[lldb-vscode] support the completion request

Summary:
The DAP has a completion request that has been unimplemented. It allows showing autocompletion tokens inside the Debug Console.
I implemented it in a very simple fashion mimicking what the user would see when autocompleting an expression inside the CLI.
There are two cases: normal variables and commands. The latter occurs when a text is prepepended with ` in the Debug Console.
These two cases work well and have tests.

Reviewers: clayborg, aadsm

Subscribers: lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D69873

1 files changed, 16 insertions, 0 deletions

diff --git a/lldb/packages/Python/lldbsuite/test/tools/lldb-vscode/completions/main.cpp b/lldb/packages/Python/lldbsuite/test/tools/lldb-vscode/completions/main.cpp
new file mode 100644
index 00000000000..14a8815a524
--- /dev/null
+++ b/lldb/packages/Python/lldbsuite/test/tools/lldb-vscode/completions/main.cpp
@@ -0,0 +1,16 @@
+#include <string>
+#include <vector>
+
+int fun(std::vector<std::string> var) {
+  return var.size(); // breakpoint 1
+}
+
+int main(int argc, char const *argv[]) {
+  int var1 = 0;
+  int var2 = 1;
+  std::string str1 = "a";
+  std::string str2 = "b";
+  std::vector<std::string> vec;
+  fun(vec);
+  return 0; // breakpoint 2
+}