1 files changed, 61 insertions, 12 deletions

diff --git a/deps/v8/src/common/ptr-compr.h b/deps/v8/src/common/ptr-compr.h
index 5a47331a54..bfe99cea9e 100644
--- a/deps/v8/src/common/ptr-compr.h
+++ b/deps/v8/src/common/ptr-compr.h
@@ -13,7 +13,7 @@ namespace v8::internal {
 // This is just a collection of compression scheme related functions. Having
 // such a class allows plugging different decompression scheme in certain
 // places by introducing another CompressionScheme class with a customized
-// implementation. This is useful, for example, for CodeDataContainer::code
+// implementation. This is useful, for example, for Code::code
 // field (see CodeObjectSlot).
 class V8HeapCompressionScheme {
  public:
@@ -24,20 +24,20 @@ class V8HeapCompressionScheme {
 
   // Compresses full-pointer representation of a tagged value to on-heap
   // representation.
-  V8_INLINE static Tagged_t CompressTagged(Address tagged);
+  // Must only be used for compressing object pointers since this function
+  // assumes that we deal with a valid address inside the pointer compression
+  // cage.
+  V8_INLINE static Tagged_t CompressObject(Address tagged);
+  // Compress a potentially invalid pointer.
+  V8_INLINE static Tagged_t CompressAny(Address tagged);
 
   // Decompresses smi value.
   V8_INLINE static Address DecompressTaggedSigned(Tagged_t raw_value);
 
-  // Decompresses weak or strong heap object pointer or forwarding pointer,
-  // preserving both weak- and smi- tags.
-  template <typename TOnHeapAddress>
-  V8_INLINE static Address DecompressTaggedPointer(TOnHeapAddress on_heap_addr,
-                                                   Tagged_t raw_value);
   // Decompresses any tagged value, preserving both weak- and smi- tags.
   template <typename TOnHeapAddress>
-  V8_INLINE static Address DecompressTaggedAny(TOnHeapAddress on_heap_addr,
-                                               Tagged_t raw_value);
+  V8_INLINE static Address DecompressTagged(TOnHeapAddress on_heap_addr,
+                                            Tagged_t raw_value);
 
   // Given a 64bit raw value, found on the stack, calls the callback function
   // with all possible pointers that may be "contained" in compressed form in
@@ -47,12 +47,61 @@ class V8HeapCompressionScheme {
   V8_INLINE static void ProcessIntermediatePointers(
       PtrComprCageBase cage_base, Address raw_value,
       ProcessPointerCallback callback);
+
+#ifdef V8_COMPRESS_POINTERS_IN_SHARED_CAGE
+  // Process-wide cage base value used for decompression.
+  V8_INLINE static void InitBase(Address base);
+  V8_INLINE static Address base();
+
+ private:
+  static V8_EXPORT_PRIVATE uintptr_t base_ V8_CONSTINIT;
+#endif  // V8_COMPRESS_POINTERS_IN_SHARED_CAGE
 };
 
 #ifdef V8_EXTERNAL_CODE_SPACE
-// Compression scheme used for fields containing Code objects (namely for the
-// CodeDataContainer::code field).
-using ExternalCodeCompressionScheme = V8HeapCompressionScheme;
+
+// Compression scheme used for fields containing InstructionStream objects
+// (namely for the Code::code field). Same as
+// V8HeapCompressionScheme but with a different base value.
+class ExternalCodeCompressionScheme {
+ public:
+  V8_INLINE static Address PrepareCageBaseAddress(Address on_heap_addr);
+
+  // Note that this compression scheme doesn't allow reconstruction of the cage
+  // base value from any arbitrary value, thus the cage base has to be passed
+  // explicitly to the decompression functions.
+  static Address GetPtrComprCageBaseAddress(Address on_heap_addr) = delete;
+
+  V8_INLINE static Address GetPtrComprCageBaseAddress(
+      PtrComprCageBase cage_base);
+
+  // Compresses full-pointer representation of a tagged value to on-heap
+  // representation.
+  // Must only be used for compressing object pointers (incl. SMI) since this
+  // function assumes pointers to be inside the pointer compression cage.
+  V8_INLINE static Tagged_t CompressObject(Address tagged);
+  // Compress anything that does not follow the above requirements (e.g. a maybe
+  // object, or a marker bit pattern).
+  V8_INLINE static Tagged_t CompressAny(Address tagged);
+
+  // Decompresses smi value.
+  V8_INLINE static Address DecompressTaggedSigned(Tagged_t raw_value);
+
+  // Decompresses any tagged value, preserving both weak- and smi- tags.
+  template <typename TOnHeapAddress>
+  V8_INLINE static Address DecompressTagged(TOnHeapAddress on_heap_addr,
+                                            Tagged_t raw_value);
+
+#ifdef V8_COMPRESS_POINTERS_IN_SHARED_CAGE
+  // Process-wide cage base value used for decompression.
+  V8_INLINE static void InitBase(Address base);
+  V8_INLINE static Address base();
+
+ private:
+  static V8_EXPORT_PRIVATE uintptr_t base_ V8_CONSTINIT;
+#endif  // V8_COMPRESS_POINTERS_IN_SHARED_CAGE
+};
+
 #endif  // V8_EXTERNAL_CODE_SPACE
 
 // Accessors for fields that may be unaligned due to pointer compression.