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Hide the quote_*! macros when the feature gate is off
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This makes it easier to experiment with improved quasiquoting as an ordinary
plugin library.

The list of quote macros in feature_gate.rs was already out of sync;
this commit also prevents that problem in the future.
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Keegan McAllister committed Sep 27, 2014
1 parent 5d653c1 commit fc1b908
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Showing 6 changed files with 74 additions and 68 deletions.
3 changes: 2 additions & 1 deletion src/librustc/driver/driver.rs
View file
Expand Up @@ -288,8 +288,9 @@ pub fn phase_2_configure_and_expand(sess: &Session,
os::setenv("PATH", os::join_paths(new_path.as_slice()).unwrap());
}
let cfg = syntax::ext::expand::ExpansionConfig {
deriving_hash_type_parameter: sess.features.borrow().default_type_params,
crate_name: crate_name.to_string(),
deriving_hash_type_parameter: sess.features.borrow().default_type_params,
enable_quotes: sess.features.borrow().quote,
};
let ret = syntax::ext::expand::expand_crate(&sess.parse_sess,
cfg,
Expand Down
57 changes: 30 additions & 27 deletions src/libsyntax/ext/base.rs
View file
Expand Up @@ -344,7 +344,7 @@ impl BlockInfo {

/// The base map of methods for expanding syntax extension
/// AST nodes into full ASTs
fn initial_syntax_expander_table() -> SyntaxEnv {
fn initial_syntax_expander_table(ecfg: &expand::ExpansionConfig) -> SyntaxEnv {
// utility function to simplify creating NormalTT syntax extensions
fn builtin_normal_expander(f: MacroExpanderFn) -> SyntaxExtension {
NormalTT(box f, None)
Expand Down Expand Up @@ -383,31 +383,33 @@ fn initial_syntax_expander_table() -> SyntaxEnv {
syntax_expanders.insert(intern("deriving"),
Decorator(box ext::deriving::expand_meta_deriving));

// Quasi-quoting expanders
syntax_expanders.insert(intern("quote_tokens"),
builtin_normal_expander(
ext::quote::expand_quote_tokens));
syntax_expanders.insert(intern("quote_expr"),
builtin_normal_expander(
ext::quote::expand_quote_expr));
syntax_expanders.insert(intern("quote_ty"),
builtin_normal_expander(
ext::quote::expand_quote_ty));
syntax_expanders.insert(intern("quote_method"),
builtin_normal_expander(
ext::quote::expand_quote_method));
syntax_expanders.insert(intern("quote_item"),
builtin_normal_expander(
ext::quote::expand_quote_item));
syntax_expanders.insert(intern("quote_pat"),
builtin_normal_expander(
ext::quote::expand_quote_pat));
syntax_expanders.insert(intern("quote_arm"),
builtin_normal_expander(
ext::quote::expand_quote_arm));
syntax_expanders.insert(intern("quote_stmt"),
builtin_normal_expander(
ext::quote::expand_quote_stmt));
if ecfg.enable_quotes {
// Quasi-quoting expanders
syntax_expanders.insert(intern("quote_tokens"),
builtin_normal_expander(
ext::quote::expand_quote_tokens));
syntax_expanders.insert(intern("quote_expr"),
builtin_normal_expander(
ext::quote::expand_quote_expr));
syntax_expanders.insert(intern("quote_ty"),
builtin_normal_expander(
ext::quote::expand_quote_ty));
syntax_expanders.insert(intern("quote_method"),
builtin_normal_expander(
ext::quote::expand_quote_method));
syntax_expanders.insert(intern("quote_item"),
builtin_normal_expander(
ext::quote::expand_quote_item));
syntax_expanders.insert(intern("quote_pat"),
builtin_normal_expander(
ext::quote::expand_quote_pat));
syntax_expanders.insert(intern("quote_arm"),
builtin_normal_expander(
ext::quote::expand_quote_arm));
syntax_expanders.insert(intern("quote_stmt"),
builtin_normal_expander(
ext::quote::expand_quote_stmt));
}

syntax_expanders.insert(intern("line"),
builtin_normal_expander(
Expand Down Expand Up @@ -464,6 +466,7 @@ pub struct ExtCtxt<'a> {
impl<'a> ExtCtxt<'a> {
pub fn new<'a>(parse_sess: &'a parse::ParseSess, cfg: ast::CrateConfig,
ecfg: expand::ExpansionConfig) -> ExtCtxt<'a> {
let env = initial_syntax_expander_table(&ecfg);
ExtCtxt {
parse_sess: parse_sess,
cfg: cfg,
Expand All @@ -472,7 +475,7 @@ impl<'a> ExtCtxt<'a> {
ecfg: ecfg,
trace_mac: false,
exported_macros: Vec::new(),
syntax_env: initial_syntax_expander_table(),
syntax_env: env,
}
}

Expand Down
43 changes: 21 additions & 22 deletions src/libsyntax/ext/expand.rs
View file
Expand Up @@ -975,8 +975,19 @@ fn new_span(cx: &ExtCtxt, sp: Span) -> Span {
}

pub struct ExpansionConfig {
pub deriving_hash_type_parameter: bool,
pub crate_name: String,
pub deriving_hash_type_parameter: bool,
pub enable_quotes: bool,
}

impl ExpansionConfig {
pub fn default(crate_name: String) -> ExpansionConfig {
ExpansionConfig {
crate_name: crate_name,
deriving_hash_type_parameter: false,
enable_quotes: false,
}
}
}

pub struct ExportedMacros {
Expand Down Expand Up @@ -1106,7 +1117,7 @@ impl<'a, 'v> Visitor<'v> for MacroExterminator<'a> {
#[cfg(test)]
mod test {
use super::{pattern_bindings, expand_crate, contains_macro_escape};
use super::{PatIdentFinder, IdentRenamer, PatIdentRenamer};
use super::{PatIdentFinder, IdentRenamer, PatIdentRenamer, ExpansionConfig};
use ast;
use ast::{Attribute_, AttrOuter, MetaWord, Name};
use attr;
Expand Down Expand Up @@ -1171,6 +1182,10 @@ mod test {
// 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 () {
Expand All @@ -1182,11 +1197,7 @@ mod test {
src,
Vec::new(), &sess);
// should fail:
let cfg = ::syntax::ext::expand::ExpansionConfig {
deriving_hash_type_parameter: false,
crate_name: "test".to_string(),
};
expand_crate(&sess,cfg,vec!(),vec!(),crate_ast);
expand_crate(&sess,test_ecfg(),vec!(),vec!(),crate_ast);
}

// make sure that macros can't escape modules
Expand All @@ -1199,11 +1210,7 @@ mod test {
"<test>".to_string(),
src,
Vec::new(), &sess);
let cfg = ::syntax::ext::expand::ExpansionConfig {
deriving_hash_type_parameter: false,
crate_name: "test".to_string(),
};
expand_crate(&sess,cfg,vec!(),vec!(),crate_ast);
expand_crate(&sess,test_ecfg(),vec!(),vec!(),crate_ast);
}

// macro_escape modules should allow macros to escape
Expand All @@ -1215,11 +1222,7 @@ mod test {
"<test>".to_string(),
src,
Vec::new(), &sess);
let cfg = ::syntax::ext::expand::ExpansionConfig {
deriving_hash_type_parameter: false,
crate_name: "test".to_string(),
};
expand_crate(&sess, cfg, vec!(), vec!(), crate_ast);
expand_crate(&sess, test_ecfg(), vec!(), vec!(), crate_ast);
}

#[test] fn test_contains_flatten (){
Expand Down Expand Up @@ -1252,11 +1255,7 @@ mod test {
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...
let cfg = ::syntax::ext::expand::ExpansionConfig {
deriving_hash_type_parameter: false,
crate_name: "test".to_string(),
};
expand_crate(&ps,cfg,vec!(),vec!(),crate_ast)
expand_crate(&ps,test_ecfg(),vec!(),vec!(),crate_ast)
}

// find the pat_ident paths in a crate
Expand Down
17 changes: 3 additions & 14 deletions src/libsyntax/feature_gate.rs
View file
Expand Up @@ -102,6 +102,7 @@ pub struct Features {
pub rustc_diagnostic_macros: bool,
pub import_shadowing: bool,
pub visible_private_types: bool,
pub quote: bool,
}

impl Features {
Expand All @@ -112,6 +113,7 @@ impl Features {
rustc_diagnostic_macros: false,
import_shadowing: false,
visible_private_types: false,
quote: false,
}
}
}
Expand Down Expand Up @@ -282,10 +284,6 @@ impl<'a, 'v> Visitor<'v> for Context<'a> {
fn visit_mac(&mut self, macro: &ast::Mac) {
let ast::MacInvocTT(ref path, _, _) = macro.node;
let id = path.segments.last().unwrap().identifier;
let quotes = ["quote_tokens", "quote_expr", "quote_ty",
"quote_item", "quote_pat", "quote_stmt"];
let msg = " is not stable enough for use and are subject to change";


if id == token::str_to_ident("macro_rules") {
self.gate_feature("macro_rules", path.span, "macro definitions are \
Expand All @@ -311,16 +309,6 @@ impl<'a, 'v> Visitor<'v> for Context<'a> {
self.gate_feature("concat_idents", path.span, "`concat_idents` is not \
stable enough for use and is subject to change");
}

else {
for &quote in quotes.iter() {
if id == token::str_to_ident(quote) {
self.gate_feature("quote",
path.span,
format!("{}{}", quote, msg).as_slice());
}
}
}
}

fn visit_foreign_item(&mut self, i: &ast::ForeignItem) {
Expand Down Expand Up @@ -483,6 +471,7 @@ pub fn check_crate(span_handler: &SpanHandler, krate: &ast::Crate) -> (Features,
rustc_diagnostic_macros: cx.has_feature("rustc_diagnostic_macros"),
import_shadowing: cx.has_feature("import_shadowing"),
visible_private_types: cx.has_feature("visible_private_types"),
quote: cx.has_feature("quote"),
},
unknown_features)
}
Expand Down
5 changes: 1 addition & 4 deletions src/libsyntax/test.rs
View file
Expand Up @@ -235,10 +235,7 @@ fn generate_test_harness(sess: &ParseSess,
sess: sess,
span_diagnostic: sd,
ext_cx: ExtCtxt::new(sess, cfg.clone(),
ExpansionConfig {
deriving_hash_type_parameter: false,
crate_name: "test".to_string(),
}),
ExpansionConfig::default("test".to_string())),
path: Vec::new(),
testfns: Vec::new(),
reexport_test_harness_main: reexport_test_harness_main,
Expand Down
17 changes: 17 additions & 0 deletions src/test/run-pass/non-built-in-quote.rs
View file
@@ -0,0 +1,17 @@
// Copyright 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.

#![feature(macro_rules)]

macro_rules! quote_tokens ( () => (()) )

pub fn main() {
quote_tokens!();
}

1 comment on commit fc1b908

@alexcrichton
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r+

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