auto merge of #11803 : sfackler/rust/simple-mac, r=brson

Now that procedural macros can be implemented outside of the compiler,
it's more important to have a reasonable API to work with. Here are the
basic changes:

* Rename SyntaxExpanderTTTrait to MacroExpander, SyntaxExpanderTT to
    BasicMacroExpander, etc. I think "procedural macro" is the right
    term for these now, right? The other option would be SynExtExpander
    or something like that.

* Stop passing the SyntaxContext to extensions. This was only ever used
    by macro_rules, which doesn't even use it anymore. I can't think of
    a context in which an external extension would need it, and removal
    allows the API to be significantly simpler - no more
    SyntaxExpanderTTItemExpanderWithoutContext wrappers to worry about.

src/libsyntax/ext/base.rs

@@ -38,91 +38,63 @@ pub struct MacroDef {
 pub type ItemDecorator =
     fn(&ExtCtxt, Span, @ast::MetaItem, ~[@ast::Item]) -> ~[@ast::Item];
 
-pub struct SyntaxExpanderTT {
-    expander: SyntaxExpanderTTExpander,
+pub struct BasicMacroExpander {
+    expander: MacroExpanderFn,
     span: Option<Span>
 }
 
-pub trait SyntaxExpanderTTTrait {
+pub trait MacroExpander {
     fn expand(&self,
               ecx: &mut ExtCtxt,
               span: Span,
-              token_tree: &[ast::TokenTree],
-              context: ast::SyntaxContext)
+              token_tree: &[ast::TokenTree])
               -> MacResult;
 }
 
-pub type SyntaxExpanderTTFunNoCtxt =
+pub type MacroExpanderFn =
     fn(ecx: &mut ExtCtxt, span: codemap::Span, token_tree: &[ast::TokenTree])
        -> MacResult;
 
-enum SyntaxExpanderTTExpander {
-    SyntaxExpanderTTExpanderWithoutContext(SyntaxExpanderTTFunNoCtxt),
-}
-
-impl SyntaxExpanderTTTrait for SyntaxExpanderTT {
+impl MacroExpander for BasicMacroExpander {
     fn expand(&self,
               ecx: &mut ExtCtxt,
               span: Span,
-              token_tree: &[ast::TokenTree],
-              _: ast::SyntaxContext)
+              token_tree: &[ast::TokenTree])
               -> MacResult {
-        match self.expander {
-            SyntaxExpanderTTExpanderWithoutContext(f) => {
-                f(ecx, span, token_tree)
-            }
-        }
+        (self.expander)(ecx, span, token_tree)
     }
 }
 
-enum SyntaxExpanderTTItemExpander {
-    SyntaxExpanderTTItemExpanderWithContext(SyntaxExpanderTTItemFun),
-    SyntaxExpanderTTItemExpanderWithoutContext(SyntaxExpanderTTItemFunNoCtxt),
-}
-
-pub struct SyntaxExpanderTTItem {
-    expander: SyntaxExpanderTTItemExpander,
+pub struct BasicIdentMacroExpander {
+    expander: IdentMacroExpanderFn,
     span: Option<Span>
 }
 
-pub trait SyntaxExpanderTTItemTrait {
+pub trait IdentMacroExpander {
     fn expand(&self,
               cx: &mut ExtCtxt,
               sp: Span,
               ident: ast::Ident,
-              token_tree: ~[ast::TokenTree],
-              context: ast::SyntaxContext)
+              token_tree: ~[ast::TokenTree])
               -> MacResult;
 }
 
-impl SyntaxExpanderTTItemTrait for SyntaxExpanderTTItem {
+impl IdentMacroExpander for BasicIdentMacroExpander {
     fn expand(&self,
               cx: &mut ExtCtxt,
               sp: Span,
               ident: ast::Ident,
-              token_tree: ~[ast::TokenTree],
-              context: ast::SyntaxContext)
+              token_tree: ~[ast::TokenTree])
               -> MacResult {
-        match self.expander {
-            SyntaxExpanderTTItemExpanderWithContext(fun) => {
-                fun(cx, sp, ident, token_tree, context)
-            }
-            SyntaxExpanderTTItemExpanderWithoutContext(fun) => {
-                fun(cx, sp, ident, token_tree)
-            }
-        }
+        (self.expander)(cx, sp, ident, token_tree)
     }
 }
 
-pub type SyntaxExpanderTTItemFun =
-    fn(&mut ExtCtxt, Span, ast::Ident, ~[ast::TokenTree], ast::SyntaxContext)
-       -> MacResult;
-
-pub type SyntaxExpanderTTItemFunNoCtxt =
+pub type IdentMacroExpanderFn =
     fn(&mut ExtCtxt, Span, ast::Ident, ~[ast::TokenTree]) -> MacResult;
 
 pub type MacroCrateRegistrationFun =
-    extern "Rust" fn(|ast::Name, SyntaxExtension|);
+    fn(|ast::Name, SyntaxExtension|);
 
 pub trait AnyMacro {
     fn make_expr(&self) -> @ast::Expr;
@@ -153,7 +125,7 @@ pub enum SyntaxExtension {
     ItemDecorator(ItemDecorator),
 
     // Token-tree expanders
-    NormalTT(~SyntaxExpanderTTTrait:'static, Option<Span>),
+    NormalTT(~MacroExpander:'static, Option<Span>),
 
     // An IdentTT is a macro that has an
     // identifier in between the name of the
@@ -163,7 +135,7 @@ pub enum SyntaxExtension {
 
     // perhaps macro_rules! will lose its odd special identifier argument,
     // and this can go away also
-    IdentTT(~SyntaxExpanderTTItemTrait:'static, Option<Span>),
+    IdentTT(~IdentMacroExpander:'static, Option<Span>),
 }
 
 pub struct BlockInfo {
@@ -192,10 +164,9 @@ pub type RenameList = ~[(ast::Ident,Name)];
 // AST nodes into full ASTs
 pub fn syntax_expander_table() -> SyntaxEnv {
     // utility function to simplify creating NormalTT syntax extensions
-    fn builtin_normal_tt_no_ctxt(f: SyntaxExpanderTTFunNoCtxt)
-                                 -> SyntaxExtension {
-        NormalTT(~SyntaxExpanderTT{
-            expander: SyntaxExpanderTTExpanderWithoutContext(f),
+    fn builtin_normal_expander(f: MacroExpanderFn) -> SyntaxExtension {
+        NormalTT(~BasicMacroExpander {
+                expander: f,
                 span: None,
             },
             None)
@@ -203,91 +174,90 @@ pub fn syntax_expander_table() -> SyntaxEnv {
 
     let mut syntax_expanders = SyntaxEnv::new();
     syntax_expanders.insert(intern(&"macro_rules"),
-                            IdentTT(~SyntaxExpanderTTItem {
-                                expander: SyntaxExpanderTTItemExpanderWithContext(
-                                    ext::tt::macro_rules::add_new_extension),
+                            IdentTT(~BasicIdentMacroExpander {
+                                expander: ext::tt::macro_rules::add_new_extension,
                                 span: None,
                             },
                             None));
     syntax_expanders.insert(intern(&"fmt"),
-                            builtin_normal_tt_no_ctxt(
+                            builtin_normal_expander(
                                 ext::fmt::expand_syntax_ext));
     syntax_expanders.insert(intern(&"format_args"),
-                            builtin_normal_tt_no_ctxt(
+                            builtin_normal_expander(
                                 ext::format::expand_args));
     syntax_expanders.insert(intern(&"env"),
-                            builtin_normal_tt_no_ctxt(
+                            builtin_normal_expander(
                                     ext::env::expand_env));
     syntax_expanders.insert(intern(&"option_env"),
-                            builtin_normal_tt_no_ctxt(
+                            builtin_normal_expander(
                                     ext::env::expand_option_env));
     syntax_expanders.insert(intern("bytes"),
-                            builtin_normal_tt_no_ctxt(
+                            builtin_normal_expander(
                                     ext::bytes::expand_syntax_ext));
     syntax_expanders.insert(intern("concat_idents"),
-                            builtin_normal_tt_no_ctxt(
+                            builtin_normal_expander(
                                     ext::concat_idents::expand_syntax_ext));
     syntax_expanders.insert(intern("concat"),
-                            builtin_normal_tt_no_ctxt(
+                            builtin_normal_expander(
                                     ext::concat::expand_syntax_ext));
     syntax_expanders.insert(intern(&"log_syntax"),
-                            builtin_normal_tt_no_ctxt(
+                            builtin_normal_expander(
                                     ext::log_syntax::expand_syntax_ext));
     syntax_expanders.insert(intern(&"deriving"),
                             ItemDecorator(ext::deriving::expand_meta_deriving));
 
     // Quasi-quoting expanders
     syntax_expanders.insert(intern(&"quote_tokens"),
-                       builtin_normal_tt_no_ctxt(
+                       builtin_normal_expander(
                             ext::quote::expand_quote_tokens));
     syntax_expanders.insert(intern(&"quote_expr"),
-                       builtin_normal_tt_no_ctxt(
+                       builtin_normal_expander(
                             ext::quote::expand_quote_expr));
     syntax_expanders.insert(intern(&"quote_ty"),
-                       builtin_normal_tt_no_ctxt(
+                       builtin_normal_expander(
                             ext::quote::expand_quote_ty));
     syntax_expanders.insert(intern(&"quote_item"),
-                       builtin_normal_tt_no_ctxt(
+                       builtin_normal_expander(
                             ext::quote::expand_quote_item));
     syntax_expanders.insert(intern(&"quote_pat"),
-                       builtin_normal_tt_no_ctxt(
+                       builtin_normal_expander(
                             ext::quote::expand_quote_pat));
     syntax_expanders.insert(intern(&"quote_stmt"),
-                       builtin_normal_tt_no_ctxt(
+                       builtin_normal_expander(
                             ext::quote::expand_quote_stmt));
 
     syntax_expanders.insert(intern(&"line"),
-                            builtin_normal_tt_no_ctxt(
+                            builtin_normal_expander(
                                     ext::source_util::expand_line));
     syntax_expanders.insert(intern(&"col"),
-                            builtin_normal_tt_no_ctxt(
+                            builtin_normal_expander(
                                     ext::source_util::expand_col));
     syntax_expanders.insert(intern(&"file"),
-                            builtin_normal_tt_no_ctxt(
+                            builtin_normal_expander(
                                     ext::source_util::expand_file));
     syntax_expanders.insert(intern(&"stringify"),
-                            builtin_normal_tt_no_ctxt(
+                            builtin_normal_expander(
                                     ext::source_util::expand_stringify));
     syntax_expanders.insert(intern(&"include"),
-                            builtin_normal_tt_no_ctxt(
+                            builtin_normal_expander(
                                     ext::source_util::expand_include));
     syntax_expanders.insert(intern(&"include_str"),
-                            builtin_normal_tt_no_ctxt(
+                            builtin_normal_expander(
                                     ext::source_util::expand_include_str));
     syntax_expanders.insert(intern(&"include_bin"),
-                            builtin_normal_tt_no_ctxt(
+                            builtin_normal_expander(
                                     ext::source_util::expand_include_bin));
     syntax_expanders.insert(intern(&"module_path"),
-                            builtin_normal_tt_no_ctxt(
+                            builtin_normal_expander(
                                     ext::source_util::expand_mod));
     syntax_expanders.insert(intern(&"asm"),
-                            builtin_normal_tt_no_ctxt(
+                            builtin_normal_expander(
                                     ext::asm::expand_asm));
     syntax_expanders.insert(intern(&"cfg"),
-                            builtin_normal_tt_no_ctxt(
+                            builtin_normal_expander(
                                     ext::cfg::expand_cfg));
     syntax_expanders.insert(intern(&"trace_macros"),
-                            builtin_normal_tt_no_ctxt(
+                            builtin_normal_expander(
                                     ext::trace_macros::expand_trace_macros));
     syntax_expanders
 }

src/libsyntax/ext/expand.rs

@@ -13,7 +13,7 @@ use ast::{Local, Ident, MacInvocTT};
 use ast::{ItemMac, Mrk, Stmt, StmtDecl, StmtMac, StmtExpr, StmtSemi};
 use ast::{TokenTree};
 use ast;
-use ast_util::{mtwt_outer_mark, new_rename, new_mark};
+use ast_util::{new_rename, new_mark};
 use ext::build::AstBuilder;
 use attr;
 use attr::AttrMetaMethods;
@@ -44,7 +44,7 @@ pub fn expand_expr(e: @ast::Expr, fld: &mut MacroExpander) -> @ast::Expr {
                 // for the other three macro invocation chunks of code
                 // in this file.
                 // Token-tree macros:
-                MacInvocTT(ref pth, ref tts, ctxt) => {
+                MacInvocTT(ref pth, ref tts, _) => {
                     if pth.segments.len() > 1u {
                         fld.cx.span_err(
                             pth.span,
@@ -77,7 +77,6 @@ pub fn expand_expr(e: @ast::Expr, fld: &mut MacroExpander) -> @ast::Expr {
                             let fm = fresh_mark();
                             // mark before:
                             let marked_before = mark_tts(*tts,fm);
-                            let marked_ctxt = new_mark(fm, ctxt);
 
                             // The span that we pass to the expanders we want to
                             // be the root of the call stack. That's the most
@@ -87,8 +86,7 @@ pub fn expand_expr(e: @ast::Expr, fld: &mut MacroExpander) -> @ast::Expr {
 
                             let expanded = match expandfun.expand(fld.cx,
                                                    mac_span.call_site,
-                                                   marked_before,
-                                                   marked_ctxt) {
+                                                   marked_before) {
                                 MRExpr(e) => e,
                                 MRAny(any_macro) => any_macro.make_expr(),
                                 _ => {
@@ -286,12 +284,12 @@ pub fn contains_macro_escape(attrs: &[ast::Attribute]) -> bool {
 // logic as for expression-position macro invocations.
 pub fn expand_item_mac(it: @ast::Item, fld: &mut MacroExpander)
                        -> SmallVector<@ast::Item> {
-    let (pth, tts, ctxt) = match it.node {
+    let (pth, tts) = match it.node {
         ItemMac(codemap::Spanned {
-            node: MacInvocTT(ref pth, ref tts, ctxt),
+            node: MacInvocTT(ref pth, ref tts, _),
             ..
         }) => {
-            (pth, (*tts).clone(), ctxt)
+            (pth, (*tts).clone())
         }
         _ => fld.cx.span_bug(it.span, "invalid item macro invocation")
     };
@@ -325,8 +323,7 @@ pub fn expand_item_mac(it: @ast::Item, fld: &mut MacroExpander)
             });
             // mark before expansion:
             let marked_before = mark_tts(tts,fm);
-            let marked_ctxt = new_mark(fm,ctxt);
-            expander.expand(fld.cx, it.span, marked_before, marked_ctxt)
+            expander.expand(fld.cx, it.span, marked_before)
         }
         Some(&IdentTT(ref expander, span)) => {
             if it.ident.name == parse::token::special_idents::invalid.name {
@@ -344,8 +341,7 @@ pub fn expand_item_mac(it: @ast::Item, fld: &mut MacroExpander)
             });
             // mark before expansion:
             let marked_tts = mark_tts(tts,fm);
-            let marked_ctxt = new_mark(fm,ctxt);
-            expander.expand(fld.cx, it.span, it.ident, marked_tts, marked_ctxt)
+            expander.expand(fld.cx, it.span, it.ident, marked_tts)
         }
         _ => {
             fld.cx.span_err(it.span, format!("{}! is not legal in item position", extnamestr));
@@ -464,11 +460,11 @@ fn load_extern_macros(crate: &ast::ViewItem, fld: &mut MacroExpander) {
 pub fn expand_stmt(s: &Stmt, fld: &mut MacroExpander) -> SmallVector<@Stmt> {
     // why the copying here and not in expand_expr?
     // looks like classic changed-in-only-one-place
-    let (pth, tts, semi, ctxt) = match s.node {
+    let (pth, tts, semi) = match s.node {
         StmtMac(ref mac, semi) => {
             match mac.node {
-                MacInvocTT(ref pth, ref tts, ctxt) => {
-                    (pth, (*tts).clone(), semi, ctxt)
+                MacInvocTT(ref pth, ref tts, _) => {
+                    (pth, (*tts).clone(), semi)
                 }
             }
         }
@@ -498,7 +494,6 @@ pub fn expand_stmt(s: &Stmt, fld: &mut MacroExpander) -> SmallVector<@Stmt> {
             let fm = fresh_mark();
             // mark before expansion:
             let marked_tts = mark_tts(tts,fm);
-            let marked_ctxt = new_mark(fm,ctxt);
 
             // See the comment in expand_expr for why we want the original span,
             // not the current mac.span.
@@ -506,8 +501,7 @@ pub fn expand_stmt(s: &Stmt, fld: &mut MacroExpander) -> SmallVector<@Stmt> {
 
             let expanded = match expandfun.expand(fld.cx,
                                                   mac_span.call_site,
-                                                  marked_tts,
-                                                  marked_ctxt) {
+                                                  marked_tts) {
                 MRExpr(e) => {
                     @codemap::Spanned {
                         node: StmtExpr(e, ast::DUMMY_NODE_ID),
@@ -923,15 +917,6 @@ pub fn replace_ctxts(expr : @ast::Expr, ctxt : SyntaxContext) -> @ast::Expr {
     fun_to_ctxt_folder(@Repainter{ctxt:ctxt}).fold_expr(expr)
 }
 
-// take the mark from the given ctxt (that has a mark at the outside),
-// and apply it to everything in the token trees, thereby cancelling
-// that mark.
-pub fn mtwt_cancel_outer_mark(tts: &[ast::TokenTree], ctxt: ast::SyntaxContext)
-    -> ~[ast::TokenTree] {
-    let outer_mark = mtwt_outer_mark(ctxt);
-    mark_tts(tts,outer_mark)
-}
-
 fn original_span(cx: &ExtCtxt) -> @codemap::ExpnInfo {
     let mut relevant_info = cx.backtrace();
     let mut einfo = relevant_info.unwrap();
@@ -1090,28 +1075,6 @@ mod test {
         }
     }
 
-    #[test] fn cancel_outer_mark_test(){
-        let invalid_name = token::special_idents::invalid.name;
-        let ident_str = @"x";
-        let tts = string_to_tts(ident_str);
-        let fm = fresh_mark();
-        let marked_once = fold::fold_tts(tts,&mut new_mark_folder(fm));
-        assert_eq!(marked_once.len(),1);
-        let marked_once_ctxt =
-            match marked_once[0] {
-                ast::TTTok(_,token::IDENT(id,_)) => id.ctxt,
-                _ => fail!(format!("unexpected shape for marked tts: {:?}",marked_once[0]))
-            };
-        assert_eq!(mtwt_marksof(marked_once_ctxt,invalid_name),~[fm]);
-        let remarked = mtwt_cancel_outer_mark(marked_once,marked_once_ctxt);
-        assert_eq!(remarked.len(),1);
-        match remarked[0] {
-            ast::TTTok(_,token::IDENT(id,_)) =>
-            assert_eq!(mtwt_marksof(id.ctxt,invalid_name),~[]),
-            _ => fail!(format!("unexpected shape for marked tts: {:?}",remarked[0]))
-        }
-    }
-
     #[test]
     fn renaming () {
         let item_ast = string_to_crate(@"fn f() -> int { a }");

src/libsyntax/ext/tt/macro_rules.rs

@@ -13,7 +13,7 @@ use ast::{TTDelim};
 use ast;
 use codemap::{Span, Spanned, DUMMY_SP};
 use ext::base::{AnyMacro, ExtCtxt, MacResult, MRAny, MRDef, MacroDef};
-use ext::base::{NormalTT, SyntaxExpanderTTTrait};
+use ext::base::{NormalTT, MacroExpander};
 use ext::base;
 use ext::tt::macro_parser::{Success, Error, Failure};
 use ext::tt::macro_parser::{NamedMatch, MatchedSeq, MatchedNonterminal};
@@ -87,18 +87,17 @@ impl AnyMacro for ParserAnyMacro {
     }
 }
 
-struct MacroRulesSyntaxExpanderTTFun {
+struct MacroRulesMacroExpander {
     name: Ident,
     lhses: @~[@NamedMatch],
     rhses: @~[@NamedMatch],
 }
 
-impl SyntaxExpanderTTTrait for MacroRulesSyntaxExpanderTTFun {
+impl MacroExpander for MacroRulesMacroExpander {
     fn expand(&self,
               cx: &mut ExtCtxt,
               sp: Span,
-              arg: &[ast::TokenTree],
-              _: ast::SyntaxContext)
+              arg: &[ast::TokenTree])
               -> MacResult {
         generic_extension(cx, sp, self.name, arg, *self.lhses, *self.rhses)
     }
@@ -175,8 +174,7 @@ fn generic_extension(cx: &ExtCtxt,
 pub fn add_new_extension(cx: &mut ExtCtxt,
                          sp: Span,
                          name: Ident,
-                         arg: ~[ast::TokenTree],
-                         _: ast::SyntaxContext)
+                         arg: ~[ast::TokenTree])
                          -> base::MacResult {
     // these spans won't matter, anyways
     fn ms(m: Matcher_) -> Matcher {
@@ -224,7 +222,7 @@ pub fn add_new_extension(cx: &mut ExtCtxt,
         _ => cx.span_bug(sp, "wrong-structured rhs")
     };
 
-    let exp = ~MacroRulesSyntaxExpanderTTFun {
+    let exp = ~MacroRulesMacroExpander {
         name: name,
         lhses: lhses,
         rhses: rhses,

src/test/auxiliary/macro_crate_test.rs

@@ -27,8 +27,8 @@ macro_rules! unexported_macro (() => (3))
 #[macro_registrar]
 pub fn macro_registrar(register: |Name, SyntaxExtension|) {
     register(token::intern("make_a_1"),
-        NormalTT(~SyntaxExpanderTT {
-            expander: SyntaxExpanderTTExpanderWithoutContext(expand_make_a_1),
+        NormalTT(~BasicMacroExpander {
+            expander: expand_make_a_1,
             span: None,
         },
         None));