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core/vm, core/vm/gen: mimic rlpgen's pattern and apply more cleanup

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jonny rhea 2026-07-06 18:04:43 -05:00
parent 2756eedd27
commit af039e9a16
6 changed files with 1005 additions and 956 deletions
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core/vm/gen/gen.go Normal file
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// Copyright 2026 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package main
import (
"bytes"
"fmt"
"go/ast"
"go/format"
"go/parser"
"go/printer"
"go/token"
"os"
"path/filepath"
"regexp"
"runtime"
"strings"
"github.com/ethereum/go-ethereum/core/vm"
"github.com/ethereum/go-ethereum/params"
)
// inlineOps maps an opcode byte to the handler whose body is spliced inline
// for that opcode. These are the hot, fork-stable opcodes with no dynamic gas.
// The value is usually an opXxx handler, but PUSH3-PUSH32 and DUP1-DUP16 are
// factory-built (one shared makePush / makeDup each), so their value is the
// factory name and emitInlineOp splices the factory body with the per-opcode size.
// Opcodes not listed here (or in directCallOps) fall through to the default case,
// which dispatches via the per-fork table.
var inlineOps = func() map[byte]string {
m := map[byte]string{
0x01: "opAdd", 0x02: "opMul", 0x03: "opSub", 0x04: "opDiv", 0x05: "opSdiv",
0x06: "opMod", 0x07: "opSmod", 0x08: "opAddmod", 0x09: "opMulmod", 0x0b: "opSignExtend",
0x10: "opLt", 0x11: "opGt", 0x12: "opSlt", 0x13: "opSgt", 0x14: "opEq", 0x15: "opIszero",
0x16: "opAnd", 0x17: "opOr", 0x18: "opXor", 0x19: "opNot", 0x1a: "opByte",
0x1b: "opSHL", 0x1c: "opSHR", 0x1d: "opSAR", 0x1e: "opCLZ",
0x50: "opPop", 0x56: "opJump", 0x57: "opJumpi", 0x58: "opPc", 0x59: "opMsize", 0x5b: "opJumpdest",
0x5f: "opPush0", 0x60: "opPush1", 0x61: "opPush2",
}
for code := 0x62; code <= 0x7f; code++ { // PUSH3-PUSH32
m[byte(code)] = "makePush"
}
for code := 0x80; code <= 0x8f; code++ { // DUP1-DUP16
m[byte(code)] = "makeDup"
}
for code := 0x90; code <= 0x9f; code++ { // SWAP1-SWAP16
m[byte(code)] = fmt.Sprintf("opSwap%d", code-0x8f)
}
return m
}()
// directCallOps lists the opcodes (dynamic gas, not inlined) whose handler,
// dynamic-gas, and memory-size functions are the same across every fork
// (verified: untouched by any enableXxx). They are emitted as direct calls to
// those functions by name instead of the indirect operation.* pointer calls
// in the default case.
var directCallOps = map[byte][3]string{
0x20: {"opKeccak256", "gasKeccak256", "memoryKeccak256"},
0x51: {"opMload", "gasMLoad", "memoryMLoad"},
0x52: {"opMstore", "gasMStore", "memoryMStore"},
0x53: {"opMstore8", "gasMStore8", "memoryMStore8"},
}
// opSpec holds the per-opcode constants the generator emits (gas, stack bounds, intro fork), derived from the per-fork tables.
type opSpec struct {
defined bool
name string
fork string
constGas uint64
minStack int
maxStack int
}
type generator struct {
fset *token.FileSet
opcodeHandlers map[string]*ast.FuncDecl
stackHelpers map[string]*ast.FuncDecl
gasHelpers map[string]*ast.FuncDecl
specs [256]opSpec
buf *bytes.Buffer
}
// p is the writer of the generated file. Every line of output is appended
// to g.buf through it.
func (g *generator) p(format string, args ...any) {
format = strings.TrimRight(strings.TrimPrefix(format, "\n"), " \t")
fmt.Fprintf(g.buf, format, args...)
}
// parseHandlers parses instructions.go, eips.go, stack.go, gascosts.go and
// interpreter.go. It returns the top-level opXxx handlers by name, the
// //gen:inline *Stack helper methods, and the gas/memory helper functions
// (chargeRegularOnly, computeMemorySize, chargeDynamicGas) whose bodies are
// spliced into the generated dispatch (all by name).
func parseHandlers(vmDir string) (fset *token.FileSet, opcodeHandlers, stackHelpers, gasHelpers map[string]*ast.FuncDecl) {
fset = token.NewFileSet()
opcodeHandlers = map[string]*ast.FuncDecl{}
stackHelpers = map[string]*ast.FuncDecl{}
gasHelpers = map[string]*ast.FuncDecl{}
for _, name := range []string{"instructions.go", "eips.go", "stack.go", "gascosts.go", "interpreter.go"} {
path := filepath.Join(vmDir, name)
f, err := parser.ParseFile(fset, path, nil, parser.ParseComments)
if err != nil {
fatalf("parse %s: %v", path, err)
}
for _, decl := range f.Decls {
fn, ok := decl.(*ast.FuncDecl)
if !ok || fn.Body == nil {
continue
}
switch {
case fn.Name.Name == "chargeRegularOnly" || fn.Name.Name == "computeMemorySize" || fn.Name.Name == "chargeDynamicGas" || fn.Name.Name == "chargeVerkleCodeChunkGas": // spliced gas/memory helpers
gasHelpers[fn.Name.Name] = fn
case fn.Recv == nil: // top-level opXxx handler
opcodeHandlers[fn.Name.Name] = fn
case methodReceiver(fn) == "Stack" && hasInlineMarker(fn): // (s *Stack) helper tagged //gen:inline
stackHelpers[fn.Name.Name] = fn
}
}
}
return fset, opcodeHandlers, stackHelpers, gasHelpers
}
// methodReceiver returns the receiver type name of a pointer-receiver method
// (e.g. "Stack" for (s *Stack)), or "" if fn is not such a method.
func methodReceiver(fn *ast.FuncDecl) string {
if fn.Recv == nil || len(fn.Recv.List) != 1 {
return ""
}
star, ok := fn.Recv.List[0].Type.(*ast.StarExpr)
if !ok {
return ""
}
id, ok := star.X.(*ast.Ident)
if !ok {
return ""
}
return id.Name
}
// hasInlineMarker reports whether fn is tagged //gen:inline, which marks a stack
// helper for splicing into the generated dispatch.
func hasInlineMarker(fn *ast.FuncDecl) bool {
if fn.Doc == nil {
return false
}
for _, c := range fn.Doc.List {
if c.Text == "//gen:inline" {
return true
}
}
return false
}
var opcodeReturnRe = regexp.MustCompile(`^(\s*)return\s+([^,]+),\s*(.+)$`)
// spliceOpcodeBody returns a named handler's body, rewritten so it can be spliced
// into the dispatch loop (see rewriteOpcodeReturns). The caller emits it with p.
func (g *generator) spliceOpcodeBody(handler string) string {
fn := g.opcodeHandlers[handler]
if fn == nil {
fatalf("no handler %q to inline", handler)
}
return g.rewriteOpcodeReturns(g.inlineStackHelpers(fn.Body.List, nil))
}
// spliceOpcodeFactoryBody splices the body of the executionFunc closure that a make*
// factory returns, substituting the factory's parameters with the per-opcode
// constants in args (positional, matching the factory signature). This lets
// closure-built handlers (makePush, makeDup) be derived from their single
// definition rather than restated in the generator. The caller emits the
// result with p.
func (g *generator) spliceOpcodeFactoryBody(factory string, args ...int) string {
fn := g.opcodeHandlers[factory]
if fn == nil {
fatalf("no factory %q to inline", factory)
}
lit := factoryClosure(factory, fn)
// Bind the factory parameters to the per-opcode constants, then inline.
names := paramNames(fn)
if len(names) != len(args) {
fatalf("factory %q takes %d params, got %d args", factory, len(names), len(args))
}
params := map[string]int{}
for i, nm := range names {
params[nm] = args[i]
}
return g.rewriteOpcodeReturns(g.inlineStackHelpers(lit.Body.List, params))
}
// factoryClosure returns the executionFunc literal that a make* factory's body
// is a single `return func(...) {...}` of.
func factoryClosure(name string, fn *ast.FuncDecl) *ast.FuncLit {
if len(fn.Body.List) != 1 {
fatalf("factory %q body is not a single return", name)
}
ret, ok := fn.Body.List[0].(*ast.ReturnStmt)
if !ok || len(ret.Results) != 1 {
fatalf("factory %q does not return a single value", name)
}
lit, ok := ret.Results[0].(*ast.FuncLit)
if !ok {
fatalf("factory %q does not return a func literal", name)
}
return lit
}
// renderAst converts AST statements back to formatted Go source text, the
// inverse of parsing. It uses the generator's fileset and emits nothing itself
// (the caller passes the result to p).
func (g *generator) renderAst(stmts []ast.Stmt) string {
var raw bytes.Buffer
cfg := printer.Config{Mode: printer.UseSpaces | printer.TabIndent, Tabwidth: 8}
for _, stmt := range stmts {
if err := cfg.Fprint(&raw, g.fset, stmt); err != nil {
fatalf("print stmt: %v", err)
}
raw.WriteByte('\n')
}
return raw.String()
}
// rewriteOpcodeReturns rewrites a printed handler body so it runs inside the
// dispatch loop: the `*pc` dereference becomes the loop's `pc` local, and each
// `return r0, r1` becomes loop control flow. Success (r1 == nil) advances pc
// and continues, an error sets err and breaks. (Stack helpers were already
// inlined by inlineStackHelpers before the body was printed.)
func (g *generator) rewriteOpcodeReturns(src string) string {
src = strings.ReplaceAll(src, "*pc", "pc")
var out bytes.Buffer
for _, line := range strings.Split(src, "\n") {
if m := opcodeReturnRe.FindStringSubmatch(line); m != nil {
indent, r0, r1 := m[1], strings.TrimSpace(m[2]), strings.TrimSpace(m[3])
if r1 == "nil" {
out.WriteString(indent + "pc++\n")
out.WriteString(indent + "continue mainLoop\n")
} else {
out.WriteString(indent + "res, err = " + r0 + ", " + r1 + "\n")
out.WriteString(indent + "break mainLoop\n")
}
continue
}
out.WriteString(line + "\n")
}
return out.String()
}
var gasReturnRe = regexp.MustCompile(`^(\s*)return\s+(\S.*)$`)
// rewriteGasReturns rewrites a spliced charge body so it runs as a gas step in
// the dispatch loop: a `return <err>` becomes the out-of-gas break, and the
// trailing `return nil` (success) is dropped so the opcode continues.
func (g *generator) rewriteGasReturns(src string) string {
var out bytes.Buffer
for _, line := range strings.Split(src, "\n") {
if m := gasReturnRe.FindStringSubmatch(line); m != nil {
indent, val := m[1], strings.TrimSpace(m[2])
if val == "nil" {
continue // success: fall through to the rest of the op
}
out.WriteString(indent + "res, err = nil, " + val + "\n")
out.WriteString(indent + "break mainLoop\n")
continue
}
out.WriteString(line + "\n")
}
return out.String()
}
// rewriteStepReturns rewrites a spliced gas-step body's (value, error) returns so
// it runs inline in the dispatch loop: a non-nil error becomes the out-of-gas
// break; on success the value is assigned to target (or dropped when target is
// empty) and the op falls through.
func (g *generator) rewriteStepReturns(src, target string) string {
var out bytes.Buffer
for _, line := range strings.Split(src, "\n") {
if m := opcodeReturnRe.FindStringSubmatch(line); m != nil {
indent, val, errVal := m[1], strings.TrimSpace(m[2]), strings.TrimSpace(m[3])
if errVal == "nil" {
if target != "" {
out.WriteString(indent + target + " = " + val + "\n")
}
continue
}
out.WriteString(indent + "res, err = nil, " + errVal + "\n")
out.WriteString(indent + "break mainLoop\n")
continue
}
out.WriteString(line + "\n")
}
return out.String()
}
// stackCall is a matched call to a tagged helper.
type stackCall struct {
helper string // helper method name
lhs []ast.Expr // assignment targets, nil for a void call like dup
tok token.Token // the assignment token, := or =
args []ast.Expr // call arguments (only dup has one)
}
// matchStackHelper matches a statement that is a single must-expand helper call,
// in one of the two normalized forms: an assignment `lhs... := scope.Stack.H(args)`
// or a bare `scope.Stack.H(args)`.
func (g *generator) matchStackHelper(stmt ast.Stmt) (stackCall, bool) {
switch s := stmt.(type) {
case *ast.AssignStmt:
if len(s.Rhs) == 1 {
if h, args, ok := g.stackHelperCall(s.Rhs[0]); ok {
return stackCall{helper: h, lhs: s.Lhs, tok: s.Tok, args: args}, true
}
}
case *ast.ExprStmt:
if h, args, ok := g.stackHelperCall(s.X); ok {
return stackCall{helper: h, args: args}, true
}
}
return stackCall{}, false
}
// stackHelperCall unwraps scope.Stack.H(args) where H is a must-expand helper.
func (g *generator) stackHelperCall(e ast.Expr) (helper string, args []ast.Expr, ok bool) {
call, isCall := e.(*ast.CallExpr)
if !isCall {
return "", nil, false
}
sel, isSel := call.Fun.(*ast.SelectorExpr) // <recv>.H
if !isSel || g.stackHelpers[sel.Sel.Name] == nil || !isStackExpr(sel.X) {
return "", nil, false
}
return sel.Sel.Name, call.Args, true
}
// isStackExpr reports whether e is the stack receiver: the `stack` local or
// scope.Stack.
func isStackExpr(e ast.Expr) bool {
switch x := e.(type) {
case *ast.Ident:
return x.Name == "stack"
case *ast.SelectorExpr:
return x.Sel.Name == "Stack"
}
return false
}
// inlineStackHelpers renders a handler body to source, inlining every must-expand
// helper call and printing other statements unchanged. params maps the factory
// parameters (makePush/makeDup) to their per-opcode constants.
func (g *generator) inlineStackHelpers(stmts []ast.Stmt, params map[string]int) string {
var out strings.Builder
// Walk the handler body one statement at a time. A statement that is a
// tagged stack-helper call gets the helper's body spliced in: the generated
// dispatch is past Go's big-function inline budget, so the call would not be
// inlined otherwise. Every other statement is printed as written.
for _, stmt := range stmts {
if call, ok := g.matchStackHelper(stmt); ok {
// e.g. `x, y := scope.Stack.pop1Peek1()` becomes the body of pop1Peek1.
out.WriteString(g.inlineStackHelper(call, params))
} else {
// A plain statement: print it verbatim, then fill in any makePush or
// makeDup factory params with this opcode's constants.
out.WriteString(substParams(g.renderAst([]ast.Stmt{stmt}), params))
}
}
return out.String()
}
// substParams replaces each factory parameter with its constant. It runs only
// on printed non-helper statements and on helper arguments, never on a helper
// expansion, so it cannot touch a field like stack.size. The parameter names do
// not textually overlap, so map order does not affect the result.
func substParams(src string, params map[string]int) string {
for name, val := range params {
src = regexp.MustCompile(`\b`+name+`\b`).ReplaceAllString(src, fmt.Sprint(val))
}
return src
}
// inlineStackHelper expands one helper call to its stack.go body. The single
// rule: the helper is straight-line statements then an optional final return
// whose result count matches the call's targets. Anything else is not in
// inlinable form and is a hard error (the shape post-condition). The receiver
// maps to the loop's `stack` local and each parameter to its call argument.
func (g *generator) inlineStackHelper(call stackCall, params map[string]int) string {
fn := g.stackHelpers[call.helper]
if fn == nil {
fatalf("no stack helper %q to inline", call.helper)
}
// Peel an optional trailing return off the body.
body := fn.Body.List
var ret *ast.ReturnStmt
if n := len(body); n > 0 {
if r, isRet := body[n-1].(*ast.ReturnStmt); isRet {
ret, body = r, body[:n-1]
}
}
results := 0
if ret != nil {
results = len(ret.Results)
}
if len(call.lhs) != results {
fatalf("stack helper %q returns %d values, call assigns %d", call.helper, results, len(call.lhs))
}
// Map the receiver to the loop local and each parameter to its argument.
names := paramNames(fn)
if len(names) != len(call.args) {
fatalf("stack helper %q takes %d params, call passes %d", call.helper, len(names), len(call.args))
}
subst := map[string]string{recvName(fn): "stack"}
for i, name := range names {
subst[name] = substParams(renderInlineExpr(call.args[i], nil), params)
}
// The leading bookkeeping statements, then bind each return expression to
// its assignment target.
var out strings.Builder
for _, stmt := range body {
out.WriteString(renderInlineStmt(stmt, subst) + "\n")
}
for i, lhs := range call.lhs {
out.WriteString(renderInlineExpr(lhs, nil) + " " + call.tok.String() + " " + renderInlineExpr(ret.Results[i], subst) + "\n")
}
return out.String()
}
// recvName returns a method's receiver name (e.g. "s").
func recvName(fn *ast.FuncDecl) string {
if names := fn.Recv.List[0].Names; len(names) > 0 {
return names[0].Name
}
return ""
}
// paramNames returns a function's parameter names, in order.
func paramNames(fn *ast.FuncDecl) []string {
var names []string
for _, f := range fn.Type.Params.List {
for _, nm := range f.Names {
names = append(names, nm.Name)
}
}
return names
}
// renderInlineStmt prints one helper-body statement with subst applied. Only the
// statement shapes the helpers use are handled; any other is not inlinable.
func renderInlineStmt(stmt ast.Stmt, subst map[string]string) string {
switch s := stmt.(type) {
case *ast.IncDecStmt: // s.inner.top++
return renderInlineExpr(s.X, subst) + s.Tok.String()
case *ast.AssignStmt: // s.size -= 2, data[x] = data[y], or the swap tuple a, b = b, a
if len(s.Lhs) == len(s.Rhs) && len(s.Lhs) >= 1 {
lhs := make([]string, len(s.Lhs))
rhs := make([]string, len(s.Rhs))
for i := range s.Lhs {
lhs[i] = renderInlineExpr(s.Lhs[i], subst)
rhs[i] = renderInlineExpr(s.Rhs[i], subst)
}
return strings.Join(lhs, ", ") + " " + s.Tok.String() + " " + strings.Join(rhs, ", ")
}
}
fatalf("inline: unsupported statement %T in stack helper", stmt)
return ""
}
// renderInlineExpr prints one helper-body expression, substituting any
// identifier found in subst. Only the shapes the helpers use are handled.
func renderInlineExpr(expr ast.Expr, subst map[string]string) string {
switch e := expr.(type) {
case *ast.Ident:
if r, ok := subst[e.Name]; ok {
return r
}
return e.Name
case *ast.BasicLit:
return e.Value
case *ast.SelectorExpr: // x.field
return renderInlineExpr(e.X, subst) + "." + e.Sel.Name
case *ast.IndexExpr: // x[i]
return renderInlineExpr(e.X, subst) + "[" + renderInlineExpr(e.Index, subst) + "]"
case *ast.BinaryExpr: // x op y
return renderInlineExpr(e.X, subst) + " " + e.Op.String() + " " + renderInlineExpr(e.Y, subst)
case *ast.UnaryExpr: // &x
return e.Op.String() + renderInlineExpr(e.X, subst)
}
fatalf("inline: unsupported expression %T in stack helper", expr)
return ""
}
// deriveSpecs records each opcode's constant values (name, intro fork, static
// gas, stack bounds) from the first fork that defines it, then checks that the
// opcodes chosen for inlining and direct-calling are safe to emit as constants
// by verifying they are fork-stable (see checkStable and checkDirectCallStable).
func (g *generator) deriveSpecs(forks []vm.GenFork) {
for code := range 256 {
for _, fork := range forks {
o := fork.Ops[code]
if !o.Defined {
continue
}
g.specs[code] = opSpec{
defined: true,
name: o.Name,
fork: fork.RuleField,
constGas: o.ConstantGas,
minStack: o.MinStack,
maxStack: o.MaxStack,
}
break // first fork that defines it wins (its intro fork)
}
}
// Every inlined opcode must be defined and have fork-stable static
// gas / stack bounds across all forks where it appears. Bail loudly otherwise.
for code, handler := range inlineOps {
g.checkStable(code, handler, forks)
}
// directCallOps opcodes emit their static gas and stack bounds as constants the
// same way, so they must be fork-stable too. Dynamic gas is allowed (it is
// charged through the named gas function, not a constant).
for code := range directCallOps {
g.checkDirectCallStable(code, forks)
}
}
// checkStable verifies an opcode selected for inlining is safe to inline: it must
// be defined, its static gas and stack bounds must be the same across every fork
// it appears in (they are emitted as constants), and it must have no dynamic gas,
// since an inlined op charges only its constant static gas. It bails loudly
// otherwise. `what` names the handler for the error message.
func (g *generator) checkStable(code byte, what string, forks []vm.GenFork) {
spec := g.specs[code]
if !spec.defined {
fatalf("opcode %#x (%s) selected for inlining but never defined", code, what)
}
for _, fork := range forks {
o := fork.Ops[code]
if !o.Defined {
continue
}
if o.ConstantGas != spec.constGas || o.MinStack != spec.minStack || o.MaxStack != spec.maxStack || o.DynamicGasFn != "" {
fatalf("opcode %#x (%s) is not fork-stable (fork %s): cannot inline", code, what, fork.Name)
}
}
}
// checkDirectCallStable verifies a directCallOps opcode is safe to direct-call. Its static
// gas and stack bounds must be the same across every fork it appears in (they are
// emitted as constants), and its handler, gas and memory functions must be the same
// across those forks too (they are called by name, so a fork that swapped one
// would otherwise be missed). Unlike checkStable it allows dynamic gas, which
// directCallOps ops carry by definition. It does not check the directCallOps map's names
// against the table, which the differential test covers.
func (g *generator) checkDirectCallStable(code byte, forks []vm.GenFork) {
spec := g.specs[code]
if !spec.defined {
fatalf("opcode %#x (directCallOps) is never defined", code)
}
var exec, dyn, mem string
seen := false
for _, fork := range forks {
o := fork.Ops[code]
if !o.Defined {
continue
}
if o.ConstantGas != spec.constGas || o.MinStack != spec.minStack || o.MaxStack != spec.maxStack {
fatalf("opcode %#x (%s) is in directCallOps but not fork-stable (fork %s): static gas or stack bounds vary, cannot emit as constants", code, spec.name, fork.Name)
}
// Handler, gas and memory functions must match across forks too, or
// direct-calling them by name would skip a fork that swapped one. Names
// come from FuncForPC via vm.GenForks (aliases resolve to the underlying
// func, still stable across forks).
if !seen {
exec, dyn, mem, seen = o.ExecuteFn, o.DynamicGasFn, o.MemorySizeFn, true
} else if o.ExecuteFn != exec || o.DynamicGasFn != dyn || o.MemorySizeFn != mem {
fatalf("opcode %#x (%s) is in directCallOps but its functions vary by fork (fork %s): got %s/%s/%s, want %s/%s/%s, cannot direct-call",
code, spec.name, fork.Name, o.ExecuteFn, o.DynamicGasFn, o.MemorySizeFn, exec, dyn, mem)
}
}
}
// generateStackChecks returns the underflow/overflow guards, mirroring the legacy
// loop's order (stack validated before gas). minExpr and maxExpr are the
// stack-bound expressions (constants on the inlined/direct paths,
// operation.minStack/maxStack in the table path). under and over select which
// guards to emit, so those paths can omit a guard whose bound is trivial.
func (g *generator) generateStackChecks(minExpr, maxExpr any, under, over bool) string {
switch {
case under && over:
return fmt.Sprintf(`if sLen := stack.len(); sLen < %v {
return nil, &ErrStackUnderflow{stackLen: sLen, required: %v}
} else if sLen > %v {
return nil, &ErrStackOverflow{stackLen: sLen, limit: %v}
}
`, minExpr, minExpr, maxExpr, maxExpr)
case under:
return fmt.Sprintf(`if sLen := stack.len(); sLen < %v {
return nil, &ErrStackUnderflow{stackLen: sLen, required: %v}
}
`, minExpr, minExpr)
case over:
return fmt.Sprintf(`if sLen := stack.len(); sLen > %v {
return nil, &ErrStackOverflow{stackLen: sLen, limit: %v}
}
`, maxExpr, maxExpr)
}
return ""
}
// generateStaticGas returns the static-gas charge, spliced call-free from the
// chargeRegularOnly body for amount: a constant on the inlined and
// direct-call paths, operation.constantGas in the table path. The receiver maps
// to contract.Gas and the method's single uint64 parameter to amount, substituted
// textually on word boundaries (which cannot touch fields like RegularGas). Its
// `return <err>` becomes the loop's out-of-gas exit and its trailing `return nil`
// is dropped so the opcode falls through to its remaining steps (see
// rewriteGasReturns).
func (g *generator) generateStaticGas(amount any) string {
fn := g.gasHelpers["chargeRegularOnly"]
if fn == nil {
fatalf("no chargeRegularOnly gas helper to inline")
}
names := paramNames(fn)
if len(names) != 1 {
fatalf("chargeRegularOnly takes %d params, want 1", len(names))
}
src := g.renderAst(fn.Body.List)
src = regexp.MustCompile(`\b`+recvName(fn)+`\b`).ReplaceAllString(src, "contract.Gas")
src = regexp.MustCompile(`\b`+names[0]+`\b`).ReplaceAllString(src, fmt.Sprint(amount))
return g.rewriteGasReturns(src)
}
// emitInlineOp emits an inlined opcode case: the stack and gas guards followed by
// the spliced opcode body. A fork-introduced opcode wraps that body in a fork gate
// so it runs only when the opcode is active for the current fork, otherwise the
// case mirrors the legacy loop's undefined-opcode handling.
func (g *generator) emitInlineOp(code byte) {
spec := g.specs[code]
g.p("case %s:\n", spec.name)
if spec.fork != "" {
g.p("if rules.%s {\n", spec.fork)
}
// stack bounds check
g.p("%s", g.generateStackChecks(spec.minStack, spec.maxStack, spec.minStack > 0, spec.maxStack < int(params.StackLimit)))
// static gas
if spec.constGas != 0 {
g.p("%s", g.generateStaticGas(spec.constGas))
}
// PUSH1-PUSH32 swap their execute function under EIP-4762 (verkle) to charge
// code-chunk gas on the immediate bytes. Defer to the table handler there.
// The constant static gas and stack guard above already match.
if code >= 0x60 && code <= 0x7f {
g.p(`
if isEIP4762 {
res, err = table[op].execute(&pc, evm, scope)
if err != nil {
break mainLoop
}
pc++
continue mainLoop
}
`)
}
// opcode body
switch h := inlineOps[code]; h {
case "makePush": // PUSH3-PUSH32: splice makePush(size, size)
n := int(code) - 0x5f
g.p("%s", g.spliceOpcodeFactoryBody("makePush", n, n))
case "makeDup": // DUP1-DUP16: splice makeDup(n)
g.p("%s", g.spliceOpcodeFactoryBody("makeDup", int(code)-0x7f))
default: // the rest: splice the opXxx handler body
g.p("%s", g.spliceOpcodeBody(h))
}
// If opcode is inactive for this fork, then close the gate
// and fall back to the legacy loop's undefined-opcode handling.
if spec.fork != "" {
g.p(`
}
res, err = opUndefined(&pc, evm, scope)
break mainLoop
`)
}
}
// emitDirectCallOp emits an opcode case identical to the default case, except
// the handler, dynamic-gas, and memory-size functions are called by name
// rather than through the indirect operation.* table pointers. Valid only for
// fork-invariant ops (see directCallOps).
func (g *generator) emitDirectCallOp(code byte) {
spec := g.specs[code]
fns := directCallOps[code]
g.p("case %s:\n", spec.name)
// stack bounds check
g.p("%s", g.generateStackChecks(spec.minStack, spec.maxStack, spec.minStack > 0, spec.maxStack < int(params.StackLimit)))
// static gas
if spec.constGas != 0 {
g.p("%s", g.generateStaticGas(spec.constGas))
}
// dynamic gas
g.p("\nvar memorySize uint64\n")
// Splice computeMemorySize's body, rewriting its operation.memorySize lookup to
// the opcode's memory-size function and its returns for the dispatch loop.
memSizeFn := g.gasHelpers["computeMemorySize"]
if memSizeFn == nil {
fatalf("no computeMemorySize gas helper to inline")
}
memSizeSrc := g.renderAst(memSizeFn.Body.List)
memSizeSrc = strings.ReplaceAll(memSizeSrc, "operation.memorySize", fns[2])
g.p("%s", g.rewriteStepReturns(memSizeSrc, "memorySize"))
// Splice chargeDynamicGas's body the same way, rewriting operation.dynamicGas to
// the opcode's gas function.
dynGasFn := g.gasHelpers["chargeDynamicGas"]
if dynGasFn == nil {
fatalf("no chargeDynamicGas gas helper to inline")
}
dynGasSrc := g.renderAst(dynGasFn.Body.List)
dynGasSrc = strings.ReplaceAll(dynGasSrc, "operation.dynamicGas", fns[1])
g.p("%s", g.rewriteStepReturns(dynGasSrc, ""))
// resize memory
g.p(`
if memorySize > 0 {
mem.Resize(memorySize)
}
`)
// call the opcode handler
g.p(`
res, err = %s(&pc, evm, scope)
if err != nil {
break mainLoop
}
`, fns[0])
// advance to the next opcode
g.p(`
pc++
continue mainLoop
`)
}
// emitDefault emits the switch's default case: every opcode not inlined or
// direct-called (the fork-varying ops such as CALL, CREATE, SSTORE, SLOAD, LOG
// and the COPY family) is dispatched through the active per-fork table, exactly
// as the legacy loop did, so their volatile gas and opcode logic stays shared
// rather than restated here.
func (g *generator) emitDefault() {
g.p(`
default:
operation := table[op]
`)
// stack bounds check
g.p("%s", g.generateStackChecks("operation.minStack", "operation.maxStack", true, true))
// static gas
g.p("%s", g.generateStaticGas("operation.constantGas"))
// dynamic gas
g.p(`
var memorySize uint64
if memorySize, _, err = contract.meterDynamicGas(operation, evm, stack, mem); err != nil {
return nil, err
}
`)
// resize memory
g.p(`
if memorySize > 0 {
mem.Resize(memorySize)
}
`)
// call the opcode handler
g.p(`
res, err = operation.execute(&pc, evm, scope)
if err != nil {
break mainLoop
}
`)
// advance to the next opcode
g.p(`
pc++
continue mainLoop
`)
}
// createFile emits the whole generated file into g.buf: the header, package and
// imports, then the execUntraced function (its locals and dispatch loop, the
// verkle code-chunk gas, and a switch with one case per opcode built by the
// emit* helpers). main formats the buffer and writes it to interpreter_gen.go.
//
// The switch has three tiers:
//
// - the hot, fork-stable opcodes (arithmetic / comparison / bitwise / PUSH /
// DUP / SWAP / POP / JUMP / JUMPI / PC / MSIZE / JUMPDEST) are inlined by
// splicing the existing opXxx handler bodies from instructions.go and
// eips.go, with their static gas and stack bounds emitted as constants
// derived from the per-fork instruction tables via vm.GenForks.
//
// - the fork-invariant ops (KECCAK256 / MLOAD / MSTORE / MSTORE8, see
// directCallOps) are called directly by name, skipping the table's function
// pointers, which Go cannot inline through.
//
// - everything fork-varying (CALL / CREATE / SSTORE / SLOAD / LOG / the COPY
// family and so on) is dispatched through the active per-fork JumpTable in
// the default case, exactly as the legacy loop did, so volatile gas and
// opcode logic stays shared rather than restated.
func (g *generator) createFile() {
// file header, package clause, and imports
g.p(`
// Code generated by core/vm/gen; DO NOT EDIT.
package vm
import (
"fmt"
"github.com/ethereum/go-ethereum/common/math"
"github.com/ethereum/go-ethereum/core/tracing"
)
`)
// execUntraced: doc comment, loop-local declarations, and the dispatch loop
g.p(`
// execUntraced is the generated, tracing-free interpreter fast path. Hot,
// fork-stable opcodes are inlined with their static gas and stack bounds emitted
// as constants. Fork-invariant ops (KECCAK256/MLOAD/MSTORE/MSTORE8) call their
// handler and gas functions directly by name. Everything fork-varying is
// dispatched through the active per-fork table in the default case. EVM.Run
// selects this path when no tracer is configured.
func (evm *EVM) execUntraced(scope *ScopeContext) (ret []byte, err error) {
var (
contract = scope.Contract
mem = scope.Memory
stack = scope.Stack
table = evm.table
rules = evm.chainRules
isEIP4762 = rules.IsEIP4762
pc = uint64(0)
res []byte
)
_ = mem
_ = rules
_ = isEIP4762
_ = table
mainLoop:
for {
`)
// verkle code-chunk gas, spliced from chargeVerkleCodeChunkGas
ccgFn := g.gasHelpers["chargeVerkleCodeChunkGas"]
if ccgFn == nil {
fatalf("no chargeVerkleCodeChunkGas gas helper to inline")
}
g.p("%s", g.rewriteGasReturns(g.renderAst(ccgFn.Body.List)))
// fetch the opcode and open the dispatch switch
g.p(`
op := contract.GetOp(pc)
switch op {
`)
// one case per inlined or direct-call opcode, in opcode order
for code := range 256 {
b := byte(code)
if _, named := inlineOps[b]; named {
g.emitInlineOp(b)
} else if _, dc := directCallOps[b]; dc {
g.emitDirectCallOp(b)
}
}
// the default case: fork-varying ops via the per-fork table
g.emitDefault()
// close the switch and loop, clear the stop token, and return
g.p(`
}
}
if err == errStopToken {
err = nil
}
return res, err
}
`)
}
func fatalf(format string, args ...any) {
fmt.Fprintf(os.Stderr, "gen: "+format+"\n", args...)
os.Exit(1)
}
// vmDir returns the core/vm directory, the parent of this generator package. It
// is resolved from this source file's own path so it does not depend on the
// directory the generator or the test happens to run from.
func vmDir() string {
_, self, _, ok := runtime.Caller(0)
if !ok {
fatalf("cannot resolve generator source path")
}
return filepath.Dir(filepath.Dir(self)) // .../core/vm/gen -> .../core/vm
}
// generate parses the opcode, gas and fork definitions under core/vm and returns
// the formatted contents of interpreter_gen.go. It is the shared core of the
// generator: main writes the result to disk, and the up-to-date test in
// gen_test.go compares it against the committed file.
func generate() ([]byte, error) {
fset, opcodeHandlers, stackHelpers, gasHelpers := parseHandlers(vmDir())
g := &generator{fset: fset, opcodeHandlers: opcodeHandlers, stackHelpers: stackHelpers, gasHelpers: gasHelpers, buf: new(bytes.Buffer)}
g.deriveSpecs(vm.GenForks())
g.createFile()
formatted, err := format.Source(g.buf.Bytes())
if err != nil {
dbg := filepath.Join(vmDir(), "interpreter_gen.go.broken")
os.WriteFile(dbg, g.buf.Bytes(), 0644)
return nil, fmt.Errorf("gofmt failed (%v); wrote unformatted output to %s", err, dbg)
}
return formatted, nil
}

42
core/vm/gen/gen_test.go Normal file
View file

@ -0,0 +1,42 @@
// Copyright 2026 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package main
import (
"bytes"
"os"
"path/filepath"
"testing"
)
// TestGeneratedDispatchUpToDate asserts that the committed interpreter_gen.go
// matches what the generator produces from the current opcode, gas and fork
// definitions. It is the CI guard against hand-edits to the generated file and
// against the generator drifting from the committed output.
func TestGeneratedDispatchUpToDate(t *testing.T) {
got, err := generate()
if err != nil {
t.Fatalf("running generator: %v", err)
}
want, err := os.ReadFile(filepath.Join(vmDir(), "interpreter_gen.go"))
if err != nil {
t.Fatalf("reading committed interpreter_gen.go: %v", err)
}
if !bytes.Equal(got, want) {
t.Fatal("interpreter_gen.go is out of date; run `go generate ./core/vm/...` and commit the result")
}
}

925
core/vm/gen/main.go
View file

@ -15,938 +15,25 @@
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>. // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
// Command gen generates core/vm/interpreter_gen.go, the EVM interpreter's untraced // Command gen generates core/vm/interpreter_gen.go, the EVM interpreter's untraced
// fast-path dispatch. The output is a switch over the opcode byte that: // fast-path dispatch, a switch over the opcode byte. The generated file is
// // committed and a CI test asserts it matches `go generate` output. Do not
// - inlines the hot, fork-stable opcodes (arithmetic / comparison / bitwise / // hand-edit interpreter_gen.go.
// PUSH / DUP / SWAP / POP / JUMP / JUMPI / PC / MSIZE / JUMPDEST) by
// splicing the existing opXxx handler bodies from instructions.go and
// eips.go, with their static gas and stack bounds baked in as constants
// derived from the per-fork instruction tables via vm.GenForks.
//
// - calls the fork-invariant ops (KECCAK256 / MLOAD / MSTORE / MSTORE8,
// see directCallOps) directly by name, skipping the table's function
// pointers, which Go cannot inline through.
//
// - dispatches everything fork-varying (CALL / CREATE / SSTORE / SLOAD / LOG /
// the COPY family and so on) through the active per-fork JumpTable in the
// default case, exactly as the legacy loop did, so volatile gas and opcode
// logic stays shared rather than restated.
//
// The generated file is committed and a CI test asserts it matches `go generate`
// output. Do not hand-edit interpreter_gen.go.
// //
// Usage: go generate ./core/vm/... // Usage: go generate ./core/vm/...
package main package main
import ( import (
"bytes"
"fmt" "fmt"
"go/ast"
"go/format"
"go/parser"
"go/printer"
"go/token"
"os" "os"
"path/filepath" "path/filepath"
"regexp"
"runtime"
"strings"
"github.com/ethereum/go-ethereum/core/vm"
) )
const stackLimit = 1024 // params.StackLimit
// inlineOps maps an opcode byte to the handler whose body is spliced inline
// for that opcode. These are the hot, fork-stable opcodes with no dynamic gas.
// The value is usually an opXxx handler, but PUSH3-PUSH32 and DUP1-DUP16 are
// factory-built (one shared makePush / makeDup each), so their value is the
// factory name and emitInlineOp splices the factory body with the per-opcode size.
// Opcodes not listed here (or in directCallOps) fall through to the default case,
// which dispatches via the per-fork table.
var inlineOps = func() map[byte]string {
m := map[byte]string{
0x01: "opAdd", 0x02: "opMul", 0x03: "opSub", 0x04: "opDiv", 0x05: "opSdiv",
0x06: "opMod", 0x07: "opSmod", 0x08: "opAddmod", 0x09: "opMulmod", 0x0b: "opSignExtend",
0x10: "opLt", 0x11: "opGt", 0x12: "opSlt", 0x13: "opSgt", 0x14: "opEq", 0x15: "opIszero",
0x16: "opAnd", 0x17: "opOr", 0x18: "opXor", 0x19: "opNot", 0x1a: "opByte",
0x1b: "opSHL", 0x1c: "opSHR", 0x1d: "opSAR", 0x1e: "opCLZ",
0x50: "opPop", 0x56: "opJump", 0x57: "opJumpi", 0x58: "opPc", 0x59: "opMsize", 0x5b: "opJumpdest",
0x5f: "opPush0", 0x60: "opPush1", 0x61: "opPush2",
}
for code := 0x62; code <= 0x7f; code++ { // PUSH3-PUSH32
m[byte(code)] = "makePush"
}
for code := 0x80; code <= 0x8f; code++ { // DUP1-DUP16
m[byte(code)] = "makeDup"
}
for code := 0x90; code <= 0x9f; code++ { // SWAP1-SWAP16
m[byte(code)] = fmt.Sprintf("opSwap%d", code-0x8f)
}
return m
}()
// directCallOps lists the opcodes (dynamic gas, not inlined) whose handler,
// dynamic-gas, and memory-size functions are the same across every fork
// (verified: untouched by any enableXxx). They are emitted as direct calls to
// those functions by name instead of the indirect operation.* pointer calls
// in the default case.
var directCallOps = map[byte][3]string{
0x20: {"opKeccak256", "gasKeccak256", "memoryKeccak256"},
0x51: {"opMload", "gasMLoad", "memoryMLoad"},
0x52: {"opMstore", "gasMStore", "memoryMStore"},
0x53: {"opMstore8", "gasMStore8", "memoryMStore8"},
}
// opSpec holds the per-opcode constants the generator bakes (gas, stack bounds, intro fork), derived from the per-fork tables.
type opSpec struct {
defined bool
name string
fork string
constGas uint64
minStack int
maxStack int
}
type generator struct {
fset *token.FileSet
opcodeHandlers map[string]*ast.FuncDecl
stackHelpers map[string]*ast.FuncDecl
gasHelpers map[string]*ast.FuncDecl
specs [256]opSpec
buf *bytes.Buffer
}
// p is the writer of the generated file. Every line of output is appended
// to g.buf through it.
func (g *generator) p(format string, args ...any) {
format = strings.TrimRight(strings.TrimPrefix(format, "\n"), " \t")
fmt.Fprintf(g.buf, format, args...)
}
// parseHandlers parses instructions.go, eips.go, stack.go, gascosts.go and
// interpreter.go. It returns the top-level opXxx handlers by name, the
// //gen:inline *Stack helper methods, and the gas/memory helper functions
// (chargeRegularOnly, computeMemorySize, chargeDynamicGas) whose bodies are
// spliced into the generated dispatch (all by name).
func parseHandlers(vmDir string) (fset *token.FileSet, opcodeHandlers, stackHelpers, gasHelpers map[string]*ast.FuncDecl) {
fset = token.NewFileSet()
opcodeHandlers = map[string]*ast.FuncDecl{}
stackHelpers = map[string]*ast.FuncDecl{}
gasHelpers = map[string]*ast.FuncDecl{}
for _, name := range []string{"instructions.go", "eips.go", "stack.go", "gascosts.go", "interpreter.go"} {
path := filepath.Join(vmDir, name)
f, err := parser.ParseFile(fset, path, nil, parser.ParseComments)
if err != nil {
fatalf("parse %s: %v", path, err)
}
for _, decl := range f.Decls {
fn, ok := decl.(*ast.FuncDecl)
if !ok || fn.Body == nil {
continue
}
switch {
case fn.Name.Name == "chargeRegularOnly" || fn.Name.Name == "computeMemorySize" || fn.Name.Name == "chargeDynamicGas" || fn.Name.Name == "chargeVerkleCodeChunkGas": // spliced gas/memory helpers
gasHelpers[fn.Name.Name] = fn
case fn.Recv == nil: // top-level opXxx handler
opcodeHandlers[fn.Name.Name] = fn
case methodReceiver(fn) == "Stack" && hasInlineMarker(fn): // (s *Stack) helper tagged //gen:inline
stackHelpers[fn.Name.Name] = fn
}
}
}
return fset, opcodeHandlers, stackHelpers, gasHelpers
}
// methodReceiver returns the receiver type name of a pointer-receiver method
// (e.g. "Stack" for (s *Stack)), or "" if fn is not such a method.
func methodReceiver(fn *ast.FuncDecl) string {
if fn.Recv == nil || len(fn.Recv.List) != 1 {
return ""
}
star, ok := fn.Recv.List[0].Type.(*ast.StarExpr)
if !ok {
return ""
}
id, ok := star.X.(*ast.Ident)
if !ok {
return ""
}
return id.Name
}
// hasInlineMarker reports whether fn is tagged //gen:inline, which marks a stack
// helper for splicing into the generated dispatch.
func hasInlineMarker(fn *ast.FuncDecl) bool {
if fn.Doc == nil {
return false
}
for _, c := range fn.Doc.List {
if c.Text == "//gen:inline" {
return true
}
}
return false
}
var opcodeReturnRe = regexp.MustCompile(`^(\s*)return\s+([^,]+),\s*(.+)$`)
// spliceOpcodeBody returns a named handler's body, rewritten so it can be spliced
// into the dispatch loop (see rewriteOpcodeReturns). The caller emits it with p.
func (g *generator) spliceOpcodeBody(handler string) string {
fn := g.opcodeHandlers[handler]
if fn == nil {
fatalf("no handler %q to inline", handler)
}
return g.rewriteOpcodeReturns(g.inlineStackHelpers(fn.Body.List, nil))
}
// spliceOpcodeFactoryBody splices the body of the executionFunc closure that a make*
// factory returns, substituting the factory's parameters with the per-opcode
// constants in args (positional, matching the factory signature). This lets
// closure-built handlers (makePush, makeDup) be derived from their single
// definition rather than restated in the generator. The caller emits the
// result with p.
func (g *generator) spliceOpcodeFactoryBody(factory string, args ...int) string {
fn := g.opcodeHandlers[factory]
if fn == nil {
fatalf("no factory %q to inline", factory)
}
lit := factoryClosure(factory, fn)
// Bind the factory parameters to the per-opcode constants, then inline.
names := paramNames(fn)
if len(names) != len(args) {
fatalf("factory %q takes %d params, got %d args", factory, len(names), len(args))
}
params := map[string]int{}
for i, nm := range names {
params[nm] = args[i]
}
return g.rewriteOpcodeReturns(g.inlineStackHelpers(lit.Body.List, params))
}
// factoryClosure returns the executionFunc literal that a make* factory's body
// is a single `return func(...) {...}` of.
func factoryClosure(name string, fn *ast.FuncDecl) *ast.FuncLit {
if len(fn.Body.List) != 1 {
fatalf("factory %q body is not a single return", name)
}
ret, ok := fn.Body.List[0].(*ast.ReturnStmt)
if !ok || len(ret.Results) != 1 {
fatalf("factory %q does not return a single value", name)
}
lit, ok := ret.Results[0].(*ast.FuncLit)
if !ok {
fatalf("factory %q does not return a func literal", name)
}
return lit
}
// renderAst converts AST statements back to formatted Go source text, the
// inverse of parsing. It uses the generator's fileset and emits nothing itself
// (the caller passes the result to p).
func (g *generator) renderAst(stmts []ast.Stmt) string {
var raw bytes.Buffer
cfg := printer.Config{Mode: printer.UseSpaces | printer.TabIndent, Tabwidth: 8}
for _, stmt := range stmts {
if err := cfg.Fprint(&raw, g.fset, stmt); err != nil {
fatalf("print stmt: %v", err)
}
raw.WriteByte('\n')
}
return raw.String()
}
// rewriteOpcodeReturns rewrites a printed handler body so it runs inside the
// dispatch loop: the `*pc` dereference becomes the loop's `pc` local, and each
// `return r0, r1` becomes loop control flow. Success (r1 == nil) advances pc
// and continues, an error sets err and breaks. (Stack helpers were already
// inlined by inlineStackHelpers before the body was printed.)
func (g *generator) rewriteOpcodeReturns(src string) string {
src = strings.ReplaceAll(src, "*pc", "pc")
var out bytes.Buffer
for _, line := range strings.Split(src, "\n") {
if m := opcodeReturnRe.FindStringSubmatch(line); m != nil {
indent, r0, r1 := m[1], strings.TrimSpace(m[2]), strings.TrimSpace(m[3])
if r1 == "nil" {
out.WriteString(indent + "pc++\n")
out.WriteString(indent + "continue mainLoop\n")
} else {
out.WriteString(indent + "res, err = " + r0 + ", " + r1 + "\n")
out.WriteString(indent + "break mainLoop\n")
}
continue
}
out.WriteString(line + "\n")
}
return out.String()
}
var gasReturnRe = regexp.MustCompile(`^(\s*)return\s+(\S.*)$`)
// rewriteGasReturns rewrites a spliced charge body so it runs as a gas step in
// the dispatch loop: a `return <err>` becomes the out-of-gas break, and the
// trailing `return nil` (success) is dropped so the opcode continues.
func (g *generator) rewriteGasReturns(src string) string {
var out bytes.Buffer
for _, line := range strings.Split(src, "\n") {
if m := gasReturnRe.FindStringSubmatch(line); m != nil {
indent, val := m[1], strings.TrimSpace(m[2])
if val == "nil" {
continue // success: fall through to the rest of the op
}
out.WriteString(indent + "res, err = nil, " + val + "\n")
out.WriteString(indent + "break mainLoop\n")
continue
}
out.WriteString(line + "\n")
}
return out.String()
}
// rewriteStepReturns rewrites a spliced gas-step body's (value, error) returns so
// it runs inline in the dispatch loop: a non-nil error becomes the out-of-gas
// break; on success the value is assigned to target (or dropped when target is
// empty) and the op falls through.
func (g *generator) rewriteStepReturns(src, target string) string {
var out bytes.Buffer
for _, line := range strings.Split(src, "\n") {
if m := opcodeReturnRe.FindStringSubmatch(line); m != nil {
indent, val, errVal := m[1], strings.TrimSpace(m[2]), strings.TrimSpace(m[3])
if errVal == "nil" {
if target != "" {
out.WriteString(indent + target + " = " + val + "\n")
}
continue
}
out.WriteString(indent + "res, err = nil, " + errVal + "\n")
out.WriteString(indent + "break mainLoop\n")
continue
}
out.WriteString(line + "\n")
}
return out.String()
}
// stackCall is a matched call to a tagged helper.
type stackCall struct {
helper string // helper method name
lhs []ast.Expr // assignment targets, nil for a void call like dup
tok token.Token // the assignment token, := or =
args []ast.Expr // call arguments (only dup has one)
}
// matchStackHelper matches a statement that is a single must-expand helper call,
// in one of the two normalized forms: an assignment `lhs... := scope.Stack.H(args)`
// or a bare `scope.Stack.H(args)`.
func (g *generator) matchStackHelper(stmt ast.Stmt) (stackCall, bool) {
switch s := stmt.(type) {
case *ast.AssignStmt:
if len(s.Rhs) == 1 {
if h, args, ok := g.stackHelperCall(s.Rhs[0]); ok {
return stackCall{helper: h, lhs: s.Lhs, tok: s.Tok, args: args}, true
}
}
case *ast.ExprStmt:
if h, args, ok := g.stackHelperCall(s.X); ok {
return stackCall{helper: h, args: args}, true
}
}
return stackCall{}, false
}
// stackHelperCall unwraps scope.Stack.H(args) where H is a must-expand helper.
func (g *generator) stackHelperCall(e ast.Expr) (helper string, args []ast.Expr, ok bool) {
call, isCall := e.(*ast.CallExpr)
if !isCall {
return "", nil, false
}
sel, isSel := call.Fun.(*ast.SelectorExpr) // <recv>.H
if !isSel || g.stackHelpers[sel.Sel.Name] == nil || !isStackExpr(sel.X) {
return "", nil, false
}
return sel.Sel.Name, call.Args, true
}
// isStackExpr reports whether e is the stack receiver: the `stack` local or
// scope.Stack.
func isStackExpr(e ast.Expr) bool {
switch x := e.(type) {
case *ast.Ident:
return x.Name == "stack"
case *ast.SelectorExpr:
return x.Sel.Name == "Stack"
}
return false
}
// inlineStackHelpers renders a handler body to source, inlining every must-expand
// helper call and printing other statements unchanged. params maps the factory
// parameters (makePush/makeDup) to their per-opcode constants.
func (g *generator) inlineStackHelpers(stmts []ast.Stmt, params map[string]int) string {
var out strings.Builder
// Walk the handler body one statement at a time. A statement that is a
// tagged stack-helper call gets the helper's body spliced in: the generated
// dispatch is past Go's big-function inline budget, so the call would not be
// inlined otherwise. Every other statement is printed as written.
for _, stmt := range stmts {
if call, ok := g.matchStackHelper(stmt); ok {
// e.g. `x, y := scope.Stack.pop1Peek1()` becomes the body of pop1Peek1.
out.WriteString(g.inlineStackHelper(call, params))
} else {
// A plain statement: print it verbatim, then fill in any makePush or
// makeDup factory params with this opcode's constants.
out.WriteString(substParams(g.renderAst([]ast.Stmt{stmt}), params))
}
}
return out.String()
}
// substParams replaces each factory parameter with its constant. It runs only
// on printed non-helper statements and on helper arguments, never on a helper
// expansion, so it cannot touch a field like stack.size. The parameter names do
// not textually overlap, so map order does not affect the result.
func substParams(src string, params map[string]int) string {
for name, val := range params {
src = regexp.MustCompile(`\b`+name+`\b`).ReplaceAllString(src, fmt.Sprint(val))
}
return src
}
// inlineStackHelper expands one helper call to its stack.go body. The single
// rule: the helper is straight-line statements then an optional final return
// whose result count matches the call's targets. Anything else is not in
// inlinable form and is a hard error (the shape post-condition). The receiver
// maps to the loop's `stack` local and each parameter to its call argument.
func (g *generator) inlineStackHelper(call stackCall, params map[string]int) string {
fn := g.stackHelpers[call.helper]
if fn == nil {
fatalf("no stack helper %q to inline", call.helper)
}
// Peel an optional trailing return off the body.
body := fn.Body.List
var ret *ast.ReturnStmt
if n := len(body); n > 0 {
if r, isRet := body[n-1].(*ast.ReturnStmt); isRet {
ret, body = r, body[:n-1]
}
}
results := 0
if ret != nil {
results = len(ret.Results)
}
if len(call.lhs) != results {
fatalf("stack helper %q returns %d values, call assigns %d", call.helper, results, len(call.lhs))
}
// Map the receiver to the loop local and each parameter to its argument.
names := paramNames(fn)
if len(names) != len(call.args) {
fatalf("stack helper %q takes %d params, call passes %d", call.helper, len(names), len(call.args))
}
subst := map[string]string{recvName(fn): "stack"}
for i, name := range names {
subst[name] = substParams(renderInlineExpr(call.args[i], nil), params)
}
// The leading bookkeeping statements, then bind each return expression to
// its assignment target.
var out strings.Builder
for _, stmt := range body {
out.WriteString(renderInlineStmt(stmt, subst) + "\n")
}
for i, lhs := range call.lhs {
out.WriteString(renderInlineExpr(lhs, nil) + " " + call.tok.String() + " " + renderInlineExpr(ret.Results[i], subst) + "\n")
}
return out.String()
}
// recvName returns a method's receiver name (e.g. "s").
func recvName(fn *ast.FuncDecl) string {
if names := fn.Recv.List[0].Names; len(names) > 0 {
return names[0].Name
}
return ""
}
// paramNames returns a function's parameter names, in order.
func paramNames(fn *ast.FuncDecl) []string {
var names []string
for _, f := range fn.Type.Params.List {
for _, nm := range f.Names {
names = append(names, nm.Name)
}
}
return names
}
// renderInlineStmt prints one helper-body statement with subst applied. Only the
// statement shapes the helpers use are handled; any other is not inlinable.
func renderInlineStmt(stmt ast.Stmt, subst map[string]string) string {
switch s := stmt.(type) {
case *ast.IncDecStmt: // s.inner.top++
return renderInlineExpr(s.X, subst) + s.Tok.String()
case *ast.AssignStmt: // s.size -= 2, data[x] = data[y], or the swap tuple a, b = b, a
if len(s.Lhs) == len(s.Rhs) && len(s.Lhs) >= 1 {
lhs := make([]string, len(s.Lhs))
rhs := make([]string, len(s.Rhs))
for i := range s.Lhs {
lhs[i] = renderInlineExpr(s.Lhs[i], subst)
rhs[i] = renderInlineExpr(s.Rhs[i], subst)
}
return strings.Join(lhs, ", ") + " " + s.Tok.String() + " " + strings.Join(rhs, ", ")
}
}
fatalf("inline: unsupported statement %T in stack helper", stmt)
return ""
}
// renderInlineExpr prints one helper-body expression, substituting any
// identifier found in subst. Only the shapes the helpers use are handled.
func renderInlineExpr(expr ast.Expr, subst map[string]string) string {
switch e := expr.(type) {
case *ast.Ident:
if r, ok := subst[e.Name]; ok {
return r
}
return e.Name
case *ast.BasicLit:
return e.Value
case *ast.SelectorExpr: // x.field
return renderInlineExpr(e.X, subst) + "." + e.Sel.Name
case *ast.IndexExpr: // x[i]
return renderInlineExpr(e.X, subst) + "[" + renderInlineExpr(e.Index, subst) + "]"
case *ast.BinaryExpr: // x op y
return renderInlineExpr(e.X, subst) + " " + e.Op.String() + " " + renderInlineExpr(e.Y, subst)
case *ast.UnaryExpr: // &x
return e.Op.String() + renderInlineExpr(e.X, subst)
}
fatalf("inline: unsupported expression %T in stack helper", expr)
return ""
}
// deriveSpecs records each opcode's bakeable constants (name, intro fork, static
// gas, stack bounds) from the first fork that defines it, then checks that the
// opcodes chosen for inlining and direct-calling are safe to bake by verifying
// their constants are fork-stable (see checkStable and checkDirectCallStable).
func (g *generator) deriveSpecs(forks []vm.GenFork) {
for code := 0; code < 256; code++ {
for _, fork := range forks {
o := fork.Ops[code]
if !o.Defined {
continue
}
g.specs[code] = opSpec{
defined: true,
name: o.Name,
fork: fork.RuleField,
constGas: o.ConstantGas,
minStack: o.MinStack,
maxStack: o.MaxStack,
}
break // first fork that defines it wins (its intro fork)
}
}
// Every inlined opcode must be defined and have fork-stable static
// gas / stack bounds across all forks where it appears. Bail loudly otherwise.
for code, handler := range inlineOps {
g.checkStable(code, handler, forks)
}
// directCallOps opcodes bake their static gas and stack bounds the same way, so
// they must be fork-stable too. Dynamic gas is allowed (it is charged through
// the named gas function, not baked).
for code := range directCallOps {
g.checkDirectCallStable(code, forks)
}
}
// checkStable verifies an opcode selected for inlining is safe to inline: it must
// be defined, its static gas and stack bounds must be the same across every fork
// it appears in (they are baked as constants), and it must have no dynamic gas,
// since an inlined op charges only the baked static gas. It bails loudly
// otherwise. `what` names the handler for the error message.
func (g *generator) checkStable(code byte, what string, forks []vm.GenFork) {
spec := g.specs[code]
if !spec.defined {
fatalf("opcode %#x (%s) selected for inlining but never defined", code, what)
}
for _, fork := range forks {
o := fork.Ops[code]
if !o.Defined {
continue
}
if o.ConstantGas != spec.constGas || o.MinStack != spec.minStack || o.MaxStack != spec.maxStack || o.DynamicGasFn != "" {
fatalf("opcode %#x (%s) is not fork-stable (fork %s): cannot inline", code, what, fork.Name)
}
}
}
// checkDirectCallStable verifies a directCallOps opcode is safe to direct-call. Its static
// gas and stack bounds must be the same across every fork it appears in (they are
// baked as constants), and its handler, gas and memory functions must be the same
// across those forks too (they are called by name, so a fork that swapped one
// would otherwise be missed). Unlike checkStable it allows dynamic gas, which
// directCallOps ops carry by definition. It does not check the directCallOps map's names
// against the table, which the differential test covers.
func (g *generator) checkDirectCallStable(code byte, forks []vm.GenFork) {
spec := g.specs[code]
if !spec.defined {
fatalf("opcode %#x (directCallOps) is never defined", code)
}
var exec, dyn, mem string
seen := false
for _, fork := range forks {
o := fork.Ops[code]
if !o.Defined {
continue
}
if o.ConstantGas != spec.constGas || o.MinStack != spec.minStack || o.MaxStack != spec.maxStack {
fatalf("opcode %#x (%s) is in directCallOps but not fork-stable (fork %s): static gas or stack bounds vary, cannot bake", code, spec.name, fork.Name)
}
// Handler, gas and memory functions must match across forks too, or
// direct-calling them by name would skip a fork that swapped one. Names
// come from FuncForPC via vm.GenForks (aliases resolve to the underlying
// func, still stable across forks).
if !seen {
exec, dyn, mem, seen = o.ExecuteFn, o.DynamicGasFn, o.MemorySizeFn, true
} else if o.ExecuteFn != exec || o.DynamicGasFn != dyn || o.MemorySizeFn != mem {
fatalf("opcode %#x (%s) is in directCallOps but its functions vary by fork (fork %s): got %s/%s/%s, want %s/%s/%s, cannot direct-call",
code, spec.name, fork.Name, o.ExecuteFn, o.DynamicGasFn, o.MemorySizeFn, exec, dyn, mem)
}
}
}
// generateStackChecks returns the underflow/overflow guards, mirroring the legacy
// loop's order (stack validated before gas). minExpr and maxExpr are the
// stack-bound expressions (baked constants on the inlined/direct paths,
// operation.minStack/maxStack in the table path). under and over select which
// guards to emit, so the baked paths can omit a guard whose bound is trivial.
func (g *generator) generateStackChecks(minExpr, maxExpr any, under, over bool) string {
switch {
case under && over:
return fmt.Sprintf(`if sLen := stack.len(); sLen < %v {
return nil, &ErrStackUnderflow{stackLen: sLen, required: %v}
} else if sLen > %v {
return nil, &ErrStackOverflow{stackLen: sLen, limit: %v}
}
`, minExpr, minExpr, maxExpr, maxExpr)
case under:
return fmt.Sprintf(`if sLen := stack.len(); sLen < %v {
return nil, &ErrStackUnderflow{stackLen: sLen, required: %v}
}
`, minExpr, minExpr)
case over:
return fmt.Sprintf(`if sLen := stack.len(); sLen > %v {
return nil, &ErrStackOverflow{stackLen: sLen, limit: %v}
}
`, maxExpr, maxExpr)
}
return ""
}
// generateStaticGas returns the static-gas charge, spliced call-free from the
// chargeRegularOnly body for amount: a baked constant on the inlined and
// direct-call paths, operation.constantGas in the table path. The receiver maps
// to contract.Gas and the method's single uint64 parameter to amount, substituted
// textually on word boundaries (which cannot touch fields like RegularGas). Its
// `return <err>` becomes the loop's out-of-gas exit and its trailing `return nil`
// is dropped so the opcode falls through to its remaining steps (see
// rewriteGasReturns).
func (g *generator) generateStaticGas(amount any) string {
fn := g.gasHelpers["chargeRegularOnly"]
if fn == nil {
fatalf("no chargeRegularOnly gas helper to inline")
}
names := paramNames(fn)
if len(names) != 1 {
fatalf("chargeRegularOnly takes %d params, want 1", len(names))
}
src := g.renderAst(fn.Body.List)
src = regexp.MustCompile(`\b`+recvName(fn)+`\b`).ReplaceAllString(src, "contract.Gas")
src = regexp.MustCompile(`\b`+names[0]+`\b`).ReplaceAllString(src, fmt.Sprint(amount))
return g.rewriteGasReturns(src)
}
// emitInlineOp emits an inlined opcode case: the stack and gas guards followed by
// the spliced opcode body. A fork-introduced opcode wraps that body in a fork gate
// so it runs only when the opcode is active for the current fork, otherwise the
// case mirrors the legacy loop's undefined-opcode handling.
func (g *generator) emitInlineOp(code byte) {
spec := g.specs[code]
g.p("case %s:\n", spec.name)
if spec.fork != "" {
g.p("if rules.%s {\n", spec.fork)
}
// stack bounds check
g.p("%s", g.generateStackChecks(spec.minStack, spec.maxStack, spec.minStack > 0, spec.maxStack < stackLimit))
// static gas
if spec.constGas != 0 {
g.p("%s", g.generateStaticGas(spec.constGas))
}
// PUSH1-PUSH32 swap their execute function under EIP-4762 (verkle) to charge
// code-chunk gas on the immediate bytes. Defer to the table handler there.
// The baked static gas and stack guard above already match.
if code >= 0x60 && code <= 0x7f {
g.p(`
if isEIP4762 {
res, err = table[op].execute(&pc, evm, scope)
if err != nil {
break mainLoop
}
pc++
continue mainLoop
}
`)
}
// opcode body
switch h := inlineOps[code]; h {
case "makePush": // PUSH3-PUSH32: splice makePush(size, size)
n := int(code) - 0x5f
g.p("%s", g.spliceOpcodeFactoryBody("makePush", n, n))
case "makeDup": // DUP1-DUP16: splice makeDup(n)
g.p("%s", g.spliceOpcodeFactoryBody("makeDup", int(code)-0x7f))
default: // the rest: splice the opXxx handler body
g.p("%s", g.spliceOpcodeBody(h))
}
// If opcode is inactive for this fork, then close the gate
// and fall back to the legacy loop's undefined-opcode handling.
if spec.fork != "" {
g.p(`
}
res, err = opUndefined(&pc, evm, scope)
break mainLoop
`)
}
}
// emitDirectCallOp emits an opcode case identical to the default case, except
// the handler, dynamic-gas, and memory-size functions are called by name
// rather than through the indirect operation.* table pointers. Valid only for
// fork-invariant ops (see directCallOps).
func (g *generator) emitDirectCallOp(code byte) {
spec := g.specs[code]
fns := directCallOps[code]
g.p("case %s:\n", spec.name)
// stack bounds check
g.p("%s", g.generateStackChecks(spec.minStack, spec.maxStack, spec.minStack > 0, spec.maxStack < stackLimit))
// static gas
if spec.constGas != 0 {
g.p("%s", g.generateStaticGas(spec.constGas))
}
// dynamic gas
g.p("\nvar memorySize uint64\n")
// Splice computeMemorySize's body, rewriting its operation.memorySize lookup to
// the opcode's memory-size function and its returns for the dispatch loop.
memSizeFn := g.gasHelpers["computeMemorySize"]
if memSizeFn == nil {
fatalf("no computeMemorySize gas helper to inline")
}
memSizeSrc := g.renderAst(memSizeFn.Body.List)
memSizeSrc = strings.ReplaceAll(memSizeSrc, "operation.memorySize", fns[2])
g.p("%s", g.rewriteStepReturns(memSizeSrc, "memorySize"))
// Splice chargeDynamicGas's body the same way, rewriting operation.dynamicGas to
// the opcode's gas function.
dynGasFn := g.gasHelpers["chargeDynamicGas"]
if dynGasFn == nil {
fatalf("no chargeDynamicGas gas helper to inline")
}
dynGasSrc := g.renderAst(dynGasFn.Body.List)
dynGasSrc = strings.ReplaceAll(dynGasSrc, "operation.dynamicGas", fns[1])
g.p("%s", g.rewriteStepReturns(dynGasSrc, ""))
// resize memory
g.p(`
if memorySize > 0 {
mem.Resize(memorySize)
}
`)
// call the opcode handler
g.p(`
res, err = %s(&pc, evm, scope)
if err != nil {
break mainLoop
}
`, fns[0])
// advance to the next opcode
g.p(`
pc++
continue mainLoop
`)
}
// emitDefault emits the switch's default case: every opcode not inlined or
// direct-called (the fork-varying ops such as CALL, CREATE, SSTORE, SLOAD, LOG
// and the COPY family) is dispatched through the active per-fork table, exactly
// as the legacy loop did, so their volatile gas and opcode logic stays shared
// rather than restated here.
func (g *generator) emitDefault() {
g.p(`
default:
operation := table[op]
`)
// stack bounds check
g.p("%s", g.generateStackChecks("operation.minStack", "operation.maxStack", true, true))
// static gas
g.p("%s", g.generateStaticGas("operation.constantGas"))
// dynamic gas
g.p(`
var memorySize uint64
if memorySize, _, err = contract.meterDynamicGas(operation, evm, stack, mem); err != nil {
return nil, err
}
`)
// resize memory
g.p(`
if memorySize > 0 {
mem.Resize(memorySize)
}
`)
// call the opcode handler
g.p(`
res, err = operation.execute(&pc, evm, scope)
if err != nil {
break mainLoop
}
`)
// advance to the next opcode
g.p(`
pc++
continue mainLoop
`)
}
// createFile emits the whole generated file into g.buf: the header, package and
// imports, then the execUntraced function (its locals and dispatch loop, the
// verkle code-chunk gas, and a switch with one case per opcode built by the
// emit* helpers). main formats the buffer and writes it to interpreter_gen.go.
func (g *generator) createFile() {
// file header, package clause, and imports
g.p(`
// Code generated by core/vm/gen; DO NOT EDIT.
package vm
import (
"fmt"
"github.com/ethereum/go-ethereum/common/math"
"github.com/ethereum/go-ethereum/core/tracing"
)
`)
// execUntraced: doc comment, loop-local declarations, and the dispatch loop
g.p(`
// execUntraced is the generated, tracing-free interpreter fast path. Hot,
// fork-stable opcodes are inlined with their static gas and stack bounds baked
// in. Fork-invariant ops (KECCAK256/MLOAD/MSTORE/MSTORE8) call their
// handler and gas functions directly by name. Everything fork-varying is
// dispatched through the active per-fork table in the default case. EVM.Run
// selects this path when no tracer is configured.
func (evm *EVM) execUntraced(scope *ScopeContext) (ret []byte, err error) {
var (
contract = scope.Contract
mem = scope.Memory
stack = scope.Stack
table = evm.table
rules = evm.chainRules
isEIP4762 = rules.IsEIP4762
pc = uint64(0)
res []byte
)
_ = mem
_ = rules
_ = isEIP4762
_ = table
mainLoop:
for {
`)
// verkle code-chunk gas, spliced from chargeVerkleCodeChunkGas
ccgFn := g.gasHelpers["chargeVerkleCodeChunkGas"]
if ccgFn == nil {
fatalf("no chargeVerkleCodeChunkGas gas helper to inline")
}
g.p("%s", g.rewriteGasReturns(g.renderAst(ccgFn.Body.List)))
// fetch the opcode and open the dispatch switch
g.p(`
op := contract.GetOp(pc)
switch op {
`)
// one case per inlined or direct-call opcode, in opcode order
for code := 0; code < 256; code++ {
b := byte(code)
if _, named := inlineOps[b]; named {
g.emitInlineOp(b)
} else if _, dc := directCallOps[b]; dc {
g.emitDirectCallOp(b)
}
}
// the default case: fork-varying ops via the per-fork table
g.emitDefault()
// close the switch and loop, clear the stop token, and return
g.p(`
}
}
if err == errStopToken {
err = nil
}
return res, err
}
`)
}
func fatalf(format string, args ...any) {
fmt.Fprintf(os.Stderr, "gen: "+format+"\n", args...)
os.Exit(1)
}
func main() { func main() {
_, self, _, ok := runtime.Caller(0) formatted, err := generate()
if !ok {
fatalf("cannot resolve generator source path")
}
vmDir := filepath.Dir(filepath.Dir(self)) // .../core/vm/gen -> .../core/vm
fset, opcodeHandlers, stackHelpers, gasHelpers := parseHandlers(vmDir)
g := &generator{fset: fset, opcodeHandlers: opcodeHandlers, stackHelpers: stackHelpers, gasHelpers: gasHelpers, buf: new(bytes.Buffer)}
g.deriveSpecs(vm.GenForks())
g.createFile()
formatted, err := format.Source(g.buf.Bytes())
if err != nil { if err != nil {
dbg := filepath.Join(vmDir, "interpreter_gen.go.broken") fatalf("%v", err)
os.WriteFile(dbg, g.buf.Bytes(), 0644)
fatalf("gofmt failed (%v); wrote unformatted output to %s", err, dbg)
}
// INTERPRETER_GEN_OUT lets the CI-match test (interpreter_gen_test.go) regenerate to a
// temporary file and diff it against the committed one, without clobbering it.
out := filepath.Join(vmDir, "interpreter_gen.go")
if env := os.Getenv("INTERPRETER_GEN_OUT"); env != "" {
out = env
} }
out := filepath.Join(vmDir(), "interpreter_gen.go")
if err := os.WriteFile(out, formatted, 0644); err != nil { if err := os.WriteFile(out, formatted, 0644); err != nil {
fatalf("write %s: %v", out, err) fatalf("write %s: %v", out, err)
} }

2
core/vm/interpreter.go
View file

@ -133,7 +133,7 @@ func (evm *EVM) Run(contract *Contract, input []byte, readOnly bool) (ret []byte
mem.Free() mem.Free()
}() }()
// The generated fast path bakes its fork gates at generate time, so it // The generated fast path resolves its fork gates at generate time, so it
// cannot see table changes made by ExtraEips. Those configs run the table // cannot see table changes made by ExtraEips. Those configs run the table
// loop, as do tracing and the differential test via forceTableLoop. // loop, as do tracing and the differential test via forceTableLoop.
if evm.forceTableLoop || len(evm.Config.ExtraEips) > 0 || evm.Config.Tracer != nil { if evm.forceTableLoop || len(evm.Config.ExtraEips) > 0 || evm.Config.Tracer != nil {

4
core/vm/interpreter_gen.go
View file

@ -10,8 +10,8 @@ import (
) )
// execUntraced is the generated, tracing-free interpreter fast path. Hot, // execUntraced is the generated, tracing-free interpreter fast path. Hot,
// fork-stable opcodes are inlined with their static gas and stack bounds baked // fork-stable opcodes are inlined with their static gas and stack bounds emitted
// in. Fork-invariant ops (KECCAK256/MLOAD/MSTORE/MSTORE8) call their // as constants. Fork-invariant ops (KECCAK256/MLOAD/MSTORE/MSTORE8) call their
// handler and gas functions directly by name. Everything fork-varying is // handler and gas functions directly by name. Everything fork-varying is
// dispatched through the active per-fork table in the default case. EVM.Run // dispatched through the active per-fork table in the default case. EVM.Run
// selects this path when no tracer is configured. // selects this path when no tracer is configured.

40
core/vm/interpreter_gen_test.go
View file

@ -16,9 +16,10 @@
package vm package vm
// Tests for the generated interpreter dispatch (interpreter_gen.go): that the // Tests for the generated interpreter dispatch (interpreter_gen.go): that it
// committed file is up to date, that it behaves identically to the table loop, // behaves identically to the table loop, and that the fast path keeps its cheap
// and that the fast path keeps its cheap stack helpers inlined. // stack helpers inlined. The check that the committed file matches the generator
// output lives with the generator, in core/vm/gen.
import ( import (
"bytes" "bytes"
@ -26,9 +27,7 @@ import (
"go/parser" "go/parser"
"go/token" "go/token"
"math/big" "math/big"
"os"
"os/exec" "os/exec"
"path/filepath"
"regexp" "regexp"
"strings" "strings"
"testing" "testing"
@ -41,33 +40,6 @@ import (
"github.com/holiman/uint256" "github.com/holiman/uint256"
) )
// TestGeneratedDispatchUpToDate asserts that the committed interpreter_gen.go matches
// what `go generate` (core/vm/gen) produces from the current opcode/gas/fork
// definitions. It is the CI guard against hand-edits to the generated file and
// against the generator drifting from the committed output.
func TestGeneratedDispatchUpToDate(t *testing.T) {
if testing.Short() {
t.Skip("skipping generator round-trip in -short mode")
}
tmp := filepath.Join(t.TempDir(), "interpreter_gen.go")
cmd := exec.Command("go", "run", "./gen")
cmd.Env = append(os.Environ(), "INTERPRETER_GEN_OUT="+tmp)
if out, err := cmd.CombinedOutput(); err != nil {
t.Fatalf("running generator: %v\n%s", err, out)
}
got, err := os.ReadFile(tmp)
if err != nil {
t.Fatalf("reading regenerated output: %v", err)
}
want, err := os.ReadFile("interpreter_gen.go")
if err != nil {
t.Fatalf("reading committed interpreter_gen.go: %v", err)
}
if string(got) != string(want) {
t.Fatalf("interpreter_gen.go is out of date; run `go generate ./core/vm/...` and commit the result")
}
}
// Differential test comparing the table loop against the generated dispatch. // Differential test comparing the table loop against the generated dispatch.
// //
// These tests prove that the generated dispatch (execUntraced) is bit-identical // These tests prove that the generated dispatch (execUntraced) is bit-identical
@ -84,7 +56,7 @@ func TestGeneratedDispatchUpToDate(t *testing.T) {
// the tracer test suites instead. // the tracer test suites instead.
// diffForks is the set of fork configurations the diff test runs every program // diffForks is the set of fork configurations the diff test runs every program
// under. Spanning forks exercises the baked runtime fork gates (e.g. SHL from // under. Spanning forks exercises the generated fork gates (e.g. SHL from
// Constantinople, PUSH0 from Shanghai, CLZ from Osaka) in both the active and // Constantinople, PUSH0 from Shanghai, CLZ from Osaka) in both the active and
// the not-yet-activated states. // the not-yet-activated states.
var diffForks = func() []struct { var diffForks = func() []struct {
@ -318,7 +290,7 @@ func diffBlockCtx(merged bool) BlockContext {
// TestExtraEIPs checks that EIPs enabled via Config.ExtraEips take effect even // TestExtraEIPs checks that EIPs enabled via Config.ExtraEips take effect even
// when they touch opcodes the generated dispatch inlines. PUSH0 (EIP-3855) on // when they touch opcodes the generated dispatch inlines. PUSH0 (EIP-3855) on
// a pre-Shanghai config is the canary: the runtime table has it enabled but // a pre-Shanghai config is the canary: the runtime table has it enabled but
// the baked fork gate does not, so execution must route through the table loop. // the generated fork gate does not, so execution must route through the table loop.
func TestExtraEIPs(t *testing.T) { func TestExtraEIPs(t *testing.T) {
code := asm(PUSH0, STOP) code := asm(PUSH0, STOP)
statedb := newDiffState(t) statedb := newDiffState(t)