2000-07-12 Michael Snyder <msnyder@cleaver.cygnus.com>

        * regcache.c (registers_changed, registers_fetched): Use
        ARCH_NUM_REGS directly, eliminating an unnecessary variable.

        This change adds pseudo-register capability to GDB.
        Pseudo-registers are handled like registers, but they
        don't come from or live on the target.  They may be
        aliases for an existing register, or they may be computed.
        * defs.h (NUM_PSEUDO_REGISTERS): Define default of zero.
        (ARCH_FETCH_PSEUDO_REGISTERS): Define default of no-op.
        (ARCH_STORE_PSEUDO_REGISTERS): Define default of no-op.
        # regcache.c (registers_changed): Mark pseudo-registers
        invalid, as well as real registers.
        (registers_fetched): Do not mark pseudo-registers as fetched
        at the same time as other (real) registers.
        (read_register_bytes): Fetch pseudo-registers (if any) from
        the target architecture module instead of from the target.
        (read_register_gen): Ditto.
        (read_register): Ditto.
        (write_register_bytes): Store pseudo-registers (if any) to
        the target architecture module instead of to the target.
        (write_register_gen): Ditto.
        (write_register): Ditto.
        (build_regcache): Allocate enough register_valid space for
        pseudo-registers as well as normal (real) ones.

1 files changed, 25 insertions, 1 deletions

diff --git a/gdb/inferior.h b/gdb/inferior.h
index 26798a5..95a8c61 100644
--- a/gdb/inferior.h
+++ b/gdb/inferior.h
@@ -52,12 +52,36 @@ extern void write_inferior_status_register (struct inferior_status
 
 /* This macro gives the number of registers actually in use by the
    inferior.  This may be less than the total number of registers,
-   perhaps depending on the actual CPU in use or program being run.  */
+   perhaps depending on the actual CPU in use or program being run.  
+   FIXME: This could be replaced by the new MULTI_ARCH capability.  */
 
 #ifndef ARCH_NUM_REGS
 #define ARCH_NUM_REGS NUM_REGS
 #endif
 
+/* This macro gives the number of pseudo-registers that live in the
+   register namespace but do not get fetched or stored on the target.
+   These pseudo-registers may be aliases for other registers, 
+   combinations of other registers, or they may be computed by GDB. 
+   FIXME: move into gdbarch.[ch] */
+#ifndef NUM_PSEUDO_REGS
+#define NUM_PSEUDO_REGS 0
+#endif
+
+/* This function is called when the value of a pseudo-register needs
+   to be updated.  Typically it will be defined on a per-architecture
+   basis.  FIXME: move into gdbarch.[ch].  */
+#ifndef ARCH_FETCH_PSEUDO_REGISTERS
+#define ARCH_FETCH_PSEUDO_REGISTERS(REGNUM) /* no-op */
+#endif
+
+/* This function is called when the value of a pseudo-register needs
+   to be set or stored.  Typically it will be defined on a per-architecture
+   basis.  FIXME: move into gdbarch.[ch].  */
+#ifndef ARCH_STORE_PSEUDO_REGISTERS
+#define ARCH_STORE_PSEUDO_REGISTERS(REGNUM) /* no-op */
+#endif
+
 extern void set_sigint_trap (void);
 
 extern void clear_sigint_trap (void);