2003-10-17 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.
        (frame_id_inner): Update comment.

3 files changed, 64 insertions, 13 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index b160034..e4ce649 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,12 @@
+2003-10-17  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. 
+	(frame_id_inner): Update comment. 
+
 2003-10-17  Andrew Cagney  <cagney@redhat.com>
 
 	* target.c (update_current_target): Perform the target cleanup.
diff --git a/gdb/frame.c b/gdb/frame.c
index e91c52a..3a4b709 100644
--- a/gdb/frame.c
+++ b/gdb/frame.c
@@ -144,9 +144,10 @@ static unsigned int backtrace_limit = UINT_MAX;
 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 @@ get_frame_id (struct frame_info *fi)
 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)
 {
@@ -292,8 +301,14 @@ frame_id_eq (struct frame_id l, struct frame_id r)
   else if (l.code_addr == 0 || r.code_addr == 0)
     /* A zero code addr is a wild card, always succeed.  */
     eq = 1;
-  else if (l.code_addr == r.code_addr)
-    /* The .stack and .code are identical, the ID's are identical.  */
+  else if (l.code_addr != r.code_addr)
+    /* If .code addresses are different, the frames are different.  */
+    eq = 0;
+  else if (l.special_addr == 0 || r.special_addr == 0)
+    /* A zero special addr is a wild card (or unused), always succeed.  */
+    eq = 1;
+  else if (l.special_addr == r.special_addr)
+    /* Frames are equal.  */
     eq = 1;
   else
     /* No luck.  */
@@ -320,7 +335,7 @@ frame_id_inner (struct frame_id l, struct frame_id r)
     /* Only return non-zero when strictly inner than.  Note that, per
        comment in "frame.h", there is some fuzz here.  Frameless
        functions are not strictly inner than (same .stack but
-       different .code).  */
+       different .code and/or .special address).  */
     inner = INNER_THAN (l.stack_addr, r.stack_addr);
   if (frame_debug)
     {
diff --git a/gdb/frame.h b/gdb/frame.h
index 4e05f16..81f07eb 100644
--- a/gdb/frame.h
+++ b/gdb/frame.h
@@ -95,8 +95,6 @@ struct frame_id
      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)
@@ -104,15 +102,33 @@ struct frame_id
      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 do not change the stack but are still distinct and have 
+     some form of distinct identifier (e.g. the ia64 which uses a 2nd 
+     stack for registers).  This field is treated as unordered - i.e. will
+     not be used in frame ordering comparisons such as frame_id_inner().
+     A zero in this field will be treated as a wild-card when comparing
+     frames for equality.  */
+  CORE_ADDR special_addr;
 };
 
 /* Methods for constructing and comparing Frame IDs.
 
-   NOTE: Given frameless functions A and B, where A calls B (and hence
+   NOTE: Given stackless functions A and B, where A calls B (and hence
    B is inner-to A).  The relationships: !eq(A,B); !eq(B,A);
-   !inner(A,B); !inner(B,A); all hold.  This is because, while B is
-   inner to A, B is not strictly inner to A (being frameless, they
-   have the same .base value).  */
+   !inner(A,B); !inner(B,A); all hold.
+
+   This is because, while B is inner-to A, B is not strictly inner-to A.  
+   Being stackless, they have an identical .stack_addr value, and differ 
+   only by their unordered .code_addr and/or .special_addr values.
+
+   Because frame_id_inner is only used as a safety net (e.g.,
+   detect a corrupt stack) the lack of strictness is not a problem.
+   Code needing to determine an exact relationship between two frames
+   must instead use frame_id_eq and frame_id_unwind.  For instance,
+   in the above, to determine that A stepped-into B, the equation
+   "A.id != B.id && A.id == id_unwind (B)" can be used.  */
 
 /* For convenience.  All fields are zero.  */
 extern const struct frame_id null_frame_id;
@@ -120,10 +136,21 @@ extern const struct frame_id null_frame_id;
 /* 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 (or zero to indicate a wild card or 
+   unused default).  */
+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).  */
 extern int frame_id_p (struct frame_id l);