Add m-esr52 at 52.6.0

1 files changed, 216 insertions, 0 deletions

diff --git a/js/src/vm/Xdr.h b/js/src/vm/Xdr.h
new file mode 100644
index 000000000..8e8c5bf17
--- /dev/null
+++ b/js/src/vm/Xdr.h
@@ -0,0 +1,216 @@
+/* -*- 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 vm_Xdr_h
+#define vm_Xdr_h
+
+#include "mozilla/EndianUtils.h"
+#include "mozilla/TypeTraits.h"
+
+#include "jsatom.h"
+#include "jsfriendapi.h"
+
+namespace js {
+
+class XDRBuffer {
+  public:
+    XDRBuffer(JSContext* cx, JS::TranscodeBuffer& buffer, size_t cursor = 0)
+      : context_(cx), buffer_(buffer), cursor_(cursor) { }
+
+    JSContext* cx() const {
+        return context_;
+    }
+
+    const uint8_t* read(size_t n) {
+        MOZ_ASSERT(cursor_ < buffer_.length());
+        uint8_t* ptr = &buffer_[cursor_];
+        cursor_ += n;
+        return ptr;
+    }
+
+    const char* readCString() {
+        char* ptr = reinterpret_cast<char*>(&buffer_[cursor_]);
+        uint8_t* end = reinterpret_cast<uint8_t*>(strchr(ptr, '\0')) + 1;
+        MOZ_ASSERT(buffer_.begin() < end);
+        MOZ_ASSERT(end <= buffer_.end());
+        cursor_ = end - buffer_.begin();
+        return ptr;
+    }
+
+    uint8_t* write(size_t n) {
+        MOZ_ASSERT(n != 0);
+        if (!buffer_.growByUninitialized(n)) {
+            JS_ReportOutOfMemory(cx());
+            return nullptr;
+        }
+        uint8_t* ptr = &buffer_[cursor_];
+        cursor_ += n;
+        return ptr;
+    }
+
+  private:
+    JSContext* const context_;
+    JS::TranscodeBuffer& buffer_;
+    size_t cursor_;
+};
+
+/*
+ * XDR serialization state.  All data is encoded in little endian.
+ */
+template <XDRMode mode>
+class XDRState {
+  public:
+    XDRBuffer buf;
+    JS::TranscodeResult resultCode_;
+
+    XDRState(JSContext* cx, JS::TranscodeBuffer& buffer, size_t cursor = 0)
+      : buf(cx, buffer, cursor), resultCode_(JS::TranscodeResult_Ok) { }
+
+    JSContext* cx() const {
+        return buf.cx();
+    }
+
+    // Record logical failures of XDR.
+    void postProcessContextErrors(JSContext* cx);
+    JS::TranscodeResult resultCode() const {
+        return resultCode_;
+    }
+    bool fail(JS::TranscodeResult code) {
+        MOZ_ASSERT(resultCode_ == JS::TranscodeResult_Ok);
+        resultCode_ = code;
+        return false;
+    }
+
+    bool codeUint8(uint8_t* n) {
+        if (mode == XDR_ENCODE) {
+            uint8_t* ptr = buf.write(sizeof(*n));
+            if (!ptr)
+                return false;
+            *ptr = *n;
+        } else {
+            *n = *buf.read(sizeof(*n));
+        }
+        return true;
+    }
+
+    bool codeUint16(uint16_t* n) {
+        if (mode == XDR_ENCODE) {
+            uint8_t* ptr = buf.write(sizeof(*n));
+            if (!ptr)
+                return false;
+            mozilla::LittleEndian::writeUint16(ptr, *n);
+        } else {
+            const uint8_t* ptr = buf.read(sizeof(*n));
+            *n = mozilla::LittleEndian::readUint16(ptr);
+        }
+        return true;
+    }
+
+    bool codeUint32(uint32_t* n) {
+        if (mode == XDR_ENCODE) {
+            uint8_t* ptr = buf.write(sizeof(*n));
+            if (!ptr)
+                return false;
+            mozilla::LittleEndian::writeUint32(ptr, *n);
+        } else {
+            const uint8_t* ptr = buf.read(sizeof(*n));
+            *n = mozilla::LittleEndian::readUint32(ptr);
+        }
+        return true;
+    }
+
+    bool codeUint64(uint64_t* n) {
+        if (mode == XDR_ENCODE) {
+            uint8_t* ptr = buf.write(sizeof(*n));
+            if (!ptr)
+                return false;
+            mozilla::LittleEndian::writeUint64(ptr, *n);
+        } else {
+            const uint8_t* ptr = buf.read(sizeof(*n));
+            *n = mozilla::LittleEndian::readUint64(ptr);
+        }
+        return true;
+    }
+
+    /*
+     * Use SFINAE to refuse any specialization which is not an enum.  Uses of
+     * this function do not have to specialize the type of the enumerated field
+     * as C++ will extract the parameterized from the argument list.
+     */
+    template <typename T>
+    bool codeEnum32(T* val, typename mozilla::EnableIf<mozilla::IsEnum<T>::value, T>::Type * = NULL)
+    {
+        uint32_t tmp;
+        if (mode == XDR_ENCODE)
+            tmp = uint32_t(*val);
+        if (!codeUint32(&tmp))
+            return false;
+        if (mode == XDR_DECODE)
+            *val = T(tmp);
+        return true;
+    }
+
+    bool codeDouble(double* dp) {
+        union DoublePun {
+            double d;
+            uint64_t u;
+        } pun;
+        if (mode == XDR_ENCODE)
+            pun.d = *dp;
+        if (!codeUint64(&pun.u))
+            return false;
+        if (mode == XDR_DECODE)
+            *dp = pun.d;
+        return true;
+    }
+
+    bool codeBytes(void* bytes, size_t len) {
+        if (len == 0)
+            return true;
+        if (mode == XDR_ENCODE) {
+            uint8_t* ptr = buf.write(len);
+            if (!ptr)
+                return false;
+            memcpy(ptr, bytes, len);
+        } else {
+            memcpy(bytes, buf.read(len), len);
+        }
+        return true;
+    }
+
+    /*
+     * During encoding the string is written into the buffer together with its
+     * terminating '\0'. During decoding the method returns a pointer into the
+     * decoding buffer and the caller must copy the string if it will outlive
+     * the decoding buffer.
+     */
+    bool codeCString(const char** sp) {
+        if (mode == XDR_ENCODE) {
+            size_t n = strlen(*sp) + 1;
+            uint8_t* ptr = buf.write(n);
+            if (!ptr)
+                return false;
+            memcpy(ptr, *sp, n);
+        } else {
+            *sp = buf.readCString();
+        }
+        return true;
+    }
+
+    bool codeChars(const JS::Latin1Char* chars, size_t nchars);
+    bool codeChars(char16_t* chars, size_t nchars);
+
+    bool codeFunction(JS::MutableHandleFunction objp);
+    bool codeScript(MutableHandleScript scriptp);
+    bool codeConstValue(MutableHandleValue vp);
+};
+
+using XDREncoder = XDRState<XDR_ENCODE>;
+using XDRDecoder = XDRState<XDR_DECODE>;
+
+} /* namespace js */
+
+#endif /* vm_Xdr_h */