chore: use DWARFS_PANIC for code that should never be reached

src/internal/worker_group.cpp

@@ -93,6 +93,9 @@ class basic_worker_group final : public worker_group::impl, private Policy {
     try {
       stop();
     } catch (...) {
+      DWARFS_PANIC(
+          fmt::format("exception thrown in worker group destructor: {}",
+                      exception_str(std::current_exception())));
     }
   }
 

src/writer/internal/chmod_transformer.cpp

@@ -25,6 +25,8 @@
 
 #include <fmt/format.h>
 
+#include <dwarfs/error.h>
+
 #include <dwarfs/writer/internal/chmod_transformer.h>
 
 namespace dwarfs::writer::internal {
@@ -173,6 +175,9 @@ chmod_transformer_::chmod_transformer_(std::string_view spec, mode_type umask)
       case 'o':
         bits = kAllOtherBits;
         break;
+      default:
+        DWARFS_PANIC("internal error: invalid ugo in mode spec");
+        break;
       }
 
       modifiers_.push_back(
@@ -330,6 +335,10 @@ chmod_transformer_::transform(mode_type mode, bool isdir) const {
     case '-':
       mode &= ~bits;
       break;
+
+    default:
+      DWARFS_PANIC("internal error: invalid operator in modifier");
+      break;
     }
   }
 

src/writer/writer_progress.cpp

@@ -22,6 +22,8 @@
 #include <folly/portability/Windows.h>
 #include <folly/system/ThreadName.h>
 
+#include <dwarfs/error.h>
+#include <dwarfs/util.h>
 #include <dwarfs/writer/writer_progress.h>
 
 #include <dwarfs/writer/internal/progress.h>
@@ -62,6 +64,9 @@ writer_progress::~writer_progress() noexcept {
       cond_.notify_all();
       thread_.join();
     } catch (...) {
+      DWARFS_PANIC(
+          fmt::format("exception thrown in writer_progress destructor: {}",
+                      exception_str(std::current_exception())));
     }
   }
 }