From 0c31e332dd6ba4f8def51ad49a0f8d8fcebf1069 Mon Sep 17 00:00:00 2001
From: moto <855818+mthrok@users.noreply.github.com>
Date: Sat, 3 Jun 2023 10:28:44 -0400
Subject: [PATCH] const

---
 torchaudio/csrc/sox/stub.cpp | 67 ++++++++++++++++++------------------
 torchaudio/csrc/sox/stub.h   |  2 +-
 2 files changed, 35 insertions(+), 34 deletions(-)

diff --git a/torchaudio/csrc/sox/stub.cpp b/torchaudio/csrc/sox/stub.cpp
index c83b6d3c440..08fb12a16cc 100644
--- a/torchaudio/csrc/sox/stub.cpp
+++ b/torchaudio/csrc/sox/stub.cpp
@@ -6,43 +6,44 @@
 namespace torchaudio::sox::detail {
 namespace {
 
+LibSoxStub get_stub(at::DynamicLibrary& handle) {
+  // Validate version: we only support 14.4.2
+  auto fn = (const sox_version_info_t* (*)())handle.sym("sox_version_info");
+  if (SOX_LIB_VERSION_CODE != fn()->version_code) {
+    auto ver = ((const char* (*)())handle.sym("sox_version"))();
+    TORCH_CHECK(false, "Need libsox 14.4.2, but found ", ver);
+  }
+
+#define get_symbol(X) (decltype(LibSoxStub::X))handle.sym(#X)
+  return LibSoxStub {
+    get_symbol(sox_add_effect),
+    get_symbol(sox_close),
+    get_symbol(sox_create_effect),
+    get_symbol(sox_create_effects_chain),
+    get_symbol(sox_delete_effect),
+    get_symbol(sox_delete_effects_chain),
+    get_symbol(sox_effect_options),
+    get_symbol(sox_find_effect),
+    get_symbol(sox_flow_effects),
+    get_symbol(sox_get_effect_fns),
+    get_symbol(sox_get_format_fns),
+    get_symbol(sox_get_globals),
+    get_symbol(sox_open_read),
+    get_symbol(sox_open_write),
+    get_symbol(sox_strerror),
+    get_symbol(sox_write)
+  };
+#undef get_symbol
+}
+
 // Handle to the dlopen-ed libsox
 class StubImpl {
   at::DynamicLibrary handle;
 
  public:
-  LibSoxStub stub{};
-
-  StubImpl(const char* name) : handle(name) {
-    // check version: we only support 14.4.2
-    {
-      auto f = (const sox_version_info_t* (*)())handle.sym("sox_version_info");
-      if (SOX_LIB_VERSION_CODE != f()->version_code) {
-        auto ver = ((const char* (*)())handle.sym("sox_version"))();
-        TORCH_CHECK(false, "Need libsox 14.4.2, but found ", ver);
-      }
-    }
-
-    // Register fanction pointers on public-facing interface
-#define set(X) stub.X = (decltype(LibSoxStub::X))handle.sym(#X)
-    set(sox_add_effect);
-    set(sox_close);
-    set(sox_create_effect);
-    set(sox_create_effects_chain);
-    set(sox_delete_effect);
-    set(sox_delete_effects_chain);
-    set(sox_effect_options);
-    set(sox_find_effect);
-    set(sox_flow_effects);
-    set(sox_get_effect_fns);
-    set(sox_get_format_fns);
-    set(sox_get_globals);
-    set(sox_open_read);
-    set(sox_open_write);
-    set(sox_strerror);
-    set(sox_write);
-#undef set
+  const LibSoxStub stub;
 
+  StubImpl(const char* name) : handle(name), stub(get_stub(handle)) {
     // Global config
     auto config = stub.sox_get_globals();
     config->verbosity = 0;
@@ -69,8 +70,8 @@ class StubImpl {
 #else
 #define EXT "so"
 #endif
-LibSoxStub& libsox_stub() {
-  static StubImpl s{"libsox." EXT};
+const LibSoxStub& libsox_stub() {
+  static const StubImpl s{"libsox." EXT};
   return s.stub;
 }
 #undef EXT
diff --git a/torchaudio/csrc/sox/stub.h b/torchaudio/csrc/sox/stub.h
index 9e1517d1348..d2b3f70e64a 100644
--- a/torchaudio/csrc/sox/stub.h
+++ b/torchaudio/csrc/sox/stub.h
@@ -60,7 +60,7 @@ struct LibSoxStub {
   size_t (*sox_write)(sox_format_t* ft, const sox_sample_t* buf, size_t len);
 };
 
-LibSoxStub& libsox_stub();
+const LibSoxStub& libsox_stub();
 
 } // namespace torchaudio::sox