pref: add -show-timings option

cmd/tools/vself.v

@@ -26,7 +26,7 @@ fn main() {
 		exit(1)
 	}
 	if result.output.len > 0 {
-		println(result.output)
+		println(result.output.trim_space())
 	}
 
 	v_file := if os.user_os() == 'windows' { 'v.exe' } else { 'v' }

cmd/v/help/build.txt

@@ -110,6 +110,16 @@ The build flags are shared by the build and run commands:
       to detect whether or not to use ANSI colors may not work in all cases.
       These options allow you to override the default detection.
 
+   -check-syntax
+      Only scan and parse the files, but then stop. Useful for very quick syntax checks.
+   
+   -show-timings
+      Print a summary about how long each compiler stage took, for example:
+         PARSE: 152ms
+         CHECK: 62ms
+         C GEN: 103ms
+         C tcc: 95ms
+      
 For C-specific build flags, use `v help build-c`.
 
 See also:

vlib/v/builder/builder.v

@@ -303,3 +303,11 @@ fn (b &Builder) print_warnings_and_errors() {
 fn verror(s string) {
 	util.verror('builder error', s)
 }
+
+pub fn (mut b Builder) timing_message(msg string) {
+	if b.pref.show_timings {
+		println(msg)
+	} else {
+		b.info(msg)
+	}
+}

vlib/v/builder/c.v

@@ -12,7 +12,7 @@ pub fn (mut b Builder) gen_c(v_files []string) string {
 	b.parse_imports()
 	t1 := time.ticks()
 	parse_time := t1 - t0
-	b.info('PARSE: ${parse_time}ms')
+	b.timing_message('PARSE: ${parse_time}ms')
 	if b.pref.only_check_syntax {
 		return ''
 	}
@@ -21,14 +21,14 @@ pub fn (mut b Builder) gen_c(v_files []string) string {
 	b.checker.check_files(b.parsed_files)
 	t2 := time.ticks()
 	check_time := t2 - t1
-	b.info('CHECK: ${check_time}ms')
+	b.timing_message('CHECK: ${check_time}ms')
 	b.print_warnings_and_errors()
 	// println('starting cgen...')
 	// TODO: move gen.cgen() to c.gen()
 	res := gen.cgen(b.parsed_files, b.table, b.pref)
 	t3 := time.ticks()
 	gen_time := t3 - t2
-	b.info('C GEN: ${gen_time}ms')
+	b.timing_message('C GEN: ${gen_time}ms')
 	// println('cgen done')
 	// println(res)
 	return res

vlib/v/builder/cc.v

@@ -478,6 +478,7 @@ fn (mut v Builder) cc() {
 		println('$ccompiler took $diff ms')
 		println('=========\n')
 	}
+    v.timing_message('C ${ccompiler:3}: ${diff}ms')
 	// Link it if we are cross compiling and need an executable
 	/*
 	if v.os == .linux && !linux_host && v.pref.build_mode != .build {

vlib/v/builder/js.v

@@ -13,16 +13,16 @@ pub fn (mut b Builder) gen_js(v_files []string) string {
 	b.parse_imports()
 	t1 := time.ticks()
 	parse_time := t1 - t0
-	b.info('PARSE: ${parse_time}ms')
+	b.timing_message('PARSE: ${parse_time}ms')
 	b.checker.check_files(b.parsed_files)
 	t2 := time.ticks()
 	check_time := t2 - t1
-	b.info('CHECK: ${check_time}ms')
+	b.timing_message('CHECK: ${check_time}ms')
 	b.print_warnings_and_errors()
 	res := js.gen(b.parsed_files, b.table, b.pref)
 	t3 := time.ticks()
 	gen_time := t3 - t2
-	b.info('JS GEN: ${gen_time}ms')
+	b.timing_message('JS GEN: ${gen_time}ms')
 	return res
 }
 

vlib/v/builder/x64.v

@@ -16,15 +16,16 @@ pub fn (mut b Builder) build_x64(v_files []string, out_file string) {
 	b.parse_imports()
 	t1 := time.ticks()
 	parse_time := t1 - t0
-	b.info('PARSE: ${parse_time}ms')
+	b.timing_message('PARSE: ${parse_time}ms')
+    
 	b.checker.check_files(b.parsed_files)
 	t2 := time.ticks()
 	check_time := t2 - t1
-	b.info('CHECK: ${check_time}ms')
+	b.timing_message('CHECK: ${check_time}ms')
 	x64.gen(b.parsed_files, out_file, b.pref)
 	t3 := time.ticks()
 	gen_time := t3 - t2
-	b.info('x64 GEN: ${gen_time}ms')
+	b.timing_message('x64 GEN: ${gen_time}ms')
 }
 
 pub fn (mut b Builder) compile_x64() {

vlib/v/pref/pref.v

@@ -117,6 +117,7 @@ pub mut:
 	is_vweb             bool // skip _ var warning in templates
 	only_check_syntax   bool // when true, just parse the files, then stop, before running checker
 	experimental        bool // enable experimental features
+	show_timings        bool // show how much time each compiler stage took
 }
 
 pub fn parse_args(args []string) (&Preferences, string) {
@@ -128,6 +129,9 @@ pub fn parse_args(args []string) (&Preferences, string) {
 		arg := args[i]
 		current_args := args[i..]
 		match arg {
+			'-show-timings' {
+				res.show_timings = true
+			}
 			'-check-syntax' {
 				res.only_check_syntax = true
 			}