Merge branch 'libevm' into arr4n/jumptable-override

Author: ARR4N

.github/pull_request_template.md

@@ -0,0 +1,5 @@
+## Why this should be merged
+
+## How this works
+
+## How this was tested

.github/workflows/libevm-delta.yml

@@ -0,0 +1,38 @@
+name: libevm delta
+
+on:
+  push:
+    branches: [ libevm ]
+  pull_request:
+    branches: [ libevm ]
+  workflow_dispatch:
+
+jobs:
+  diffs:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0 # everything
+          fetch-tags: true
+      
+      - name: Color-blindness a11y
+        run: | # https://davidmathlogic.com/colorblind/#%23D81B60-%231E88E5-%23FFC107-%23004D40:~:text=8%20pairs%20of%20contrasting%20colors
+          git config color.diff.old "#DC3220";
+          git config color.diff.new "#005AB5";
+
+      - name: git diff libevm-base
+        run: |
+          git diff --diff-filter=a --word-diff --unified=0 --color=always \
+            libevm-base \
+            ':(exclude).golangci.yml' \
+            ':(exclude).github/**';
+      
+      - name: git diff libevm-base..libevm
+        run: |
+          git checkout libevm --;
+          git diff --diff-filter=a --word-diff --unified=0 --color=always \
+            libevm-base \
+            ':(exclude).golangci.yml' \
+            ':(exclude).github/**';
+

core/evm.go

@@ -73,6 +73,7 @@ func NewEVMBlockContext(header *types.Header, chain ChainContext, author *common
 		BlobBaseFee: blobBaseFee,
 		GasLimit:    header.GasLimit,
 		Random:      random,
+		Header:      header,
 	}
 }
 

core/vm/contracts.go

@@ -174,8 +174,7 @@ func (args *evmCallArgs) RunPrecompiledContract(p PrecompiledContract, input []b
 		return nil, 0, ErrOutOfGas
 	}
 	suppliedGas -= gasCost
-	output, err := args.run(p, input)
-	return output, suppliedGas, err
+	return args.run(p, input, suppliedGas)
 }
 
 // ECRECOVER implemented as a native contract.

core/vm/contracts.libevm.go

@@ -2,73 +2,180 @@ package vm
 
 import (
 	"fmt"
+	"math/big"
 
 	"github.com/holiman/uint256"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/libevm"
 	"github.com/ethereum/go-ethereum/params"
 )
 
 // evmCallArgs mirrors the parameters of the [EVM] methods Call(), CallCode(),
 // DelegateCall() and StaticCall(). Its fields are identical to those of the
-// parameters, prepended with the receiver name. As {Delegate,Static}Call don't
-// accept a value, they MUST set the respective field to nil.
+// parameters, prepended with the receiver name and appended with additional
+// values. As {Delegate,Static}Call don't accept a value, they MUST set the
+// respective field to nil.
 //
 // Instantiation can be achieved by merely copying the parameter names, in
 // order, which is trivially achieved with AST manipulation:
 //
 //	func (evm *EVM) Call(caller ContractRef, addr common.Address, input []byte, gas uint64, value *uint256.Int) ... {
-//		...
-//		args := &evmCallArgs{evm, caller, addr, input, gas, value}
+//	    ...
+//	    args := &evmCallArgs{evm, caller, addr, input, gas, value, false}
 type evmCallArgs struct {
-	evm    *EVM
+	evm *EVM
+	// args:start
 	caller ContractRef
 	addr   common.Address
 	input  []byte
 	gas    uint64
 	value  *uint256.Int
+	// args:end
+
+	// evm.interpreter.readOnly is only set to true via a call to
+	// EVMInterpreter.Run() so, if a precompile is called directly with
+	// StaticCall(), then readOnly might not be set yet. StaticCall() MUST set
+	// this to forceReadOnly and all other methods MUST set it to
+	// inheritReadOnly; i.e. equivalent to the boolean they each pass to
+	// EVMInterpreter.Run().
+	readWrite rwInheritance
 }
 
+type rwInheritance uint8
+
+const (
+	inheritReadOnly rwInheritance = iota + 1
+	forceReadOnly
+)
+
 // run runs the [PrecompiledContract], differentiating between stateful and
 // regular types.
-func (args *evmCallArgs) run(p PrecompiledContract, input []byte) (ret []byte, err error) {
+func (args *evmCallArgs) run(p PrecompiledContract, input []byte, suppliedGas uint64) (ret []byte, remainingGas uint64, err error) {
 	if p, ok := p.(statefulPrecompile); ok {
-		return p.run(args.evm.StateDB, &args.evm.chainRules, args.caller.Address(), args.addr, input)
+		return p(args, input, suppliedGas)
 	}
-	return p.Run(input)
+	// Gas consumption for regular precompiles was already handled by the native
+	// RunPrecompiledContract(), which called this method.
+	ret, err = p.Run(input)
+	return ret, suppliedGas, err
 }
 
-// PrecompiledStatefulRun is the stateful equivalent of the Run() method of a
+// PrecompiledStatefulContract is the stateful equivalent of a
 // [PrecompiledContract].
-type PrecompiledStatefulRun func(_ StateDB, _ *params.Rules, caller, self common.Address, input []byte) ([]byte, error)
+type PrecompiledStatefulContract func(env PrecompileEnvironment, input []byte, suppliedGas uint64) (ret []byte, remainingGas uint64, err error)
 
 // NewStatefulPrecompile constructs a new PrecompiledContract that can be used
 // via an [EVM] instance but MUST NOT be called directly; a direct call to Run()
 // reserves the right to panic. See other requirements defined in the comments
 // on [PrecompiledContract].
-func NewStatefulPrecompile(run PrecompiledStatefulRun, requiredGas func([]byte) uint64) PrecompiledContract {
-	return statefulPrecompile{
-		gas: requiredGas,
-		run: run,
-	}
+func NewStatefulPrecompile(run PrecompiledStatefulContract) PrecompiledContract {
+	return statefulPrecompile(run)
 }
 
-type statefulPrecompile struct {
-	gas func([]byte) uint64
-	run PrecompiledStatefulRun
-}
+// statefulPrecompile implements the [PrecompiledContract] interface to allow a
+// [PrecompiledStatefulContract] to be carried with regular geth plumbing. The
+// methods are defined on this unexported type instead of directly on
+// [PrecompiledStatefulContract] to hide implementation details.
+type statefulPrecompile PrecompiledStatefulContract
 
-func (p statefulPrecompile) RequiredGas(input []byte) uint64 {
-	return p.gas(input)
-}
+// RequiredGas always returns zero as this gas is consumed by native geth code
+// before the contract is run.
+func (statefulPrecompile) RequiredGas([]byte) uint64 { return 0 }
 
 func (p statefulPrecompile) Run([]byte) ([]byte, error) {
 	// https://google.github.io/styleguide/go/best-practices.html#when-to-panic
 	// This would indicate an API misuse and would occur in tests, not in
 	// production.
-	panic(fmt.Sprintf("BUG: call to %T.Run(); MUST call %T", p, p.run))
+	panic(fmt.Sprintf("BUG: call to %T.Run(); MUST call %T itself", p, p))
+}
+
+// A PrecompileEnvironment provides information about the context in which a
+// precompiled contract is being run.
+type PrecompileEnvironment interface {
+	Rules() params.Rules
+	ReadOnly() bool
+	// StateDB will be non-nil i.f.f !ReadOnly().
+	StateDB() StateDB
+	// ReadOnlyState will always be non-nil.
+	ReadOnlyState() libevm.StateReader
+	Addresses() *libevm.AddressContext
+
+	BlockHeader() (types.Header, error)
+	BlockNumber() *big.Int
+	BlockTime() uint64
+}
+
+//
+// ****** SECURITY ******
+//
+// If you are updating PrecompileEnvironment to provide the ability to call back
+// into another contract, you MUST revisit the evmCallArgs.forceReadOnly flag.
+//
+// It is possible that forceReadOnly is true but evm.interpreter.readOnly is
+// false. This is safe for now, but may not be if recursive calling *from* a
+// precompile is enabled.
+//
+// ****** SECURITY ******
+
+var _ PrecompileEnvironment = (*evmCallArgs)(nil)
+
+func (args *evmCallArgs) Rules() params.Rules { return args.evm.chainRules }
+
+func (args *evmCallArgs) ReadOnly() bool {
+	if args.readWrite == inheritReadOnly {
+		if args.evm.interpreter.readOnly { //nolint:gosimple // Clearer code coverage for difficult-to-test branch
+			return true
+		}
+		return false
+	}
+	// Even though args.readWrite may be some value other than forceReadOnly,
+	// that would be an invalid use of the API so we default to read-only as the
+	// safest failure mode.
+	return true
 }
 
+func (args *evmCallArgs) StateDB() StateDB {
+	if args.ReadOnly() {
+		return nil
+	}
+	return args.evm.StateDB
+}
+
+func (args *evmCallArgs) ReadOnlyState() libevm.StateReader {
+	// Even though we're actually returning a full state database, the user
+	// would have to actively circumvent the returned interface to use it. At
+	// that point they're off-piste and it's not our problem.
+	return args.evm.StateDB
+}
+
+func (args *evmCallArgs) Addresses() *libevm.AddressContext {
+	return &libevm.AddressContext{
+		Origin: args.evm.TxContext.Origin,
+		Caller: args.caller.Address(),
+		Self:   args.addr,
+	}
+}
+
+func (args *evmCallArgs) BlockHeader() (types.Header, error) {
+	hdr := args.evm.Context.Header
+	if hdr == nil {
+		// Although [core.NewEVMBlockContext] sets the field and is in the
+		// typical hot path (e.g. miner), there are other ways to create a
+		// [vm.BlockContext] (e.g. directly in tests) that may result in no
+		// available header.
+		return types.Header{}, fmt.Errorf("nil %T in current %T", hdr, args.evm.Context)
+	}
+	return *hdr, nil
+}
+
+func (args *evmCallArgs) BlockNumber() *big.Int {
+	return new(big.Int).Set(args.evm.Context.BlockNumber)
+}
+
+func (args *evmCallArgs) BlockTime() uint64 { return args.evm.Context.Time }
+
 var (
 	// These lock in the assumptions made when implementing [evmCallArgs]. If
 	// these break then the struct fields SHOULD be changed to match these