From 8115dffa1e76ab007223199dfbc8c1298d2bf06e Mon Sep 17 00:00:00 2001
From: Tom Tromey <tromey@adacore.com>
Date: Tue, 16 May 2023 07:36:08 -0600
Subject: [PATCH] Handle DAP supportsVariableType capability

A DAP client can report the supportsVariableType capability in the
initialize request.  In this case, gdb can include the type of a
variable or expression in various results.
---
 gdb/python/lib/gdb/dap/evaluate.py  |  1 -
 gdb/python/lib/gdb/dap/server.py    | 11 +++++++++++
 gdb/python/lib/gdb/dap/varref.py    |  3 +++
 gdb/testsuite/gdb.dap/basic-dap.exp |  3 ++-
 gdb/testsuite/lib/dap-support.exp   |  4 +++-
 5 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/gdb/python/lib/gdb/dap/evaluate.py b/gdb/python/lib/gdb/dap/evaluate.py
index 1db6962f8e0..2b400651b67 100644
--- a/gdb/python/lib/gdb/dap/evaluate.py
+++ b/gdb/python/lib/gdb/dap/evaluate.py
@@ -70,7 +70,6 @@ def _repl(command, frame_id):
     }
 
 
-# FIXME supportsVariableType handling
 @request("evaluate")
 def eval_request(
     *,
diff --git a/gdb/python/lib/gdb/dap/server.py b/gdb/python/lib/gdb/dap/server.py
index be66676f730..b1c75ab967f 100644
--- a/gdb/python/lib/gdb/dap/server.py
+++ b/gdb/python/lib/gdb/dap/server.py
@@ -186,6 +186,17 @@ def capability(name, value=True):
     return wrap
 
 
+def client_bool_capability(name):
+    """Return the value of a boolean client capability.
+
+    If the capability was not specified, or did not have boolean type,
+    False is returned."""
+    global _server
+    if name in _server.config and isinstance(_server.config[name], bool):
+        return _server.config[name]
+    return False
+
+
 @request("initialize")
 def initialize(**args):
     global _server, _capabilities
diff --git a/gdb/python/lib/gdb/dap/varref.py b/gdb/python/lib/gdb/dap/varref.py
index 88c34c20468..23f18d647c3 100644
--- a/gdb/python/lib/gdb/dap/varref.py
+++ b/gdb/python/lib/gdb/dap/varref.py
@@ -15,6 +15,7 @@
 
 import gdb
 from .startup import in_gdb_thread
+from .server import client_bool_capability
 from abc import abstractmethod
 
 
@@ -165,6 +166,8 @@ class VariableReference(BaseReference):
             result["memoryReference"] = hex(int(self.value))
         elif self.value.address is not None:
             result["memoryReference"] = hex(int(self.value.address))
+        if client_bool_capability("supportsVariableType"):
+            result["type"] = str(self.value.type)
         return result
 
     @in_gdb_thread
diff --git a/gdb/testsuite/gdb.dap/basic-dap.exp b/gdb/testsuite/gdb.dap/basic-dap.exp
index 9aaa94051e6..ca0d1be9f12 100644
--- a/gdb/testsuite/gdb.dap/basic-dap.exp
+++ b/gdb/testsuite/gdb.dap/basic-dap.exp
@@ -162,7 +162,8 @@ dap_match_values "global value in main" [lindex $obj 0] \
 set obj [dap_check_request_and_response "set global in main" \
 	     setExpression {o expression [s global_variable] value [s 23]}]
 dap_match_values "global value in main after set" [lindex $obj 0] \
-    "body result" 23
+    "body result" 23 \
+    "body type" int
 
 set obj [dap_request_and_response \
 	     evaluate {o expression [s nosuchvariable]}]
diff --git a/gdb/testsuite/lib/dap-support.exp b/gdb/testsuite/lib/dap-support.exp
index 8667164fa11..5c547480d09 100644
--- a/gdb/testsuite/lib/dap-support.exp
+++ b/gdb/testsuite/lib/dap-support.exp
@@ -230,7 +230,9 @@ proc _dap_initialize {name} {
     if {[dap_gdb_start]} {
 	return ""
     }
-    return [dap_check_request_and_response $name initialize]
+    return [dap_check_request_and_response $name initialize \
+		{o clientID [s "gdb testsuite"] \
+		     supportsVariableType [l true]}]
 }
 
 # Start gdb, send a DAP initialize request, and then a launch request
-- 
2.30.2