[Lldb-commits] [lldb] [lldb-dap] Add feature to remember last non-empty expression. (PR #107485)

[via lldb-commits]

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@@ -1376,6 +1382,16 @@ void request_evaluate(const llvm::json::Object &request) {
     EmplaceSafeString(body, "result", result);
     body.try_emplace("variablesReference", (int64_t)0);
   } else {
+    if (context == "repl") {
+      // If the expression is empty and the last expression was for a
+      // variable, set the expression to the previous expression (repeat the
+      // evaluation); otherwise save the current non-empty expression for the
+      // next (possibly empty) variable expression.
+      if (expression.empty())
+        expression = g_dap.last_nonempty_var_expression;
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cmtice wrote:

Your description of the behavior is not correct.   last_nonempty_var_expression is now being used for two purposes: It both holds the last non-empty var expression IF-AND-ONLY-IF the last expression was a var expression; or it indicates that the last expression was a command, by being empty itself. Note the very first thing we do, unconditionally, when processing a command is to clear this variable.

When we receive an empty expression, we check to see if the most recent non-empty expression was a command (test to see if last_nonempty_var_expression is empty). If it was a command, then we pass the empty expression to the command interpreter. If the most recent non-empty expression was a variable expression (i.e. last_nonempty_var_expression is NOT empty), then we treat the empty expression as a variable expression, re-evalulating the contents of last_nonempty_var_expression.

https://github.com/llvm/llvm-project/pull/107485