[decompiler] Fix rlet in top level and detect matrix and stack inline construction (#547)

* top level in rlet

* detect matrix and vector inline 0

* pretty print the symbol map

decompiler/analysis/final_output.cpp

@@ -141,6 +141,26 @@ std::string careful_function_to_string(
 }
 }  // namespace
 
+std::string add_indent(const std::string& in, int indent, bool indent_first_line) {
+  if (in.empty()) {
+    return in;
+  }
+
+  std::string indent_str(indent, ' ');
+  std::string result;
+
+  char prev_char = indent_first_line ? '\n' : ' ';
+  for (char c : in) {
+    if (prev_char == '\n') {
+      result += indent_str;
+    }
+    result += c;
+    prev_char = c;
+  }
+
+  return result;
+}
+
 std::string write_from_top_level(const Function& top_level,
                                  const DecompilerTypeSystem& dts,
                                  const LinkedObjectFile& file,
@@ -198,6 +218,23 @@ std::string write_from_top_level(const Function& top_level,
     }
   }
 
+  // look for the whole thing being in an rlet
+  bool in_rlet = false;
+  if (forms.size() == 1) {
+    auto as_rlet = dynamic_cast<RLetElement*>(forms.at(0));
+    if (as_rlet) {
+      forms = as_rlet->body->elts();
+      in_rlet = true;
+      result += "(rlet ";
+      result += add_indent(pretty_print::to_string(as_rlet->reg_list()), 6, false);
+      result += '\n';
+      if (as_rlet->needs_vf0_init()) {
+        result += "(init-vf0-vector)\n";
+      }
+      result += '\n';
+    }
+  }
+
   // (set! identity L312)
   constexpr int func_name = 1;
   constexpr int label = 2;
@@ -370,6 +407,10 @@ std::string write_from_top_level(const Function& top_level,
     result += ")\n";
   }
 
+  if (in_rlet) {
+    result += ")\n";
+  }
+
   return result;
 }
 }  // namespace decompiler