if_chain! {
    if let Stmt_::StmtDecl(ref decl, _) = stmt.node
    if let Decl_::DeclLocal(ref local) = decl.node;
    if let Some(ref init) = local.init
    if let Expr_::ExprMatch(ref expr, ref arms, MatchSource::Normal) = init.node;
    if let Expr_::ExprLit(ref lit) = expr.node;
    if let LitKind::Int(42, _) = lit.node;
    if arms.len() == 3;
    if let Expr_::ExprLit(ref lit1) = arms[0].body.node;
    if let LitKind::Int(5, _) = lit1.node;
    if arms[0].pats.len() == 1;
    if let PatKind::Lit(ref lit_expr) = arms[0].pats[0].node
    if let Expr_::ExprLit(ref lit2) = lit_expr.node;
    if let LitKind::Int(16, _) = lit2.node;
    if let Expr_::ExprBlock(ref block) = arms[1].body.node;
    if let Stmt_::StmtDecl(ref decl1, _) = block.node
    if let Decl_::DeclLocal(ref local1) = decl1.node;
    if let Some(ref init1) = local1.init
    if let Expr_::ExprLit(ref lit3) = init1.node;
    if let LitKind::Int(3, _) = lit3.node;
    if let PatKind::Binding(BindingAnnotation::Unannotated, _, name, None) = local1.pat.node;
    if name.node.as_str() == "x";
    if let Expr_::ExprPath(ref path) = local1.pat.node;
    if match_qpath(path, &["x"]);
    if arms[1].pats.len() == 1;
    if let PatKind::Lit(ref lit_expr1) = arms[1].pats[0].node
    if let Expr_::ExprLit(ref lit4) = lit_expr1.node;
    if let LitKind::Int(17, _) = lit4.node;
    if let Expr_::ExprLit(ref lit5) = arms[2].body.node;
    if let LitKind::Int(1, _) = lit5.node;
    if arms[2].pats.len() == 1;
    if let PatKind::Wild = arms[2].pats[0].node;
    if let PatKind::Binding(BindingAnnotation::Unannotated, _, name1, None) = local.pat.node;
    if name1.node.as_str() == "a";
    then {
        // report your lint here
    }
}