Add log crate and add a generic logger.

This is the first step of integrating the log crate as the main way to
log messages from the kernel.

Also, reexport all log macros. This module should eventually be the
only logging API used in the kernel.

Signed-off-by: Wren Turkal <wt@penguintechs.org>

Cargo.lock

@@ -15,6 +15,11 @@ name = "cc"
 version = "1.0.52"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "cfg-if"
+version = "0.1.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "goblin"
 version = "0.2.1"
@@ -31,6 +36,7 @@ dependencies = [
  "bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "goblin 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "linked_list_allocator 0.8.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.4.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "paste 0.1.18 (registry+https://github.com/rust-lang/crates.io-index)",
  "raw-cpuid 8.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "redox_syscall 0.2.0",
@@ -64,6 +70,14 @@ dependencies = [
  "scopeguard 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "log"
+version = "0.4.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "paste"
 version = "0.1.18"
@@ -194,10 +208,12 @@ dependencies = [
 "checksum bit_field 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)" = "a165d606cf084741d4ac3a28fb6e9b1eb0bd31f6cd999098cfddb0b2ab381dc0"
 "checksum bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
 "checksum cc 1.0.52 (registry+https://github.com/rust-lang/crates.io-index)" = "c3d87b23d6a92cd03af510a5ade527033f6aa6fa92161e2d5863a907d4c5e31d"
+"checksum cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)" = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
 "checksum goblin 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "ddd5e3132801a1ac34ac53b97acde50c4685414dd2f291b9ea52afa6f07468c8"
 "checksum linked_list_allocator 0.6.6 (registry+https://github.com/rust-lang/crates.io-index)" = "47de1a43fad0250ee197e9e124e5b5deab3d7b39d4428ae8a6d741ceb340c362"
 "checksum linked_list_allocator 0.8.4 (registry+https://github.com/rust-lang/crates.io-index)" = "e70e46c13c0e8374c26cec5752e3347ca1087d9711de8f45aa513a7700efd73d"
 "checksum lock_api 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)" = "c4da24a77a3d8a6d4862d95f72e6fdb9c09a643ecdb402d754004a557f2bec75"
+"checksum log 0.4.11 (registry+https://github.com/rust-lang/crates.io-index)" = "4fabed175da42fed1fa0746b0ea71f412aa9d35e76e95e59b192c64b9dc2bf8b"
 "checksum paste 0.1.18 (registry+https://github.com/rust-lang/crates.io-index)" = "45ca20c77d80be666aef2b45486da86238fabe33e38306bd3118fe4af33fa880"
 "checksum paste-impl 0.1.18 (registry+https://github.com/rust-lang/crates.io-index)" = "d95a7db200b97ef370c8e6de0088252f7e0dfff7d047a28528e47456c0fc98b6"
 "checksum plain 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "b4596b6d070b27117e987119b4dac604f3c58cfb0b191112e24771b2faeac1a6"

Cargo.toml

@@ -12,6 +12,7 @@ crate-type = ["staticlib"]
 [dependencies]
 bitflags = "1.2.1"
 linked_list_allocator = "0.8.4"
+log = { version = "0.4" }
 raw-cpuid = "8.0.0"
 redox_syscall = { path = "syscall" }
 slab_allocator = { path = "slab_allocator", optional = true }

src/log.rs

@@ -33,3 +33,21 @@ impl Log {
         }
     }
 }
+
+struct RedoxLogger {
+    log_func: fn(&log::Record),
+}
+
+impl ::log::Log for RedoxLogger {
+    fn enabled(&self, _: &log::Metadata<'_>) -> bool {
+        false
+    }
+    fn log(&self, record: &log::Record<'_>) {
+        (self.log_func)(&record)
+    }
+    fn flush(&self) {}
+}
+
+static _LOGGER: RedoxLogger = RedoxLogger { log_func: |_| {} };
+
+pub use log::{debug, error, info, trace, warn};