auto merge of #5293 : brson/rust/logging, r=brson

r? @graydon

This removes `log` from the language. Because we can't quite implement it as a syntax extension (probably need globals at the least) it simply renames the keyword to `__log` and hides it behind macros.

After this the only way to log is with `debug!`, `info!`, etc. I figure that if there is demand for `log!` we can add it back later.

I am not sure that we ever agreed on this course of action, though I *think* there is consensus that `log` shouldn't be a statement.

Author: bors

doc/rust.md

@@ -212,7 +212,7 @@ do drop
 else enum extern
 false fn for
 if impl
-let log loop
+let loop
 match mod mut
 priv pub pure
 ref return
@@ -805,21 +805,20 @@ 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 'log(core::info, core::float::sin(1.0));'
-    log(foo, sin(1.0));
+    // Equivalent to 'info!(core::float::sin(1.0));'
+    info!(sin(1.0));
 
-    // Equivalent to 'log(core::info, core::option::Some(1.0));'
-    log(info, Some(1.0));
+    // Equivalent to 'info!(core::option::Some(1.0));'
+    info!(Some(1.0));
 
-    // Equivalent to 'log(core::info,
-    //                    core::str::to_upper(core::str::slice("foo", 0, 1)));'
-    log(info, to_upper(slice("foo", 0, 1)));
+    // Equivalent to
+    // 'info!(core::str::to_upper(core::str::slice("foo", 0, 1)));'
+    info!(to_upper(slice("foo", 0, 1)));
 }
 ~~~~
 
@@ -990,7 +989,7 @@ output slot type would normally be. For example:
 
 ~~~~
 fn my_err(s: &str) -> ! {
-    log(info, s);
+    info!(s);
     fail!();
 }
 ~~~~
@@ -2397,58 +2396,6 @@ 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
 
@@ -3149,7 +3096,7 @@ communication facilities.
 
 The runtime contains a system for directing [logging
 expressions](#log-expressions) to a logging console and/or internal logging
-buffers. Logging expressions can be enabled per module.
+buffers. Logging 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

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) => log(info, a + b + (c as int))
+  (a, b, c) => 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) => log(info, a + b + (c as int))
+  MyTup(a, b, c) => info!(a + b + (c as int))
 }
 ~~~~
 

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) {
-    log(debug, s);
+    debug!("%s", s);
     if config.verbose { io::println(s); }
 }

src/libcore/core.rc

@@ -216,14 +216,17 @@ 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;
 
 
@@ -251,9 +254,13 @@ 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;

src/libcore/io.rs

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

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);
-                log(debug, fmt!("get_env_pairs: %s",
-                                env_pair));
+                debug!("get_env_pairs: %s",
+                       env_pair);
                 result.push(env_pair);
             });
             result
@@ -219,9 +219,8 @@ pub fn env() -> ~[(~str,~str)] {
             let mut pairs = ~[];
             for input.each |p| {
                 let vs = str::splitn_char(*p, '=', 1);
-                log(debug,
-                    fmt!("splitting: len: %u",
-                    vs.len()));
+                debug!("splitting: len: %u",
+                    vs.len());
                 fail_unless!(vs.len() == 2);
                 pairs.push((copy vs[0], copy vs[1]));
             }
@@ -682,10 +681,10 @@ pub fn list_dir(p: &Path) -> ~[~str] {
             let input = p.to_str();
             let mut strings = ~[];
             let input_ptr = ::cast::transmute(&input[0]);
-            log(debug, "os::list_dir -- BEFORE OPENDIR");
+            debug!("os::list_dir -- BEFORE OPENDIR");
             let dir_ptr = opendir(input_ptr);
             if (dir_ptr as uint != 0) {
-        log(debug, "os::list_dir -- opendir() SUCCESS");
+        debug!("os::list_dir -- opendir() SUCCESS");
                 let mut entry_ptr = readdir(dir_ptr);
                 while (entry_ptr as uint != 0) {
                     strings.push(
@@ -697,11 +696,11 @@ pub fn list_dir(p: &Path) -> ~[~str] {
                 closedir(dir_ptr);
             }
             else {
-        log(debug, "os::list_dir -- opendir() FAILURE");
+        debug!("os::list_dir -- opendir() FAILURE");
             }
-            log(debug,
-                fmt!("os::list_dir -- AFTER -- #: %?",
-                     strings.len()));
+            debug!(
+                "os::list_dir -- AFTER -- #: %?",
+                     strings.len());
             strings
         }
         #[cfg(windows)]
@@ -1258,7 +1257,6 @@ 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};
@@ -1274,7 +1272,7 @@ mod tests {
 
     #[test]
     pub fn last_os_error() {
-        log(debug, os::last_os_error());
+        debug!(os::last_os_error());
     }
 
     #[test]
@@ -1320,7 +1318,7 @@ mod tests {
         while i < 100 { s += ~"aaaaaaaaaa"; i += 1; }
         let n = make_rand_name();
         setenv(n, s);
-        log(debug, copy s);
+        debug!(copy s);
         fail_unless!(getenv(n) == option::Some(s));
     }
 
@@ -1329,7 +1327,7 @@ mod tests {
         let path = os::self_exe_path();
         fail_unless!(path.is_some());
         let path = path.get();
-        log(debug, copy path);
+        debug!(copy path);
 
         // Hard to test this function
         fail_unless!(path.is_absolute);
@@ -1342,7 +1340,7 @@ mod tests {
         fail_unless!(vec::len(e) > 0u);
         for vec::each(e) |p| {
             let (n, v) = copy *p;
-            log(debug, copy n);
+            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
@@ -1367,10 +1365,10 @@ mod tests {
     fn test() {
         fail_unless!((!Path("test-path").is_absolute));
 
-        log(debug, ~"Current working directory: " + getcwd().to_str());
+        debug!(~"Current working directory: " + getcwd().to_str());
 
-        log(debug, make_absolute(&Path("test-path")));
-        log(debug, make_absolute(&Path("/usr/bin")));
+        debug!(make_absolute(&Path("test-path")));
+        debug!(make_absolute(&Path("/usr/bin")));
     }
 
     #[test]
@@ -1433,7 +1431,7 @@ mod tests {
         fail_unless!((vec::len(dirs) > 0u));
 
         for vec::each(dirs) |dir| {
-            log(debug, copy *dir);
+            debug!(copy *dir);
         }
     }
 

src/libcore/prelude.rs

@@ -82,18 +82,3 @@ 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;