auto merge of #9005 : alexcrichton/rust/rusty-log, r=brson

Also redefine all of the standard logging macros to use more rust code instead
of custom LLVM translation code. This makes them a bit easier to understand, but
also more flexibile for future types of logging.

Additionally, this commit removes the LogType language item in preparation for
changing how logging is performed.

8 files changed, 49 insertions, 83 deletions

diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 6957f9ae351..c4038932613 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -550,7 +550,9 @@ pub enum Expr_ {
     ExprBreak(Option<Ident>),
     ExprAgain(Option<Ident>),
     ExprRet(Option<@Expr>),
-    ExprLog(@Expr, @Expr),
+
+    /// Gets the log level for the enclosing module
+    ExprLogLevel,
 
     ExprInlineAsm(inline_asm),
 
diff --git a/src/libsyntax/ext/expand.rs b/src/libsyntax/ext/expand.rs
index 099fa54c0c2..50a14c0fd71 100644
--- a/src/libsyntax/ext/expand.rs
+++ b/src/libsyntax/ext/expand.rs
@@ -870,59 +870,41 @@ pub fn std_macros() -> @str {
 
     macro_rules! ignore (($($x:tt)*) => (()))
 
-    macro_rules! error (
-        ($arg:expr) => (
-            __log(1u32, fmt!( \"%?\", $arg ))
-        );
-        ($( $arg:expr ),+) => (
-            __log(1u32, fmt!( $($arg),+ ))
-        )
-    )
-
-    macro_rules! warn (
-        ($arg:expr) => (
-            __log(2u32, fmt!( \"%?\", $arg ))
-        );
-        ($( $arg:expr ),+) => (
-            __log(2u32, fmt!( $($arg),+ ))
-        )
-    )
-
-    macro_rules! info (
-        ($arg:expr) => (
-            __log(3u32, fmt!( \"%?\", $arg ))
-        );
-        ($( $arg:expr ),+) => (
-            __log(3u32, fmt!( $($arg),+ ))
-        )
-    )
-
-    macro_rules! debug (
-        ($arg:expr) => (
-            if cfg!(debug) { __log(4u32, fmt!( \"%?\", $arg )) }
-        );
-        ($( $arg:expr ),+) => (
-            if cfg!(debug) { __log(4u32, fmt!( $($arg),+ )) }
-        )
-    )
-
-    macro_rules! error2 (
-        ($($arg:tt)*) => ( __log(1u32, format!($($arg)*)))
-    )
-
-    macro_rules! warn2 (
-        ($($arg:tt)*) => ( __log(2u32, format!($($arg)*)))
-    )
-
-    macro_rules! info2 (
-        ($($arg:tt)*) => ( __log(3u32, format!($($arg)*)))
+    macro_rules! log(
+        ($lvl:expr, $arg:expr) => ({
+            let lvl = $lvl;
+            if lvl <= __log_level() {
+                ::std::logging::log(lvl, fmt!(\"%?\", $arg))
+            }
+        });
+        ($lvl:expr, $($arg:expr),+) => ({
+            let lvl = $lvl;
+            if lvl <= __log_level() {
+                ::std::logging::log(lvl, fmt!($($arg),+))
+            }
+        })
     )
+    macro_rules! error( ($($arg:tt)+) => (log!(1u32, $($arg)+)) )
+    macro_rules! warn ( ($($arg:tt)+) => (log!(2u32, $($arg)+)) )
+    macro_rules! info ( ($($arg:tt)+) => (log!(3u32, $($arg)+)) )
+    macro_rules! debug( ($($arg:tt)+) => (
+        if cfg!(debug) { log!(4u32, $($arg)+) }
+    ))
 
-    macro_rules! debug2 (
-        ($($arg:tt)*) => (
-            if cfg!(debug) { __log(4u32, format!($($arg)*)) }
-        )
+    macro_rules! log2(
+        ($lvl:expr, $($arg:tt)+) => ({
+            let lvl = $lvl;
+            if lvl <= __log_level() {
+                ::std::logging::log(lvl, format!($($arg)+))
+            }
+        })
     )
+    macro_rules! error2( ($($arg:tt)+) => (log2!(1u32, $($arg)+)) )
+    macro_rules! warn2 ( ($($arg:tt)+) => (log2!(2u32, $($arg)+)) )
+    macro_rules! info2 ( ($($arg:tt)+) => (log2!(3u32, $($arg)+)) )
+    macro_rules! debug2( ($($arg:tt)+) => (
+        if cfg!(debug) { log2!(4u32, $($arg)+) }
+    ))
 
     macro_rules! fail(
         () => (
@@ -1149,13 +1131,13 @@ pub fn std_macros() -> @str {
     //              allocation but should rather delegate to an invocation of
     //              write! instead of format!
     macro_rules! print (
-        ($($arg:tt)+) => ( ::std::io::print(format!($($arg)+)))
+        ($($arg:tt)+) => (::std::io::print(format!($($arg)+)))
     )
 
     // FIXME(#6846) once stdio is redesigned, this shouldn't perform an
     //              allocation but should rather delegate to an io::Writer
     macro_rules! println (
-        ($($arg:tt)+) => ({ print!($($arg)+); ::std::io::println(\"\"); })
+        ($($arg:tt)+) => (::std::io::println(format!($($arg)+)))
     )
 
     // NOTE: use this after a snapshot lands to abstract the details
diff --git a/src/libsyntax/fold.rs b/src/libsyntax/fold.rs
index 11e39163992..664bd3f128a 100644
--- a/src/libsyntax/fold.rs
+++ b/src/libsyntax/fold.rs
@@ -617,12 +617,7 @@ pub fn noop_fold_expr(e: &Expr_, fld: @ast_fold) -> Expr_ {
         ExprRet(ref e) => {
             ExprRet(e.map_move(|x| fld.fold_expr(x)))
         }
-        ExprLog(lv, e) => {
-            ExprLog(
-                fld.fold_expr(lv),
-                fld.fold_expr(e)
-            )
-        }
+        ExprLogLevel => ExprLogLevel,
         ExprInlineAsm(ref a) => {
             ExprInlineAsm(inline_asm {
                 inputs: a.inputs.map(|&(c, input)| (c, fld.fold_expr(input))),
diff --git a/src/libsyntax/oldvisit.rs b/src/libsyntax/oldvisit.rs
index 850f73096ed..80e037bce81 100644
--- a/src/libsyntax/oldvisit.rs
+++ b/src/libsyntax/oldvisit.rs
@@ -567,10 +567,7 @@ pub fn visit_expr<E:Clone>(ex: @Expr, (e, v): (E, vt<E>)) {
         ExprBreak(_) => (),
         ExprAgain(_) => (),
         ExprRet(eo) => visit_expr_opt(eo, (e.clone(), v)),
-        ExprLog(lv, x) => {
-            (v.visit_expr)(lv, (e.clone(), v));
-            (v.visit_expr)(x, (e.clone(), v));
-        }
+        ExprLogLevel => (),
         ExprMac(ref mac) => visit_mac(mac, (e.clone(), v)),
         ExprParen(x) => (v.visit_expr)(x, (e.clone(), v)),
         ExprInlineAsm(ref a) => {
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index b8615352504..9410d0194c3 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -26,7 +26,7 @@ use ast::{Expr, Expr_, ExprAddrOf, ExprMatch, ExprAgain};
 use ast::{ExprAssign, ExprAssignOp, ExprBinary, ExprBlock};
 use ast::{ExprBreak, ExprCall, ExprCast, ExprDoBody};
 use ast::{ExprField, ExprFnBlock, ExprIf, ExprIndex};
-use ast::{ExprLit, ExprLog, ExprLoop, ExprMac};
+use ast::{ExprLit, ExprLogLevel, ExprLoop, ExprMac};
 use ast::{ExprMethodCall, ExprParen, ExprPath, ExprRepeat};
 use ast::{ExprRet, ExprSelf, ExprStruct, ExprTup, ExprUnary};
 use ast::{ExprVec, ExprVstore, ExprVstoreMutBox};
@@ -1832,13 +1832,10 @@ impl Parser {
                 }
             }
             hi = self.last_span.hi;
-        } else if self.eat_keyword(keywords::__Log) {
-            // LOG expression
+        } else if self.eat_keyword(keywords::__LogLevel) {
+            // LOG LEVEL expression
             self.expect(&token::LPAREN);
-            let lvl = self.parse_expr();
-            self.expect(&token::COMMA);
-            let e = self.parse_expr();
-            ex = ExprLog(lvl, e);
+            ex = ExprLogLevel;
             hi = self.span.hi;
             self.expect(&token::RPAREN);
         } else if self.eat_keyword(keywords::Return) {
diff --git a/src/libsyntax/parse/token.rs b/src/libsyntax/parse/token.rs
index 6b3a95a14f8..fa00b536837 100644
--- a/src/libsyntax/parse/token.rs
+++ b/src/libsyntax/parse/token.rs
@@ -456,7 +456,7 @@ fn mk_fresh_ident_interner() -> @ident_interner {
         "if",                 // 42
         "impl",               // 43
         "let",                // 44
-        "__log",              // 45
+        "__log_level",        // 45
         "loop",               // 46
         "match",              // 47
         "mod",                // 48
@@ -606,7 +606,7 @@ pub mod keywords {
         Impl,
         In,
         Let,
-        __Log,
+        __LogLevel,
         Loop,
         Match,
         Mod,
@@ -651,7 +651,7 @@ pub mod keywords {
                 Impl => Ident { name: 43, ctxt: 0 },
                 In => Ident { name: 63, ctxt: 0 },
                 Let => Ident { name: 44, ctxt: 0 },
-                __Log => Ident { name: 45, ctxt: 0 },
+                __LogLevel => Ident { name: 45, ctxt: 0 },
                 Loop => Ident { name: 46, ctxt: 0 },
                 Match => Ident { name: 47, ctxt: 0 },
                 Mod => Ident { name: 48, ctxt: 0 },
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index 282b66b2c59..ca0ff81b65b 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -1414,13 +1414,9 @@ pub fn print_expr(s: @ps, expr: &ast::Expr) {
           _ => ()
         }
       }
-      ast::ExprLog(lexp, expr) => {
-        word(s.s, "__log");
+      ast::ExprLogLevel => {
+        word(s.s, "__log_level");
         popen(s);
-        print_expr(s, lexp);
-        word(s.s, ",");
-        space_if_not_bol(s);
-        print_expr(s, expr);
         pclose(s);
       }
       ast::ExprInlineAsm(ref a) => {
diff --git a/src/libsyntax/visit.rs b/src/libsyntax/visit.rs
index 191b4509a80..ea8edf0b3d1 100644
--- a/src/libsyntax/visit.rs
+++ b/src/libsyntax/visit.rs
@@ -643,10 +643,7 @@ pub fn walk_expr<E:Clone, V:Visitor<E>>(visitor: &mut V, expression: @Expr, env:
         ExprRet(optional_expression) => {
             walk_expr_opt(visitor, optional_expression, env.clone())
         }
-        ExprLog(level, subexpression) => {
-            visitor.visit_expr(level, env.clone());
-            visitor.visit_expr(subexpression, env.clone());
-        }
+        ExprLogLevel => {}
         ExprMac(ref macro) => walk_mac(visitor, macro, env.clone()),
         ExprParen(subexpression) => {
             visitor.visit_expr(subexpression, env.clone())