[6/7] Handle the static link in FrameDecorator

diff --git a/gdb/python/lib/gdb/FrameDecorator.py b/gdb/python/lib/gdb/FrameDecorator.py
index 39ee2e2547c..b6eb1ab1de0 100644
--- a/gdb/python/lib/gdb/FrameDecorator.py
+++ b/gdb/python/lib/gdb/FrameDecorator.py
@@ -213,18 +213,36 @@  class DAPFrameDecorator(_FrameDecoratorBase):
             return sal.symtab.fullname()
         return None
 
+    def frame_locals(self):
+        """Return an iterable of local variables for this frame, if
+        any.  The iterable object contains objects conforming with the
+        Symbol/Value interface.  If there are no frame locals, or if
+        this frame is deemed to be a special case, return None."""
+
+        if hasattr(self._base, "frame_locals"):
+            return self._base.frame_locals()
+
+        frame = self.inferior_frame()
+        args = FrameVars(frame)
+        return args.fetch_frame_locals(True)
+
 
 class SymValueWrapper(object):
     """A container class conforming to the Symbol/Value interface
     which holds frame locals or frame arguments."""
 
-    def __init__(self, symbol, value):
+    # The FRAME argument is needed here because gdb.Symbol doesn't
+    # carry the block with it, and so read_var can't find symbols from
+    # outer (static link) frames.
+    def __init__(self, frame, symbol):
+        self.frame = frame
         self.sym = symbol
-        self.val = value
 
     def value(self):
         """Return the value associated with this symbol, or None"""
-        return self.val
+        if self.frame is None:
+            return None
+        return self.frame.read_var(self.sym)
 
     def symbol(self):
         """Return the symbol, or Python text, associated with this
@@ -240,32 +258,50 @@  class FrameVars(object):
     def __init__(self, frame):
         self.frame = frame
 
-    def fetch_frame_locals(self):
+    def fetch_frame_locals(self, follow_link=False):
         """Public utility method to fetch frame local variables for
         the stored frame.  Frame arguments are not fetched.  If there
         are no frame local variables, return an empty list."""
         lvars = []
 
+        frame = self.frame
         try:
-            block = self.frame.block()
+            block = frame.block()
         except RuntimeError:
             block = None
 
+        traversed_link = False
         while block is not None:
             if block.is_global or block.is_static:
                 break
             for sym in block:
+                # Exclude arguments from the innermost function, but
+                # if we found and traversed a static link, just treat
+                # all such variables as "local".
                 if sym.is_argument:
+                    if not traversed_link:
+                        continue
+                elif not sym.is_variable:
+                    # We use an 'elif' here because is_variable
+                    # returns False for arguments as well.  Anyway,
+                    # don't include non-variables here.
                     continue
-                if sym.is_variable:
-                    lvars.append(SymValueWrapper(sym, None))
+                lvars.append(SymValueWrapper(frame, sym))
 
-            # Stop when the function itself is seen, to avoid showing
-            # variables from outer functions in a nested function.
             if block.function is not None:
-                break
-
-            block = block.superblock
+                if not follow_link:
+                    break
+                # If the frame has a static link, follow it here.
+                traversed_link = True
+                frame = frame.static_link()
+                if frame is None:
+                    break
+                try:
+                    block = frame.block()
+                except RuntimeError:
+                    block = None
+            else:
+                block = block.superblock
 
         return lvars
 
@@ -287,10 +323,12 @@  class FrameVars(object):
             for sym in block:
                 if not sym.is_argument:
                     continue
-                args.append(SymValueWrapper(sym, None))
+                args.append(SymValueWrapper(None, sym))
 
             # Stop when the function itself is seen, to avoid showing
             # variables from outer functions in a nested function.
+            # Note that we don't traverse the static link for
+            # arguments, only for locals.
             if block.function is not None:
                 break
 
diff --git a/gdb/testsuite/gdb.dap/ada-nested.exp b/gdb/testsuite/gdb.dap/ada-nested.exp
new file mode 100644
index 00000000000..1a02f4f352e
--- /dev/null
+++ b/gdb/testsuite/gdb.dap/ada-nested.exp
@@ -0,0 +1,91 @@ 
+# Copyright 2023 Free Software Foundation, Inc.
+#
+# This program 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 3 of the License, or
+# (at your option) any later version.
+#
+# This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Check the scope of a nested function.
+
+load_lib ada.exp
+load_lib dap-support.exp
+
+require allow_ada_tests allow_dap_tests
+
+standard_ada_testfile prog
+
+if {[gdb_compile_ada "${srcfile}" "${binfile}" executable \
+	 {debug additional_flags=-gnata}] != ""} {
+    return -1
+}
+
+if {[dap_launch $binfile] == ""} {
+    return
+}
+
+set line [gdb_get_line_number "STOP"]
+set obj [dap_check_request_and_response "set breakpoint" \
+	     setBreakpoints \
+	     [format {o source [o path [%s]] \
+			  breakpoints [a [o line [i %d]]]} \
+		  [list s $srcfile] $line]]
+set fn_bpno [dap_get_breakpoint_number $obj]
+
+dap_check_request_and_response "start inferior" configurationDone
+
+dap_wait_for_event_and_check "stopped at breakpoint" stopped \
+    "body reason" breakpoint \
+    "body hitBreakpointIds" $fn_bpno
+
+set bt [lindex [dap_check_request_and_response "backtrace" stackTrace \
+		    {o threadId [i 1]}] \
+	    0]
+set frame_id [dict get [lindex [dict get $bt body stackFrames] 0] id]
+
+set scopes [dap_check_request_and_response "get scopes" scopes \
+		[format {o frameId [i %d]} $frame_id]]
+set scopes [dict get [lindex $scopes 0] body scopes]
+
+# This is what the implementation does, so we can assume it, but check
+# just in case something changes.
+lassign $scopes args locals _ignore
+gdb_assert {[dict get $args name] == "Arguments"} "argument scope"
+gdb_assert {[dict get $locals name] == "Locals"} "local scope"
+
+gdb_assert {[dict get $locals namedVariables] == 3} "two locals"
+
+set num [dict get $locals variablesReference]
+set refs [lindex [dap_check_request_and_response "fetch variables" \
+		      "variables" \
+		      [format {o variablesReference [i %d] count [i 3]} \
+			   $num]] \
+	      0]
+
+foreach var [dict get $refs body variables] {
+    set name [dict get $var name]
+
+    switch $name {
+	"i" {
+	    gdb_assert {[dict get $var value] == "1"} "check value of i"
+	}
+	"x" {
+	    gdb_assert {[dict get $var value] == "12"} "check value of x"
+	}
+	"outer_arg" {
+	    gdb_assert {[dict get $var value] == "1"} "check value of outer_arg"
+	}
+	default {
+	    fail "unknown variable $name"
+	}
+    }
+}
+
+dap_shutdown
diff --git a/gdb/testsuite/gdb.dap/ada-nested/prog.adb b/gdb/testsuite/gdb.dap/ada-nested/prog.adb
new file mode 100644
index 00000000000..6b38835a94c
--- /dev/null
+++ b/gdb/testsuite/gdb.dap/ada-nested/prog.adb
@@ -0,0 +1,32 @@ 
+--  Copyright 2023 Free Software Foundation, Inc.
+--
+--  This program 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 3 of the License, or
+--  (at your option) any later version.
+--
+--  This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+
+procedure Foo is
+   X  : Integer := 12;
+
+   procedure Outer (Outer_Arg : Integer) is
+      procedure Bump (Stride : Integer) is
+      begin
+         X := X + Stride;          -- STOP
+      end;
+   begin
+      Bump (Outer_Arg);
+   end;
+
+begin
+   for I in 1 .. 20 loop
+      Outer (1);
+   end loop;
+end Foo;