification of the file, and distribution when not linked into
+ * a combined executable.)
+ *
+ * This file is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include "test_lib.h"
+
+#undef BEGIN_TEST
+#define BEGIN_TEST(name) extern void testfunc__##name(void);
+#include "test_contents"
+
+int main(int argc, char **argv)
+{
+#undef BEGIN_TEST
+#define BEGIN_TEST(name) testfunc__##name();
+#include "test_contents"
+
+	return 0;
+}