WrapperCodeGenerator: add script for generating wrappers

- ExportInstructionSet: export instruction set based on input version to json
- ImportInstructionSet: import instruction set from json
- OpCodeWrapperGenerator: generate wrappers for an instruction set

WrapperCodeGenerator/main.go

@@ -0,0 +1,219 @@
+package main
+
+import (
+	"encoding/json"
+	"os"
+	"text/template"
+
+	"github.com/ethereum/go-ethereum/core/vm"
+	"github.com/ethereum/go-ethereum/params"
+)
+
+type InstructionSetJSON struct {
+    Version string `json:"version"`
+    InstructionSet []vm.OperationAttribute `json:"instruction_set"`
+}
+func ExportInstructionSet(version string) {
+	// Get the instruction set
+	var rules params.Rules
+    switch {
+    case version == "Homestead":
+        rules = params.Rules{
+            IsHomestead: true,
+        }
+    case version == "TangerineWhistle":
+        rules = params.Rules{
+            IsEIP150: true,
+        }
+    case version == "SpuriousDragon":
+        rules = params.Rules{
+            IsEIP158: true,
+        }
+    case version == "Byzantium":
+        rules = params.Rules{
+            IsByzantium: true,
+        }
+    case version == "Constantinople":
+        rules = params.Rules{
+            IsConstantinople: true,
+        }
+    case version == "Istanbul":
+        rules = params.Rules{
+            IsIstanbul: true,
+        }
+    case version == "Berlin":
+        rules = params.Rules{
+            IsBerlin: true,
+        }
+    case version == "London":
+        rules = params.Rules{
+            IsLondon: true,
+        }
+    default:
+        // frontier by default
+        rules = params.Rules{
+
+        }
+    }
+	instructionSet := vm.ExportInstructionSet(rules)
+
+	// Export the instruction set to json
+	file, err := os.Create("instruction_set.json")
+	if err != nil {
+		panic(err)
+	}
+	defer file.Close()
+
+	encoder := json.NewEncoder(file)
+	encoder.SetIndent("", "  ")
+	err = encoder.Encode(
+        InstructionSetJSON{
+            Version: version,
+            InstructionSet: instructionSet,
+        },
+    )
+	if err != nil {
+		panic(err)
+	}
+}
+
+func ImportInstructionSet() InstructionSetJSON {
+	// Import the instruction set from json
+	file, err := os.Open("instruction_set.json")
+	if err != nil {
+		panic(err)
+	}
+	defer file.Close()
+
+	decoder := json.NewDecoder(file)
+    var instructionSetJSON InstructionSetJSON
+	err = decoder.Decode(&instructionSetJSON)
+	if err != nil {
+		panic(err)
+	}
+	return instructionSetJSON
+}
+
+func OpCodeWrapperGenerator() {
+	// Get instruction set
+	instructionSetJSON := ImportInstructionSet()
+
+	// Define the template
+	tmpl := template.Must(template.New("opcode").Parse(`
+package vm
+
+import "github.com/ethereum/go-ethereum/common/math"
+{{$parent := .}}
+{{range .InstructionSet}}
+func {{.Name}}Wrapper{{$parent.Version}}(operation *operation, pc *uint64, in *EVMInterpreter, callContext *ScopeContext) ([]byte, error) {
+{{- if .Supported}}
+	{{- if or .MemorySize .DynamicCost}}
+    mem := callContext.Memory
+	{{- end}}
+    stack := callContext.Stack
+    contract := callContext.Contract
+    var err error
+    var res []byte	
+
+    in.evm.Context.Counter++
+
+    if sLen := stack.len(); sLen < {{.MinStack}} {
+        return nil, &ErrStackUnderflow{stackLen: sLen, required: {{.MinStack}}}
+    } else if sLen > {{.MaxStack}} {
+        return nil, &ErrStackOverflow{stackLen: sLen, limit: {{.MaxStack}}}
+    }
+    {{- if or .Writes (eq .Name "opCall")}}
+    if in.readOnly && in.evm.chainRules.IsByzantium {
+        {{- if .Writes}}
+        return nil, ErrWriteProtection
+        {{- else if (eq .Name "opCall")}}
+        if stack.Back(2).Sign() != 0 {
+            return nil, ErrWriteProtection
+        }
+        {{- end}}
+    }
+    {{- end}}
+    {{- if not .DynamicCost}}
+    if !contract.UseGas({{.ConstantGas}}) {
+        return nil, ErrOutOfGas
+    }
+    {{- end}}
+    {{- if or .MemorySize .DynamicCost}}
+    var memorySize uint64
+    {{- end}}
+    {{- if .MemorySize}}
+    memSize, overflow := operation.memorySize(stack)
+    if overflow {
+        return nil, ErrGasUintOverflow
+    }
+    if memorySize, overflow = math.SafeMul(toWordSize(memSize), 32); overflow {
+        return nil, ErrGasUintOverflow
+    }
+    {{- end}}
+    {{- if .DynamicCost}}
+    var dynamicCost uint64
+    dynamicCost, err = operation.dynamicGas(in.evm, contract, stack, mem, memorySize)
+    if err != nil || !contract.UseGas({{.ConstantGas}} + dynamicCost) {
+        return nil, ErrOutOfGas
+    }
+    {{- end}}
+    {{- if or .MemorySize .DynamicCost}}
+    if memorySize > 0 {
+        mem.Resize(memorySize)
+    }
+    {{- end}}
+    res, err = operation.execute(pc, in, callContext)
+    {{- if .Returns}}
+    in.returnData = res
+    {{- end}}
+    if err != nil {
+        return nil, err
+    }
+    {{- if .Reverts}}
+    return res, ErrExecutionReverted
+    {{- end}}
+    {{- if and (not .Jumps) (not .Reverts)}}
+    *pc++
+    {{- end}}
+    {{- if not .Reverts}}
+    return res, nil
+    {{- end}}
+{{- else}}
+	return nil, nil
+{{- end}}
+}
+{{end}}
+var stringToWrapper{{$parent.Version}} = map[string]executionWrapperFunc{
+{{- range .InstructionSet}}
+    "{{.Name}}": {{.Name}}Wrapper{{$parent.Version}},{{end}}
+}
+`))
+
+	// Create the source file
+    file, err := os.Create("instruction_wrapper_" + instructionSetJSON.Version + ".go")
+    if err != nil {
+        panic(err)
+    }
+    defer file.Close()
+
+	// Execute the template and write to the source file
+    err = tmpl.Execute(file, instructionSetJSON)
+    if err != nil {
+        panic(err)
+    }
+}
+
+func main() {
+    if len(os.Args) > 1 {
+        version := os.Args[1]
+        ExportInstructionSet(version)
+        OpCodeWrapperGenerator()
+    } else {
+        // export all by default
+        versions := []string{"Homestead", "TangerineWhistle", "SpuriousDragon", "Byzantium", "Constantinople", "Istanbul", "Berlin", "London", "Frontier"}
+        for _, version := range versions {
+            ExportInstructionSet(version)
+            OpCodeWrapperGenerator()
+        }
+    }
+}