[Lldb-commits] [lldb] [lldb] Implement a formatter bytecode interpreter in C++ (PR #114333)

[Dave Lee via lldb-commits]

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@@ -0,0 +1,41 @@
+// A bare-bones llvm::Optional reimplementation.
+
+template <typename T> struct MyOptionalStorage {
+  MyOptionalStorage(T val) : value(val), hasVal(true) {}
+  MyOptionalStorage() {}
+  T value;
+  bool hasVal = false;
+};
+
+template <typename T> struct MyOptional {
+  MyOptionalStorage<T> Storage;
+  MyOptional(T val) : Storage(val) {}
+  MyOptional() {}
+  T &operator*() { return Storage.value; }
+};
+
+void stop() {}
+
+int main(int argc, char **argv) {
+  MyOptional<int> x, y = 42;
+  stop(); // break here
+  return *y;
+}
+
+__attribute__((used, section("__DATA_CONST,__lldbformatters"))) unsigned char
+    _MyOptional_type_summary[] =
+        "\x01"             // version
+        "\xa4"             // record size
+        "\x01"             // record size
+        "\x10"             // type name size
+        "^MyOptional<.+>$" // type name
+        "\x00"             // flags
+        "\x00"             // sig_summary
+        "\x8d"             // program size
+        "\x01"             // program size
+        "\x1\x22\x7Storage#\x12\x60\x1,C\x10\x1\x5\x11\x2\x1\x22\x6hasVal#"
+        "\x12\x60\x1,\x10\x1e\x2\x22\x1b<could not read MyOptional>\x10G#!\x60 "
+        "\x0P\x10\x6\x22\x4None\x10\x36\x1#\x15\x60 "
+        "\x0#\x16\x60\x5\x22\x5value#\x12\x60\x5#\x17\x60\x1,"
+        "\x10\x6\x22\x4None\x10\x11\x1#\x0\x60\x1#R\x60\x10\x3# "
+        "\x60\x10\x1\x2\x12\x12\x12\x12"; // summary function
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kastiglione wrote:

did you write this with assembly? could you include that in the tests? It'll be hard to modify such tests if we have to work with the bytecode directly.

https://github.com/llvm/llvm-project/pull/114333