1 files changed, 124 insertions, 0 deletions
diff --git a/js/src/jit/x86-shared/Patching-x86-shared.h b/js/src/jit/x86-shared/Patching-x86-shared.h
new file mode 100644
index 000000000..b73492870
--- /dev/null
+++ b/js/src/jit/x86-shared/Patching-x86-shared.h
@@ -0,0 +1,124 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * 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 jit_x86_shared_Patching_x86_shared_h
+#define jit_x86_shared_Patching_x86_shared_h
+
+namespace js {
+namespace jit {
+
+namespace X86Encoding {
+
+inline void*
+GetPointer(const void* where)
+{
+    void* res;
+    memcpy(&res, (const char*)where - sizeof(void*), sizeof(void*));
+    return res;
+}
+
+inline void
+SetPointer(void* where, const void* value)
+{
+    memcpy((char*)where - sizeof(void*), &value, sizeof(void*));
+}
+
+inline int32_t
+GetInt32(const void* where)
+{
+    int32_t res;
+    memcpy(&res, (const char*)where - sizeof(int32_t), sizeof(int32_t));
+    return res;
+}
+
+inline void
+SetInt32(void* where, int32_t value)
+{
+    memcpy((char*)where - sizeof(int32_t), &value, sizeof(int32_t));
+}
+
+inline void
+SetRel32(void* from, void* to)
+{
+    intptr_t offset = reinterpret_cast<intptr_t>(to) - reinterpret_cast<intptr_t>(from);
+    MOZ_ASSERT(offset == static_cast<int32_t>(offset),
+               "offset is too great for a 32-bit relocation");
+    if (offset != static_cast<int32_t>(offset))
+        MOZ_CRASH("offset is too great for a 32-bit relocation");
+
+    SetInt32(from, offset);
+}
+
+inline void*
+GetRel32Target(void* where)
+{
+    int32_t rel = GetInt32(where);
+    return (char*)where + rel;
+}
+
+class JmpSrc {
+  public:
+    JmpSrc()
+        : offset_(-1)
+    {
+    }
+
+    explicit JmpSrc(int32_t offset)
+        : offset_(offset)
+    {
+    }
+
+    int32_t offset() const {
+        return offset_;
+    }
+
+    bool isSet() const {
+        return offset_ != -1;
+    }
+
+  private:
+    int offset_;
+};
+
+class JmpDst {
+  public:
+    JmpDst()
+        : offset_(-1)
+        , used_(false)
+    {
+    }
+
+    bool isUsed() const { return used_; }
+    void used() { used_ = true; }
+    bool isValid() const { return offset_ != -1; }
+
+    explicit JmpDst(int32_t offset)
+        : offset_(offset)
+        , used_(false)
+    {
+        MOZ_ASSERT(offset_ == offset);
+    }
+    int32_t offset() const {
+        return offset_;
+    }
+  private:
+    int32_t offset_ : 31;
+    bool used_ : 1;
+};
+
+inline bool
+CanRelinkJump(void* from, void* to)
+{
+    intptr_t offset = static_cast<char*>(to) - static_cast<char*>(from);
+    return (offset == static_cast<int32_t>(offset));
+}
+
+} // namespace X86Encoding
+
+} // namespace jit
+} // namespace js
+
+#endif /* jit_x86_shared_Patching_x86_shared_h */