From 8cfb4bfeb951da9ddceefc711bf897ae3cad7d61 Mon Sep 17 00:00:00 2001
From: Stephan <kiffie@users.noreply.github.com>
Date: Thu, 29 Jun 2023 21:46:56 +0200
Subject: [PATCH] add optional logging

---
 mips-mcu-alloc/.cargo/config |  5 -----
 mips-mcu-alloc/Cargo.toml    |  3 ++-
 mips-mcu-alloc/README.md     |  2 ++
 mips-mcu-alloc/src/lib.rs    | 15 ++++++++++++---
 4 files changed, 16 insertions(+), 9 deletions(-)
 delete mode 100644 mips-mcu-alloc/.cargo/config

diff --git a/mips-mcu-alloc/.cargo/config b/mips-mcu-alloc/.cargo/config
deleted file mode 100644
index 8a80fe9..0000000
--- a/mips-mcu-alloc/.cargo/config
+++ /dev/null
@@ -1,5 +0,0 @@
-[build]
-target = "mipsel-unknown-none"
-
-[unstable]
-build-std = ["core", "compiler_builtins", "alloc"]
diff --git a/mips-mcu-alloc/Cargo.toml b/mips-mcu-alloc/Cargo.toml
index 5c04a29..ca487a1 100644
--- a/mips-mcu-alloc/Cargo.toml
+++ b/mips-mcu-alloc/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "mips-mcu-alloc"
 description = "A heap allocator for MIPS based microcontrollers"
-version = "0.6.0"
+version = "0.6.1"
 authors = ["Stephan <kiffie@mailbox.org>"]
 repository = "https://github.com/kiffie/pic32-rs/tree/master/mips-mcu-alloc"
 license = "MIT OR Apache-2.0"
@@ -15,6 +15,7 @@ include = ["README.md", "/src", "LICENSE"]
 mips-mcu = "0.3.0"
 mips-rt = "0.3.0"
 critical-section = "1.0.0"
+log = { version = "0.4.19", optional = true }
 
 [dependencies.linked_list_allocator]
 default-features = false
diff --git a/mips-mcu-alloc/README.md b/mips-mcu-alloc/README.md
index 25a4819..77b6211 100644
--- a/mips-mcu-alloc/README.md
+++ b/mips-mcu-alloc/README.md
@@ -9,6 +9,8 @@ The heap is placed at a location determined by the linker and automatically exte
 to fullfil allocation requests. Automatic heap extension fails if the heap would collide
 with the stack.
 
+Memory allocation and heap extension can be traced via logging by activating the `log` feature.
+
 Example:
 
 ```rust
diff --git a/mips-mcu-alloc/src/lib.rs b/mips-mcu-alloc/src/lib.rs
index a1c9327..a1fdc75 100644
--- a/mips-mcu-alloc/src/lib.rs
+++ b/mips-mcu-alloc/src/lib.rs
@@ -6,7 +6,7 @@
 //!
 //! # Example
 //!
-//! ```
+//! ```ignore
 //! #![feature(global_allocator)]
 //! #![feature(alloc_error_handler)]
 //!
@@ -19,8 +19,6 @@
 //! #[global_allocator]
 //! static ALLOCATOR: MipsMcuHeap = MipsMcuHeap::empty();
 //!
-//! entry!(main);
-//!
 //! #[entry]
 //! fn main() -> ! {
 //!     ALLOCATOR.init();
@@ -50,6 +48,9 @@ use critical_section::{self, Mutex};
 use linked_list_allocator::Heap;
 use mips_rt::heap_start;
 
+#[cfg(feature = "log")]
+use log::{debug, trace};
+
 /// Heap extension is performed stepwise. This constant defines the size of one extension step.
 const EXTEND_INCREMENT: usize = 1024;
 
@@ -71,6 +72,8 @@ impl MipsMcuHeap {
     /// Initialize heap with heap start location from linker and a defined initial size
     pub fn init(&self) {
         let bottom = heap_start() as *mut u8;
+        #[cfg(feature = "log")]
+        debug!("heap init, bottom = {bottom:?}, size = {EXTEND_INCREMENT}");
         critical_section::with(|cs| {
             unsafe {
                 self.heap
@@ -109,6 +112,8 @@ unsafe impl GlobalAlloc for MipsMcuHeap {
             if let Ok(p) = critical_section::with(|cs| {
                 self.heap.borrow(cs).borrow_mut().allocate_first_fit(layout)
             }) {
+                #[cfg(feature = "log")]
+                trace!("alloc at {:?}, {:?}, stack_pointer = {:?}", p.as_ptr(), layout, stack_pointer());
                 break p.as_ptr();
             } else {
                 // this must be a u8 pointer
@@ -120,6 +125,8 @@ unsafe impl GlobalAlloc for MipsMcuHeap {
                     critical_section::with(|cs| {
                         self.heap.borrow(cs).borrow_mut().extend(EXTEND_INCREMENT)
                     });
+                    #[cfg(feature = "log")]
+                    debug!("extended heap, top = {:?}, stack_pointer = {:?}", self.top(), stack_pointer());
                 } else {
                     break ptr::null_mut();
                 }
@@ -128,6 +135,8 @@ unsafe impl GlobalAlloc for MipsMcuHeap {
     }
 
     unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
+        #[cfg(feature = "log")]
+        trace!("dealloc at {ptr:?}, {layout:?}");
         critical_section::with(|cs| {
             self.heap
                 .borrow(cs)