---

yaml
---
r: 51311
b: refs/heads/incoming
c: e28d4b3
h: refs/heads/master
i:
  51309: e258e60
  51307: 5bd2628
  51303: 2668356
  51295: 67f8bde
v: v3

Author: brson

[refs]

@@ -6,7 +6,7 @@ refs/heads/try: 8eb2bab100b42f0ba751552d8eff00eb2134c55a
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b
 refs/heads/try2: 147ecfdd8221e4a4d4e090486829a06da1e0ca3c
-refs/heads/incoming: 9c7e16e48d15b3380cc680f6194fe3516867d2db
+refs/heads/incoming: e28d4b3516f0703ddb5407bf8cd7fc7e273743bb
 refs/heads/dist-snap: 8b98e5a296d95c5e832db0756828e5bec31c6f50
 refs/tags/release-0.2: c870d2dffb391e14efb05aa27898f1f6333a9596
 refs/tags/release-0.3: b5f0d0f648d9a6153664837026ba1be43d3e2503

branches/incoming/doc/rust.md

@@ -212,7 +212,7 @@ do drop
 else enum extern
 false fn for
 if impl
-let loop
+let log loop
 match mod mut
 priv pub pure
 ref return
@@ -805,20 +805,21 @@ Use declarations support a number of "convenience" notations:
 An example of `use` declarations:
 
 ~~~~
+use foo = core::info;
 use core::float::sin;
 use core::str::{slice, to_upper};
 use core::option::Some;
 
 fn main() {
-    // Equivalent to 'info!(core::float::sin(1.0));'
-    info!(sin(1.0));
+    // Equivalent to 'log(core::info, core::float::sin(1.0));'
+    log(foo, sin(1.0));
 
-    // Equivalent to 'info!(core::option::Some(1.0));'
-    info!(Some(1.0));
+    // Equivalent to 'log(core::info, core::option::Some(1.0));'
+    log(info, Some(1.0));
 
-    // Equivalent to
-    // 'info!(core::str::to_upper(core::str::slice("foo", 0, 1)));'
-    info!(to_upper(slice("foo", 0, 1)));
+    // Equivalent to 'log(core::info,
+    //                    core::str::to_upper(core::str::slice("foo", 0, 1)));'
+    log(info, to_upper(slice("foo", 0, 1)));
 }
 ~~~~
 
@@ -989,7 +990,7 @@ output slot type would normally be. For example:
 
 ~~~~
 fn my_err(s: &str) -> ! {
-    info!(s);
+    log(info, s);
     fail!();
 }
 ~~~~
@@ -2396,6 +2397,58 @@ fn max(a: int, b: int) -> int {
 }
 ~~~~
 
+### Log expressions
+
+~~~~~~~~{.ebnf .gram}
+log_expr : "log" '(' level ',' expr ')' ;
+~~~~~~~~
+
+Evaluating a `log` expression may, depending on runtime configuration, cause a
+value to be appended to an internal diagnostic logging buffer provided by the
+runtime or emitted to a system console. Log expressions are enabled or
+disabled dynamically at run-time on a per-task and per-item basis. See
+[logging system](#logging-system).
+
+Each `log` expression must be provided with a *level* argument in
+addition to the value to log. The logging level is a `u32` value, where
+lower levels indicate more-urgent levels of logging. By default, the lowest
+four logging levels (`1_u32 ... 4_u32`) are predefined as the constants
+`error`, `warn`, `info` and `debug` in the `core` library.
+
+Additionally, the macros `error!`, `warn!`, `info!` and `debug!` are defined
+in the default syntax-extension namespace. These expand into calls to the
+logging facility composed with calls to the `fmt!` string formatting
+syntax-extension.
+
+The following examples all produce the same output, logged at the `error`
+logging level:
+
+~~~~
+# let filename = "bulbasaur";
+
+// Full version, logging a value.
+log(core::error, ~"file not found: " + filename);
+
+// Log-level abbreviated, since core::* is used by default.
+log(error, ~"file not found: " + filename);
+
+// Formatting the message using a format-string and fmt!
+log(error, fmt!("file not found: %s", filename));
+
+// Using the error! macro, that expands to the previous call.
+error!("file not found: %s", filename);
+~~~~
+
+A `log` expression is *not evaluated* when logging at the specified logging-level, module or task is disabled at runtime.
+This makes inactive `log` expressions very cheap;
+they should be used extensively in Rust code, as diagnostic aids,
+as they add little overhead beyond a single integer-compare and branch at runtime.
+
+Logging is presently implemented as a language built-in feature,
+as it makes use of compiler-provided, per-module data tables and flags.
+In the future, logging will move into a library, and will no longer be a core expression type.
+It is therefore recommended to use the macro forms of logging (`error!`, `debug!`, etc.) to minimize disruption in code that uses logging.
+
 
 # Type system
 
@@ -3096,7 +3149,7 @@ communication facilities.
 
 The runtime contains a system for directing [logging
 expressions](#log-expressions) to a logging console and/or internal logging
-buffers. Logging can be enabled per module.
+buffers. Logging expressions can be enabled per module.
 
 Logging output is enabled by setting the `RUST_LOG` environment
 variable.  `RUST_LOG` accepts a logging specification made up of a

branches/incoming/doc/tutorial.md

@@ -744,7 +744,7 @@ unit, `()`, as the empty tuple if you like).
 ~~~~
 let mytup: (int, int, float) = (10, 20, 30.0);
 match mytup {
-  (a, b, c) => info!(a + b + (c as int))
+  (a, b, c) => log(info, a + b + (c as int))
 }
 ~~~~
 
@@ -760,7 +760,7 @@ For example:
 struct MyTup(int, int, float);
 let mytup: MyTup = MyTup(10, 20, 30.0);
 match mytup {
-  MyTup(a, b, c) => info!(a + b + (c as int))
+  MyTup(a, b, c) => log(info, a + b + (c as int))
 }
 ~~~~
 

branches/incoming/src/compiletest/util.rs

@@ -46,6 +46,6 @@ pub fn path_div() -> ~str { ~":" }
 pub fn path_div() -> ~str { ~";" }
 
 pub fn logv(config: config, s: ~str) {
-    debug!("%s", s);
+    log(debug, s);
     if config.verbose { io::println(s); }
 }

branches/incoming/src/libcore/core.rc

@@ -216,17 +216,14 @@ pub use clone::Clone;
  * more-verbosity. Error is the bottom level, default logging level is
  * warn-and-below.
  */
+
 /// The error log level
-#[cfg(stage0)]
 pub const error : u32 = 1_u32;
 /// The warning log level
-#[cfg(stage0)]
 pub const warn : u32 = 2_u32;
 /// The info log level
-#[cfg(stage0)]
 pub const info : u32 = 3_u32;
 /// The debug log level
-#[cfg(stage0)]
 pub const debug : u32 = 4_u32;
 
 
@@ -254,13 +251,9 @@ pub mod rt;
 // can be resolved within libcore.
 #[doc(hidden)] // FIXME #3538
 pub mod core {
-    #[cfg(stage0)]
     pub const error : u32 = 1_u32;
-    #[cfg(stage0)]
     pub const warn : u32 = 2_u32;
-    #[cfg(stage0)]
     pub const info : u32 = 3_u32;
-    #[cfg(stage0)]
     pub const debug : u32 = 4_u32;
 
     pub use cmp;

branches/incoming/src/libcore/io.rs

@@ -683,7 +683,7 @@ impl Writer for *libc::FILE {
                                         *self);
                 if nout != len as size_t {
                     error!("error writing buffer");
-                    error!("%s", os::last_os_error());
+                    log(error, os::last_os_error());
                     fail!();
                 }
             }
@@ -733,7 +733,7 @@ impl Writer for fd_t {
                     let nout = libc::write(*self, vb, len as size_t);
                     if nout < 0 as ssize_t {
                         error!("error writing buffer");
-                        error!("%s", os::last_os_error());
+                        log(error, os::last_os_error());
                         fail!();
                     }
                     count += nout as uint;
@@ -1288,6 +1288,7 @@ pub mod fsync {
 
 #[cfg(test)]
 mod tests {
+    use debug;
     use i32;
     use io::{BytesWriter, SeekCur, SeekEnd, SeekSet};
     use io;
@@ -1300,10 +1301,10 @@ mod tests {
     #[test]
     fn test_simple() {
         let tmpfile = &Path("tmp/lib-io-test-simple.tmp");
-        debug!(tmpfile);
+        log(debug, tmpfile);
         let frood: ~str =
             ~"A hoopy frood who really knows where his towel is.";
-        debug!(copy frood);
+        log(debug, copy frood);
         {
             let out: io::Writer =
                 result::get(
@@ -1312,7 +1313,7 @@ mod tests {
         }
         let inp: io::Reader = result::get(&io::file_reader(tmpfile));
         let frood2: ~str = inp.read_c_str();
-        debug!(copy frood2);
+        log(debug, copy frood2);
         fail_unless!(frood == frood2);
     }
 

branches/incoming/src/libcore/os.rs

@@ -208,8 +208,8 @@ pub fn env() -> ~[(~str,~str)] {
             let mut result = ~[];
             ptr::array_each(environ, |e| {
                 let env_pair = str::raw::from_c_str(e);
-                debug!("get_env_pairs: %s",
-                       env_pair);
+                log(debug, fmt!("get_env_pairs: %s",
+                                env_pair));
                 result.push(env_pair);
             });
             result
@@ -219,8 +219,9 @@ pub fn env() -> ~[(~str,~str)] {
             let mut pairs = ~[];
             for input.each |p| {
                 let vs = str::splitn_char(*p, '=', 1);
-                debug!("splitting: len: %u",
-                    vs.len());
+                log(debug,
+                    fmt!("splitting: len: %u",
+                    vs.len()));
                 fail_unless!(vs.len() == 2);
                 pairs.push((copy vs[0], copy vs[1]));
             }
@@ -681,10 +682,10 @@ pub fn list_dir(p: &Path) -> ~[~str] {
             let input = p.to_str();
             let mut strings = ~[];
             let input_ptr = ::cast::transmute(&input[0]);
-            debug!("os::list_dir -- BEFORE OPENDIR");
+            log(debug, "os::list_dir -- BEFORE OPENDIR");
             let dir_ptr = opendir(input_ptr);
             if (dir_ptr as uint != 0) {
-        debug!("os::list_dir -- opendir() SUCCESS");
+        log(debug, "os::list_dir -- opendir() SUCCESS");
                 let mut entry_ptr = readdir(dir_ptr);
                 while (entry_ptr as uint != 0) {
                     strings.push(
@@ -696,11 +697,11 @@ pub fn list_dir(p: &Path) -> ~[~str] {
                 closedir(dir_ptr);
             }
             else {
-        debug!("os::list_dir -- opendir() FAILURE");
+        log(debug, "os::list_dir -- opendir() FAILURE");
             }
-            debug!(
-                "os::list_dir -- AFTER -- #: %?",
-                     strings.len());
+            log(debug,
+                fmt!("os::list_dir -- AFTER -- #: %?",
+                     strings.len()));
             strings
         }
         #[cfg(windows)]
@@ -1257,6 +1258,7 @@ pub mod consts {
 #[cfg(test)]
 #[allow(non_implicitly_copyable_typarams)]
 mod tests {
+    use debug;
     use libc::{c_int, c_void, size_t};
     use libc;
     use option::{None, Option, Some};
@@ -1272,7 +1274,7 @@ mod tests {
 
     #[test]
     pub fn last_os_error() {
-        debug!(os::last_os_error());
+        log(debug, os::last_os_error());
     }
 
     #[test]
@@ -1318,7 +1320,7 @@ mod tests {
         while i < 100 { s += ~"aaaaaaaaaa"; i += 1; }
         let n = make_rand_name();
         setenv(n, s);
-        debug!(copy s);
+        log(debug, copy s);
         fail_unless!(getenv(n) == option::Some(s));
     }
 
@@ -1327,7 +1329,7 @@ mod tests {
         let path = os::self_exe_path();
         fail_unless!(path.is_some());
         let path = path.get();
-        debug!(copy path);
+        log(debug, copy path);
 
         // Hard to test this function
         fail_unless!(path.is_absolute);
@@ -1340,7 +1342,7 @@ mod tests {
         fail_unless!(vec::len(e) > 0u);
         for vec::each(e) |p| {
             let (n, v) = copy *p;
-            debug!(copy n);
+            log(debug, copy n);
             let v2 = getenv(n);
             // MingW seems to set some funky environment variables like
             // "=C:=C:\MinGW\msys\1.0\bin" and "!::=::\" that are returned
@@ -1365,10 +1367,10 @@ mod tests {
     fn test() {
         fail_unless!((!Path("test-path").is_absolute));
 
-        debug!(~"Current working directory: " + getcwd().to_str());
+        log(debug, ~"Current working directory: " + getcwd().to_str());
 
-        debug!(make_absolute(&Path("test-path")));
-        debug!(make_absolute(&Path("/usr/bin")));
+        log(debug, make_absolute(&Path("test-path")));
+        log(debug, make_absolute(&Path("/usr/bin")));
     }
 
     #[test]
@@ -1431,7 +1433,7 @@ mod tests {
         fail_unless!((vec::len(dirs) > 0u));
 
         for vec::each(dirs) |dir| {
-            debug!(copy *dir);
+            log(debug, copy *dir);
         }
     }
 

branches/incoming/src/libcore/prelude.rs

@@ -82,3 +82,18 @@ pub use u64;
 pub use u8;
 pub use uint;
 pub use vec;
+
+/*
+ * Export the log levels as global constants. Higher levels mean
+ * more-verbosity. Error is the bottom level, default logging level is
+ * warn-and-below.
+ */
+
+/// The error log level
+pub const error : u32 = 1_u32;
+/// The warning log level
+pub const warn : u32 = 2_u32;
+/// The info log level
+pub const info : u32 = 3_u32;
+/// The debug log level
+pub const debug : u32 = 4_u32;