Improve VSCode DAP logpoint value summary (#71723)

Currently VSCode logpoint uses `SBValue::GetValue` to get the value for
printing. This is not providing an intuitive result for std::string or
char * -- it shows the pointer value instead of the string content.

This patch improves by prefers `SBValue::GetSummary()` before using
`SBValue::GetValue()`.

---------

Co-authored-by: jeffreytan81 <jeffreytan@fb.com>

3 files changed, 12 insertions, 5 deletions

diff --git a/lldb/tools/lldb-dap/BreakpointBase.cpp b/lldb/tools/lldb-dap/BreakpointBase.cpp
index cd12f97..bc9bde9 100644
--- a/lldb/tools/lldb-dap/BreakpointBase.cpp
+++ b/lldb/tools/lldb-dap/BreakpointBase.cpp
@@ -8,6 +8,7 @@
 
 #include "BreakpointBase.h"
 #include "DAP.h"
+#include "JSONUtils.h"
 #include "llvm/ADT/StringExtras.h"
 
 using namespace lldb_dap;
@@ -295,9 +296,7 @@ bool BreakpointBase::BreakpointHitCallback(
           frame.GetValueForVariablePath(expr, lldb::eDynamicDontRunTarget);
       if (value.GetError().Fail())
         value = frame.EvaluateExpression(expr);
-      const char *expr_val = value.GetValue();
-      if (expr_val)
-        output += expr_val;
+      output += ValueToString(value);
     } else {
       output += messagePart.text;
     }
diff --git a/lldb/tools/lldb-dap/JSONUtils.cpp b/lldb/tools/lldb-dap/JSONUtils.cpp
index 46528a2..2ff1761 100644
--- a/lldb/tools/lldb-dap/JSONUtils.cpp
+++ b/lldb/tools/lldb-dap/JSONUtils.cpp
@@ -210,8 +210,7 @@ static std::optional<std::string> TryCreateAutoSummary(lldb::SBValue value) {
   return TryCreateAutoSummaryForContainer(value);
 }
 
-void SetValueForKey(lldb::SBValue &v, llvm::json::Object &object,
-                    llvm::StringRef key) {
+std::string ValueToString(lldb::SBValue v) {
   std::string result;
   llvm::raw_string_ostream strm(result);
 
@@ -242,6 +241,12 @@ void SetValueForKey(lldb::SBValue &v, llvm::json::Object &object,
       }
     }
   }
+  return result;
+}
+
+void SetValueForKey(lldb::SBValue &v, llvm::json::Object &object,
+                    llvm::StringRef key) {
+  std::string result = ValueToString(v);
   EmplaceSafeString(object, key, result);
 }
 
diff --git a/lldb/tools/lldb-dap/JSONUtils.h b/lldb/tools/lldb-dap/JSONUtils.h
index d829e65..02ee499 100644
--- a/lldb/tools/lldb-dap/JSONUtils.h
+++ b/lldb/tools/lldb-dap/JSONUtils.h
@@ -167,6 +167,9 @@ std::vector<std::string> GetStrings(const llvm::json::Object *obj,
 void FillResponse(const llvm::json::Object &request,
                   llvm::json::Object &response);
 
+/// Utility function to convert SBValue \v into a string.
+std::string ValueToString(lldb::SBValue v);
+
 /// Emplace the string value from an SBValue into the supplied object
 /// using \a key as the key that will contain the value.
 ///