From b4d83f8db2e4d331a0077aef993bbf85576fada8 Mon Sep 17 00:00:00 2001
From: Daniel Lubarov <daniel@lubarov.com>
Date: Wed, 3 Aug 2022 13:40:43 -0700
Subject: [PATCH] More metadata fields

---
 evm/src/cpu/kernel/context_metadata.rs | 20 +++++++++++++++++++-
 evm/src/cpu/kernel/global_metadata.rs  | 10 ++++++++--
 2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/evm/src/cpu/kernel/context_metadata.rs b/evm/src/cpu/kernel/context_metadata.rs
index cf0bfc23..5b6ce303 100644
--- a/evm/src/cpu/kernel/context_metadata.rs
+++ b/evm/src/cpu/kernel/context_metadata.rs
@@ -7,10 +7,20 @@ pub(crate) enum ContextMetadata {
     ParentProgramCounter = 1,
     CalldataSize = 2,
     ReturndataSize = 3,
+    /// The address of the account associated with this context.
+    Address = 4,
+    /// The size of the code under the account associated with this context.
+    /// While this information could be obtained from the state trie, it is best to cache it since
+    /// the `CODESIZE` instruction is very cheap.
+    CodeSize = 5,
+    /// The address of the caller who spawned this context.
+    Caller = 6,
+    /// The value (in wei) deposited by the caller.
+    CallValue = 7,
 }
 
 impl ContextMetadata {
-    pub(crate) const COUNT: usize = 4;
+    pub(crate) const COUNT: usize = 8;
 
     pub(crate) fn all() -> [Self; Self::COUNT] {
         [
@@ -18,6 +28,10 @@ impl ContextMetadata {
             Self::ParentProgramCounter,
             Self::CalldataSize,
             Self::ReturndataSize,
+            Self::Address,
+            Self::CodeSize,
+            Self::Caller,
+            Self::CallValue,
         ]
     }
 
@@ -28,6 +42,10 @@ impl ContextMetadata {
             ContextMetadata::ParentProgramCounter => "CTX_METADATA_PARENT_PC",
             ContextMetadata::CalldataSize => "CTX_METADATA_CALLDATA_SIZE",
             ContextMetadata::ReturndataSize => "CTX_METADATA_RETURNDATA_SIZE",
+            ContextMetadata::Address => "CTX_METADATA_ADDRESS",
+            ContextMetadata::CodeSize => "CTX_METADATA_CODE_SIZE",
+            ContextMetadata::Caller => "CTX_METADATA_CALLER",
+            ContextMetadata::CallValue => "CTX_METADATA_CALL_VALUE",
         }
     }
 }
diff --git a/evm/src/cpu/kernel/global_metadata.rs b/evm/src/cpu/kernel/global_metadata.rs
index 23c5a4c7..6343a2e6 100644
--- a/evm/src/cpu/kernel/global_metadata.rs
+++ b/evm/src/cpu/kernel/global_metadata.rs
@@ -5,19 +5,25 @@ pub(crate) enum GlobalMetadata {
     /// The largest context ID that has been used so far in this execution. Tracking this allows us
     /// give each new context a unique ID, so that its memory will be zero-initialized.
     LargestContext = 0,
+    /// The address of the sender of the transaction.
+    Origin = 1,
+    /// The size of active memory, in bytes.
+    MemorySize = 2,
 }
 
 impl GlobalMetadata {
-    pub(crate) const COUNT: usize = 1;
+    pub(crate) const COUNT: usize = 3;
 
     pub(crate) fn all() -> [Self; Self::COUNT] {
-        [Self::LargestContext]
+        [Self::LargestContext, Self::Origin, Self::MemorySize]
     }
 
     /// The variable name that gets passed into kernel assembly code.
     pub(crate) fn var_name(&self) -> &'static str {
         match self {
             GlobalMetadata::LargestContext => "GLOBAL_METADATA_LARGEST_CONTEXT",
+            GlobalMetadata::Origin => "GLOBAL_METADATA_ORIGIN",
+            GlobalMetadata::MemorySize => "GLOBAL_METADATA_MEMORY_SIZE",
         }
     }
 }