From e28f713ada67af2380bd7052cb85b2e255a62a6a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C3=A9ter=20Szil=C3=A1gyi?= <peterke@gmail.com>
Date: Mon, 20 Sep 2021 16:29:07 +0300
Subject: [PATCH] internal: support optional filter expression for debug.stacks
 (#23605)

* internal: support optional filter expression for debug.stacks

* internal/debug: fix string regexp

* internal/debug: support searching for line numbers too
---
 go.mod                      |  1 +
 go.sum                      |  6 ++++++
 internal/debug/api.go       | 40 +++++++++++++++++++++++++++++++++++--
 internal/web3ext/web3ext.go |  3 ++-
 4 files changed, 47 insertions(+), 3 deletions(-)

diff --git a/go.mod b/go.mod
index ce19afc850..b63368085a 100644
--- a/go.mod
+++ b/go.mod
@@ -35,6 +35,7 @@ require (
 	github.com/google/uuid v1.1.5
 	github.com/gorilla/websocket v1.4.2
 	github.com/graph-gophers/graphql-go v0.0.0-20201113091052-beb923fada29
+	github.com/hashicorp/go-bexpr v0.1.10 // indirect
 	github.com/hashicorp/golang-lru v0.5.5-0.20210104140557-80c98217689d
 	github.com/holiman/bloomfilter/v2 v2.0.3
 	github.com/holiman/uint256 v1.2.0
diff --git a/go.sum b/go.sum
index 3d8a04236f..0890b8c5e0 100644
--- a/go.sum
+++ b/go.sum
@@ -216,6 +216,8 @@ github.com/gorilla/websocket v1.4.2 h1:+/TMaTYc4QFitKJxsQ7Yye35DkWvkdLcvGKqM+x0U
 github.com/gorilla/websocket v1.4.2/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
 github.com/graph-gophers/graphql-go v0.0.0-20201113091052-beb923fada29 h1:sezaKhEfPFg8W0Enm61B9Gs911H8iesGY5R8NDPtd1M=
 github.com/graph-gophers/graphql-go v0.0.0-20201113091052-beb923fada29/go.mod h1:9CQHMSxwO4MprSdzoIEobiHpoLtHm77vfxsvsIN5Vuc=
+github.com/hashicorp/go-bexpr v0.1.10 h1:9kuI5PFotCboP3dkDYFr/wi0gg0QVbSNz5oFRpxn4uE=
+github.com/hashicorp/go-bexpr v0.1.10/go.mod h1:oxlubA2vC/gFVfX1A6JGp7ls7uCDlfJn732ehYYg+g0=
 github.com/hashicorp/golang-lru v0.5.0/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
 github.com/hashicorp/golang-lru v0.5.1/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
 github.com/hashicorp/golang-lru v0.5.5-0.20210104140557-80c98217689d h1:dg1dEPuWpEqDnvIw251EVy4zlP8gWbsGj4BsUKCRpYs=
@@ -307,6 +309,10 @@ github.com/mattn/go-runewidth v0.0.9/go.mod h1:H031xJmbD/WCDINGzjvQ9THkh0rPKHF+m
 github.com/mattn/go-sqlite3 v1.11.0/go.mod h1:FPy6KqzDD04eiIsT53CuJW3U88zkxoIYsOqkbpncsNc=
 github.com/mattn/go-tty v0.0.0-20180907095812-13ff1204f104/go.mod h1:XPvLUNfbS4fJH25nqRHfWLMa1ONC8Amw+mIA639KxkE=
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
+github.com/mitchellh/mapstructure v1.4.1 h1:CpVNEelQCZBooIPDn+AR3NpivK/TIKU8bDxdASFVQag=
+github.com/mitchellh/mapstructure v1.4.1/go.mod h1:bFUtVrKA4DC2yAKiSyO/QUcy7e+RRV2QTWOzhPopBRo=
+github.com/mitchellh/pointerstructure v1.2.0 h1:O+i9nHnXS3l/9Wu7r4NrEdwA2VFTicjUEN1uBnDo34A=
+github.com/mitchellh/pointerstructure v1.2.0/go.mod h1:BRAsLI5zgXmw97Lf6s25bs8ohIXc3tViBH44KcwB2g4=
 github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
 github.com/modern-go/reflect2 v1.0.1/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
 github.com/mschoch/smat v0.0.0-20160514031455-90eadee771ae/go.mod h1:qAyveg+e4CE+eKJXWVjKXM4ck2QobLqTDytGJbLLhJg=
diff --git a/internal/debug/api.go b/internal/debug/api.go
index efd8626776..b1f815085c 100644
--- a/internal/debug/api.go
+++ b/internal/debug/api.go
@@ -27,6 +27,7 @@ import (
 	"os"
 	"os/user"
 	"path/filepath"
+	"regexp"
 	"runtime"
 	"runtime/debug"
 	"runtime/pprof"
@@ -35,6 +36,7 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/log"
+	"github.com/hashicorp/go-bexpr"
 )
 
 // Handler is the global debugging handler.
@@ -189,10 +191,44 @@ func (*HandlerT) WriteMemProfile(file string) error {
 	return writeProfile("heap", file)
 }
 
-// Stacks returns a printed representation of the stacks of all goroutines.
-func (*HandlerT) Stacks() string {
+// Stacks returns a printed representation of the stacks of all goroutines. It
+// also permits the following optional filters to be used:
+//   - filter: boolean expression of packages to filter for
+func (*HandlerT) Stacks(filter *string) string {
 	buf := new(bytes.Buffer)
 	pprof.Lookup("goroutine").WriteTo(buf, 2)
+
+	// If any filtering was requested, execute them now
+	if filter != nil && len(*filter) > 0 {
+		expanded := *filter
+
+		// The input filter is a logical expression of package names. Transform
+		// it into a proper boolean expression that can be fed into a parser and
+		// interpreter:
+		//
+		// E.g. (eth || snap) && !p2p -> (eth in Value || snap in Value) && p2p not in Value
+		expanded = regexp.MustCompile("[:/\\.A-Za-z0-9_-]+").ReplaceAllString(expanded, "`$0` in Value")
+		expanded = regexp.MustCompile("!(`[:/\\.A-Za-z0-9_-]+`)").ReplaceAllString(expanded, "$1 not")
+		expanded = strings.Replace(expanded, "||", "or", -1)
+		expanded = strings.Replace(expanded, "&&", "and", -1)
+		log.Info("Expanded filter expression", "filter", *filter, "expanded", expanded)
+
+		expr, err := bexpr.CreateEvaluator(expanded)
+		if err != nil {
+			log.Error("Failed to parse filter expression", "expanded", expanded, "err", err)
+			return ""
+		}
+		// Split the goroutine dump into segments and filter each
+		dump := buf.String()
+		buf.Reset()
+
+		for _, trace := range strings.Split(dump, "\n\n") {
+			if ok, _ := expr.Evaluate(map[string]string{"Value": trace}); ok {
+				buf.WriteString(trace)
+				buf.WriteString("\n\n")
+			}
+		}
+	}
 	return buf.String()
 }
 
diff --git a/internal/web3ext/web3ext.go b/internal/web3ext/web3ext.go
index 927dba1897..fe15cb0509 100644
--- a/internal/web3ext/web3ext.go
+++ b/internal/web3ext/web3ext.go
@@ -278,7 +278,8 @@ web3._extend({
 		new web3._extend.Method({
 			name: 'stacks',
 			call: 'debug_stacks',
-			params: 0,
+			params: 1,
+			inputFormatter: [null],
 			outputFormatter: console.log
 		}),
 		new web3._extend.Method({