Bug 1812276 - Add a minimal shlwapi.h wrapper, like we do with windows.h. r=nika

Differential Revision: https://phabricator.services.mozilla.com/D167879

config/moz.build

@@ -80,6 +80,17 @@ if CONFIG["WRAP_STL_INCLUDES"]:
             ],
             flags=[stl_compiler],
         )
+        GeneratedFile(
+            "/dist/stl_wrappers/shlwapi.h",
+            script="make-windows-h-wrapper.py",
+            entry_point="generate",
+            inputs=[
+                "shlwapi-h-constant.decls.h",
+                "shlwapi-h-unicode.decls.h",
+                "shlwapi-h-wrapper.template.h",
+            ],
+            flags=[stl_compiler],
+        )
 
 if CONFIG["WRAP_SYSTEM_INCLUDES"]:
     include("system-headers.mozbuild")

config/shlwapi-h-constant.decls.h

@@ -0,0 +1,23 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * This file contains a series of C-style declarations for constants defined in
+ * shlwapi.h using #define. Adding a new constant should be a simple as adding
+ * its name (and optionally type) to this file.
+ *
+ * This file is processed by make-windows-h-wrapper.py to generate a wrapper for
+ * the header which removes the defines usually implementing these constants.
+ *
+ * Wrappers defined in this file will be declared as `constexpr` values,
+ * and will have their value derived from the windows.h define.
+ *
+ * NOTE: This is *NOT* a real C header, but rather an input to the avove script.
+ * Only basic declarations in the form found here are allowed.
+ */
+
+// XXX(glandium): We don't have any here, because they don't look like they
+// could cause problems.

config/shlwapi-h-unicode.decls.h

@@ -0,0 +1,24 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * This file contains a series of C-style function prototypes for A/W-suffixed
+ * Win32 APIs defined by shlwapi.h.
+ *
+ * This file is processed by make-windows-h-wrapper.py to generate a wrapper for
+ * the header which removes the defines usually implementing these aliases.
+ *
+ * Wrappers defined in this file will have the 'stdcall' calling convention,
+ * will be defined as 'inline', and will only be defined if the corresponding
+ * #define directive has not been #undef-ed.
+ *
+ * NOTE: This is *NOT* a real C header, but rather an input to the avove script.
+ * Only basic declarations in the form found here are allowed.
+ */
+
+// XXX(glandium): there are a ton more, but this is the one that is causing
+// immediate problems.
+HRESULT GetAcceptLanguages(LPTSTR, DWORD*);

config/shlwapi-h-wrapper.template.h

@@ -0,0 +1,41 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_shlwapi_h
+#define mozilla_shlwapi_h
+
+// Include the "real" shlwapi.h header.
+//
+// Also turn off deprecation warnings, as we may be wrapping deprecated fns.
+
+#pragma GCC system_header
+#include_next <shlwapi.h>
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+
+// Check if the header should be disabled
+#if defined(MOZ_DISABLE_WINDOWS_WRAPPER)
+#  define MOZ_WINDOWS_WRAPPER_DISABLED_REASON "explicitly disabled"
+
+#elif !defined(__cplusplus)
+#  define MOZ_WINDOWS_WRAPPER_DISABLED_REASON "non-C++ source file"
+
+#else
+// We're allowed to wrap in the current context. Define `MOZ_WRAPPED_SHLWAPI_H`
+// to note that fact, and perform the wrapping.
+#  define MOZ_WRAPPED_SHLWAPI_H
+extern "C++" {
+
+$ { decls }
+
+}  // extern "C++"
+
+#endif  // enabled
+
+#pragma GCC diagnostic pop
+
+#endif  // !defined(mozilla_shlwapi_h)