vweb: check function and route parameter count (#6761)

vlib/net/http/backend_windows.c.v

@@ -8,7 +8,7 @@ module http
 #include "vschannel.c"
 fn C.new_tls_context() C.TlsContext
 
-fn (req &Request) ssl_do(port int, method Method, host_name, path string) ?Response {
+fn (req &Request) ssl_do(port int, method Method, host_name string, path string) ?Response {
 	mut ctx := C.new_tls_context()
 	C.vschannel_init(&ctx)
 	mut buff := malloc(C.vsc_init_resp_buff_size)

vlib/net/http/download_windows.c.v

@@ -8,7 +8,7 @@ module http
 
 #include <urlmon.h>
 
-fn download_file_with_progress(url, out string, cb, cb_finished voidptr) {
+fn download_file_with_progress(url string, out string, cb voidptr, cb_finished voidptr) {
 }
 
 /*

vlib/v/ast/ast.v

@@ -260,6 +260,7 @@ pub:
 	receiver      Field
 	receiver_pos  token.Position
 	is_method     bool
+	method_idx    int
 	rec_mut       bool // is receiver mutable
 	rec_share     table.ShareType
 	language      table.Language
@@ -275,6 +276,7 @@ pub mut:
 	stmts         []Stmt
 	return_type   table.Type
 	comments      []Comment // comments *after* the header, but *before* `{`; used for InterfaceDecl
+	source_file   &File = 0
 }
 
 // break, continue

vlib/v/checker/checker.v

@@ -31,7 +31,7 @@ pub struct Checker {
 	pref              &pref.Preferences // Preferences shared from V struct
 pub mut:
 	table             &table.Table
-	file              ast.File
+	file              &ast.File = 0
 	nr_errors         int
 	nr_warnings       int
 	errors            []errors.Error
@@ -61,6 +61,7 @@ mut:
 	error_details     []string
 	generic_funcs     []&ast.FnDecl
 	vmod_file_content string // needed for @VMOD_FILE, contents of the file, *NOT its path*
+	vweb_gen_types    []table.Type // vweb route checks
 }
 
 pub fn new_checker(table &table.Table, pref &pref.Preferences) Checker {
@@ -71,7 +72,7 @@ pub fn new_checker(table &table.Table, pref &pref.Preferences) Checker {
 	}
 }
 
-pub fn (mut c Checker) check(ast_file ast.File) {
+pub fn (mut c Checker) check(ast_file &ast.File) {
 	c.file = ast_file
 	for i, ast_import in ast_file.imports {
 		for j in 0 .. i {
@@ -112,7 +113,7 @@ pub fn (mut c Checker) check_scope_vars(sc &ast.Scope) {
 }
 
 // not used right now
-pub fn (mut c Checker) check2(ast_file ast.File) []errors.Error {
+pub fn (mut c Checker) check2(ast_file &ast.File) []errors.Error {
 	c.file = ast_file
 	for stmt in ast_file.stmts {
 		c.stmt(stmt)
@@ -147,6 +148,7 @@ pub fn (mut c Checker) check_files(ast_files []ast.File) {
 			has_main_fn = true
 		}
 	}
+	c.verify_all_vweb_routes()
 	// Make sure fn main is defined in non lib builds
 	if c.pref.build_mode == .build_module || c.pref.is_test {
 		return
@@ -4207,17 +4209,17 @@ fn (mut c Checker) post_process_generic_fns() {
 	// Loop thru each generic function concrete type.
 	// Check each specific fn instantiation.
 	for i in 0 .. c.generic_funcs.len {
-		mut node := c.generic_funcs[i]
 		if c.table.fn_gen_types.len == 0 {
 			// no concrete types, so just skip:
 			continue
 		}
-		// eprintln('>> post_process_generic_fns $c.file.path | $node.name , c.table.fn_gen_types.len: $c.table.fn_gen_types.len')
+		mut node := c.generic_funcs[i]
 		for gen_type in c.table.fn_gen_types[node.name] {
 			c.cur_generic_type = gen_type
-			// sym:=c.table.get_type_symbol(gen_type)
-			// println('\ncalling check for $node.name for type $sym.source_name')
 			c.fn_decl(mut node)
+			if node.name in ['vweb.run_app', 'vweb.run'] {
+				c.vweb_gen_types << gen_type
+			}
 		}
 		c.cur_generic_type = 0
 		c.generic_funcs[i] = 0
@@ -4266,6 +4268,8 @@ fn (mut c Checker) fn_decl(mut node ast.FnDecl) {
 			c.error('cannot define new methods on non-local `$sym.source_name` (' +
 				'current module is `$c.mod`, `$sym.source_name` is from `$sym.mod`)', node.pos)
 		}
+		// needed for proper error reporting during vweb route checking
+		sym.methods[node.method_idx].source_fn = voidptr(node)
 	}
 	if node.language == .v {
 		// Make sure all types are valid
@@ -4322,6 +4326,7 @@ fn (mut c Checker) fn_decl(mut node ast.FnDecl) {
 		c.error('missing return at end of function `$node.name`', node.pos)
 	}
 	c.returns = false
+	node.source_file = c.file
 }
 
 fn has_top_return(stmts []ast.Stmt) bool {
@@ -4342,3 +4347,45 @@ fn has_top_return(stmts []ast.Stmt) bool {
 	}
 	return false
 }
+
+fn (mut c Checker) verify_vweb_params_for_method(m table.Fn) (bool, int, int) {
+	margs := m.params.len - 1 // first arg is the receiver/this
+	if m.attrs.len == 0 {
+		// allow non custom routed methods, with 1:1 mapping
+		return true, -1, margs
+	}
+	mut route_attributes := 0
+	for a in m.attrs {
+		if a.name.starts_with('/') {
+			route_attributes += a.name.count(':')
+		}
+	}
+	return route_attributes == margs, route_attributes, margs
+}
+
+fn (mut c Checker) verify_all_vweb_routes() {
+	if c.vweb_gen_types.len == 0 {
+		return
+	}
+	typ_vweb_result := c.table.find_type_idx('vweb.Result')
+	for vgt in c.vweb_gen_types {
+		sym_app := c.table.get_type_symbol(vgt)
+		for m in sym_app.methods {
+			if m.return_type_source_name == 'vweb.Result' {
+				is_ok, nroute_attributes, nargs := c.verify_vweb_params_for_method(m)
+				if !is_ok {
+					f := &ast.FnDecl(m.source_fn)
+					if isnil(f) {
+						continue
+					}
+					if f.return_type == typ_vweb_result &&
+						f.receiver.typ == m.params[0].typ && f.name == m.name {
+						c.file = f.source_file // setup of file path for the warning
+						c.warn('mismatched parameters count between vweb method `${sym_app.name}.$m.name` ($nargs) and route attribute $m.attrs ($nroute_attributes)',
+							f.pos)
+					}
+				}
+			}
+		}
+	}
+}

vlib/v/checker/tests/vweb_routing_checks.out

@@ -0,0 +1,14 @@
+vlib/v/checker/tests/vweb_routing_checks.vv:22:1: error: mismatched parameters count between vweb method `App.bar` (1) and route attribute ['/bar'] (0)
+   20 | // segfault because path taks 0 vars and fcn takes 1 arg
+   21 | ['/bar']
+   22 | pub fn (mut app App) bar(a string) vweb.Result {
+      | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+   23 |     app.vweb.html('works')
+   24 |     return vweb.Result{}
+vlib/v/checker/tests/vweb_routing_checks.vv:29:1: error: mismatched parameters count between vweb method `App.cow` (0) and route attribute ['/cow/:low'] (1)
+   27 | // no segfault, but it shouldnt compile
+   28 | ['/cow/:low']
+   29 | pub fn (mut app App) cow() vweb.Result {
+      | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+   30 |     app.vweb.html('works')
+   31 |     return vweb.Result{}

vlib/v/checker/tests/vweb_routing_checks.vv

@@ -0,0 +1,50 @@
+import vweb
+
+struct App {
+	pub mut:
+	vweb vweb.Context
+}
+
+pub fn (mut app App) no_attributes(a string) vweb.Result {
+	return vweb.Result{}
+}
+
+// works fine, as long as fcn gets 1 arg and route takes 1 var
+['/foo/:bar']
+pub fn (mut app App) foo(a string) vweb.Result {
+	eprintln('foo')
+	app.vweb.html('works')
+	return vweb.Result{}
+}
+
+// segfault because path taks 0 vars and fcn takes 1 arg
+['/bar']
+pub fn (mut app App) bar(a string) vweb.Result {
+	app.vweb.html('works')
+	return vweb.Result{}
+}
+
+// no segfault, but it shouldnt compile
+['/cow/:low']
+pub fn (mut app App) cow() vweb.Result {
+	app.vweb.html('works')
+	return vweb.Result{}
+}
+
+pub fn (app App) init_once() {
+	//
+}
+
+pub fn (app App) init() {
+	//
+}
+
+pub fn (mut app App) index() {
+	app.vweb.html('hello')
+}
+
+fn main() {
+	port := 8181
+	mut app := App{}
+	vweb.run_app<App>(mut app, port)
+}

vlib/v/parser/fn.v

@@ -258,15 +258,15 @@ fn (mut p Parser) fn_decl() ast.FnDecl {
 	mut return_type := table.void_type
 	if p.tok.kind.is_start_of_type() ||
 		(p.tok.kind == .key_fn && p.tok.line_nr == p.prev_tok.line_nr) {
-		end_pos = p.tok.position()
 		return_type = p.parse_type()
 	}
+	mut type_sym_method_idx := 0
 	// Register
 	if is_method {
 		mut type_sym := p.table.get_type_symbol(rec_type)
 		ret_type_sym := p.table.get_type_symbol(return_type)
 		// p.warn('reg method $type_sym.name . $name ()')
-		type_sym.register_method(table.Fn{
+		type_sym_method_idx = type_sym.register_method(table.Fn{
 			name: name
 			params: params
 			return_type: return_type
@@ -307,6 +307,7 @@ fn (mut p Parser) fn_decl() ast.FnDecl {
 			language: language
 		})
 	}
+	end_pos = p.prev_tok.position()
 	// Body
 	p.cur_fn_name = name
 	mut stmts := []ast.Stmt{}
@@ -336,6 +337,7 @@ fn (mut p Parser) fn_decl() ast.FnDecl {
 		}
 		receiver_pos: receiver_pos
 		is_method: is_method
+		method_idx: type_sym_method_idx
 		rec_mut: rec_mut
 		language: language
 		no_body: no_body

vlib/v/table/table.v

@@ -38,6 +38,7 @@ pub:
 	attrs                   []Attr
 pub mut:
 	name                    string
+	source_fn               voidptr // set in the checker, while processing fn declarations
 }
 
 fn (f &Fn) method_equals(o &Fn) bool {
@@ -162,9 +163,12 @@ pub fn (mut t Table) register_fn(new_fn Fn) {
 	t.fns[new_fn.name] = new_fn
 }
 
-pub fn (mut t TypeSymbol) register_method(new_fn Fn) {
+pub fn (mut t TypeSymbol) register_method(new_fn Fn) int {
+	// returns a method index, stored in the ast.FnDecl
+	// for faster lookup in the checker's fn_decl method
 	// println('reg me $new_fn.name nr_args=$new_fn.args.len')
 	t.methods << new_fn
+	return t.methods.len - 1
 }
 
 pub fn (t &Table) register_aggregate_method(mut sym TypeSymbol, name string) ?Fn {

vlib/vweb/vweb.v

@@ -485,7 +485,11 @@ fn handle_conn<T>(conn net.Socket, mut app T) {
 			// search again for method
 			if action == method.name && method.attrs.len > 0 {
 				// call action method
+				if method.args.len == vars.len {
 					app.$method(vars)
+				} else {
+					eprintln('warning: uneven parameters count (${method.args.len}) in `$method.name`, compared to the vweb route `$method.attrs` (${vars.len})')
+				}
 			}
 		}
 	}