rust/src/libsyntax/ext/expand.rs
Steve Klabnik 7828c3dd28 Rename fail! to panic!
https://github.com/rust-lang/rfcs/pull/221

The current terminology of "task failure" often causes problems when
writing or speaking about code. You often want to talk about the
possibility of an operation that returns a Result "failing", but cannot
because of the ambiguity with task failure. Instead, you have to speak
of "the failing case" or "when the operation does not succeed" or other
circumlocutions.

Likewise, we use a "Failure" header in rustdoc to describe when
operations may fail the task, but it would often be helpful to separate
out a section describing the "Err-producing" case.

We have been steadily moving away from task failure and toward Result as
an error-handling mechanism, so we should optimize our terminology
accordingly: Result-producing functions should be easy to describe.

To update your code, rename any call to `fail!` to `panic!` instead.
Assuming you have not created your own macro named `panic!`, this
will work on UNIX based systems:

    grep -lZR 'fail!' . | xargs -0 -l sed -i -e 's/fail!/panic!/g'

You can of course also do this by hand.

[breaking-change]
2014-10-29 11:43:07 -04:00

1767 lines
68 KiB
Rust

// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use ast::{Block, Crate, DeclLocal, ExprMac, PatMac};
use ast::{Local, Ident, MacInvocTT};
use ast::{ItemMac, Mrk, Stmt, StmtDecl, StmtMac, StmtExpr, StmtSemi};
use ast::TokenTree;
use ast;
use ext::mtwt;
use ext::build::AstBuilder;
use attr;
use attr::AttrMetaMethods;
use codemap;
use codemap::{Span, Spanned, ExpnInfo, NameAndSpan, MacroBang, MacroAttribute};
use ext::base::*;
use fold;
use fold::*;
use parse;
use parse::token::{fresh_mark, fresh_name, intern};
use parse::token;
use ptr::P;
use util::small_vector::SmallVector;
use visit;
use visit::Visitor;
enum Either<L,R> {
Left(L),
Right(R)
}
pub fn expand_expr(e: P<ast::Expr>, fld: &mut MacroExpander) -> P<ast::Expr> {
e.and_then(|ast::Expr {id, node, span}| match node {
// expr_mac should really be expr_ext or something; it's the
// entry-point for all syntax extensions.
ast::ExprMac(mac) => {
let expanded_expr = match expand_mac_invoc(mac, span,
|r| r.make_expr(),
mark_expr, fld) {
Some(expr) => expr,
None => {
return DummyResult::raw_expr(span);
}
};
// Keep going, outside-in.
//
let fully_expanded = fld.fold_expr(expanded_expr);
fld.cx.bt_pop();
fully_expanded.map(|e| ast::Expr {
id: ast::DUMMY_NODE_ID,
node: e.node,
span: span,
})
}
ast::ExprWhile(cond, body, opt_ident) => {
let cond = fld.fold_expr(cond);
let (body, opt_ident) = expand_loop_block(body, opt_ident, fld);
fld.cx.expr(span, ast::ExprWhile(cond, body, opt_ident))
}
// Desugar ExprWhileLet
// From: `[opt_ident]: while let <pat> = <expr> <body>`
ast::ExprWhileLet(pat, expr, body, opt_ident) => {
// to:
//
// [opt_ident]: loop {
// match <expr> {
// <pat> => <body>,
// _ => break
// }
// }
// `<pat> => <body>`
let pat_arm = {
let body_expr = fld.cx.expr_block(body);
fld.cx.arm(pat.span, vec![pat], body_expr)
};
// `_ => break`
let break_arm = {
let pat_under = fld.cx.pat_wild(span);
let break_expr = fld.cx.expr_break(span);
fld.cx.arm(span, vec![pat_under], break_expr)
};
// `match <expr> { ... }`
let arms = vec![pat_arm, break_arm];
let match_expr = fld.cx.expr(span,
ast::ExprMatch(expr, arms, ast::MatchWhileLetDesugar));
// `[opt_ident]: loop { ... }`
let loop_block = fld.cx.block_expr(match_expr);
let (loop_block, opt_ident) = expand_loop_block(loop_block, opt_ident, fld);
fld.cx.expr(span, ast::ExprLoop(loop_block, opt_ident))
}
// Desugar ExprIfLet
// From: `if let <pat> = <expr> <body> [<elseopt>]`
ast::ExprIfLet(pat, expr, body, mut elseopt) => {
// to:
//
// match <expr> {
// <pat> => <body>,
// [_ if <elseopt_if_cond> => <elseopt_if_body>,]
// _ => [<elseopt> | ()]
// }
// `<pat> => <body>`
let pat_arm = {
let body_expr = fld.cx.expr_block(body);
fld.cx.arm(pat.span, vec![pat], body_expr)
};
// `[_ if <elseopt_if_cond> => <elseopt_if_body>,]`
let else_if_arms = {
let mut arms = vec![];
loop {
let elseopt_continue = elseopt
.and_then(|els| els.and_then(|els| match els.node {
// else if
ast::ExprIf(cond, then, elseopt) => {
let pat_under = fld.cx.pat_wild(span);
arms.push(ast::Arm {
attrs: vec![],
pats: vec![pat_under],
guard: Some(cond),
body: fld.cx.expr_block(then)
});
elseopt.map(|elseopt| (elseopt, true))
}
_ => Some((P(els), false))
}));
match elseopt_continue {
Some((e, true)) => {
elseopt = Some(e);
}
Some((e, false)) => {
elseopt = Some(e);
break;
}
None => {
elseopt = None;
break;
}
}
}
arms
};
// `_ => [<elseopt> | ()]`
let else_arm = {
let pat_under = fld.cx.pat_wild(span);
let else_expr = elseopt.unwrap_or_else(|| fld.cx.expr_lit(span, ast::LitNil));
fld.cx.arm(span, vec![pat_under], else_expr)
};
let mut arms = Vec::with_capacity(else_if_arms.len() + 2);
arms.push(pat_arm);
arms.extend(else_if_arms.into_iter());
arms.push(else_arm);
let match_expr = fld.cx.expr(span, ast::ExprMatch(expr, arms, ast::MatchIfLetDesugar));
fld.fold_expr(match_expr)
}
// Desugar support for ExprIfLet in the ExprIf else position
ast::ExprIf(cond, blk, elseopt) => {
let elseopt = elseopt.map(|els| els.and_then(|els| match els.node {
ast::ExprIfLet(..) => {
// wrap the if-let expr in a block
let span = els.span;
let blk = P(ast::Block {
view_items: vec![],
stmts: vec![],
expr: Some(P(els)),
id: ast::DUMMY_NODE_ID,
rules: ast::DefaultBlock,
span: span
});
fld.cx.expr_block(blk)
}
_ => P(els)
}));
let if_expr = fld.cx.expr(span, ast::ExprIf(cond, blk, elseopt));
if_expr.map(|e| noop_fold_expr(e, fld))
}
ast::ExprLoop(loop_block, opt_ident) => {
let (loop_block, opt_ident) = expand_loop_block(loop_block, opt_ident, fld);
fld.cx.expr(span, ast::ExprLoop(loop_block, opt_ident))
}
ast::ExprForLoop(pat, head, body, opt_ident) => {
let pat = fld.fold_pat(pat);
let head = fld.fold_expr(head);
let (body, opt_ident) = expand_loop_block(body, opt_ident, fld);
fld.cx.expr(span, ast::ExprForLoop(pat, head, body, opt_ident))
}
ast::ExprFnBlock(capture_clause, fn_decl, block) => {
let (rewritten_fn_decl, rewritten_block)
= expand_and_rename_fn_decl_and_block(fn_decl, block, fld);
let new_node = ast::ExprFnBlock(capture_clause,
rewritten_fn_decl,
rewritten_block);
P(ast::Expr{id:id, node: new_node, span: fld.new_span(span)})
}
ast::ExprProc(fn_decl, block) => {
let (rewritten_fn_decl, rewritten_block)
= expand_and_rename_fn_decl_and_block(fn_decl, block, fld);
let new_node = ast::ExprProc(rewritten_fn_decl, rewritten_block);
P(ast::Expr{id:id, node: new_node, span: fld.new_span(span)})
}
_ => {
P(noop_fold_expr(ast::Expr {
id: id,
node: node,
span: span
}, fld))
}
})
}
/// Expand a (not-ident-style) macro invocation. Returns the result
/// of expansion and the mark which must be applied to the result.
/// Our current interface doesn't allow us to apply the mark to the
/// result until after calling make_expr, make_items, etc.
fn expand_mac_invoc<T>(mac: ast::Mac, span: codemap::Span,
parse_thunk: |Box<MacResult>|->Option<T>,
mark_thunk: |T,Mrk|->T,
fld: &mut MacroExpander)
-> Option<T>
{
match mac.node {
// it would almost certainly be cleaner to pass the whole
// macro invocation in, rather than pulling it apart and
// marking the tts and the ctxt separately. This also goes
// for the other three macro invocation chunks of code
// in this file.
// Token-tree macros:
MacInvocTT(pth, tts, _) => {
if pth.segments.len() > 1u {
fld.cx.span_err(pth.span,
"expected macro name without module \
separators");
// let compilation continue
return None;
}
let extname = pth.segments[0].identifier;
let extnamestr = token::get_ident(extname);
match fld.cx.syntax_env.find(&extname.name) {
None => {
fld.cx.span_err(
pth.span,
format!("macro undefined: '{}!'",
extnamestr.get()).as_slice());
// let compilation continue
None
}
Some(rc) => match *rc {
NormalTT(ref expandfun, exp_span) => {
fld.cx.bt_push(ExpnInfo {
call_site: span,
callee: NameAndSpan {
name: extnamestr.get().to_string(),
format: MacroBang,
span: exp_span,
},
});
let fm = fresh_mark();
let marked_before = mark_tts(tts.as_slice(), fm);
// The span that we pass to the expanders we want to
// be the root of the call stack. That's the most
// relevant span and it's the actual invocation of
// the macro.
let mac_span = fld.cx.original_span();
let opt_parsed = {
let expanded = expandfun.expand(fld.cx,
mac_span,
marked_before.as_slice());
parse_thunk(expanded)
};
let parsed = match opt_parsed {
Some(e) => e,
None => {
fld.cx.span_err(
pth.span,
format!("non-expression macro in expression position: {}",
extnamestr.get().as_slice()
).as_slice());
return None;
}
};
Some(mark_thunk(parsed,fm))
}
_ => {
fld.cx.span_err(
pth.span,
format!("'{}' is not a tt-style macro",
extnamestr.get()).as_slice());
None
}
}
}
}
}
}
/// Rename loop label and expand its loop body
///
/// The renaming procedure for loop is different in the sense that the loop
/// body is in a block enclosed by loop head so the renaming of loop label
/// must be propagated to the enclosed context.
fn expand_loop_block(loop_block: P<Block>,
opt_ident: Option<Ident>,
fld: &mut MacroExpander) -> (P<Block>, Option<Ident>) {
match opt_ident {
Some(label) => {
let new_label = fresh_name(&label);
let rename = (label, new_label);
// The rename *must not* be added to the pending list of current
// syntax context otherwise an unrelated `break` or `continue` in
// the same context will pick that up in the deferred renaming pass
// and be renamed incorrectly.
let mut rename_list = vec!(rename);
let mut rename_fld = IdentRenamer{renames: &mut rename_list};
let renamed_ident = rename_fld.fold_ident(label);
// The rename *must* be added to the enclosed syntax context for
// `break` or `continue` to pick up because by definition they are
// in a block enclosed by loop head.
fld.cx.syntax_env.push_frame();
fld.cx.syntax_env.info().pending_renames.push(rename);
let expanded_block = expand_block_elts(loop_block, fld);
fld.cx.syntax_env.pop_frame();
(expanded_block, Some(renamed_ident))
}
None => (fld.fold_block(loop_block), opt_ident)
}
}
// eval $e with a new exts frame.
// must be a macro so that $e isn't evaluated too early.
macro_rules! with_exts_frame (
($extsboxexpr:expr,$macros_escape:expr,$e:expr) =>
({$extsboxexpr.push_frame();
$extsboxexpr.info().macros_escape = $macros_escape;
let result = $e;
$extsboxexpr.pop_frame();
result
})
)
// When we enter a module, record it, for the sake of `module!`
pub fn expand_item(it: P<ast::Item>, fld: &mut MacroExpander)
-> SmallVector<P<ast::Item>> {
let it = expand_item_modifiers(it, fld);
let mut decorator_items = SmallVector::zero();
let mut new_attrs = Vec::new();
for attr in it.attrs.iter() {
let mname = attr.name();
match fld.cx.syntax_env.find(&intern(mname.get())) {
Some(rc) => match *rc {
Decorator(ref dec) => {
attr::mark_used(attr);
fld.cx.bt_push(ExpnInfo {
call_site: attr.span,
callee: NameAndSpan {
name: mname.get().to_string(),
format: MacroAttribute,
span: None
}
});
// we'd ideally decorator_items.push_all(expand_item(item, fld)),
// but that double-mut-borrows fld
let mut items: SmallVector<P<ast::Item>> = SmallVector::zero();
dec.expand(fld.cx, attr.span, &*attr.node.value, &*it,
|item| items.push(item));
decorator_items.extend(items.into_iter()
.flat_map(|item| expand_item(item, fld).into_iter()));
fld.cx.bt_pop();
}
_ => new_attrs.push((*attr).clone()),
},
_ => new_attrs.push((*attr).clone()),
}
}
let mut new_items = match it.node {
ast::ItemMac(..) => expand_item_mac(it, fld),
ast::ItemMod(_) | ast::ItemForeignMod(_) => {
fld.cx.mod_push(it.ident);
let macro_escape = contains_macro_escape(new_attrs.as_slice());
let result = with_exts_frame!(fld.cx.syntax_env,
macro_escape,
noop_fold_item(it, fld));
fld.cx.mod_pop();
result
},
_ => {
let it = P(ast::Item {
attrs: new_attrs,
..(*it).clone()
});
noop_fold_item(it, fld)
}
};
new_items.push_all(decorator_items);
new_items
}
fn expand_item_modifiers(mut it: P<ast::Item>, fld: &mut MacroExpander)
-> P<ast::Item> {
// partition the attributes into ItemModifiers and others
let (modifiers, other_attrs) = it.attrs.partitioned(|attr| {
match fld.cx.syntax_env.find(&intern(attr.name().get())) {
Some(rc) => match *rc { Modifier(_) => true, _ => false },
_ => false
}
});
// update the attrs, leave everything else alone. Is this mutation really a good idea?
it = P(ast::Item {
attrs: other_attrs,
..(*it).clone()
});
if modifiers.is_empty() {
return it;
}
for attr in modifiers.iter() {
let mname = attr.name();
match fld.cx.syntax_env.find(&intern(mname.get())) {
Some(rc) => match *rc {
Modifier(ref mac) => {
attr::mark_used(attr);
fld.cx.bt_push(ExpnInfo {
call_site: attr.span,
callee: NameAndSpan {
name: mname.get().to_string(),
format: MacroAttribute,
span: None,
}
});
it = mac.expand(fld.cx, attr.span, &*attr.node.value, it);
fld.cx.bt_pop();
}
_ => unreachable!()
},
_ => unreachable!()
}
}
// expansion may have added new ItemModifiers
expand_item_modifiers(it, fld)
}
/// Expand item_underscore
fn expand_item_underscore(item: ast::Item_, fld: &mut MacroExpander) -> ast::Item_ {
match item {
ast::ItemFn(decl, fn_style, abi, generics, body) => {
let (rewritten_fn_decl, rewritten_body)
= expand_and_rename_fn_decl_and_block(decl, body, fld);
let expanded_generics = fold::noop_fold_generics(generics,fld);
ast::ItemFn(rewritten_fn_decl, fn_style, abi, expanded_generics, rewritten_body)
}
_ => noop_fold_item_underscore(item, fld)
}
}
// does this attribute list contain "macro_escape" ?
fn contains_macro_escape(attrs: &[ast::Attribute]) -> bool {
attr::contains_name(attrs, "macro_escape")
}
// Support for item-position macro invocations, exactly the same
// logic as for expression-position macro invocations.
pub fn expand_item_mac(it: P<ast::Item>, fld: &mut MacroExpander)
-> SmallVector<P<ast::Item>> {
let (extname, path_span, tts) = match it.node {
ItemMac(codemap::Spanned {
node: MacInvocTT(ref pth, ref tts, _),
..
}) => {
(pth.segments[0].identifier, pth.span, (*tts).clone())
}
_ => fld.cx.span_bug(it.span, "invalid item macro invocation")
};
let extnamestr = token::get_ident(extname);
let fm = fresh_mark();
let def_or_items = {
let mut expanded = match fld.cx.syntax_env.find(&extname.name) {
None => {
fld.cx.span_err(path_span,
format!("macro undefined: '{}!'",
extnamestr).as_slice());
// let compilation continue
return SmallVector::zero();
}
Some(rc) => match *rc {
NormalTT(ref expander, span) => {
if it.ident.name != parse::token::special_idents::invalid.name {
fld.cx
.span_err(path_span,
format!("macro {}! expects no ident argument, \
given '{}'",
extnamestr,
token::get_ident(it.ident)).as_slice());
return SmallVector::zero();
}
fld.cx.bt_push(ExpnInfo {
call_site: it.span,
callee: NameAndSpan {
name: extnamestr.get().to_string(),
format: MacroBang,
span: span
}
});
// mark before expansion:
let marked_before = mark_tts(tts.as_slice(), fm);
expander.expand(fld.cx, it.span, marked_before.as_slice())
}
IdentTT(ref expander, span) => {
if it.ident.name == parse::token::special_idents::invalid.name {
fld.cx.span_err(path_span,
format!("macro {}! expects an ident argument",
extnamestr.get()).as_slice());
return SmallVector::zero();
}
fld.cx.bt_push(ExpnInfo {
call_site: it.span,
callee: NameAndSpan {
name: extnamestr.get().to_string(),
format: MacroBang,
span: span
}
});
// mark before expansion:
let marked_tts = mark_tts(tts.as_slice(), fm);
expander.expand(fld.cx, it.span, it.ident, marked_tts)
}
LetSyntaxTT(ref expander, span) => {
if it.ident.name == parse::token::special_idents::invalid.name {
fld.cx.span_err(path_span,
format!("macro {}! expects an ident argument",
extnamestr.get()).as_slice());
return SmallVector::zero();
}
fld.cx.bt_push(ExpnInfo {
call_site: it.span,
callee: NameAndSpan {
name: extnamestr.get().to_string(),
format: MacroBang,
span: span
}
});
// DON'T mark before expansion:
expander.expand(fld.cx, it.span, it.ident, tts)
}
_ => {
fld.cx.span_err(it.span,
format!("{}! is not legal in item position",
extnamestr.get()).as_slice());
return SmallVector::zero();
}
}
};
match expanded.make_def() {
Some(def) => Left(def),
None => Right(expanded.make_items())
}
};
let items = match def_or_items {
Left(MacroDef { name, ext }) => {
// hidden invariant: this should only be possible as the
// result of expanding a LetSyntaxTT, and thus doesn't
// need to be marked. Not that it could be marked anyway.
// create issue to recommend refactoring here?
fld.cx.syntax_env.insert(intern(name.as_slice()), ext);
if attr::contains_name(it.attrs.as_slice(), "macro_export") {
fld.cx.exported_macros.push(it);
}
SmallVector::zero()
}
Right(Some(items)) => {
items.into_iter()
.map(|i| mark_item(i, fm))
.flat_map(|i| fld.fold_item(i).into_iter())
.collect()
}
Right(None) => {
fld.cx.span_err(path_span,
format!("non-item macro in item position: {}",
extnamestr.get()).as_slice());
return SmallVector::zero();
}
};
fld.cx.bt_pop();
items
}
/// Expand a stmt
//
// I don't understand why this returns a vector... it looks like we're
// half done adding machinery to allow macros to expand into multiple statements.
fn expand_stmt(s: Stmt, fld: &mut MacroExpander) -> SmallVector<P<Stmt>> {
let (mac, semi) = match s.node {
StmtMac(mac, semi) => (mac, semi),
_ => return expand_non_macro_stmt(s, fld)
};
let expanded_stmt = match expand_mac_invoc(mac, s.span,
|r| r.make_stmt(),
mark_stmt, fld) {
Some(stmt) => stmt,
None => {
return SmallVector::zero();
}
};
// Keep going, outside-in.
let fully_expanded = fld.fold_stmt(expanded_stmt);
fld.cx.bt_pop();
if semi {
fully_expanded.into_iter().map(|s| s.map(|Spanned {node, span}| {
Spanned {
node: match node {
StmtExpr(e, stmt_id) => StmtSemi(e, stmt_id),
_ => node /* might already have a semi */
},
span: span
}
})).collect()
} else {
fully_expanded
}
}
// expand a non-macro stmt. this is essentially the fallthrough for
// expand_stmt, above.
fn expand_non_macro_stmt(Spanned {node, span: stmt_span}: Stmt, fld: &mut MacroExpander)
-> SmallVector<P<Stmt>> {
// is it a let?
match node {
StmtDecl(decl, node_id) => decl.and_then(|Spanned {node: decl, span}| match decl {
DeclLocal(local) => {
// take it apart:
let rewritten_local = local.map(|Local {id, pat, ty, init, source, span}| {
// expand the ty since TyFixedLengthVec contains an Expr
// and thus may have a macro use
let expanded_ty = fld.fold_ty(ty);
// expand the pat (it might contain macro uses):
let expanded_pat = fld.fold_pat(pat);
// find the PatIdents in the pattern:
// oh dear heaven... this is going to include the enum
// names, as well... but that should be okay, as long as
// the new names are gensyms for the old ones.
// generate fresh names, push them to a new pending list
let idents = pattern_bindings(&*expanded_pat);
let mut new_pending_renames =
idents.iter().map(|ident| (*ident, fresh_name(ident))).collect();
// rewrite the pattern using the new names (the old
// ones have already been applied):
let rewritten_pat = {
// nested binding to allow borrow to expire:
let mut rename_fld = IdentRenamer{renames: &mut new_pending_renames};
rename_fld.fold_pat(expanded_pat)
};
// add them to the existing pending renames:
fld.cx.syntax_env.info().pending_renames
.extend(new_pending_renames.into_iter());
Local {
id: id,
ty: expanded_ty,
pat: rewritten_pat,
// also, don't forget to expand the init:
init: init.map(|e| fld.fold_expr(e)),
source: source,
span: span
}
});
SmallVector::one(P(Spanned {
node: StmtDecl(P(Spanned {
node: DeclLocal(rewritten_local),
span: span
}),
node_id),
span: stmt_span
}))
}
_ => {
noop_fold_stmt(Spanned {
node: StmtDecl(P(Spanned {
node: decl,
span: span
}),
node_id),
span: stmt_span
}, fld)
}
}),
_ => {
noop_fold_stmt(Spanned {
node: node,
span: stmt_span
}, fld)
}
}
}
// expand the arm of a 'match', renaming for macro hygiene
fn expand_arm(arm: ast::Arm, fld: &mut MacroExpander) -> ast::Arm {
// expand pats... they might contain macro uses:
let expanded_pats = arm.pats.move_map(|pat| fld.fold_pat(pat));
if expanded_pats.len() == 0 {
panic!("encountered match arm with 0 patterns");
}
// all of the pats must have the same set of bindings, so use the
// first one to extract them and generate new names:
let idents = pattern_bindings(&*expanded_pats[0]);
let new_renames = idents.into_iter().map(|id| (id, fresh_name(&id))).collect();
// apply the renaming, but only to the PatIdents:
let mut rename_pats_fld = PatIdentRenamer{renames:&new_renames};
let rewritten_pats = expanded_pats.move_map(|pat| rename_pats_fld.fold_pat(pat));
// apply renaming and then expansion to the guard and the body:
let mut rename_fld = IdentRenamer{renames:&new_renames};
let rewritten_guard =
arm.guard.map(|g| fld.fold_expr(rename_fld.fold_expr(g)));
let rewritten_body = fld.fold_expr(rename_fld.fold_expr(arm.body));
ast::Arm {
attrs: arm.attrs.move_map(|x| fld.fold_attribute(x)),
pats: rewritten_pats,
guard: rewritten_guard,
body: rewritten_body,
}
}
/// A visitor that extracts the PatIdent (binding) paths
/// from a given thingy and puts them in a mutable
/// array
#[deriving(Clone)]
struct PatIdentFinder {
ident_accumulator: Vec<ast::Ident>
}
impl<'v> Visitor<'v> for PatIdentFinder {
fn visit_pat(&mut self, pattern: &ast::Pat) {
match *pattern {
ast::Pat { id: _, node: ast::PatIdent(_, ref path1, ref inner), span: _ } => {
self.ident_accumulator.push(path1.node);
// visit optional subpattern of PatIdent:
for subpat in inner.iter() {
self.visit_pat(&**subpat)
}
}
// use the default traversal for non-PatIdents
_ => visit::walk_pat(self, pattern)
}
}
}
/// find the PatIdent paths in a pattern
fn pattern_bindings(pat: &ast::Pat) -> Vec<ast::Ident> {
let mut name_finder = PatIdentFinder{ident_accumulator:Vec::new()};
name_finder.visit_pat(pat);
name_finder.ident_accumulator
}
/// find the PatIdent paths in a
fn fn_decl_arg_bindings(fn_decl: &ast::FnDecl) -> Vec<ast::Ident> {
let mut pat_idents = PatIdentFinder{ident_accumulator:Vec::new()};
for arg in fn_decl.inputs.iter() {
pat_idents.visit_pat(&*arg.pat);
}
pat_idents.ident_accumulator
}
// expand a block. pushes a new exts_frame, then calls expand_block_elts
pub fn expand_block(blk: P<Block>, fld: &mut MacroExpander) -> P<Block> {
// see note below about treatment of exts table
with_exts_frame!(fld.cx.syntax_env,false,
expand_block_elts(blk, fld))
}
// expand the elements of a block.
pub fn expand_block_elts(b: P<Block>, fld: &mut MacroExpander) -> P<Block> {
b.map(|Block {id, view_items, stmts, expr, rules, span}| {
let new_view_items = view_items.into_iter().map(|x| fld.fold_view_item(x)).collect();
let new_stmts = stmts.into_iter().flat_map(|x| {
// perform all pending renames
let renamed_stmt = {
let pending_renames = &mut fld.cx.syntax_env.info().pending_renames;
let mut rename_fld = IdentRenamer{renames:pending_renames};
rename_fld.fold_stmt(x).expect_one("rename_fold didn't return one value")
};
// expand macros in the statement
fld.fold_stmt(renamed_stmt).into_iter()
}).collect();
let new_expr = expr.map(|x| {
let expr = {
let pending_renames = &mut fld.cx.syntax_env.info().pending_renames;
let mut rename_fld = IdentRenamer{renames:pending_renames};
rename_fld.fold_expr(x)
};
fld.fold_expr(expr)
});
Block {
id: fld.new_id(id),
view_items: new_view_items,
stmts: new_stmts,
expr: new_expr,
rules: rules,
span: span
}
})
}
fn expand_pat(p: P<ast::Pat>, fld: &mut MacroExpander) -> P<ast::Pat> {
match p.node {
PatMac(_) => {}
_ => return noop_fold_pat(p, fld)
}
p.map(|ast::Pat {node, span, ..}| {
let (pth, tts) = match node {
PatMac(mac) => match mac.node {
MacInvocTT(pth, tts, _) => {
(pth, tts)
}
},
_ => unreachable!()
};
if pth.segments.len() > 1u {
fld.cx.span_err(pth.span, "expected macro name without module separators");
return DummyResult::raw_pat(span);
}
let extname = pth.segments[0].identifier;
let extnamestr = token::get_ident(extname);
let marked_after = match fld.cx.syntax_env.find(&extname.name) {
None => {
fld.cx.span_err(pth.span,
format!("macro undefined: '{}!'",
extnamestr).as_slice());
// let compilation continue
return DummyResult::raw_pat(span);
}
Some(rc) => match *rc {
NormalTT(ref expander, tt_span) => {
fld.cx.bt_push(ExpnInfo {
call_site: span,
callee: NameAndSpan {
name: extnamestr.get().to_string(),
format: MacroBang,
span: tt_span
}
});
let fm = fresh_mark();
let marked_before = mark_tts(tts.as_slice(), fm);
let mac_span = fld.cx.original_span();
let expanded = match expander.expand(fld.cx,
mac_span,
marked_before.as_slice()).make_pat() {
Some(e) => e,
None => {
fld.cx.span_err(
pth.span,
format!(
"non-pattern macro in pattern position: {}",
extnamestr.get()
).as_slice()
);
return DummyResult::raw_pat(span);
}
};
// mark after:
mark_pat(expanded,fm)
}
_ => {
fld.cx.span_err(span,
format!("{}! is not legal in pattern position",
extnamestr.get()).as_slice());
return DummyResult::raw_pat(span);
}
}
};
let fully_expanded =
fld.fold_pat(marked_after).node.clone();
fld.cx.bt_pop();
ast::Pat {
id: ast::DUMMY_NODE_ID,
node: fully_expanded,
span: span
}
})
}
/// A tree-folder that applies every rename in its (mutable) list
/// to every identifier, including both bindings and varrefs
/// (and lots of things that will turn out to be neither)
pub struct IdentRenamer<'a> {
renames: &'a mtwt::RenameList,
}
impl<'a> Folder for IdentRenamer<'a> {
fn fold_ident(&mut self, id: Ident) -> Ident {
Ident {
name: id.name,
ctxt: mtwt::apply_renames(self.renames, id.ctxt),
}
}
fn fold_mac(&mut self, macro: ast::Mac) -> ast::Mac {
fold::noop_fold_mac(macro, self)
}
}
/// A tree-folder that applies every rename in its list to
/// the idents that are in PatIdent patterns. This is more narrowly
/// focused than IdentRenamer, and is needed for FnDecl,
/// where we want to rename the args but not the fn name or the generics etc.
pub struct PatIdentRenamer<'a> {
renames: &'a mtwt::RenameList,
}
impl<'a> Folder for PatIdentRenamer<'a> {
fn fold_pat(&mut self, pat: P<ast::Pat>) -> P<ast::Pat> {
match pat.node {
ast::PatIdent(..) => {},
_ => return noop_fold_pat(pat, self)
}
pat.map(|ast::Pat {id, node, span}| match node {
ast::PatIdent(binding_mode, Spanned{span: sp, node: ident}, sub) => {
let new_ident = Ident{name: ident.name,
ctxt: mtwt::apply_renames(self.renames, ident.ctxt)};
let new_node =
ast::PatIdent(binding_mode,
Spanned{span: self.new_span(sp), node: new_ident},
sub.map(|p| self.fold_pat(p)));
ast::Pat {
id: id,
node: new_node,
span: self.new_span(span)
}
},
_ => unreachable!()
})
}
fn fold_mac(&mut self, macro: ast::Mac) -> ast::Mac {
fold::noop_fold_mac(macro, self)
}
}
// expand a method
fn expand_method(m: P<ast::Method>, fld: &mut MacroExpander) -> SmallVector<P<ast::Method>> {
m.and_then(|m| match m.node {
ast::MethDecl(ident,
generics,
abi,
explicit_self,
fn_style,
decl,
body,
vis) => {
let id = fld.new_id(m.id);
let (rewritten_fn_decl, rewritten_body)
= expand_and_rename_fn_decl_and_block(decl,body,fld);
SmallVector::one(P(ast::Method {
attrs: m.attrs.move_map(|a| fld.fold_attribute(a)),
id: id,
span: fld.new_span(m.span),
node: ast::MethDecl(fld.fold_ident(ident),
noop_fold_generics(generics, fld),
abi,
fld.fold_explicit_self(explicit_self),
fn_style,
rewritten_fn_decl,
rewritten_body,
vis)
}))
},
ast::MethMac(mac) => {
let maybe_new_methods =
expand_mac_invoc(mac, m.span,
|r| r.make_methods(),
|meths, mark| meths.move_map(|m| mark_method(m, mark)),
fld);
let new_methods = match maybe_new_methods {
Some(methods) => methods,
None => SmallVector::zero()
};
// expand again if necessary
let new_methods = new_methods.into_iter()
.flat_map(|m| fld.fold_method(m).into_iter()).collect();
fld.cx.bt_pop();
new_methods
}
})
}
/// Given a fn_decl and a block and a MacroExpander, expand the fn_decl, then use the
/// PatIdents in its arguments to perform renaming in the FnDecl and
/// the block, returning both the new FnDecl and the new Block.
fn expand_and_rename_fn_decl_and_block(fn_decl: P<ast::FnDecl>, block: P<ast::Block>,
fld: &mut MacroExpander)
-> (P<ast::FnDecl>, P<ast::Block>) {
let expanded_decl = fld.fold_fn_decl(fn_decl);
let idents = fn_decl_arg_bindings(&*expanded_decl);
let renames =
idents.iter().map(|id : &ast::Ident| (*id,fresh_name(id))).collect();
// first, a renamer for the PatIdents, for the fn_decl:
let mut rename_pat_fld = PatIdentRenamer{renames: &renames};
let rewritten_fn_decl = rename_pat_fld.fold_fn_decl(expanded_decl);
// now, a renamer for *all* idents, for the body:
let mut rename_fld = IdentRenamer{renames: &renames};
let rewritten_body = fld.fold_block(rename_fld.fold_block(block));
(rewritten_fn_decl,rewritten_body)
}
/// A tree-folder that performs macro expansion
pub struct MacroExpander<'a, 'b:'a> {
pub cx: &'a mut ExtCtxt<'b>,
}
impl<'a, 'b> Folder for MacroExpander<'a, 'b> {
fn fold_expr(&mut self, expr: P<ast::Expr>) -> P<ast::Expr> {
expand_expr(expr, self)
}
fn fold_pat(&mut self, pat: P<ast::Pat>) -> P<ast::Pat> {
expand_pat(pat, self)
}
fn fold_item(&mut self, item: P<ast::Item>) -> SmallVector<P<ast::Item>> {
expand_item(item, self)
}
fn fold_item_underscore(&mut self, item: ast::Item_) -> ast::Item_ {
expand_item_underscore(item, self)
}
fn fold_stmt(&mut self, stmt: P<ast::Stmt>) -> SmallVector<P<ast::Stmt>> {
stmt.and_then(|stmt| expand_stmt(stmt, self))
}
fn fold_block(&mut self, block: P<Block>) -> P<Block> {
expand_block(block, self)
}
fn fold_arm(&mut self, arm: ast::Arm) -> ast::Arm {
expand_arm(arm, self)
}
fn fold_method(&mut self, method: P<ast::Method>) -> SmallVector<P<ast::Method>> {
expand_method(method, self)
}
fn new_span(&mut self, span: Span) -> Span {
new_span(self.cx, span)
}
}
fn new_span(cx: &ExtCtxt, sp: Span) -> Span {
/* this discards information in the case of macro-defining macros */
Span {
lo: sp.lo,
hi: sp.hi,
expn_id: cx.backtrace(),
}
}
pub struct ExpansionConfig {
pub crate_name: String,
pub deriving_hash_type_parameter: bool,
pub enable_quotes: bool,
pub recursion_limit: uint,
}
impl ExpansionConfig {
pub fn default(crate_name: String) -> ExpansionConfig {
ExpansionConfig {
crate_name: crate_name,
deriving_hash_type_parameter: false,
enable_quotes: false,
recursion_limit: 64,
}
}
}
pub struct ExportedMacros {
pub crate_name: Ident,
pub macros: Vec<String>,
}
pub fn expand_crate(parse_sess: &parse::ParseSess,
cfg: ExpansionConfig,
// these are the macros being imported to this crate:
imported_macros: Vec<ExportedMacros>,
user_exts: Vec<NamedSyntaxExtension>,
c: Crate) -> Crate {
let mut cx = ExtCtxt::new(parse_sess, c.config.clone(), cfg);
let mut expander = MacroExpander {
cx: &mut cx,
};
for ExportedMacros { crate_name, macros } in imported_macros.into_iter() {
let name = format!("<{} macros>", token::get_ident(crate_name))
.into_string();
for source in macros.into_iter() {
let item = parse::parse_item_from_source_str(name.clone(),
source,
expander.cx.cfg(),
expander.cx.parse_sess())
.expect("expected a serialized item");
expand_item_mac(item, &mut expander);
}
}
for (name, extension) in user_exts.into_iter() {
expander.cx.syntax_env.insert(name, extension);
}
let mut ret = expander.fold_crate(c);
ret.exported_macros = expander.cx.exported_macros.clone();
parse_sess.span_diagnostic.handler().abort_if_errors();
return ret;
}
// HYGIENIC CONTEXT EXTENSION:
// all of these functions are for walking over
// ASTs and making some change to the context of every
// element that has one. a CtxtFn is a trait-ified
// version of a closure in (SyntaxContext -> SyntaxContext).
// the ones defined here include:
// Marker - add a mark to a context
// A Marker adds the given mark to the syntax context
struct Marker { mark: Mrk }
impl Folder for Marker {
fn fold_ident(&mut self, id: Ident) -> Ident {
ast::Ident {
name: id.name,
ctxt: mtwt::apply_mark(self.mark, id.ctxt)
}
}
fn fold_mac(&mut self, Spanned {node, span}: ast::Mac) -> ast::Mac {
Spanned {
node: match node {
MacInvocTT(path, tts, ctxt) => {
MacInvocTT(self.fold_path(path),
self.fold_tts(tts.as_slice()),
mtwt::apply_mark(self.mark, ctxt))
}
},
span: span,
}
}
}
// apply a given mark to the given token trees. Used prior to expansion of a macro.
fn mark_tts(tts: &[TokenTree], m: Mrk) -> Vec<TokenTree> {
noop_fold_tts(tts, &mut Marker{mark:m})
}
// apply a given mark to the given expr. Used following the expansion of a macro.
fn mark_expr(expr: P<ast::Expr>, m: Mrk) -> P<ast::Expr> {
Marker{mark:m}.fold_expr(expr)
}
// apply a given mark to the given pattern. Used following the expansion of a macro.
fn mark_pat(pat: P<ast::Pat>, m: Mrk) -> P<ast::Pat> {
Marker{mark:m}.fold_pat(pat)
}
// apply a given mark to the given stmt. Used following the expansion of a macro.
fn mark_stmt(expr: P<ast::Stmt>, m: Mrk) -> P<ast::Stmt> {
Marker{mark:m}.fold_stmt(expr)
.expect_one("marking a stmt didn't return exactly one stmt")
}
// apply a given mark to the given item. Used following the expansion of a macro.
fn mark_item(expr: P<ast::Item>, m: Mrk) -> P<ast::Item> {
Marker{mark:m}.fold_item(expr)
.expect_one("marking an item didn't return exactly one item")
}
// apply a given mark to the given item. Used following the expansion of a macro.
fn mark_method(expr: P<ast::Method>, m: Mrk) -> P<ast::Method> {
Marker{mark:m}.fold_method(expr)
.expect_one("marking an item didn't return exactly one method")
}
/// Check that there are no macro invocations left in the AST:
pub fn check_for_macros(sess: &parse::ParseSess, krate: &ast::Crate) {
visit::walk_crate(&mut MacroExterminator{sess:sess}, krate);
}
/// A visitor that ensures that no macro invocations remain in an AST.
struct MacroExterminator<'a>{
sess: &'a parse::ParseSess
}
impl<'a, 'v> Visitor<'v> for MacroExterminator<'a> {
fn visit_mac(&mut self, macro: &ast::Mac) {
self.sess.span_diagnostic.span_bug(macro.span,
"macro exterminator: expected AST \
with no macro invocations");
}
}
#[cfg(test)]
mod test {
use super::{pattern_bindings, expand_crate, contains_macro_escape};
use super::{PatIdentFinder, IdentRenamer, PatIdentRenamer, ExpansionConfig};
use ast;
use ast::{Attribute_, AttrOuter, MetaWord, Name};
use attr;
use codemap;
use codemap::Spanned;
use ext::mtwt;
use fold::Folder;
use parse;
use parse::token;
use ptr::P;
use util::parser_testing::{string_to_parser};
use util::parser_testing::{string_to_pat, string_to_crate, strs_to_idents};
use visit;
use visit::Visitor;
// a visitor that extracts the paths
// from a given thingy and puts them in a mutable
// array (passed in to the traversal)
#[deriving(Clone)]
struct PathExprFinderContext {
path_accumulator: Vec<ast::Path> ,
}
impl<'v> Visitor<'v> for PathExprFinderContext {
fn visit_expr(&mut self, expr: &ast::Expr) {
match expr.node {
ast::ExprPath(ref p) => {
self.path_accumulator.push(p.clone());
// not calling visit_path, but it should be fine.
}
_ => visit::walk_expr(self, expr)
}
}
}
// find the variable references in a crate
fn crate_varrefs(the_crate : &ast::Crate) -> Vec<ast::Path> {
let mut path_finder = PathExprFinderContext{path_accumulator:Vec::new()};
visit::walk_crate(&mut path_finder, the_crate);
path_finder.path_accumulator
}
/// A Visitor that extracts the identifiers from a thingy.
// as a side note, I'm starting to want to abstract over these....
struct IdentFinder {
ident_accumulator: Vec<ast::Ident>
}
impl<'v> Visitor<'v> for IdentFinder {
fn visit_ident(&mut self, _: codemap::Span, id: ast::Ident){
self.ident_accumulator.push(id);
}
}
/// Find the idents in a crate
fn crate_idents(the_crate: &ast::Crate) -> Vec<ast::Ident> {
let mut ident_finder = IdentFinder{ident_accumulator: Vec::new()};
visit::walk_crate(&mut ident_finder, the_crate);
ident_finder.ident_accumulator
}
// these following tests are quite fragile, in that they don't test what
// *kind* of failure occurs.
fn test_ecfg() -> ExpansionConfig {
ExpansionConfig::default("test".to_string())
}
// make sure that macros can't escape fns
#[should_fail]
#[test] fn macros_cant_escape_fns_test () {
let src = "fn bogus() {macro_rules! z (() => (3+4))}\
fn inty() -> int { z!() }".to_string();
let sess = parse::new_parse_sess();
let crate_ast = parse::parse_crate_from_source_str(
"<test>".to_string(),
src,
Vec::new(), &sess);
// should fail:
expand_crate(&sess,test_ecfg(),vec!(),vec!(),crate_ast);
}
// make sure that macros can't escape modules
#[should_fail]
#[test] fn macros_cant_escape_mods_test () {
let src = "mod foo {macro_rules! z (() => (3+4))}\
fn inty() -> int { z!() }".to_string();
let sess = parse::new_parse_sess();
let crate_ast = parse::parse_crate_from_source_str(
"<test>".to_string(),
src,
Vec::new(), &sess);
expand_crate(&sess,test_ecfg(),vec!(),vec!(),crate_ast);
}
// macro_escape modules should allow macros to escape
#[test] fn macros_can_escape_flattened_mods_test () {
let src = "#[macro_escape] mod foo {macro_rules! z (() => (3+4))}\
fn inty() -> int { z!() }".to_string();
let sess = parse::new_parse_sess();
let crate_ast = parse::parse_crate_from_source_str(
"<test>".to_string(),
src,
Vec::new(), &sess);
expand_crate(&sess, test_ecfg(), vec!(), vec!(), crate_ast);
}
#[test] fn test_contains_flatten (){
let attr1 = make_dummy_attr ("foo");
let attr2 = make_dummy_attr ("bar");
let escape_attr = make_dummy_attr ("macro_escape");
let attrs1 = vec!(attr1.clone(), escape_attr, attr2.clone());
assert_eq!(contains_macro_escape(attrs1.as_slice()),true);
let attrs2 = vec!(attr1,attr2);
assert_eq!(contains_macro_escape(attrs2.as_slice()),false);
}
// make a MetaWord outer attribute with the given name
fn make_dummy_attr(s: &str) -> ast::Attribute {
Spanned {
span:codemap::DUMMY_SP,
node: Attribute_ {
id: attr::mk_attr_id(),
style: AttrOuter,
value: P(Spanned {
node: MetaWord(token::intern_and_get_ident(s)),
span: codemap::DUMMY_SP,
}),
is_sugared_doc: false,
}
}
}
fn expand_crate_str(crate_str: String) -> ast::Crate {
let ps = parse::new_parse_sess();
let crate_ast = string_to_parser(&ps, crate_str).parse_crate_mod();
// the cfg argument actually does matter, here...
expand_crate(&ps,test_ecfg(),vec!(),vec!(),crate_ast)
}
// find the pat_ident paths in a crate
fn crate_bindings(the_crate : &ast::Crate) -> Vec<ast::Ident> {
let mut name_finder = PatIdentFinder{ident_accumulator:Vec::new()};
visit::walk_crate(&mut name_finder, the_crate);
name_finder.ident_accumulator
}
#[test] fn macro_tokens_should_match(){
expand_crate_str(
"macro_rules! m((a)=>(13)) fn main(){m!(a);}".to_string());
}
// should be able to use a bound identifier as a literal in a macro definition:
#[test] fn self_macro_parsing(){
expand_crate_str(
"macro_rules! foo ((zz) => (287u;))
fn f(zz : int) {foo!(zz);}".to_string()
);
}
// renaming tests expand a crate and then check that the bindings match
// the right varrefs. The specification of the test case includes the
// text of the crate, and also an array of arrays. Each element in the
// outer array corresponds to a binding in the traversal of the AST
// induced by visit. Each of these arrays contains a list of indexes,
// interpreted as the varrefs in the varref traversal that this binding
// should match. So, for instance, in a program with two bindings and
// three varrefs, the array ~[~[1,2],~[0]] would indicate that the first
// binding should match the second two varrefs, and the second binding
// should match the first varref.
//
// Put differently; this is a sparse representation of a boolean matrix
// indicating which bindings capture which identifiers.
//
// Note also that this matrix is dependent on the implicit ordering of
// the bindings and the varrefs discovered by the name-finder and the path-finder.
//
// The comparisons are done post-mtwt-resolve, so we're comparing renamed
// names; differences in marks don't matter any more.
//
// oog... I also want tests that check "bound-identifier-=?". That is,
// not just "do these have the same name", but "do they have the same
// name *and* the same marks"? Understanding this is really pretty painful.
// in principle, you might want to control this boolean on a per-varref basis,
// but that would make things even harder to understand, and might not be
// necessary for thorough testing.
type RenamingTest = (&'static str, Vec<Vec<uint>>, bool);
#[test]
fn automatic_renaming () {
let tests: Vec<RenamingTest> =
vec!(// b & c should get new names throughout, in the expr too:
("fn a() -> int { let b = 13; let c = b; b+c }",
vec!(vec!(0,1),vec!(2)), false),
// both x's should be renamed (how is this causing a bug?)
("fn main () {let x: int = 13;x;}",
vec!(vec!(0)), false),
// the use of b after the + should be renamed, the other one not:
("macro_rules! f (($x:ident) => (b + $x)) fn a() -> int { let b = 13; f!(b)}",
vec!(vec!(1)), false),
// the b before the plus should not be renamed (requires marks)
("macro_rules! f (($x:ident) => ({let b=9; ($x + b)})) fn a() -> int { f!(b)}",
vec!(vec!(1)), false),
// the marks going in and out of letty should cancel, allowing that $x to
// capture the one following the semicolon.
// this was an awesome test case, and caught a *lot* of bugs.
("macro_rules! letty(($x:ident) => (let $x = 15;))
macro_rules! user(($x:ident) => ({letty!($x); $x}))
fn main() -> int {user!(z)}",
vec!(vec!(0)), false)
);
for (idx,s) in tests.iter().enumerate() {
run_renaming_test(s,idx);
}
}
// no longer a fixme #8062: this test exposes a *potential* bug; our system does
// not behave exactly like MTWT, but a conversation with Matthew Flatt
// suggests that this can only occur in the presence of local-expand, which
// we have no plans to support. ... unless it's needed for item hygiene....
#[ignore]
#[test] fn issue_8062(){
run_renaming_test(
&("fn main() {let hrcoo = 19; macro_rules! getx(()=>(hrcoo)); getx!();}",
vec!(vec!(0)), true), 0)
}
// FIXME #6994:
// the z flows into and out of two macros (g & f) along one path, and one
// (just g) along the other, so the result of the whole thing should
// be "let z_123 = 3; z_123"
#[ignore]
#[test] fn issue_6994(){
run_renaming_test(
&("macro_rules! g (($x:ident) =>
({macro_rules! f(($y:ident)=>({let $y=3;$x}));f!($x)}))
fn a(){g!(z)}",
vec!(vec!(0)),false),
0)
}
// match variable hygiene. Should expand into
// fn z() {match 8 {x_1 => {match 9 {x_2 | x_2 if x_2 == x_1 => x_2 + x_1}}}}
#[test] fn issue_9384(){
run_renaming_test(
&("macro_rules! bad_macro (($ex:expr) => ({match 9 {x | x if x == $ex => x + $ex}}))
fn z() {match 8 {x => bad_macro!(x)}}",
// NB: the third "binding" is the repeat of the second one.
vec!(vec!(1,3),vec!(0,2),vec!(0,2)),
true),
0)
}
// interpolated nodes weren't getting labeled.
// should expand into
// fn main(){let g1_1 = 13; g1_1}}
#[test] fn pat_expand_issue_15221(){
run_renaming_test(
&("macro_rules! inner ( ($e:pat ) => ($e))
macro_rules! outer ( ($e:pat ) => (inner!($e)))
fn main() { let outer!(g) = 13; g;}",
vec!(vec!(0)),
true),
0)
}
// create a really evil test case where a $x appears inside a binding of $x
// but *shouldn't* bind because it was inserted by a different macro....
// can't write this test case until we have macro-generating macros.
// method arg hygiene
// method expands to fn get_x(&self_0, x_1:int) {self_0 + self_2 + x_3 + x_1}
#[test] fn method_arg_hygiene(){
run_renaming_test(
&("macro_rules! inject_x (()=>(x))
macro_rules! inject_self (()=>(self))
struct A;
impl A{fn get_x(&self, x: int) {self + inject_self!() + inject_x!() + x;} }",
vec!(vec!(0),vec!(3)),
true),
0)
}
// ooh, got another bite?
// expands to struct A; impl A {fn thingy(&self_1) {self_1;}}
#[test] fn method_arg_hygiene_2(){
run_renaming_test(
&("struct A;
macro_rules! add_method (($T:ty) =>
(impl $T { fn thingy(&self) {self;} }))
add_method!(A)",
vec!(vec!(0)),
true),
0)
}
// item fn hygiene
// expands to fn q(x_1:int){fn g(x_2:int){x_2 + x_1};}
#[test] fn issue_9383(){
run_renaming_test(
&("macro_rules! bad_macro (($ex:expr) => (fn g(x:int){ x + $ex }))
fn q(x:int) { bad_macro!(x); }",
vec!(vec!(1),vec!(0)),true),
0)
}
// closure arg hygiene (ExprFnBlock)
// expands to fn f(){(|x_1 : int| {(x_2 + x_1)})(3);}
#[test] fn closure_arg_hygiene(){
run_renaming_test(
&("macro_rules! inject_x (()=>(x))
fn f(){(|x : int| {(inject_x!() + x)})(3);}",
vec!(vec!(1)),
true),
0)
}
// closure arg hygiene (ExprProc)
// expands to fn f(){(proc(x_1 : int) {(x_2 + x_1)})(3);}
#[test] fn closure_arg_hygiene_2(){
run_renaming_test(
&("macro_rules! inject_x (()=>(x))
fn f(){ (proc(x : int){(inject_x!() + x)})(3); }",
vec!(vec!(1)),
true),
0)
}
// macro_rules in method position. Sadly, unimplemented.
#[test] fn macro_in_method_posn(){
expand_crate_str(
"macro_rules! my_method (() => (fn thirteen(&self) -> int {13}))
struct A;
impl A{ my_method!()}
fn f(){A.thirteen;}".to_string());
}
// another nested macro
// expands to impl Entries {fn size_hint(&self_1) {self_1;}
#[test] fn item_macro_workaround(){
run_renaming_test(
&("macro_rules! item { ($i:item) => {$i}}
struct Entries;
macro_rules! iterator_impl {
() => { item!( impl Entries { fn size_hint(&self) { self;}})}}
iterator_impl! { }",
vec!(vec!(0)), true),
0)
}
// run one of the renaming tests
fn run_renaming_test(t: &RenamingTest, test_idx: uint) {
let invalid_name = token::special_idents::invalid.name;
let (teststr, bound_connections, bound_ident_check) = match *t {
(ref str,ref conns, bic) => (str.to_string(), conns.clone(), bic)
};
let cr = expand_crate_str(teststr.to_string());
let bindings = crate_bindings(&cr);
let varrefs = crate_varrefs(&cr);
// must be one check clause for each binding:
assert_eq!(bindings.len(),bound_connections.len());
for (binding_idx,shouldmatch) in bound_connections.iter().enumerate() {
let binding_name = mtwt::resolve(bindings[binding_idx]);
let binding_marks = mtwt::marksof(bindings[binding_idx].ctxt, invalid_name);
// shouldmatch can't name varrefs that don't exist:
assert!((shouldmatch.len() == 0) ||
(varrefs.len() > *shouldmatch.iter().max().unwrap()));
for (idx,varref) in varrefs.iter().enumerate() {
let print_hygiene_debug_info = || {
// good lord, you can't make a path with 0 segments, can you?
let final_varref_ident = match varref.segments.last() {
Some(pathsegment) => pathsegment.identifier,
None => panic!("varref with 0 path segments?")
};
let varref_name = mtwt::resolve(final_varref_ident);
let varref_idents : Vec<ast::Ident>
= varref.segments.iter().map(|s| s.identifier)
.collect();
println!("varref #{}: {}, resolves to {}",idx, varref_idents, varref_name);
let string = token::get_ident(final_varref_ident);
println!("varref's first segment's string: \"{}\"", string.get());
println!("binding #{}: {}, resolves to {}",
binding_idx, bindings[binding_idx], binding_name);
mtwt::with_sctable(|x| mtwt::display_sctable(x));
};
if shouldmatch.contains(&idx) {
// it should be a path of length 1, and it should
// be free-identifier=? or bound-identifier=? to the given binding
assert_eq!(varref.segments.len(),1);
let varref_name = mtwt::resolve(varref.segments[0].identifier);
let varref_marks = mtwt::marksof(varref.segments[0]
.identifier
.ctxt,
invalid_name);
if !(varref_name==binding_name) {
println!("uh oh, should match but doesn't:");
print_hygiene_debug_info();
}
assert_eq!(varref_name,binding_name);
if bound_ident_check {
// we're checking bound-identifier=?, and the marks
// should be the same, too:
assert_eq!(varref_marks,binding_marks.clone());
}
} else {
let varref_name = mtwt::resolve(varref.segments[0].identifier);
let fail = (varref.segments.len() == 1)
&& (varref_name == binding_name);
// temp debugging:
if fail {
println!("failure on test {}",test_idx);
println!("text of test case: \"{}\"", teststr);
println!("");
println!("uh oh, matches but shouldn't:");
print_hygiene_debug_info();
}
assert!(!fail);
}
}
}
}
#[test] fn fmt_in_macro_used_inside_module_macro() {
let crate_str = "macro_rules! fmt_wrap(($b:expr)=>($b.to_string()))
macro_rules! foo_module (() => (mod generated { fn a() { let xx = 147; fmt_wrap!(xx);}}))
foo_module!()
".to_string();
let cr = expand_crate_str(crate_str);
// find the xx binding
let bindings = crate_bindings(&cr);
let cxbinds: Vec<&ast::Ident> =
bindings.iter().filter(|b| {
let ident = token::get_ident(**b);
let string = ident.get();
"xx" == string
}).collect();
let cxbinds: &[&ast::Ident] = cxbinds.as_slice();
let cxbind = match cxbinds {
[b] => b,
_ => panic!("expected just one binding for ext_cx")
};
let resolved_binding = mtwt::resolve(*cxbind);
let varrefs = crate_varrefs(&cr);
// the xx binding should bind all of the xx varrefs:
for (idx,v) in varrefs.iter().filter(|p| {
p.segments.len() == 1
&& "xx" == token::get_ident(p.segments[0].identifier).get()
}).enumerate() {
if mtwt::resolve(v.segments[0].identifier) != resolved_binding {
println!("uh oh, xx binding didn't match xx varref:");
println!("this is xx varref \\# {}", idx);
println!("binding: {}", cxbind);
println!("resolves to: {}", resolved_binding);
println!("varref: {}", v.segments[0].identifier);
println!("resolves to: {}",
mtwt::resolve(v.segments[0].identifier));
mtwt::with_sctable(|x| mtwt::display_sctable(x));
}
assert_eq!(mtwt::resolve(v.segments[0].identifier),
resolved_binding);
};
}
#[test]
fn pat_idents(){
let pat = string_to_pat(
"(a,Foo{x:c @ (b,9),y:Bar(4,d)})".to_string());
let idents = pattern_bindings(&*pat);
assert_eq!(idents, strs_to_idents(vec!("a","c","b","d")));
}
// test the list of identifier patterns gathered by the visitor. Note that
// 'None' is listed as an identifier pattern because we don't yet know that
// it's the name of a 0-ary variant, and that 'i' appears twice in succession.
#[test]
fn crate_bindings_test(){
let the_crate = string_to_crate("fn main (a : int) -> int {|b| {
match 34 {None => 3, Some(i) | i => j, Foo{k:z,l:y} => \"banana\"}} }".to_string());
let idents = crate_bindings(&the_crate);
assert_eq!(idents, strs_to_idents(vec!("a","b","None","i","i","z","y")));
}
// test the IdentRenamer directly
#[test]
fn ident_renamer_test () {
let the_crate = string_to_crate("fn f(x : int){let x = x; x}".to_string());
let f_ident = token::str_to_ident("f");
let x_ident = token::str_to_ident("x");
let int_ident = token::str_to_ident("int");
let renames = vec!((x_ident,Name(16)));
let mut renamer = IdentRenamer{renames: &renames};
let renamed_crate = renamer.fold_crate(the_crate);
let idents = crate_idents(&renamed_crate);
let resolved : Vec<ast::Name> = idents.iter().map(|id| mtwt::resolve(*id)).collect();
assert_eq!(resolved,vec!(f_ident.name,Name(16),int_ident.name,Name(16),Name(16),Name(16)));
}
// test the PatIdentRenamer; only PatIdents get renamed
#[test]
fn pat_ident_renamer_test () {
let the_crate = string_to_crate("fn f(x : int){let x = x; x}".to_string());
let f_ident = token::str_to_ident("f");
let x_ident = token::str_to_ident("x");
let int_ident = token::str_to_ident("int");
let renames = vec!((x_ident,Name(16)));
let mut renamer = PatIdentRenamer{renames: &renames};
let renamed_crate = renamer.fold_crate(the_crate);
let idents = crate_idents(&renamed_crate);
let resolved : Vec<ast::Name> = idents.iter().map(|id| mtwt::resolve(*id)).collect();
let x_name = x_ident.name;
assert_eq!(resolved,vec!(f_ident.name,Name(16),int_ident.name,Name(16),x_name,x_name));
}
}