add directory gnu

gnu/gcc/gcc-2.2.2/cp-input.c

@@ -0,0 +1,184 @@
+/* Input handling for G++.
+   Written by Ken Raeburn of Watchmaker Computing.
+   Copyright (C) 1992 Free Software Foundation, Inc.
+
+This file is part of GNU CC.
+
+GNU CC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU CC 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 GNU CC; see the file COPYING.  If not, write to
+the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+/* G++ needs to do enough saving and re-parsing of text that it is
+   necessary to abandon the simple FILE* model and use a mechanism where
+   we can pre-empt one input stream with another derived from saved text;
+   we may need to do this arbitrarily often, and cannot depend on having
+   the GNU library available, so FILE objects just don't cut it.
+
+   This file is written as a separate module, but can be included by
+   cp-lex.c for very minor efficiency gains (primarily in function
+   inlining).  */
+
+#include <assert.h>
+#include <stdio.h>
+#include "obstack.h"
+
+extern FILE *finput;
+
+struct pending_input *save_pending_input ();
+void restore_pending_input ();
+
+struct input_source {
+  /* saved string */
+  char *str;
+  int length;
+  /* current position, when reading as input */
+  int offset;
+  /* obstack to free this input string from when finished, if any */
+  struct obstack *obstack;
+  /* linked list maintenance */
+  struct input_source *next;
+  /* values to restore after reading all of current string */
+  char *filename;
+  int lineno;
+  struct pending_input *input;
+  int putback_char;
+};
+
+static struct input_source *input, *free_inputs;
+
+extern char *input_filename;
+extern int lineno;
+
+#ifdef __GNUC__
+#define inline __inline__
+#else
+#define inline
+#endif
+
+static inline struct input_source *
+allocate_input ()
+{
+  struct input_source *inp;
+  if (free_inputs)
+    {
+      inp = free_inputs;
+      free_inputs = inp->next;
+      inp->next = 0;
+      return inp;
+    }
+  inp = (struct input_source *) xmalloc (sizeof (struct input_source));
+  inp->next = 0;
+  inp->obstack = 0;
+  return inp;
+}
+
+static inline void
+free_input (inp)
+     struct input_source *inp;
+{
+  if (inp->obstack)
+    obstack_free (inp->obstack, inp->str);
+  inp->obstack = 0;
+  inp->str = 0;
+  inp->length = 0;
+  inp->next = free_inputs;
+  free_inputs = inp;
+}
+
+static int putback_char = -1;
+
+/* Some of these external functions are declared inline in case this file
+   is included in cp-lex.c.  */
+
+inline
+void
+feed_input (str, len, delete)
+     char *str;
+     struct obstack *delete;
+{
+  struct input_source *inp = allocate_input ();
+
+  /* This shouldn't be necessary.  */
+  while (len && !str[len-1])
+    len--;
+
+  inp->str = str;
+  inp->length = len;
+  inp->obstack = delete;
+  inp->offset = 0;
+  inp->next = input;
+  inp->filename = input_filename;
+  inp->lineno = lineno;
+  inp->input = save_pending_input ();
+  inp->putback_char = putback_char;
+  putback_char = -1;
+  input = inp;
+}
+
+struct pending_input *to_be_restored; /* XXX */
+extern int end_of_file;
+
+int
+getch ()
+{
+  if (putback_char != -1)
+    {
+      int ch = putback_char;
+      putback_char = -1;
+      return ch;
+    }
+  if (input)
+    {
+      if (input->offset == input->length)
+	{
+	  struct input_source *inp = input;
+	  assert (putback_char == -1);
+	  to_be_restored = inp->input;
+	  input->offset++;
+	  return EOF;
+	}
+      else if (input->offset > input->length)
+	{
+	  struct input_source *inp = input;
+
+	  end_of_file = 0;
+	  input = inp->next;
+	  input_filename = inp->filename;
+	  lineno = inp->lineno;
+	  /* Get interface/implementation back in sync. */
+	  extract_interface_info ();
+	  putback_char = inp->putback_char;
+	  free_input (inp);
+	  return getch ();
+	}
+      if (input)
+	return input->str[input->offset++];
+    }
+  return getc (finput);
+}
+
+inline
+void
+put_back (ch)
+     int ch;
+{
+  assert (putback_char == -1);
+  putback_char = ch;
+}
+
+inline
+int
+input_redirected ()
+{
+  return input != 0;
+}