dwarf2 EH support

From-SVN: r15257

gcc/frame.h

+/* Copyright (C) 1997 Free Software Foundation, Inc.
+   This file is part of GNU CC.  */
+
+typedef struct frame_state
+{
+  void *cfa;
+  void *eh_ptr;
+  long cfa_offset;
+  long args_size;
+  long reg_or_offset[FIRST_PSEUDO_REGISTER+1];
+  unsigned short cfa_reg;
+  unsigned short retaddr_column;
+  char saved[FIRST_PSEUDO_REGISTER+1];
+} frame_state;
+
+/* Values for 'saved' above.  */
+#define REG_UNSAVED 0
+#define REG_SAVED_OFFSET 1
+#define REG_SAVED_REG 2
+
+/* Called either from crtbegin.o or a static constructor to register the
+   unwind info for an object or translation unit, respectively.  */
+
+extern void __register_frame (void *);
+
+/* Called from crtend.o to deregister the unwind info for an object.  */
+
+extern void __deregister_frame (void *);
+
+/* Called from __throw to find the registers to restore for a given
+   PC_TARGET.  The caller should allocate a local variable of `struct
+   frame_state' (declared in frame.h) and pass its address to STATE_IN.
+   Returns NULL on failure, otherwise returns STATE_IN.  */
+
+extern struct frame_state *__frame_state_for (void *, struct frame_state *);