checker: do not allow copying any map lvalue (#8662)

cmd/tools/repeat.v

@@ -256,7 +256,7 @@ fn (mut context Context) run() {
 				summary[k] = s
 			}
 			// merge current raw results to the previous ones
-			old_oms := context.results[icmd].oms
+			old_oms := context.results[icmd].oms.move()
 			mut new_oms := map[string][]int{}
 			for k, v in m {
 				if old_oms[k].len == 0 {
@@ -266,7 +266,7 @@ fn (mut context Context) run() {
 					new_oms[k] << v
 				}
 			}
-			context.results[icmd].oms = new_oms
+			context.results[icmd].oms = new_oms.move()
 			// println('')
 		}
 	}
@@ -276,7 +276,7 @@ fn (mut context Context) run() {
 		for k, v in context.results[icmd].oms {
 			new_full_summary[k] = new_aints(v, context.nmins, context.nmaxs)
 		}
-		context.results[icmd].summary = new_full_summary
+		context.results[icmd].summary = new_full_summary.move()
 	}
 }
 

cmd/tools/vdoctor.v

@@ -35,13 +35,12 @@ fn (mut a App) collect_info() {
 		})
 	}
 	if os_kind == 'linux' {
-		info := a.cpu_info()
 		mut cpu_details := ''
 		if cpu_details == '' {
-			cpu_details = info['model name']
+			cpu_details = a.cpu_info('model name')
 		}
 		if cpu_details == '' {
-			cpu_details = info['hardware']
+			cpu_details = a.cpu_info('hardware')
 		}
 		if cpu_details == '' {
 			cpu_details = os.uname().machine
@@ -61,8 +60,7 @@ fn (mut a App) collect_info() {
 	})
 	if os_kind == 'linux' {
 		os_details = a.get_linux_os_name()
-		info := a.cpu_info()
+		if 'hypervisor' in a.cpu_info('flags') {
-		if 'hypervisor' in info['flags'] {
 			if 'microsoft' in wsl_check {
 				// WSL 2 is a Managed VM and Full Linux Kernel
 				// See https://docs.microsoft.com/en-us/windows/wsl/compare-versions
@@ -233,16 +231,15 @@ fn (mut a App) get_linux_os_name() string {
 	return os_details
 }
 
-fn (mut a App) cpu_info() map[string]string {
+fn (mut a App) cpu_info(key string) string {
 	if a.cached_cpuinfo.len > 0 {
-		return a.cached_cpuinfo
+		return a.cached_cpuinfo[key]
 	}
 	info := os.exec('cat /proc/cpuinfo') or {
-		return a.cached_cpuinfo
+		return a.cached_cpuinfo[key]
 	}
-	vals := a.parse(info.output, ':')
+	a.cached_cpuinfo = a.parse(info.output, ':')
-	a.cached_cpuinfo = vals
+	return a.cached_cpuinfo[key]
-	return vals
 }
 
 fn (mut a App) git_info() string {

vlib/net/http/http.v

@@ -163,8 +163,8 @@ fn fetch_with_method(method Method, url string, _config FetchConfig) ?Response {
 
 fn build_url_from_fetch(_url string, config FetchConfig) ?string {
 	mut url := urllib.parse(_url) ?
-	params := config.params
+	params := unsafe {config.params}
-	if params.keys().len == 0 {
+	if params.len == 0 {
 		return url.str()
 	}
 	mut pieces := []string{}

vlib/v/checker/checker.v

@@ -2717,8 +2717,8 @@ pub fn (mut c Checker) assign_stmt(mut assign_stmt ast.AssignStmt) {
 				assign_stmt.pos)
 		}
 		if left_sym.kind == .map && !c.inside_unsafe && assign_stmt.op in [.assign, .decl_assign]
-			&& right_sym.kind == .map && (left is ast.Ident && !left.is_blank_ident())
+			&& right_sym.kind == .map && !right_type.is_ptr() && !left.is_blank_ident()
-			&& right is ast.Ident {
+			&& right.is_lvalue() {
 			// Do not allow `a = b`
 			c.error('cannot copy map: call `move` or `clone` method first (or use `unsafe`)',
 				right.position())
@@ -5596,7 +5596,7 @@ fn (mut c Checker) sql_expr(mut node ast.SqlExpr) table.Type {
 		sub_structs[int(f.typ)] = n
 	}
 	node.fields = fields
-	node.sub_structs = sub_structs
+	node.sub_structs = sub_structs.move()
 	if node.has_where {
 		c.expr(node.where_expr)
 	}
@@ -5648,7 +5648,7 @@ fn (mut c Checker) sql_stmt(mut node ast.SqlStmt) table.Type {
 		sub_structs[int(f.typ)] = n
 	}
 	node.fields = fields
-	node.sub_structs = sub_structs
+	node.sub_structs = sub_structs.move()
 	c.expr(node.db_expr)
 	if node.kind == .update {
 		for expr in node.update_exprs {

vlib/v/gen/js/js.v

@@ -115,7 +115,7 @@ pub fn gen(files []ast.File, table &table.Table, pref &pref.Preferences) string
 			out += '/** @namespace $name */\n'
 		}
 		out += 'const $name = (function ('
-		imports := g.namespaces[node.name].imports
+		imports := unsafe {g.namespaces[node.name].imports}
 		for i, key in imports.keys() {
 			if i > 0 {
 				out += ', '

vlib/v/markused/markused.v

@@ -178,8 +178,8 @@ pub fn mark_used(mut the_table table.Table, pref &pref.Preferences, ast_files []
 		}
 	}
 
-	the_table.used_fns = walker.used_fns
+	the_table.used_fns = walker.used_fns.move()
-	the_table.used_consts = walker.used_consts
+	the_table.used_consts = walker.used_consts.move()
 
 	$if trace_skip_unused ? {
 		eprintln('>> the_table.used_fns: $the_table.used_fns.keys()')