1 files changed, 74 insertions, 0 deletions
diff --git a/js/src/jit/shared/Assembler-shared.cpp b/js/src/jit/shared/Assembler-shared.cpp
new file mode 100644
index 0000000000..96dcf69a72
--- /dev/null
+++ b/js/src/jit/shared/Assembler-shared.cpp
@@ -0,0 +1,74 @@
+/* -*- 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 "jit/shared/Assembler-shared.h"
+
+#include "jit/JitSpewer.h"
+#include "vm/NativeObject.h"
+
+namespace js::jit {
+
+void BaseObjectElementIndex::staticAssertions() {
+  NativeObject::elementsSizeMustNotOverflow();
+}
+
+void BaseObjectSlotIndex::staticAssertions() {
+  NativeObject::slotsSizeMustNotOverflow();
+}
+
+AssemblerShared::~AssemblerShared() {
+#ifdef DEBUG
+  while (hasCreator()) {
+    popCreator();
+  }
+#endif
+}
+
+#ifdef DEBUG
+void AssemblerShared::pushCreator(const char* who) {
+  (void)creators_.append(who);
+  JitSpewStart(JitSpew_Codegen, "# BEGIN creators: ");
+  bool first = true;
+  for (const char* str : creators_) {
+    JitSpewCont(JitSpew_Codegen, "%s%s", first ? "" : "/", str);
+    first = false;
+  }
+  JitSpewCont(JitSpew_Codegen, "\n");
+}
+
+void AssemblerShared::popCreator() {
+  JitSpewStart(JitSpew_Codegen, "# END   creators: ");
+  bool first = true;
+  for (const char* str : creators_) {
+    JitSpewCont(JitSpew_Codegen, "%s%s", first ? "" : "/", str);
+    first = false;
+  }
+  JitSpewCont(JitSpew_Codegen, "\n");
+  if (creators_.empty()) {
+    JitSpew(JitSpew_Codegen, " ");
+  }
+  MOZ_ASSERT(!creators_.empty());
+  creators_.popBack();
+}
+
+bool AssemblerShared::hasCreator() const {
+  // If you get failures of assertions of the form `MOZ_ASSERT(hasCreator())`,
+  // what this means is that a `MacroAssembler` (or, really, anything that
+  // inherits from `js::jit::AssemblerShared`) has emitted code or data from a
+  // place, in the SM C++ hierarchy, that is not nested within an
+  // `AutoCreatedBy` RAII scope.  Consequently the emitted instructions/data
+  // won't have any owner that is identifiable in the `IONFLAGS=codegen`
+  // output.
+  //
+  // Fixing this is easy: work back up the crash stack and decide on a place
+  // to put an `AutoCreatedBy` call.  A bit of grepping for `AutoCreatedBy`
+  // should make it obvious what to do.  If in doubt, add `AutoCreatedBy`
+  // calls liberally; "extra" ones are harmless.
+  return !creators_.empty();
+}
+#endif
+
+}  // namespace js::jit