1 files changed, 123 insertions, 0 deletions
diff --git a/xpcom/string/RustStringAPI.cpp b/xpcom/string/RustStringAPI.cpp
new file mode 100644
index 0000000000..55ce6b9eeb
--- /dev/null
+++ b/xpcom/string/RustStringAPI.cpp
@@ -0,0 +1,123 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=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/. */
+
+#include "nsISupports.h"
+#include "nsString.h"
+
+// Extern "C" utilities used by the rust nsString bindings.
+
+// Provide rust bindings to the nsA[C]String types
+extern "C" {
+
+// This is a no-op on release, so we ifdef it out such that using it in release
+// results in a linker error.
+#ifdef DEBUG
+void Gecko_IncrementStringAdoptCount(void* aData) {
+  MOZ_LOG_CTOR(aData, "StringAdopt", 1);
+}
+#elif defined(MOZ_DEBUG_RUST)
+void Gecko_IncrementStringAdoptCount(void* aData) {}
+#endif
+
+void Gecko_FinalizeCString(nsACString* aThis) { aThis->~nsACString(); }
+
+void Gecko_AssignCString(nsACString* aThis, const nsACString* aOther) {
+  aThis->Assign(*aOther);
+}
+
+void Gecko_TakeFromCString(nsACString* aThis, nsACString* aOther) {
+  aThis->Assign(std::move(*aOther));
+}
+
+void Gecko_AppendCString(nsACString* aThis, const nsACString* aOther) {
+  aThis->Append(*aOther);
+}
+
+void Gecko_SetLengthCString(nsACString* aThis, uint32_t aLength) {
+  aThis->SetLength(aLength);
+}
+
+bool Gecko_FallibleAssignCString(nsACString* aThis, const nsACString* aOther) {
+  return aThis->Assign(*aOther, mozilla::fallible);
+}
+
+bool Gecko_FallibleTakeFromCString(nsACString* aThis, nsACString* aOther) {
+  return aThis->Assign(std::move(*aOther), mozilla::fallible);
+}
+
+bool Gecko_FallibleAppendCString(nsACString* aThis, const nsACString* aOther) {
+  return aThis->Append(*aOther, mozilla::fallible);
+}
+
+bool Gecko_FallibleSetLengthCString(nsACString* aThis, uint32_t aLength) {
+  return aThis->SetLength(aLength, mozilla::fallible);
+}
+
+char* Gecko_BeginWritingCString(nsACString* aThis) {
+  return aThis->BeginWriting();
+}
+
+char* Gecko_FallibleBeginWritingCString(nsACString* aThis) {
+  return aThis->BeginWriting(mozilla::fallible);
+}
+
+uint32_t Gecko_StartBulkWriteCString(nsACString* aThis, uint32_t aCapacity,
+                                     uint32_t aUnitsToPreserve,
+                                     bool aAllowShrinking) {
+  return aThis->StartBulkWriteImpl(aCapacity, aUnitsToPreserve, aAllowShrinking)
+      .unwrapOr(UINT32_MAX);
+}
+
+void Gecko_FinalizeString(nsAString* aThis) { aThis->~nsAString(); }
+
+void Gecko_AssignString(nsAString* aThis, const nsAString* aOther) {
+  aThis->Assign(*aOther);
+}
+
+void Gecko_TakeFromString(nsAString* aThis, nsAString* aOther) {
+  aThis->Assign(std::move(*aOther));
+}
+
+void Gecko_AppendString(nsAString* aThis, const nsAString* aOther) {
+  aThis->Append(*aOther);
+}
+
+void Gecko_SetLengthString(nsAString* aThis, uint32_t aLength) {
+  aThis->SetLength(aLength);
+}
+
+bool Gecko_FallibleAssignString(nsAString* aThis, const nsAString* aOther) {
+  return aThis->Assign(*aOther, mozilla::fallible);
+}
+
+bool Gecko_FallibleTakeFromString(nsAString* aThis, nsAString* aOther) {
+  return aThis->Assign(std::move(*aOther), mozilla::fallible);
+}
+
+bool Gecko_FallibleAppendString(nsAString* aThis, const nsAString* aOther) {
+  return aThis->Append(*aOther, mozilla::fallible);
+}
+
+bool Gecko_FallibleSetLengthString(nsAString* aThis, uint32_t aLength) {
+  return aThis->SetLength(aLength, mozilla::fallible);
+}
+
+char16_t* Gecko_BeginWritingString(nsAString* aThis) {
+  return aThis->BeginWriting();
+}
+
+char16_t* Gecko_FallibleBeginWritingString(nsAString* aThis) {
+  return aThis->BeginWriting(mozilla::fallible);
+}
+
+uint32_t Gecko_StartBulkWriteString(nsAString* aThis, uint32_t aCapacity,
+                                    uint32_t aUnitsToPreserve,
+                                    bool aAllowShrinking) {
+  return aThis->StartBulkWriteImpl(aCapacity, aUnitsToPreserve, aAllowShrinking)
+      .unwrapOr(UINT32_MAX);
+}
+
+}  // extern "C"