checker, cgen: fix if/match expr with continue or break in a branch (#18466)

vlib/v/checker/if.v

@@ -414,7 +414,7 @@ fn (mut c Checker) if_expr(mut node ast.IfExpr) ast.Type {
 								node.pos)
 						}
 					}
-				} else if !node.is_comptime && stmt !is ast.Return {
+				} else if !node.is_comptime && stmt !in [ast.Return, ast.BranchStmt] {
 					c.error('`${if_kind}` expression requires an expression as the last statement of every branch',
 						branch.pos)
 				}

vlib/v/checker/match.v

@@ -90,7 +90,7 @@ fn (mut c Checker) match_expr(mut node ast.MatchExpr) ast.Type {
 						c.check_match_branch_last_stmt(stmt, ret_type, expr_type)
 					}
 				}
-			} else if stmt !is ast.Return {
+			} else if stmt !in [ast.Return, ast.BranchStmt] {
 				if node.is_expr && ret_type != ast.void_type {
 					c.error('`match` expression requires an expression as the last statement of every branch',
 						stmt.pos)

vlib/v/gen/c/cgen.v

@@ -1802,7 +1802,7 @@ fn (mut g Gen) stmts_with_tmp_var(stmts []ast.Stmt, tmp_var string) bool {
 				g.set_current_pos_as_last_stmt_pos()
 				g.skip_stmt_pos = true
 				mut is_noreturn := false
-				if stmt is ast.Return {
+				if stmt in [ast.Return, ast.BranchStmt] {
 					is_noreturn = true
 				} else if stmt is ast.ExprStmt {
 					is_noreturn = is_noreturn_callexpr(stmt.expr)

vlib/v/gen/c/if.v

@@ -25,6 +25,8 @@ fn (mut g Gen) need_tmp_var_in_if(node ast.IfExpr) bool {
 					}
 				} else if branch.stmts[0] is ast.Return {
 					return true
+				} else if branch.stmts[0] is ast.BranchStmt {
+					return true
 				}
 			}
 		}

vlib/v/gen/c/match.v

@@ -29,6 +29,8 @@ fn (mut g Gen) need_tmp_var_in_match(node ast.MatchExpr) bool {
 					}
 				} else if branch.stmts[0] is ast.Return {
 					return true
+				} else if branch.stmts[0] is ast.BranchStmt {
+					return true
 				}
 			}
 		}

vlib/v/tests/if_expr_with_continue_in_branch_test.v

@@ -0,0 +1,17 @@
+fn test_if_expr_with_continue_in_branch() {
+	mut result := []int{}
+	for i in 0 .. 10 {
+		s := if i < 2 {
+			100 + i
+		} else {
+			continue
+		}
+
+		println(s)
+		result << s
+	}
+	println(result)
+	assert result.len == 2
+	assert result[0] == 100
+	assert result[1] == 101
+}