From 909dd4a109c35ef7a12ecbed7168efc6c97d0a83 Mon Sep 17 00:00:00 2001
From: Felix Lange <fjl@twurst.com>
Date: Thu, 14 Sep 2023 12:28:40 +0200
Subject: [PATCH] rlp/rlpgen: remove build tag (#28106)

* rlp/rlpgen: remove build tag

This tag was supposed to prevent unstable output when types reference each other. Imagine
there are two struct types A and B, where a reference to type B is in A. If I run rlpgen
on type B first, and then on type A, the generator will see the B.EncodeRLP method and
call it. However, if I run rlpgen on type A first, it will inline the encoding of B.

The solution I chose for the initial release of rlpgen was to just ignore methods
generated by rlpgen using a build tag. But there is a problem with this: if any code in
the package calls EncodeRLP explicitly, the package can't be loaded without errors anymore
in rlpgen, because the loader ignores it. Would be nice if there was a way to just make it
ignore invalid functions during type checking (they're not necessary for rlpgen), but
golang.org/x/tools/go/packages does not provide a way of ignoring them.

Luckily, the types we use rlpgen with do not reference each other right now, so we can
just remove the build tags for now.
---
 core/types/gen_account_rlp.go    | 3 ---
 core/types/gen_header_rlp.go     | 3 ---
 core/types/gen_log_rlp.go        | 3 ---
 core/types/gen_withdrawal_rlp.go | 3 ---
 rlp/rlpgen/main.go               | 7 ++-----
 5 files changed, 2 insertions(+), 17 deletions(-)

diff --git a/core/types/gen_account_rlp.go b/core/types/gen_account_rlp.go
index 5181d8841..3fb36f403 100644
--- a/core/types/gen_account_rlp.go
+++ b/core/types/gen_account_rlp.go
@@ -1,8 +1,5 @@
 // Code generated by rlpgen. DO NOT EDIT.
 
-//go:build !norlpgen
-// +build !norlpgen
-
 package types
 
 import "github.com/ethereum/go-ethereum/rlp"
diff --git a/core/types/gen_header_rlp.go b/core/types/gen_header_rlp.go
index b91a255a5..ed6a1a002 100644
--- a/core/types/gen_header_rlp.go
+++ b/core/types/gen_header_rlp.go
@@ -1,8 +1,5 @@
 // Code generated by rlpgen. DO NOT EDIT.
 
-//go:build !norlpgen
-// +build !norlpgen
-
 package types
 
 import "github.com/ethereum/go-ethereum/rlp"
diff --git a/core/types/gen_log_rlp.go b/core/types/gen_log_rlp.go
index cbdb6736e..7e8962966 100644
--- a/core/types/gen_log_rlp.go
+++ b/core/types/gen_log_rlp.go
@@ -1,8 +1,5 @@
 // Code generated by rlpgen. DO NOT EDIT.
 
-//go:build !norlpgen
-// +build !norlpgen
-
 package types
 
 import "github.com/ethereum/go-ethereum/rlp"
diff --git a/core/types/gen_withdrawal_rlp.go b/core/types/gen_withdrawal_rlp.go
index d0b4e0147..6a97c04c8 100644
--- a/core/types/gen_withdrawal_rlp.go
+++ b/core/types/gen_withdrawal_rlp.go
@@ -1,8 +1,5 @@
 // Code generated by rlpgen. DO NOT EDIT.
 
-//go:build !norlpgen
-// +build !norlpgen
-
 package types
 
 import "github.com/ethereum/go-ethereum/rlp"
diff --git a/rlp/rlpgen/main.go b/rlp/rlpgen/main.go
index 25d4393cc..b3a74b9df 100644
--- a/rlp/rlpgen/main.go
+++ b/rlp/rlpgen/main.go
@@ -73,9 +73,8 @@ type Config struct {
 func (cfg *Config) process() (code []byte, err error) {
 	// Load packages.
 	pcfg := &packages.Config{
-		Mode:       packages.NeedName | packages.NeedTypes | packages.NeedImports | packages.NeedDeps,
-		Dir:        cfg.Dir,
-		BuildFlags: []string{"-tags", "norlpgen"},
+		Mode: packages.NeedName | packages.NeedTypes,
+		Dir:  cfg.Dir,
 	}
 	ps, err := packages.Load(pcfg, pathOfPackageRLP, ".")
 	if err != nil {
@@ -117,8 +116,6 @@ func (cfg *Config) process() (code []byte, err error) {
 	// This is done here to avoid processing these lines with gofmt.
 	var header bytes.Buffer
 	fmt.Fprint(&header, "// Code generated by rlpgen. DO NOT EDIT.\n\n")
-	fmt.Fprint(&header, "//go:build !norlpgen\n")
-	fmt.Fprint(&header, "// +build !norlpgen\n\n")
 	return append(header.Bytes(), code...), nil
 }