RFA: frame id enhancement

["J. Johnston" <jjohnstn at redhat dot com>]

The following patch enhances the frame id support to allow an architecture
to set a special address for the frame.  This enables architectures such as the
ia64 (which has a 2nd stack) to properly mark distinct frames.  I added a
new routine that builds frame ids that has a special address parameter.  The
current frame_id_build() has been changed to call the new routine with a default
special address of 0.  This means that existing calls to frame_id_build() require
no changes.

Ok to commit to mainline?

-- Jeff J.

2003-10-06  Jeff Johnston  <jjohnstn@redhat.com>

	* frame.h (struct frame_id): Add new field: special_addr.
	(frame_id_build_special): New prototype.
	* frame.c (frame_id_build_special): New function.
	(frame_id_build): Change to call frame_id_build_special().
	(frame_id_eq): Change to also test special_addr field.

Index: frame.c
===================================================================
RCS file: /cvs/src/src/gdb/frame.c,v
retrieving revision 1.145
diff -u -r1.145 frame.c
--- frame.c	2 Oct 2003 20:28:29 -0000	1.145
+++ frame.c	6 Oct 2003 21:07:51 -0000
@@ -144,9 +144,10 @@
 void
 fprint_frame_id (struct ui_file *file, struct frame_id id)
 {
-  fprintf_unfiltered (file, "{stack=0x%s,code=0x%s}",
+  fprintf_unfiltered (file, "{stack=0x%s,code=0x%s,special=0x%s}",
 		      paddr_nz (id.stack_addr),
-		      paddr_nz (id.code_addr));
+		      paddr_nz (id.code_addr),
+		      paddr_nz (id.special_addr));
 }
 
 static void
@@ -256,14 +257,22 @@
 const struct frame_id null_frame_id; /* All zeros.  */
 
 struct frame_id
-frame_id_build (CORE_ADDR stack_addr, CORE_ADDR code_addr)
+frame_id_build_special (CORE_ADDR stack_addr, CORE_ADDR code_addr,
+			CORE_ADDR special_addr)
 {
   struct frame_id id;
   id.stack_addr = stack_addr;
   id.code_addr = code_addr;
+  id.special_addr = special_addr;
   return id;
 }
 
+struct frame_id
+frame_id_build (CORE_ADDR stack_addr, CORE_ADDR code_addr)
+{
+  return frame_id_build_special (stack_addr, code_addr, 0);
+}
+
 int
 frame_id_p (struct frame_id l)
 {
@@ -288,6 +297,9 @@
     eq = 0;
   else if (l.stack_addr != r.stack_addr)
     /* If .stack addresses are different, the frames are different.  */
+    eq = 0;
+  else if (l.special_addr != r.special_addr)
+    /* If .special addresses are different, the frames are different.  */
     eq = 0;
   else if (l.code_addr == 0 || r.code_addr == 0)
     /* A zero code addr is a wild card, always succeed.  */
Index: frame.h
===================================================================
RCS file: /cvs/src/src/gdb/frame.h,v
retrieving revision 1.109
diff -u -r1.109 frame.h
--- frame.h	28 Sep 2003 22:32:19 -0000	1.109
+++ frame.h	6 Oct 2003 21:07:52 -0000
@@ -95,8 +95,6 @@
      is used.  Watch out for all the legacy targets that still use the
      function pointer register or stack pointer register.  They are
      wrong.  */
-  /* NOTE: cagney/2002-11-16: The ia64 has two stacks and hence two
-     frame bases.  This will need to be expanded to accomodate that.  */
   CORE_ADDR stack_addr;
   /* The frame's code address.  This shall be constant through out the
      lifetime of the frame.  While the PC (a.k.a. resume address)
@@ -104,6 +102,12 @@
      Typically, it is set to the address of the entry point of the
      frame's function (as returned by frame_func_unwind().  */
   CORE_ADDR code_addr;
+  /* The frame's special address.  This shall be constant through out the
+     lifetime of the frame.  This is used for architectures that may have
+     frames that have the same stack_addr and code_addr but are distinct
+     due to some other qualification (e.g. the ia64 uses a register 
+     stack which is distinct from the memory stack).  */
+  CORE_ADDR special_addr;
 };
 
 /* Methods for constructing and comparing Frame IDs.
@@ -120,9 +124,19 @@
 /* Construct a frame ID.  The first parameter is the frame's constant
    stack address (typically the outer-bound), and the second the
    frame's constant code address (typically the entry point) (or zero,
-   to indicate a wild card).  */
+   to indicate a wild card).  The special identifier address is
+   defaulted to zero.  */
 extern struct frame_id frame_id_build (CORE_ADDR stack_addr,
 				       CORE_ADDR code_addr);
+
+/* Construct a special frame ID.  The first parameter is the frame's constant
+   stack address (typically the outer-bound), the second is the
+   frame's constant code address (typically the entry point) (or zero,
+   to indicate a wild card), and the third parameter is the frame's
+   special identifier address.  */
+extern struct frame_id frame_id_build_special (CORE_ADDR stack_addr,
+					       CORE_ADDR code_addr,
+					       CORE_ADDR special_addr);
 
 /* Returns non-zero when L is a valid frame (a valid frame has a
    non-zero .base).  */