internal, log: support debug log prints, displaying log origins

internal/debug/flags.go

@@ -30,12 +30,12 @@ import (
 var (
 	verbosityFlag = cli.IntFlag{
 		Name:  "verbosity",
-		Usage: "Logging verbosity: 0=silent, 1=error, 2=warn, 3=info, 4=core, 5=debug, 6=detail",
+		Usage: "Logging verbosity: 0=silent, 1=error, 2=warn, 3=info, 4=debug, 5=detail",
 		Value: 3,
 	}
 	vmoduleFlag = cli.StringFlag{
 		Name:  "vmodule",
-		Usage: "Per-module verbosity: comma-separated list of <pattern>=<level> (e.g. eth/*=6,p2p=5)",
+		Usage: "Per-module verbosity: comma-separated list of <pattern>=<level> (e.g. eth/*=5,p2p=4)",
 		Value: "",
 	}
 	backtraceAtFlag = cli.StringFlag{
@@ -43,6 +43,10 @@ var (
 		Usage: "Request a stack trace at a specific logging statement (e.g. \"block.go:271\")",
 		Value: "",
 	}
+	debugFlag = cli.BoolFlag{
+		Name:  "debug",
+		Usage: "Prepends log messages with call-site location (file and line number)",
+	}
 	pprofFlag = cli.BoolFlag{
 		Name:  "pprof",
 		Usage: "Enable the pprof HTTP server",
@@ -78,17 +82,21 @@ var (
 
 // Flags holds all command-line flags required for debugging.
 var Flags = []cli.Flag{
-	verbosityFlag, vmoduleFlag, backtraceAtFlag,
+	verbosityFlag, vmoduleFlag, backtraceAtFlag, debugFlag,
 	pprofFlag, pprofAddrFlag, pprofPortFlag,
 	memprofilerateFlag, blockprofilerateFlag, cpuprofileFlag, traceFlag,
 }
 
+// glogger is the glog handler used by Geth, allowing the debug APIs to modify
+// verbosity levels, vmodules and backtrace locations.
 var glogger = log.NewGlogHandler(log.StreamHandler(os.Stderr, log.TerminalFormat()))
 
 // Setup initializes profiling and logging based on the CLI flags.
 // It should be called as early as possible in the program.
 func Setup(ctx *cli.Context) error {
 	// logging
+	log.PrintOrigins(ctx.GlobalBool(debugFlag.Name))
+
 	glogger.Verbosity(log.Lvl(ctx.GlobalInt(verbosityFlag.Name)))
 	glogger.Vmodule(ctx.GlobalString(vmoduleFlag.Name))
 	glogger.BacktraceAt(ctx.GlobalString(backtraceAtFlag.Name))