add metadata with build details for contract verification

Author: simsonraj

contracts/scripts/native_solc_compile_all_shared

@@ -20,6 +20,7 @@ compileContract() {
   local contract
   contract=$(basename "$path")
   echo "Compiling" "$contract"
+  dir=$CONTRACTS_DIR/solc/$PROJECT/$contract
 
   local current_project="$PROJECT"
   if [ -n "$project" ]; then
@@ -31,7 +32,9 @@ compileContract() {
   local command
   command="forge build $CONTRACTS_DIR/src/v0.8/$current_project/"$path.sol" \
    --root $CONTRACTS_DIR \
-   --extra-output-files bin abi"
+   --extra-output-files bin abi metadata \
+   --build-info \
+   --build-info-path $dir/build"
 
   # Add version if provided
   if [ -n "$version" ]; then
@@ -41,9 +44,12 @@ compileContract() {
 
   # Output directory
   command="$command \
-   -o $CONTRACTS_DIR/solc/$PROJECT/$contract"
+   -o $dir"
 
   $command
+
+  # Move the build info to an expected file name
+  mv $(find $dir/build -type f -name '*.json' ! -name 'build.json') $dir/build/build.json
 }
 
 # Various contracts are compiled with v0.8.19 instead of the default specified in foundry.toml.

gethwrappers/abigen.go

@@ -2,6 +2,7 @@ package gethwrappers
 
 import (
 	"bytes"
+	"encoding/json"
 	"fmt"
 	"go/ast"
 	"go/format"
@@ -11,6 +12,7 @@ import (
 	"os/exec"
 	"path/filepath"
 	"regexp"
+	"strconv"
 	"strings"
 
 	"github.com/ethereum/go-ethereum/accounts/abi"
@@ -28,7 +30,29 @@ var GethVersion = fmt.Sprintf("%d.%d.%d", version.Major, version.Minor, version.
 // AbigenArgs is the arguments to the abigen executable. E.g., Bin is the -bin
 // arg.
 type AbigenArgs struct {
-	Bin, ABI, Out, Type, Pkg string
+	Bin, ABI, BuildInfo, Metadata, Out, BuildInfoOut, Type, Pkg string
+}
+
+// compiler defines the compiler section of contract metadata.
+type compiler struct {
+	Version string `json:"version"`
+}
+
+// metadata defines the sections of the contract metadata required for verification.
+type metadata struct {
+	Compiler compiler `json:"compiler"`
+}
+
+// standardInput defines the sections of the Solidity standard input required for verification.
+type standardInput struct {
+	Version  string         `json:"version"`
+	Language string         `json:"language"`
+	Settings map[string]any `json:"settings"`
+	Sources  map[string]any `json:"sources"`
+}
+
+type buildInfo struct {
+	Input standardInput `json:"input"`
 }
 
 // Abigen calls Abigen  with the given arguments
@@ -70,6 +94,55 @@ func Abigen(a AbigenArgs) {
 	}
 
 	ImproveAbigenOutput(a.Out, a.ABI)
+
+	// Add build info to exported package
+	info, err := os.ReadFile(a.BuildInfo)
+	if err != nil {
+		Exit("Error while reading build info file", err)
+	}
+	// Unmarshal into BuildInfo struct to filter out unnecessary fields
+	// and marshal back to JSON bytes afterwards
+	var build buildInfo
+	err = json.Unmarshal(info, &build)
+	if err != nil {
+		Exit("Error while unmarshalling build info JSON", err)
+	}
+	// Get version from metadata file, as it contains the commit hash required by etherscan
+	metadataBytes, err := os.ReadFile(a.Metadata)
+	if err != nil {
+		Exit("Error while reading metadata file", err)
+	}
+	var metadata metadata
+	err = json.Unmarshal(metadataBytes, &metadata)
+	if err != nil {
+		Exit("Error while unmarshalling metadata JSON", err)
+	}
+
+	if !strings.HasPrefix(metadata.Compiler.Version, "v") {
+		// Verification requires the version to be prefixed with "v"
+		metadata.Compiler.Version = "v" + metadata.Compiler.Version
+	}
+	build.Input.Version = metadata.Compiler.Version
+
+	refinedMeta, err := json.Marshal(build.Input)
+	if err != nil {
+		Exit("Error while marshalling build info JSON", err)
+	}
+	// Export the metadata as a variable in the generated Go file
+	var buf bytes.Buffer
+	if err := json.Compact(&buf, refinedMeta); err != nil {
+		Exit("Error while compacting build info JSON", err)
+	}
+	code := fmt.Sprintf(
+		"%s\npackage %s\n\nvar SolidityStandardInput = %s\n",
+		headerComment,
+		a.Pkg,
+		strconv.Quote(buf.String()),
+	)
+	err = os.WriteFile(a.BuildInfoOut, []byte(code), 0600)
+	if err != nil {
+		Exit("Error while writing build info file", err)
+	}
 }
 
 func ImproveAbigenOutput(path string, abiPath string) {

gethwrappers/generation/generate/genwrapper/genwrapper.go

@@ -24,7 +24,7 @@ import (
 // <project>/generated/<pkgName>/<pkgName>.go. The suffix will take place after
 // the <project>/generated, so the overridden location would be
 // <project>/generated/<outDirSuffixInput>/<pkgName>/<pkgName>.go.
-func GenWrapper(abiPath, binPath, className, pkgName, outDirSuffixInput string) {
+func GenWrapper(abiPath, binPath, buildInfoPath, metadataPath, className, pkgName, outDirSuffixInput string) {
 	fmt.Println("Generating", pkgName, "contract wrapper")
 
 	cwd, err := os.Getwd() // gethwrappers directory
@@ -38,9 +38,17 @@ func GenWrapper(abiPath, binPath, className, pkgName, outDirSuffixInput string)
 			mkdErr)
 	}
 	outPath := filepath.Join(outDir, pkgName+".go")
+	metadataOutPath := filepath.Join(outDir, pkgName+"_metadata.go")
 
 	gethwrappers.Abigen(gethwrappers.AbigenArgs{
-		Bin: binPath, ABI: abiPath, Out: outPath, Type: className, Pkg: pkgName,
+		Bin:          binPath,
+		ABI:          abiPath,
+		BuildInfo:    buildInfoPath,
+		Metadata:     metadataPath,
+		Out:          outPath,
+		BuildInfoOut: metadataOutPath,
+		Type:         className,
+		Pkg:          pkgName,
 	})
 
 	// Build succeeded, so update the versions db with the new contract data

gethwrappers/generation/generate/wrap.go

@@ -17,5 +17,5 @@ func main() {
 		outDirSuffix = os.Args[5]
 	}
 
-	genwrapper.GenWrapper(abiPath, binPath, className, pkgName, outDirSuffix)
+	genwrapper.GenWrapper(abiPath, binPath, "", "", className, pkgName, outDirSuffix)
 }

gethwrappers/generation/generate_automation/wrap.go

@@ -17,7 +17,9 @@ func main() {
 	pkgName := os.Args[3]
 
 	abiPath := rootDir + project + "/" + inputClassName + "/" + inputClassName + ".sol/" + inputClassName + ".abi.json"
+	metadataPath := rootDir + project + "/" + inputClassName + "/" + inputClassName + ".sol/" + inputClassName + ".metadata.json"
 	binPath := rootDir + project + "/" + inputClassName + "/" + inputClassName + ".sol/" + inputClassName + ".bin"
+	buildInfoPath := rootDir + project + "/" + inputClassName + "/build/build.json"
 
-	genwrapper.GenWrapper(abiPath, binPath, outputClassName, pkgName, "")
+	genwrapper.GenWrapper(abiPath, binPath, buildInfoPath, metadataPath, outputClassName, pkgName, "")
 }

gethwrappers/generation/wrap.go

@@ -26,7 +26,9 @@ func main() {
 	}
 
 	abiPath := rootDir + project + "/" + className + "/" + className + ".sol/" + className + ".abi.json"
+	metadataPath := rootDir + project + "/" + className + "/" + className + ".sol/" + className + ".metadata.json"
 	binPath := rootDir + project + "/" + className + "/" + className + ".sol/" + className + ".bin"
+	buildInfoPath := rootDir + project + "/" + className + "/build/build.json"
 
-	genwrapper.GenWrapper(abiPath, binPath, className, pkgName, outDirSuffix)
+	genwrapper.GenWrapper(abiPath, binPath, buildInfoPath, metadataPath, className, pkgName, outDirSuffix)
 }