1 files changed, 39 insertions, 0 deletions
diff --git a/src/debug.cc b/src/debug.cc
new file mode 100644
index 00000000..55f7e4d3
--- /dev/null
+++ b/src/debug.cc
@@ -0,0 +1,39 @@
+#include "debug.hh" 
+
+#include "buffer_manager.hh" 
+#include "buffer_utils.hh" 
+#include "utils.hh" 
+
+namespace Kakoune
+{
+
+void write_to_debug_buffer(StringView str)
+{
+    if (not BufferManager::has_instance())
+    {
+        write(2, str);
+        write(2, "\n");
+        return;
+    }
+
+    constexpr StringView debug_buffer_name = "*debug*";
+    // Try to ensure we keep an empty line at the end of the debug buffer
+    // where the user can put its cursor to scroll with new messages
+    const bool eol_back = not str.empty() and str.back() == '\n';
+    if (Buffer* buffer = BufferManager::instance().get_buffer_ifp(debug_buffer_name))
+    {
+        buffer->flags() &= ~Buffer::Flags::ReadOnly;
+        auto restore = on_scope_end([buffer] { buffer->flags() |= Buffer::Flags::ReadOnly; });
+
+        buffer->insert(buffer->back_coord(), eol_back ? str : str + "\n");
+    }
+    else
+    {
+        String line = str + (eol_back ? "\n" : "\n\n");
+        create_buffer_from_string(
+            debug_buffer_name.str(), Buffer::Flags::NoUndo | Buffer::Flags::Debug | Buffer::Flags::ReadOnly,
+            line);
+    }
+}
+
+}