cgen: fix defer stmts with if exprs and or blocks that return a value (#25651)

Author: StunxFS

vlib/v/gen/c/assign.v

@@ -34,18 +34,22 @@ fn (mut g Gen) expr_with_opt_or_block(expr ast.Expr, expr_typ ast.Type, var_expr
 			defer {
 				g.inside_or_block = false
 			}
-			stmts := (expr as ast.Ident).or_expr.stmts
+			or_expr := (expr as ast.Ident).or_expr
+			stmts := or_expr.stmts
+			scope := or_expr.scope
 			// handles stmt block which returns something
 			// e.g. { return none }
 			if stmts.len > 0 && stmts.last() is ast.ExprStmt && stmts.last().typ != ast.void_type {
-				g.gen_or_block_stmts(c_name(var_expr.str()), '', stmts, ret_typ, false)
+				g.gen_or_block_stmts(c_name(var_expr.str()), '', stmts, ret_typ, false,
+					scope, expr.pos())
 			} else {
 				// handles stmt block which doesn't returns value
 				// e.g. { return }
 				g.stmts(stmts)
 				if stmts.len > 0 && stmts.last() is ast.ExprStmt {
 					g.writeln(';')
 				}
+				g.write_defer_stmts(scope, false, expr.pos())
 			}
 		}
 		g.writeln('}')

vlib/v/gen/c/cgen.v

@@ -7237,7 +7237,7 @@ fn (mut g Gen) sort_structs(typesa []&ast.TypeSymbol) []&ast.TypeSymbol {
 }
 
 fn (mut g Gen) gen_or_block_stmts(cvar_name string, cast_typ string, stmts []ast.Stmt, return_type ast.Type,
-	is_option bool) {
+	is_option bool, scope &ast.Scope, pos token.Pos) {
 	g.indent++
 	for i, stmt in stmts {
 		if i == stmts.len - 1 {
@@ -7247,6 +7247,7 @@ fn (mut g Gen) gen_or_block_stmts(cvar_name string, cast_typ string, stmts []ast
 				|| expr_stmt.typ in [ast.none_type, ast.error_type]) {
 				// `return foo() or { error('failed') }`
 				if g.cur_fn != unsafe { nil } {
+					g.write_defer_stmts(scope, true, pos)
 					if g.cur_fn.return_type.has_flag(.result) {
 						g.write('return ')
 						g.gen_result_error(g.cur_fn.return_type, expr_stmt.expr)
@@ -7262,6 +7263,7 @@ fn (mut g Gen) gen_or_block_stmts(cvar_name string, cast_typ string, stmts []ast
 					g.write('${cvar_name} = ')
 					g.gen_option_error(return_type, expr_stmt.expr)
 					g.writeln(';')
+					g.write_defer_stmts(scope, false, pos)
 				} else if return_type == ast.rvoid_type {
 					// fn returns !, do not fill var.data
 					old_inside_opt_data := g.inside_opt_data
@@ -7318,6 +7320,7 @@ fn (mut g Gen) gen_or_block_stmts(cvar_name string, cast_typ string, stmts []ast
 						g.write(', sizeof(${cast_typ}))')
 					}
 					g.writeln(';')
+					g.write_defer_stmts(scope, return_wrapped, pos)
 					g.stmt_path_pos.delete_last()
 					if return_wrapped {
 						g.writeln('return ${cvar_name};')
@@ -7376,13 +7379,19 @@ fn (mut g Gen) or_block(var_name string, or_block ast.OrExpr, return_type ast.Ty
 		}
 		stmts := or_block.stmts
 		if stmts.len > 0 && stmts.last() is ast.ExprStmt && stmts.last().typ != ast.void_type {
-			g.gen_or_block_stmts(cvar_name, mr_styp, stmts, return_type, true)
+			g.gen_or_block_stmts(cvar_name, mr_styp, stmts, return_type, true, or_block.scope,
+				or_block.pos)
 		} else {
 			g.stmts(stmts)
-			if stmts.len > 0 && stmts.last() is ast.ExprStmt {
-				g.writeln(';')
+			if stmts.len > 0 {
+				stmt_last := stmts.last()
+				if stmt_last is ast.ExprStmt {
+					g.writeln(';')
+				}
+				if stmt_last !in [ast.Return, ast.BranchStmt] {
+					g.write_defer_stmts(or_block.scope, false, or_block.pos)
+				}
 			}
-			g.write_defer_stmts(or_block.scope, false, or_block.pos)
 		}
 		g.or_expr_return_type = ast.void_type
 	} else if or_block.kind == .propagate_result

vlib/v/gen/c/if.v

@@ -484,18 +484,19 @@ fn (mut g Gen) if_expr(node ast.IfExpr) {
 				g.expected_cast_type = node.typ
 			}
 			g.stmts_with_tmp_var(branch.stmts, tmp)
+			g.write_defer_stmts(branch.scope, false, node.pos)
 			g.expected_cast_type = prev_expected_cast_type
-			if !is_else && (branch.stmts.len > 0
-				&& branch.stmts[branch.stmts.len - 1] !in [ast.Return, ast.BranchStmt]) {
+			if !is_else
+				&& (branch.stmts.len > 0 && branch.stmts.last() !in [ast.Return, ast.BranchStmt]) {
 				g.writeln('\tgoto ${exit_label};')
 			}
 		} else {
 			// restore if_expr stmt header pos
 			stmt_pos := g.nth_stmt_pos(0)
 			g.stmts(branch.stmts)
+			g.write_defer_stmts(branch.scope, false, node.pos)
 			g.stmt_path_pos << stmt_pos
 		}
-		g.write_defer_stmts(branch.scope, false, node.pos)
 	}
 	if node.branches.len > 0 {
 		g.writeln('}')

vlib/v/tests/defer/defer_fixed_array_test.v

@@ -1,3 +1,5 @@
+// vtest vflags: -scoped-defer
+
 fn foo() {
 	a := [u8(1), 2, 3]!
 	defer {

vlib/v/tests/defer/defer_if_comptime_test.v

@@ -1,3 +1,5 @@
+// vtest vflags: -scoped-defer
+
 fn test_main() {
 	defer {
 		$if foo ? {

vlib/v/tests/defer/defer_return_test.v

@@ -1,3 +1,5 @@
+// vtest vflags: -scoped-defer
+
 @[heap]
 struct Hwe {
 mut:

vlib/v/tests/defer/defer_static_test.v

@@ -1,3 +1,5 @@
+// vtest vflags: -scoped-defer
+
 @[unsafe]
 fn g() {
 	mut static levels := 0

vlib/v/tests/defer/defer_test.v

@@ -1,3 +1,5 @@
+// vtest vflags: -scoped-defer
+
 fn foo() string {
 	println('foo()')
 	return 'foo'

vlib/v/tests/defer/defer_use_returned_value_test.v

@@ -1,3 +1,5 @@
+// vtest vflags: -scoped-defer
+
 struct Test {
 mut:
 	a int

vlib/v/tests/defer/defer_with_fn_var_test.v

@@ -1,3 +1,5 @@
+// vtest vflags: -scoped-defer
+
 @[has_globals]
 module main