all: improve -skip-unused, track consts, walk all AST nodes, support tests

vlib/builtin/float.v

@@ -26,7 +26,7 @@ pub fn (d float_literal) str() string {
 	return f64(d).str()
 }
 
-// strsci returns the `f64` as a `string` in scientific notation with `digit_num` deciamals displayed, max 17 digits.
+// strsci returns the `f64` as a `string` in scientific notation with `digit_num` decimals displayed, max 17 digits.
 // Example: assert f64(1.234).strsci(3) == '1.234e+00'
 [inline]
 pub fn (x f64) strsci(digit_num int) string {

vlib/v/checker/mark_used.v

@@ -8,46 +8,47 @@ import v.checker.mark_used_walker
 // mark_used walks the AST, starting at main() and marks all used fns transitively
 fn (mut c Checker) mark_used(ast_files []ast.File) {
 	util.timing_start(@METHOD)
-	mut walker := mark_used_walker.Walker{
-		files: ast_files
-	}
-
-	mut allfns := map[string]ast.FnDecl{}
+	util.timing_start('all_fn_and_const')
+	mut all_fns := map[string]ast.FnDecl{}
+	mut all_consts := map[string]ast.ConstField{}
 	for i in 0 .. ast_files.len {
 		file := unsafe { &ast_files[i] }
 		for node in file.stmts {
-			if node is ast.FnDecl {
-				fkey := if node.is_method {
-					'${int(node.receiver.typ)}.$node.name'
-				} else {
-					node.name
+			match node {
+				ast.FnDecl {
+					fkey := if node.is_method {
+						'${int(node.receiver.typ)}.$node.name'
+					} else {
+						node.name
+					}
+					all_fns[fkey] = node
 				}
-				allfns[fkey] = node
+				ast.ConstDecl {
+					for cfield in node.fields {
+						ckey := cfield.name
+						all_consts[ckey] = cfield
+					}
+				}
+				else {}
 			}
 		}
 	}
-	all_fn_root_names := [
+	util.timing_measure('all_fn_and_const')
+
+	mut all_fn_root_names := [
 		'main.main',
 		'__new_array',
 		'__new_array_with_default',
 		'new_array_from_c_array',
-		'panic',
 		'memdup',
 		'vstrlen',
-		'tos2',
 		'tos',
+		'tos2',
+		'tos3',
 		'isnil',
-		'utf8_char_len',
+		/* utf8_str_visible_length is used by c/str.v */
 		'utf8_str_visible_length',
 		'builtin_init',
-		'print_backtrace_skipping_top_frames',
-		'print_backtrace_skipping_top_frames_mac',
-		'print_backtrace_skipping_top_frames_linux',
-		'print_backtrace_skipping_top_frames_freebsd',
-		'print_backtrace_skipping_top_frames_windows',
-		'print_backtrace_skipping_top_frames_mingw',
-		'print_backtrace_skipping_top_frames_msvc',
-		'print_backtrace_skipping_top_frames_tcc',
 		/* byteptr and charptr */
 		'3.vstring',
 		'3.vstring_with_len',
@@ -55,8 +56,6 @@ fn (mut c Checker) mark_used(ast_files []ast.File) {
 		'4.vstring_with_len',
 		/* string. methods */
 		'18.add',
-		'18.all_after',
-		'18.all_before',
 		'18.trim_space',
 		'18.replace',
 		'18.clone',
@@ -81,9 +80,13 @@ fn (mut c Checker) mark_used(ast_files []ast.File) {
 		'19.add',
 		/* other array methods */
 		'21.get',
+		'21.set',
 		'21.get_unsafe',
+		'21.set_unsafe',
+		'21.slice',
+		'21.slice2',
 		'59.get',
-		'65557.free',
+		'59.set',
 		'65557.push',
 		'65557.set',
 		'65557.set_unsafe',
@@ -91,28 +94,75 @@ fn (mut c Checker) mark_used(ast_files []ast.File) {
 		'os.getwd',
 		'os.init_os_args',
 	]
-	// println( allfns.keys() )
-	for fn_name in all_fn_root_names {
-		walker.fn_decl(mut allfns[fn_name])
+
+	// implicit string builders are generated in auto_eq_methods.v
+	mut sb_mut_type := ''
+	if sbfn := c.table.find_fn('strings.new_builder') {
+		sb_mut_type = sbfn.return_type.set_nr_muls(1).str() + '.'
 	}
 
-	$if trace_skip_unused ? {
+	for k, _ in all_fns {
+		if k.ends_with('.init') {
+			all_fn_root_names << k
+		}
+		if k.ends_with('.free') {
+			all_fn_root_names << k
+		}
+		if c.pref.is_test && (k.starts_with('test_') || k.contains('.test_')) {
+			all_fn_root_names << k
+		}
+		if sb_mut_type != '' && k.starts_with(sb_mut_type) {
+			all_fn_root_names << k
+		}
+	}
+	if c.pref.is_debug {
+		all_fn_root_names << 'panic_debug'
+	}
+	if c.pref.is_test {
+		all_fn_root_names << 'main.cb_assertion_ok'
+		all_fn_root_names << 'main.cb_assertion_failed'
+		if benched_tests_sym := c.table.find_type('main.BenchedTests') {
+			bts_type := benched_tests_sym.methods[0].params[0].typ
+			all_fn_root_names << '${bts_type}.testing_step_start'
+			all_fn_root_names << '${bts_type}.testing_step_end'
+			all_fn_root_names << '${bts_type}.end_testing'
+			all_fn_root_names << 'main.start_testing'
+		}
+	}
+
+	mut walker := mark_used_walker.Walker{
+		files: ast_files
+		all_fns: all_fns
+		all_consts: all_consts
+	}
+	// println( all_fns.keys() )
+	walker.mark_root_fns(all_fn_root_names)
+
+	if walker.n_asserts > 0 {
+		walker.fn_decl(mut all_fns['__print_assert_failure'])
+	}
+	if walker.n_maps > 0 {
+		for k, mut mfn in all_fns {
+			if k == 'new_map_2' || k.starts_with('map_') || k.ends_with('set_1')
+				|| k.ends_with('exists_1')|| k.ends_with('get_1') {
+				walker.fn_decl(mut mfn)
+			}
+		}
+	}
+
+	$if trace_skip_unused_fn_names ? {
 		for key, _ in walker.used_fns {
 			println('> used fn key: $key')
 		}
 	}
 
 	c.table.used_fns = walker.used_fns
-	//
-	c.table.used_fns['term.can_show_color_on_stdin'] = true
-	c.table.used_fns['term.can_show_color_on_stdout'] = true
-	c.table.used_fns['term.can_show_color_on_stderr'] = true
-	//
-	c.table.used_fns['main.can_use_relative_paths'] = true
-	//
-	// eprintln('>>> c.table.used_fns: $c.table.used_fns')
-	util.timing_measure(@METHOD)
+	c.table.used_consts = walker.used_consts
 
-	// println(walker.used_fns)
-	// c.walk(ast_files)
+	$if trace_skip_unused ? {
+		eprintln('>> c.table.used_fns: $c.table.used_fns.keys()')
+		eprintln('>> c.table.used_consts: $c.table.used_consts.keys()')
+		eprintln('>> walker.n_maps: $walker.n_maps')
+	}
+	util.timing_measure(@METHOD)
 }

vlib/v/checker/mark_used_walker/walker.v

@@ -8,25 +8,61 @@ import v.ast
 
 pub struct Walker {
 pub mut:
-	used_fns map[string]bool // used_fns['println'] == true
+	used_fns    map[string]bool // used_fns['println'] == true
+	used_consts map[string]bool // used_consts['os.args'] == true
+	n_maps      int
+	n_asserts   int
 mut:
-	files []ast.File
+	files      []ast.File
+	all_fns    map[string]ast.FnDecl
+	all_consts map[string]ast.ConstField
 }
 
-/*
-fn (mut w Walker) walk_files(ast_files []ast.File) {
-		t := time.ticks()
-*/
+pub fn (mut w Walker) mark_fn_as_used(fkey string) {
+	$if trace_skip_unused_marked ? {
+		eprintln('    fn > |$fkey|')
+	}
+	w.used_fns[fkey] = true
+}
+
+pub fn (mut w Walker) mark_const_as_used(ckey string) {
+	$if trace_skip_unused_marked ? {
+		eprintln('    const > |$ckey|')
+	}
+	w.used_consts[ckey] = true
+	cfield := w.all_consts[ckey] or { return }
+	w.expr(cfield.expr)
+}
+
+pub fn (mut w Walker) mark_root_fns(all_fn_root_names []string) {
+	for fn_name in all_fn_root_names {
+		if fn_name !in w.used_fns {
+			$if trace_skip_unused_roots ? {
+				println('>>>> $fn_name uses: ')
+			}
+			w.fn_decl(mut w.all_fns[fn_name])
+		}
+	}
+}
 
 pub fn (mut w Walker) stmt(node ast.Stmt) {
 	match mut node {
+		ast.AssertStmt {
+			w.expr(node.expr)
+			w.n_asserts++
+		}
 		ast.AssignStmt {
-			for l in node.left {
-				w.expr(l)
-			}
-			for r in node.right {
-				w.expr(r)
-			}
+			w.exprs(node.left)
+			w.exprs(node.right)
+		}
+		ast.Block {
+			w.stmts(node.stmts)
+		}
+		ast.CompFor {
+			w.stmts(node.stmts)
+		}
+		ast.ConstDecl {
+			w.const_fields(node.fields)
 		}
 		ast.ExprStmt {
 			w.expr(node.expr)
@@ -34,92 +70,295 @@ pub fn (mut w Walker) stmt(node ast.Stmt) {
 		ast.FnDecl {
 			w.fn_decl(mut node)
 		}
+		ast.ForCStmt {
+			w.expr(node.cond)
+			w.stmt(node.inc)
+			w.stmts(node.stmts)
+		}
+		ast.ForInStmt {
+			w.expr(node.cond)
+			w.expr(node.high)
+			w.stmts(node.stmts)
+		}
 		ast.ForStmt {
 			w.expr(node.cond)
-			for stmt in node.stmts {
-				w.stmt(stmt)
+			w.stmts(node.stmts)
+		}
+		ast.GoStmt {
+			w.expr(node.call_expr)
+		}
+		ast.Return {
+			w.exprs(node.exprs)
+		}
+		ast.SqlStmt {
+			w.expr(node.db_expr)
+			w.expr(node.where_expr)
+			w.exprs(node.update_exprs)
+		}
+		ast.StructDecl {
+			w.struct_fields(node.fields)
+		}
+		ast.DeferStmt {
+			w.stmts(node.stmts)
+		}
+		ast.GlobalDecl {
+			for gf in node.fields {
+				if gf.has_expr {
+					w.expr(gf.expr)
+				}
 			}
 		}
-		else {}
+		ast.BranchStmt {}
+		ast.EnumDecl {}
+		ast.GotoLabel {}
+		ast.GotoStmt {}
+		ast.HashStmt {}
+		ast.Import {}
+		ast.InterfaceDecl {}
+		ast.Module {}
+		ast.TypeDecl {}
+	}
+}
+
+fn (mut w Walker) defer_stmts(stmts []ast.DeferStmt) {
+	for stmt in stmts {
+		w.stmts(stmt.stmts)
+	}
+}
+
+fn (mut w Walker) stmts(stmts []ast.Stmt) {
+	for stmt in stmts {
+		w.stmt(stmt)
+	}
+}
+
+fn (mut w Walker) exprs(exprs []ast.Expr) {
+	for expr in exprs {
+		w.expr(expr)
 	}
 }
 
 fn (mut w Walker) expr(node ast.Expr) {
 	match mut node {
+		ast.AnonFn {
+			w.fn_decl(mut node.decl)
+		}
+		ast.Assoc {
+			w.exprs(node.exprs)
+		}
+		ast.ArrayInit {
+			w.expr(node.len_expr)
+			w.expr(node.cap_expr)
+			w.expr(node.default_expr)
+			w.exprs(node.exprs)
+		}
+		ast.ArrayDecompose {
+			w.expr(node.expr)
+		}
 		ast.CallExpr {
 			w.call_expr(mut node)
 		}
+		ast.CastExpr {
+			w.expr(node.expr)
+			w.expr(node.arg)
+		}
+		ast.ChanInit {
+			w.expr(node.cap_expr)
+		}
+		ast.ConcatExpr {
+			w.exprs(node.vals)
+		}
+		ast.ComptimeSelector {
+			w.expr(node.left)
+			w.expr(node.field_expr)
+		}
+		ast.ComptimeCall {
+			w.expr(node.left)
+			if node.is_vweb {
+				w.stmts(node.vweb_tmpl.stmts)
+			}
+		}
 		ast.GoExpr {
 			w.expr(node.go_stmt.call_expr)
 		}
 		ast.IndexExpr {
 			w.expr(node.left)
 			w.expr(node.index)
+			w.or_block(node.or_expr)
+		}
+		ast.InfixExpr {
+			w.expr(node.left)
+			w.expr(node.right)
+			w.or_block(node.or_block)
+		}
+		ast.IfGuardExpr {
+			w.expr(node.expr)
 		}
 		ast.IfExpr {
+			w.expr(node.left)
 			for b in node.branches {
 				w.expr(b.cond)
-				for stmt in b.stmts {
-					w.stmt(stmt)
-				}
+				w.stmts(b.stmts)
 			}
 		}
+		ast.Ident {
+			if node.kind == .constant {
+				w.mark_const_as_used(node.name)
+			}
+		}
+		ast.Likely {
+			w.expr(node.expr)
+		}
+		ast.MapInit {
+			w.exprs(node.keys)
+			w.exprs(node.vals)
+			w.n_maps++
+		}
 		ast.MatchExpr {
 			w.expr(node.cond)
 			for b in node.branches {
-				for expr in b.exprs {
-					w.expr(expr)
-				}
-				for stmt in b.stmts {
-					w.stmt(stmt)
-				}
+				w.exprs(b.exprs)
+				w.stmts(b.stmts)
 			}
 		}
-		else {}
+		ast.None {
+			w.mark_fn_as_used('opt_none')
+		}
+		ast.ParExpr {
+			w.expr(node.expr)
+		}
+		ast.PrefixExpr {
+			w.expr(node.right)
+		}
+		ast.PostfixExpr {
+			w.expr(node.expr)
+		}
+		ast.RangeExpr {
+			if node.has_low {
+				w.expr(node.low)
+			}
+			if node.has_high {
+				w.expr(node.high)
+			}
+		}
+		ast.SizeOf {
+			w.expr(node.expr)
+		}
+		ast.StringInterLiteral {
+			w.exprs(node.exprs)
+		}
+		ast.SelectorExpr {
+			w.expr(node.expr)
+		}
+		ast.SqlExpr {
+			w.expr(node.db_expr)
+			w.expr(node.offset_expr)
+			w.expr(node.order_expr)
+			w.expr(node.limit_expr)
+			w.expr(node.where_expr)
+		}
+		ast.StructInit {
+			// eprintln('>>>> ast.StructInit: $node')
+			w.expr(node.update_expr)
+			for sif in node.fields {
+				w.expr(sif.expr)
+			}
+			for sie in node.embeds {
+				w.expr(sie.expr)
+			}
+		}
+		ast.TypeOf {
+			w.expr(node.expr)
+		}
+		///
+		ast.AsCast {
+			w.expr(node.expr)
+		}
+		ast.AtExpr {}
+		ast.BoolLiteral {}
+		ast.FloatLiteral {}
+		ast.CharLiteral {}
+		ast.IntegerLiteral {}
+		ast.StringLiteral {}
+		ast.CTempVar {
+			w.expr(node.orig)
+		}
+		ast.Comment {}
+		ast.EnumVal {}
+		ast.LockExpr {
+			w.stmts(node.stmts)
+		}
+		ast.OffsetOf {}
+		ast.OrExpr {
+			w.or_block(node)
+		}
+		ast.SelectExpr {
+			for branch in node.branches {
+				w.stmt(branch.stmt)
+				w.stmts(branch.stmts)
+			}
+		}
+		ast.Type {}
+		ast.UnsafeExpr {
+			w.expr(node.expr)
+		}
 	}
 }
 
 pub fn (mut w Walker) fn_decl(mut node ast.FnDecl) {
+	if node.language == .c {
+		return
+	}
 	fkey := if node.is_method { '${int(node.receiver.typ)}.$node.name' } else { node.name }
 	if w.used_fns[fkey] {
 		// This function is already known to be called, meaning it has been processed already.
 		// Save CPU time and do nothing.
 		return
 	}
-	if node.language == .c {
-		return
-	}
-	w.used_fns[fkey] = true
-	for stmt in node.stmts {
-		w.stmt(stmt)
-	}
+	w.mark_fn_as_used(fkey)
+	w.stmts(node.stmts)
+	w.defer_stmts(node.defer_stmts)
 }
 
 pub fn (mut w Walker) call_expr(mut node ast.CallExpr) {
+	if node.language == .c {
+		return
+	}
+	w.expr(node.left)
+	for arg in node.args {
+		w.expr(arg.expr)
+	}
+	w.or_block(node.or_block)
+	//
 	fn_name := if node.is_method { node.receiver_type.str() + '.' + node.name } else { node.name }
-	// fn_name := node.name
-	// println('call_expr $fn_name')
-	// if node.is_method {
-	// println('M $node.name $node.receiver_type')
-	//}
 	if w.used_fns[fn_name] {
 		return
 	}
-	// w.used_fns[fn_name] = true
-	// Find the FnDecl for this CallExpr, mark the function as used, and process
-	// all its statements.
-	loop: for file in w.files {
-		for stmt in file.stmts {
-			if stmt is ast.FnDecl {
-				if stmt.name == node.name
-					&& (!node.is_method || (node.receiver_type == stmt.receiver.typ)) {
-					w.used_fns[fn_name] = true
-					for fn_stmt in stmt.stmts {
-						w.stmt(fn_stmt)
-					}
-					break loop
-				}
-			}
+	stmt := w.all_fns[fn_name] or { return }
+	if stmt.name == node.name {
+		if !node.is_method || (node.receiver_type == stmt.receiver.typ) {
+			w.mark_fn_as_used(fn_name)
+			w.stmts(stmt.stmts)
 		}
 	}
 }
+
+pub fn (mut w Walker) struct_fields(sfields []ast.StructField) {
+	for sf in sfields {
+		if sf.has_default_expr {
+			w.expr(sf.default_expr)
+		}
+	}
+}
+
+pub fn (mut w Walker) const_fields(cfields []ast.ConstField) {
+	for cf in cfields {
+		w.expr(cf.expr)
+	}
+}
+
+pub fn (mut w Walker) or_block(node ast.OrExpr) {
+	if node.kind == .block {
+		w.stmts(node.stmts)
+	}
+}

vlib/v/gen/c/cgen.v

@@ -4725,6 +4725,15 @@ fn (mut g Gen) const_decl(node ast.ConstDecl) {
 		g.inside_const = false
 	}
 	for field in node.fields {
+		if g.pref.skip_unused {
+			if field.name !in g.table.used_consts {
+				$if trace_skip_unused_consts ? {
+					eprintln('>> skipping unused const name: $field.name')
+				}
+				continue
+			}
+		}
+
 		name := c_name(field.name)
 		// TODO hack. Cut the generated value and paste it into definitions.
 		pos := g.out.len

vlib/v/gen/c/fn.v

@@ -30,7 +30,7 @@ fn (mut g Gen) gen_fn_decl(node ast.FnDecl, skip bool) {
 	if g.pref.skip_unused {
 		fkey := if node.is_method { '${int(node.receiver.typ)}.$node.name' } else { node.name }
 		is_used_by_main := g.table.used_fns[fkey]
-		$if trace_skip_unused ? {
+		$if trace_skip_unused_fns ? {
 			println('> is_used_by_main: $is_used_by_main | node.name: $node.name | fkey: $fkey | node.is_method: $node.is_method')
 		}
 		if !is_used_by_main {

vlib/v/table/table.v

@@ -20,6 +20,7 @@ pub mut:
 	cmod_prefix   string // needed for table.type_to_str(Type) while vfmt; contains `os.`
 	is_fmt        bool
 	used_fns      map[string]bool // filled in by the checker, when pref.skip_unused = true;
+	used_consts   map[string]bool // filled in by the checker, when pref.skip_unused = true;
 }
 
 pub struct Fn {

vlib/v/tests/skip_unused/assert_passes_test.vv

@@ -0,0 +1,3 @@
+fn test_abc() {
+	assert 'abc' == 'abc'
+}

vlib/v/tests/skip_unused/assert_works_test.run.out

@@ -0,0 +1,5 @@
+vlib/v/tests/skip_unused/assert_works_test.vv:2: fn test_abc
+   > assert 'abc' == 'xyz'
+     Left value: abc
+    Right value: xyz
+

vlib/v/tests/skip_unused/assert_works_test.skip_unused.run.out

@@ -0,0 +1,5 @@
+vlib/v/tests/skip_unused/assert_works_test.vv:2: fn test_abc
+   > assert 'abc' == 'xyz'
+     Left value: abc
+    Right value: xyz
+

vlib/v/tests/skip_unused/assert_works_test.vv

@@ -0,0 +1,3 @@
+fn test_abc() {
+	assert 'abc' == 'xyz'
+}