add pprof rule for profiling VictoriaLogs

Author: vadimalekseev

Makefile

@@ -270,8 +270,30 @@ release-vlutils-windows-goarch: \
 		vlagent-windows-$(GOARCH)-prod.exe \
 		vlogscli-windows-$(GOARCH)-prod.exe
 
-pprof-cpu:
-	go tool pprof -trim_path=github.com/VictoriaMetrics/VictoriaLogs $(PPROF_FILE)
+# Define the list of paths where pprof can find the source code.
+# Start with the current working directory.
+SOURCE_PATH := $(shell pwd)
+
+# Add path to the Go standard library source code.
+SOURCE_PATH := $(SOURCE_PATH):$(shell go env GOROOT)/src
+
+# Add the directory that contains project dependencies.
+SOURCE_PATH := $(SOURCE_PATH):$(shell go env GOMODCACHE)
+
+# Special case: file names with uppercase letters in the GOMODCACHE directory are escaped.
+# For example, a module named 'github.com/VictoriaMetrics/VictoriaMetrics' will be placed at the following path:
+# $GOMODCACHE/github.com/!victoria!metrics/!victoria!metrics
+# Since pprof does not perform this escaping when searching for the source code,
+# we need to completely remove this prefix and set the SOURCE_PATH to the root of the VictoriaMetrics source code.
+# TRIM_PATH must be synced with go.mod
+# See: https://pkg.go.dev/golang.org/x/mod/module#hdr-Escaped_Paths
+SOURCE_PATH := $(SOURCE_PATH):$(shell pwd)/vendor/github.com/VictoriaMetrics/VictoriaMetrics
+TRIM_PATH := github.com/VictoriaMetrics/[email protected]
+
+PPROF_FILE ?= cpu.pprof
+
+pprof:
+	go tool pprof -trim_path $(TRIM_PATH) -source_path $(SOURCE_PATH) $(PPROF_FILE)
 
 fmt:
 	gofmt -l -w -s ./lib