1 files changed, 133 insertions, 0 deletions
diff --git a/support/mph.h b/support/mph.h
new file mode 100644
index 00000000000..49a5e9781fc
--- /dev/null
+++ b/support/mph.h
@@ -0,0 +1,133 @@
+/*
+ * Common/shared macros and routines.
+ *
+ * This file contains macros of the form
+ *
+ *   mph_return_if_TYPE_overflow(val);
+ *
+ * Which tests `val' for a TYPE underflow/overflow (that is, is `val' within
+ * the range for TYPE?).  If `val' can't fit in TYPE, errno is set to
+ * EOVERFLOW, and `return -1' is executed (which is why it's a macro).
+ *
+ * Assumptions:
+ *
+ * I'm working from GLibc, so that's the basis for my assumptions.  They may
+ * not be completely portable, in which case I'll need to fix my assumptions.
+ * :-(
+ *
+ * See the typedefs for type size assumptions.  These typedefs *must* be kept
+ * in sync with the types used in Mono.Posix.dll.
+ */
+
+#ifndef INC_mph_H
+#define INC_mph_H
+
+#include <config.h>
+
+#include <limits.h>             /* LONG_MAX, ULONG_MAX */
+#include <errno.h>              /* for ERANGE */
+#include <glib/gtypes.h>        /* for g* types, etc. */
+
+#ifdef HAVE_STDINT_H
+#include <stdint.h>             /* for SIZE_MAX */
+#endif
+
+#if __APPLE__ || __BSD__
+#define MPH_ON_BSD
+#endif
+
+typedef    gint64 mph_blkcnt_t;
+typedef    gint64 mph_blksize_t;
+typedef   guint64 mph_dev_t;
+typedef   guint64 mph_ino_t;
+typedef   guint64 mph_nlink_t;
+typedef    gint64 mph_off_t;
+typedef   guint64 mph_size_t;
+typedef    gint64 mph_ssize_t;
+typedef    gint32 mph_pid_t;
+typedef   guint32 mph_gid_t;
+typedef   guint32 mph_uid_t;
+typedef    gint64 mph_time_t;
+typedef    gint64 mph_clock_t;
+
+#ifdef HAVE_LARGE_FILE_SUPPORT
+#define MPH_OFF_T_MAX G_MAXINT64
+#define MPH_OFF_T_MIN G_MININT64
+#else
+#define MPH_OFF_T_MAX G_MAXINT32
+#define MPH_OFF_T_MIN G_MININT32
+#endif
+
+#ifdef SIZE_MAX
+#define MPH_SIZE_T_MAX SIZE_MAX
+#elif SIZEOF_SIZE_T == 8
+#define MPH_SIZE_T_MAX  G_MAXUINT64
+#elif SIZEOF_SIZE_T == 4
+#define MPH_SIZE_T_MAX  G_MAXUINT32
+#else
+#error "sizeof(size_t) is unknown!"
+#endif
+
+#define _mph_return_val_if_cb_(val, ret, cb) G_STMT_START{ \
+	if (cb (val)) { \
+		errno = EOVERFLOW; \
+		return ret; \
+	}}G_STMT_END
+
+#define mph_have_long_overflow(var) ((var) > LONG_MAX || (var) < LONG_MIN)
+
+#define mph_return_val_if_long_overflow(var, ret) \
+	_mph_return_val_if_cb_(var, ret, mph_have_long_overflow)
+
+#define mph_return_if_long_overflow(var) mph_return_val_if_long_overflow(var, -1)
+
+#define mph_have_ulong_overflow(var) ((var) > ULONG_MAX)
+
+#define mph_return_val_if_ulong_overflow(var, ret) \
+	_mph_return_val_if_cb_(var, ret, mph_have_ulong_overflow)
+
+#define mph_return_if_ulong_overflow(var) mph_return_val_if_ulong_overflow(var, -1)
+
+#define mph_have_size_t_overflow(var) ((var) > MPH_SIZE_T_MAX)
+
+#define mph_return_val_if_size_t_overflow(var, ret) \
+	_mph_return_val_if_cb_(var, ret, mph_have_size_t_overflow)
+
+#define mph_return_if_size_t_overflow(var) mph_return_val_if_size_t_overflow(var, -1)
+
+#define mph_have_off_t_overflow(var) \
+	(((var) < MPH_OFF_T_MIN) || ((var) > MPH_OFF_T_MAX))
+
+#define mph_return_val_if_off_t_overflow(var, ret) \
+	_mph_return_val_if_cb_(var, ret, mph_have_off_t_overflow)
+
+#define mph_return_if_off_t_overflow(var) mph_return_val_if_size_t_overflow(var, -1)
+
+#define mph_return_if_time_t_overflow(var) mph_return_if_long_overflow(var)
+
+/*
+ * Helper function for functions which use ERANGE (such as getpwnam_r and
+ * getgrnam_r).  These functions accept buffers which are dynamically
+ * allocated so that they're only as large as necessary.  However, Linux and
+ * Mac OS X differ on how to signal an error value.
+ *
+ * Linux returns the error value directly, while Mac OS X is more traditional,
+ * returning -1 and setting errno accordingly.
+ *
+ * Unify the checking in one place.
+ */
+static inline int
+recheck_range (int ret)
+{
+	if (ret == ERANGE)
+		return 1;
+	if (ret == -1)
+		return errno == ERANGE;
+	return 0;
+}
+
+#endif /* ndef INC_mph_H */
+
+/*
+ * vim: noexpandtab
+ */