Update mach_override to upstream 1a1bb352

third_party/mach_override/libudis86/input.c

+/* udis86 - libudis86/input.c
+ *
+ * Copyright (c) 2002-2009 Vivek Thampi
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without modification, 
+ * are permitted provided that the following conditions are met:
+ * 
+ *     * Redistributions of source code must retain the above copyright notice, 
+ *       this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright notice, 
+ *       this list of conditions and the following disclaimer in the documentation 
+ *       and/or other materials provided with the distribution.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND 
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR 
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON 
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include "extern.h"
+#include "types.h"
+#include "input.h"
+#include "udint.h"
+
+/* 
+ * inp_init
+ *    Initializes the input system.
+ */
+static void
+inp_init(struct ud *u)
+{
+  u->inp_curr = 0;
+  u->inp_fill = 0;
+  u->inp_ctr  = 0;
+  u->inp_end  = 0;
+}
+
+
+/* -----------------------------------------------------------------------------
+ * inp_buff_hook() - Hook for buffered inputs.
+ * -----------------------------------------------------------------------------
+ */
+static int 
+inp_buff_hook(struct ud* u)
+{
+  if (u->inp_buff < u->inp_buff_end)
+  return *u->inp_buff++;
+  else  return -1;
+}
+
+#ifndef __UD_STANDALONE__
+/* -----------------------------------------------------------------------------
+ * inp_file_hook() - Hook for FILE inputs.
+ * -----------------------------------------------------------------------------
+ */
+static int 
+inp_file_hook(struct ud* u)
+{
+  return fgetc(u->inp_file);
+}
+#endif /* __UD_STANDALONE__*/
+
+/* =============================================================================
+ * ud_inp_set_hook() - Sets input hook.
+ * =============================================================================
+ */
+void 
+ud_set_input_hook(register struct ud* u, int (*hook)(struct ud*))
+{
+  u->inp_hook = hook;
+  inp_init(u);
+}
+
+/* =============================================================================
+ * ud_inp_set_buffer() - Set buffer as input.
+ * =============================================================================
+ */
+void 
+ud_set_input_buffer(register struct ud* u, const uint8_t* buf, size_t len)
+{
+  u->inp_hook = inp_buff_hook;
+  u->inp_buff = buf;
+  u->inp_buff_end = buf + len;
+  inp_init(u);
+}
+
+#ifndef __UD_STANDALONE__
+/* =============================================================================
+ * ud_input_set_file() - Set buffer as input.
+ * =============================================================================
+ */
+void 
+ud_set_input_file(register struct ud* u, FILE* f)
+{
+  u->inp_hook = inp_file_hook;
+  u->inp_file = f;
+  inp_init(u);
+}
+#endif /* __UD_STANDALONE__ */
+
+/* =============================================================================
+ * ud_input_skip() - Skip n input bytes.
+ * =============================================================================
+ */
+void 
+ud_input_skip(struct ud* u, size_t n)
+{
+  while (n--) {
+    u->inp_hook(u);
+  }
+}
+
+/* =============================================================================
+ * ud_input_end() - Test for end of input.
+ * =============================================================================
+ */
+int 
+ud_input_end(const struct ud* u)
+{
+  return (u->inp_curr == u->inp_fill) && u->inp_end;
+}
+
+
+/* 
+ * ud_inp_next
+ *    Loads and returns the next byte from input.
+ *
+ *    inp_curr and inp_fill are pointers to the cache. The program is
+ *    written based on the property that they are 8-bits in size, and
+ *    will eventually wrap around forming a circular buffer. So, the 
+ *    size of the cache is 256 in size, kind of unnecessary yet 
+ *    optimal.
+ *
+ *    A buffer inp_sess stores the bytes disassembled for a single
+ *    session.
+ */
+uint8_t
+ud_inp_next(struct ud* u) 
+{
+  int c = -1;
+  /* if current pointer is not upto the fill point in the 
+   * input cache.
+   */
+  if (u->inp_curr != u->inp_fill) {
+    c = u->inp_cache[ ++u->inp_curr ];
+  /* if !end-of-input, call the input hook and get a byte */
+  } else if (u->inp_end || (c = u->inp_hook(u)) == -1) {
+    /* end-of-input, mark it as an error, since the decoder,
+     * expected a byte more.
+     */
+    UDERR(u, "byte expected, eoi received");
+    /* flag end of input */
+    u->inp_end = 1;
+    return 0;
+  } else {
+    /* increment pointers, we have a new byte.  */
+    u->inp_curr = ++u->inp_fill;
+    /* add the byte to the cache */
+    u->inp_cache[u->inp_fill] = c;
+  }
+  /* record bytes input per decode-session. */
+  u->inp_sess[u->inp_ctr++] = c;
+  /* return byte */
+  return  (uint8_t) c;
+}
+
+/*
+vim: set ts=2 sw=2 expandtab
+*/