1 files changed, 401 insertions, 0 deletions
diff --git a/src/util/errors.c b/src/util/errors.c
new file mode 100644
index 0000000..feed6a8
--- /dev/null
+++ b/src/util/errors.c
@@ -0,0 +1,401 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "git2_util.h"
+
+#include "errors.h"
+#include "posix.h"
+#include "str.h"
+#include "runtime.h"
+
+/*
+ * Some static error data that is used when we're out of memory, TLS
+ * has not been setup, or TLS has failed.
+ */
+
+static git_error oom_error = {
+	"Out of memory",
+	GIT_ERROR_NOMEMORY
+};
+
+static git_error uninitialized_error = {
+	"library has not been initialized",
+	GIT_ERROR_INVALID
+};
+
+static git_error tlsdata_error = {
+	"thread-local data initialization failure",
+	GIT_ERROR_THREAD
+};
+
+static git_error no_error = {
+	"no error",
+	GIT_ERROR_NONE
+};
+
+#define IS_STATIC_ERROR(err) \
+	((err) == &oom_error || (err) == &uninitialized_error || \
+	 (err) == &tlsdata_error || (err) == &no_error)
+
+/* Per-thread error state (TLS) */
+
+static git_tlsdata_key tls_key;
+
+struct error_threadstate {
+	/* The error message buffer. */
+	git_str message;
+
+	/* Error information, set by `git_error_set` and friends. */
+	git_error error;
+
+	/*
+	 * The last error to occur; points to the error member of this
+	 * struct _or_ a static error.
+	 */
+	git_error *last;
+};
+
+static void threadstate_dispose(struct error_threadstate *threadstate)
+{
+	if (!threadstate)
+		return;
+
+	git_str_dispose(&threadstate->message);
+}
+
+static struct error_threadstate *threadstate_get(void)
+{
+	struct error_threadstate *threadstate;
+
+	if ((threadstate = git_tlsdata_get(tls_key)) != NULL)
+		return threadstate;
+
+	/*
+	 * Avoid git__malloc here, since if it fails, it sets an error
+	 * message, which requires thread state, which would allocate
+	 * here, which would fail, which would set an error message...
+	 */
+
+	if ((threadstate = git__allocator.gmalloc(
+			sizeof(struct error_threadstate),
+			__FILE__, __LINE__)) == NULL)
+		return NULL;
+
+	memset(threadstate, 0, sizeof(struct error_threadstate));
+
+	if (git_str_init(&threadstate->message, 0) < 0) {
+		git__allocator.gfree(threadstate);
+		return NULL;
+	}
+
+	git_tlsdata_set(tls_key, threadstate);
+	return threadstate;
+}
+
+static void GIT_SYSTEM_CALL threadstate_free(void *threadstate)
+{
+	threadstate_dispose(threadstate);
+	git__free(threadstate);
+}
+
+static void git_error_global_shutdown(void)
+{
+	struct error_threadstate *threadstate;
+
+	threadstate = git_tlsdata_get(tls_key);
+	git_tlsdata_set(tls_key, NULL);
+
+	threadstate_dispose(threadstate);
+	git__free(threadstate);
+
+	git_tlsdata_dispose(tls_key);
+}
+
+int git_error_global_init(void)
+{
+	if (git_tlsdata_init(&tls_key, &threadstate_free) != 0)
+		return -1;
+
+	return git_runtime_shutdown_register(git_error_global_shutdown);
+}
+
+static void set_error_from_buffer(int error_class)
+{
+	struct error_threadstate *threadstate = threadstate_get();
+	git_error *error;
+	git_str *buf;
+
+	if (!threadstate)
+		return;
+
+	error = &threadstate->error;
+	buf = &threadstate->message;
+
+	error->message = buf->ptr;
+	error->klass = error_class;
+
+	threadstate->last = error;
+}
+
+static void set_error(int error_class, char *string)
+{
+	struct error_threadstate *threadstate = threadstate_get();
+	git_str *buf;
+
+	if (!threadstate)
+		return;
+
+	buf = &threadstate->message;
+
+	git_str_clear(buf);
+
+	if (string)
+		git_str_puts(buf, string);
+
+	if (!git_str_oom(buf))
+		set_error_from_buffer(error_class);
+}
+
+void git_error_set_oom(void)
+{
+	struct error_threadstate *threadstate = threadstate_get();
+
+	if (!threadstate)
+		return;
+
+	threadstate->last = &oom_error;
+}
+
+void git_error_set(int error_class, const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	git_error_vset(error_class, fmt, ap);
+	va_end(ap);
+}
+
+void git_error_vset(int error_class, const char *fmt, va_list ap)
+{
+#ifdef GIT_WIN32
+	DWORD win32_error_code = (error_class == GIT_ERROR_OS) ? GetLastError() : 0;
+#endif
+
+	struct error_threadstate *threadstate = threadstate_get();
+	int error_code = (error_class == GIT_ERROR_OS) ? errno : 0;
+	git_str *buf;
+
+	if (!threadstate)
+		return;
+
+	buf = &threadstate->message;
+
+	git_str_clear(buf);
+
+	if (fmt) {
+		git_str_vprintf(buf, fmt, ap);
+		if (error_class == GIT_ERROR_OS)
+			git_str_PUTS(buf, ": ");
+	}
+
+	if (error_class == GIT_ERROR_OS) {
+#ifdef GIT_WIN32
+		char *win32_error = git_win32_get_error_message(win32_error_code);
+		if (win32_error) {
+			git_str_puts(buf, win32_error);
+			git__free(win32_error);
+
+			SetLastError(0);
+		}
+		else
+#endif
+		if (error_code)
+			git_str_puts(buf, strerror(error_code));
+
+		if (error_code)
+			errno = 0;
+	}
+
+	if (!git_str_oom(buf))
+		set_error_from_buffer(error_class);
+}
+
+int git_error_set_str(int error_class, const char *string)
+{
+	struct error_threadstate *threadstate = threadstate_get();
+	git_str *buf;
+
+	GIT_ASSERT_ARG(string);
+
+	if (!threadstate)
+		return -1;
+
+	buf = &threadstate->message;
+
+	git_str_clear(buf);
+	git_str_puts(buf, string);
+
+	if (git_str_oom(buf))
+		return -1;
+
+	set_error_from_buffer(error_class);
+	return 0;
+}
+
+void git_error_clear(void)
+{
+	struct error_threadstate *threadstate = threadstate_get();
+
+	if (!threadstate)
+		return;
+
+	if (threadstate->last != NULL) {
+		set_error(0, NULL);
+		threadstate->last = NULL;
+	}
+
+	errno = 0;
+#ifdef GIT_WIN32
+	SetLastError(0);
+#endif
+}
+
+bool git_error_exists(void)
+{
+	struct error_threadstate *threadstate;
+
+	if ((threadstate = threadstate_get()) == NULL)
+		return true;
+
+	return threadstate->last != NULL;
+}
+
+const git_error *git_error_last(void)
+{
+	struct error_threadstate *threadstate;
+
+	/* If the library is not initialized, return a static error. */
+	if (!git_runtime_init_count())
+		return &uninitialized_error;
+
+	if ((threadstate = threadstate_get()) == NULL)
+		return &tlsdata_error;
+
+	if (!threadstate->last)
+		return &no_error;
+
+	return threadstate->last;
+}
+
+int git_error_save(git_error **out)
+{
+	struct error_threadstate *threadstate = threadstate_get();
+	git_error *error, *dup;
+
+	if (!threadstate) {
+		*out = &tlsdata_error;
+		return -1;
+	}
+
+	error = threadstate->last;
+
+	if (!error || error == &no_error) {
+		*out = &no_error;
+		return 0;
+	} else if (IS_STATIC_ERROR(error)) {
+		*out = error;
+		return 0;
+	}
+
+	if ((dup = git__malloc(sizeof(git_error))) == NULL) {
+		*out = &oom_error;
+		return -1;
+	}
+
+	dup->klass = error->klass;
+	dup->message = git__strdup(error->message);
+
+	if (!dup->message) {
+		*out = &oom_error;
+		return -1;
+	}
+
+	*out = dup;
+	return 0;
+}
+
+int git_error_restore(git_error *error)
+{
+	struct error_threadstate *threadstate = threadstate_get();
+
+	GIT_ASSERT_ARG(error);
+
+	if (IS_STATIC_ERROR(error) && threadstate)
+		threadstate->last = error;
+	else
+		set_error(error->klass, error->message);
+
+	git_error_free(error);
+	return 0;
+}
+
+void git_error_free(git_error *error)
+{
+	if (!error)
+		return;
+
+	if (IS_STATIC_ERROR(error))
+		return;
+
+	git__free(error->message);
+	git__free(error);
+}
+
+int git_error_system_last(void)
+{
+#ifdef GIT_WIN32
+	return GetLastError();
+#else
+	return errno;
+#endif
+}
+
+void git_error_system_set(int code)
+{
+#ifdef GIT_WIN32
+	SetLastError(code);
+#else
+	errno = code;
+#endif
+}
+
+/* Deprecated error values and functions */
+
+#ifndef GIT_DEPRECATE_HARD
+
+#include "git2/deprecated.h"
+
+const git_error *giterr_last(void)
+{
+	return git_error_last();
+}
+
+void giterr_clear(void)
+{
+	git_error_clear();
+}
+
+void giterr_set_str(int error_class, const char *string)
+{
+	git_error_set_str(error_class, string);
+}
+
+void giterr_set_oom(void)
+{
+	git_error_set_oom();
+}
+#endif