From f66d410f3ba767efb91c6b9545d373267cd975f2 Mon Sep 17 00:00:00 2001

From: rpm-build <rpm-build>

Date: Sat, 7 Sep 2019 20:43:40 +0200

Subject: [PATCH] enddianness.patch

Bug 1488552 - Ensure proper running on 64-bit and 32-bit BE platforms.

---

 js/src/gc/Marking-inl.h       | 16 ++++++++++++++++

 js/src/gc/RelocationOverlay.h | 13 ++++++++++++-

 js/src/jsfriendapi.h          |  8 ++++++++

 js/src/vm/StringType.h        | 13 +++++++++++++

 4 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/js/src/gc/Marking-inl.h b/js/src/gc/Marking-inl.h

index 6d2a4c7..c773c21 100644

--- a/js/src/gc/Marking-inl.h

+++ b/js/src/gc/Marking-inl.h

@@ -82,12 +82,28 @@ inline void RelocationOverlay::forwardTo(Cell* cell) {

   MOZ_ASSERT(!isForwarded());

   // The location of magic_ is important because it must never be valid to see

   // the value Relocated there in a GC thing that has not been moved.

+#if MOZ_LITTLE_ENDIAN || JS_BITS_PER_WORD == 32

+  // On 32-bit, the magic_ aliases with whatever comes after the first

+  // pointer; on little-endian 64-bit, the magic_ aliases with the

+  // 32 most significant bits of the pointer, which are the second half.

   static_assert(offsetof(RelocationOverlay, magic_) ==

                     offsetof(JSObject, group_) + sizeof(uint32_t),

                 "RelocationOverlay::magic_ is in the wrong location");

   static_assert(offsetof(RelocationOverlay, magic_) ==

                     offsetof(js::Shape, base_) + sizeof(uint32_t),

                 "RelocationOverlay::magic_ is in the wrong location");

+#elif JS_BITS_PER_WORD == 64

+  // On big-endian 64-bit, the magic_ aliases with the 32 most

+  // significant bits of the pointer, but now that's the first half.

+  static_assert(offsetof(RelocationOverlay, magic_) ==

+                    offsetof(JSObject, group_),

+                "RelocationOverlay::magic_ is in the wrong location");

+  static_assert(offsetof(RelocationOverlay, magic_) ==

+                    offsetof(js::Shape, base_),

+                "RelocationOverlay::magic_ is in the wrong location");

+#else

+#  error "Unknown endianness or word size"

+#endif

   static_assert(

       offsetof(RelocationOverlay, magic_) == offsetof(JSString, d.u1.length),

       "RelocationOverlay::magic_ is in the wrong location");

diff --git a/js/src/gc/RelocationOverlay.h b/js/src/gc/RelocationOverlay.h

index a568843..399a541 100644

--- a/js/src/gc/RelocationOverlay.h

+++ b/js/src/gc/RelocationOverlay.h

@@ -33,14 +33,25 @@ class RelocationOverlay {

   /* See comment in js/public/HeapAPI.h. */

   static const uint32_t Relocated = js::gc::Relocated;

+#if MOZ_LITTLE_ENDIAN || JS_BITS_PER_WORD == 32

   /*

-   * Keep the low 32 bits untouched. Use them to distinguish strings from

+   * Keep the first 32 bits untouched. Use them to distinguish strings from

    * objects in the nursery.

    */

   uint32_t preserve_;

   /* Set to Relocated when moved. */

   uint32_t magic_;

+#elif JS_BITS_PER_WORD == 64

+  /*

+   * On big-endian, we need to reorder to keep preserve_ lined up with the

+   * low 32 bits of the aligned group_ pointer in JSObject.

+   */

+  uint32_t magic_;

+  uint32_t preserve_;

+#else

+#  error "Unknown endianness or word size"

+#endif

   /* The location |this| was moved to. */

   Cell* newLocation_;

diff --git a/js/src/jsfriendapi.h b/js/src/jsfriendapi.h

index 4b8d18a..70ce0a1 100644

--- a/js/src/jsfriendapi.h

+++ b/js/src/jsfriendapi.h

@@ -9,6 +9,7 @@

 #include "mozilla/Atomics.h"

 #include "mozilla/Casting.h"

+#include "mozilla/EndianUtils.h"

 #include "mozilla/Maybe.h"

 #include "mozilla/MemoryReporting.h"

 #include "mozilla/UniquePtr.h"

@@ -609,8 +610,15 @@ struct String {

   static const uint32_t LATIN1_CHARS_BIT = JS_BIT(6);

   static const uint32_t EXTERNAL_FLAGS = LINEAR_BIT | NON_ATOM_BIT | JS_BIT(5);

   static const uint32_t TYPE_FLAGS_MASK = JS_BIT(6) - 1;

+#if MOZ_LITTLE_ENDIAN || JS_BITS_PER_WORD == 32

   uint32_t flags;

   uint32_t length;

+#elif JS_BITS_PER_WORD == 64

+  uint32_t length;

+  uint32_t flags;

+#else

+#  error "Unknown endianness or word size"

+#endif

   union {

     const JS::Latin1Char* nonInlineCharsLatin1;

     const char16_t* nonInlineCharsTwoByte;

diff --git a/js/src/vm/StringType.h b/js/src/vm/StringType.h

index cde3427..c3400db 100644

--- a/js/src/vm/StringType.h

+++ b/js/src/vm/StringType.h

@@ -7,6 +7,7 @@

 #ifndef vm_StringType_h

 #define vm_StringType_h

+#include "mozilla/EndianUtils.h"

 #include "mozilla/MemoryReporting.h"

 #include "mozilla/PodOperations.h"

 #include "mozilla/Range.h"

@@ -168,8 +169,20 @@ class JSString : public js::gc::Cell {

   struct Data {

     union {

       struct {

+#if MOZ_LITTLE_ENDIAN || JS_BITS_PER_WORD == 32

         uint32_t flags;  /* JSString */

         uint32_t length; /* JSString */

+#elif JS_BITS_PER_WORD == 64

+        /*

+         * On big-endian, we need to reorder to keep flags lined up

+         * with the low 32 bits of the aligned group_ pointer in

+         * JSObject.

+         */

+        uint32_t length; /* JSString */

+        uint32_t flags;  /* JSString */

+#else

+#  error "Unknown endianness or word size"

+#endif

       };

       uintptr_t flattenData; /* JSRope (temporary while flattening) */

     } u1;

-- 

2.23.0