log: mw_log_fmt_macro implementation

- Replacement for `format_args!` macros.
- Replacement for `Debug` derive macro.
- Unit tests.

Author: arkjedrz

Cargo.lock

@@ -2,9 +2,13 @@
 resolver = "2"
 # Split to default members without tests and examples.
 # Used when executing cargo from project root.
-default-members = ["src/containers", "src/log/mw_log_fmt"]
+default-members = [
+    "src/containers",
+    "src/log/mw_log_fmt",
+    "src/log/mw_log_fmt_macro",
+]
 # Include tests and examples as a member for IDE support and Bazel builds.
-members = ["src/containers", "src/log/mw_log_fmt"]
+members = ["src/containers", "src/log/mw_log_fmt", "src/log/mw_log_fmt_macro"]
 
 
 [workspace.package]
@@ -16,6 +20,7 @@ authors = ["S-CORE Contributors"]
 
 [workspace.dependencies]
 mw_log_fmt = { path = "src/log/mw_log_fmt" }
+mw_log_fmt_macro = { path = "src/log/mw_log_fmt_macro" }
 
 
 [workspace.lints.clippy]

Cargo.toml

@@ -37,7 +37,7 @@ package log <<component>> {
         +trace!(...) : ()
     }
 
-    class mw_log_macro <<module>> {
+    class mw_log_fmt_macro <<module>> {
         +mw_log_format_args!(format_string: &str, args...) : Arguments<'_>
         +mw_log_format_args_nl!(format_string: &str, args...) : Arguments<'_>
     }
@@ -57,7 +57,7 @@ package log <<component>> {
 
     mw_log -- Level
     mw_log -- LevelFilter
-    mw_log -- mw_log_macro
+    mw_log -- mw_log_fmt_macro
     mw_log -right- mw_log_fmt
 }
 

docs/module/log/architecture/_assets/interface.puml

@@ -5,10 +5,10 @@ package "log" <<component>> {
 
     component "mw_log_fmt"
 
-    component "mw_log_macro"
+    component "mw_log_fmt_macro"
 
     mw_log ..> mw_log_fmt : use
-    mw_log ..> mw_log_macro : use
+    mw_log ..> mw_log_fmt_macro : use
 }
 
 component "mw_log_subscriber" <<component>>

docs/module/log/architecture/_assets/static_view.puml

@@ -217,8 +217,8 @@ package "mw_log_fmt crate" {
     mw_log_fmt -- Arguments
 }
 
-package "mw_log_macro crate" {
-    +class mw_log_macro <<module>> {
+package "mw_log_fmt_macro crate" {
+    +class mw_log_fmt_macro <<module>> {
         +mw_log_format_args!(format_string: &str, args...) : Arguments<'_>
         +mw_log_format_args_nl!(format_string: &str, args...) : Arguments<'_>
     }
@@ -262,7 +262,7 @@ package "mw_log_subscriber crate" {
 }
 
 "mw_log crate" -[hidden]down-> "mw_log_fmt crate"
-"mw_log crate" -[hidden]up-> "mw_log_macro crate"
+"mw_log crate" -[hidden]up-> "mw_log_fmt_macro crate"
 
 "mw_log crate" -[hidden]down------> "mw_log_subscriber crate"
 "mw_log_fmt crate" -[hidden]down------> "mw_log_subscriber crate"

docs/module/log/detailed_design/_assets/class_diagram.puml

@@ -7,7 +7,7 @@ participant "mw_log <<module>>" as mw_log
 end box
 
 box #LightGreen
-participant "mw_log_macro <<module>>" as mw_log_macro
+participant "mw_log_fmt_macro <<module>>" as mw_log_fmt_macro
 end box
 
 box #LightPink
@@ -36,8 +36,8 @@ alt log-level-check-failed
     mw_log --> actor
 
 else log-level-check-passed
-    mw_log -> mw_log_macro : mw_log_format_args!()
-    mw_log_macro --> mw_log
+    mw_log -> mw_log_fmt_macro : mw_log_format_args!()
+    mw_log_fmt_macro --> mw_log
 
     mw_log -> logger : log()
 

docs/module/log/detailed_design/_assets/log_op.puml

@@ -36,7 +36,9 @@ Log component consists of three units:
 
 - `mw_log` - modelled after `log` Rust library.
 - `mw_log_fmt` - replacement for `core::fmt` provided by Rust core library.
-- `mw_log_macro` - replacement for `format_args` macro provided by Rust compiler.
+- `mw_log_fmt_macro` - replacement for macros provided by Rust compiler:
+  - `mw_log_format_args!` - replacement for `format_args!`
+  - `ScoreDebug` - replacement for `Debug`
 
 Most common approach in Rust is that formatting always results in a string.
 This means that the `log` library always receives a pre-formatted string.

docs/module/log/detailed_design/index.rst

@@ -80,7 +80,9 @@ impl<'a> DebugStruct<'a> {
     pub fn finish(&mut self) -> Result {
         if self.has_fields {
             let empty_spec = FormatSpec::new();
-            self.result = self.result.and_then(|_| self.writer.write_str(" }", &empty_spec));
+            self.result = self
+                .result
+                .and_then(|_| self.writer.write_str(" }", &empty_spec));
         }
         self.result
     }
@@ -426,7 +428,10 @@ impl<'a> DebugMap<'a> {
         F: FnOnce(Writer) -> Result,
     {
         self.result = self.result.and_then(|_| {
-            assert!(self.has_key, "attempted to format a map value before its key");
+            assert!(
+                self.has_key,
+                "attempted to format a map value before its key"
+            );
             value_fmt(self.writer)?;
             self.has_key = false;
             Ok(())
@@ -452,7 +457,10 @@ impl<'a> DebugMap<'a> {
     /// Marks the map as non-exhaustive, indicating to the reader that there are some other entries that are not shown in the debug representation.
     pub fn finish_non_exhaustive(&mut self) -> Result {
         self.result = self.result.and_then(|_| {
-            assert!(!self.has_key, "attempted to finish a map with a partial entry");
+            assert!(
+                !self.has_key,
+                "attempted to finish a map with a partial entry"
+            );
 
             let empty_spec = FormatSpec::new();
             if self.has_fields {
@@ -472,7 +480,10 @@ impl<'a> DebugMap<'a> {
     /// Otherwise this method will panic.
     pub fn finish(&mut self) -> Result {
         self.result = self.result.and_then(|_| {
-            assert!(!self.has_key, "attempted to finish a map with a partial entry");
+            assert!(
+                !self.has_key,
+                "attempted to finish a map with a partial entry"
+            );
             let empty_spec = FormatSpec::new();
             self.writer.write_str("}", &empty_spec)
         });
@@ -740,7 +751,10 @@ mod tests {
             .finish_non_exhaustive()
             .map_err(|_| panic!("failed to finish"));
 
-        assert_eq!(writer.get(), "{\"first\": 123, \"second\": 456, \"third\": 789, ..}");
+        assert_eq!(
+            writer.get(),
+            "{\"first\": 123, \"second\": 456, \"third\": 789, ..}"
+        );
     }
 
     #[test]

src/log/mw_log_fmt/builders.rs

@@ -153,7 +153,10 @@ mod tests {
             Fragment::Placeholder(Placeholder::new(&-100i8, FormatSpec::new())),
             Fragment::Placeholder(Placeholder::new(&-1234i16, FormatSpec::new())),
             Fragment::Placeholder(Placeholder::new(&-123456i32, FormatSpec::new())),
-            Fragment::Placeholder(Placeholder::new(&-1200000000000000000i64, FormatSpec::new())),
+            Fragment::Placeholder(Placeholder::new(
+                &-1200000000000000000i64,
+                FormatSpec::new(),
+            )),
             Fragment::Placeholder(Placeholder::new(&123u8, FormatSpec::new())),
             Fragment::Placeholder(Placeholder::new(&1234u16, FormatSpec::new())),
             Fragment::Placeholder(Placeholder::new(&123456u32, FormatSpec::new())),
@@ -194,7 +197,10 @@ mod tests {
             Fragment::Placeholder(Placeholder::new(&-100i8, FormatSpec::new())),
             Fragment::Placeholder(Placeholder::new(&-1234i16, FormatSpec::new())),
             Fragment::Placeholder(Placeholder::new(&-123456i32, FormatSpec::new())),
-            Fragment::Placeholder(Placeholder::new(&-1200000000000000000i64, FormatSpec::new())),
+            Fragment::Placeholder(Placeholder::new(
+                &-1200000000000000000i64,
+                FormatSpec::new(),
+            )),
             Fragment::Placeholder(Placeholder::new(&123u8, FormatSpec::new())),
             Fragment::Placeholder(Placeholder::new(&1234u16, FormatSpec::new())),
             Fragment::Placeholder(Placeholder::new(&123456u32, FormatSpec::new())),

src/log/mw_log_fmt/fmt.rs

@@ -0,0 +1,42 @@
+# *******************************************************************************
+# Copyright (c) 2025 Contributors to the Eclipse Foundation
+#
+# See the NOTICE file(s) distributed with this work for additional
+# information regarding copyright ownership.
+#
+# This program and the accompanying materials are made available under the
+# terms of the Apache License Version 2.0 which is available at
+# https://www.apache.org/licenses/LICENSE-2.0
+#
+# SPDX-License-Identifier: Apache-2.0
+# *******************************************************************************
+load("@rules_rust//rust:defs.bzl", "rust_proc_macro", "rust_test")
+
+rust_proc_macro(
+    name = "mw_log_fmt_macro",
+    srcs = glob(["*.rs"]),
+    # TODO: expose required interface through `mw_log` and make it private again.
+    # visibility = ["//visibility:private"],
+    visibility = ["//visibility:public"],
+    deps = [
+        "//src/log/mw_log_fmt",
+        "@score_crates//:proc_macro2",
+        "@score_crates//:quote",
+        "@score_crates//:syn",
+    ],
+)
+
+rust_test(
+    name = "tests",
+    srcs = glob(["tests/**/*.rs"]),
+    proc_macro_deps = [
+        "//src/log/mw_log_fmt_macro",
+    ],
+    tags = [
+        "unit_tests",
+        "ut",
+    ],
+    deps = [
+        "//src/log/mw_log_fmt",
+    ],
+)