Improve standard library linking and variable typing process, to make it fully adaptive to any function/variable and not hardcoded.

- Added a new `shim-metadata-gen` crate to automatically generate JSON metadata (added to Makefile) for shim methods in the compiled stdlib JAR, which is used through include_bytes! to allow the codegen backend to use it.
- Added types to OOMIR variables and modified lower1 to provide this info and lower2 to use this to actually use the appropriate instructions for different types and deal with variables in the correct way.
- Removed unsigned types from OOMIR and adjusted type mappings accordingly, as the JVM doesn't support them (this means we deal with u -> i coversion at the lower1 stage, which is more idiomatic to do this at then lower2).

Author: IntegralPilot

Cargo.lock

@@ -4,7 +4,10 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
+regex = "1.11.1"
 ristretto_classfile = { version = "0.16.0" }
+serde = { version = "1.0.219", features = ["derive"] }
+serde_json = "1.0.140"
 
 [lib]
 crate-type = ["dylib"]

Cargo.toml

@@ -1,35 +1,77 @@
-# Makefile
+# === Phony Targets ===
+.PHONY: all clean help rust clean-rust java-linker clean-java-linker \
+        shim-metadata-gen clean-shim-metadata-gen \
+        asm-processor clean-asm-processor \
+        library clean-library
 
-.PHONY: all rust java-linker asm-processor clean clean-rust clean-java-linker clean-asm-processor library clean-library
+# === Terminal Colors ===
+GREEN  := \033[1;32m
+CYAN   := \033[1;36m
+RESET  := \033[0m
 
-all: rust java-linker asm-processor library
+# === Default Target ===
+all: rust java-linker asm-processor
+	@echo "$(GREEN)✨ Build complete! ✨$(RESET)"
 
-# --- Rust root project ---
-rust:
+# === Help ===
+help:
+	@echo "$(CYAN)🛠️  Makefile for building the project$(RESET)"
+	@echo ""
+	@echo "Available targets:"
+	@echo "  make all                  - Build all components"
+	@echo "  make clean                - Clean all components"
+	@echo "  make rust                 - Build the Rust root project"
+	@echo "  make java-linker          - Build the Java Linker subproject"
+	@echo "  make shim-metadata-gen    - Generate library shim metadata"
+	@echo "  make asm-processor        - Build the ASM processor"
+	@echo "  make library              - Build the standard library shim"
+	@echo "  make clean-*              - Clean individual components"
+
+# === Rust root project (Cargo) ===
+rust: shim-metadata-gen
+	@echo "$(CYAN)📦 Building Rust root project...$(RESET)"
 	cargo build
 
 clean-rust:
+	@echo "$(CYAN)🧹 Cleaning Rust root project...$(RESET)"
 	cargo clean
 
-# --- Java Linker Rust Subproject ---
+# === Java Linker Subproject ===
 java-linker:
+	@echo "$(CYAN)📦 Building Java Linker...$(RESET)"
 	cd java-linker && cargo build
 
 clean-java-linker:
+	@echo "$(CYAN)🧹 Cleaning Java Linker...$(RESET)"
 	cd java-linker && cargo clean
 
-# --- ASM Processor (Gradle) ---
+# === Library shim metadata generator ===
+shim-metadata-gen: library
+	@echo "$(CYAN)🔧 Generating shim metadata...$(RESET)"
+	cd shim-metadata-gen && rm -f core.json && cargo run -- ../library/build/libs/library-0.1.0.jar ./core.json
+
+clean-shim-metadata-gen:
+	@echo "$(CYAN)🧹 Cleaning shim-metadata-gen...$(RESET)"
+	cd shim-metadata-gen && cargo clean
+
+# === ASM Processor (Gradle) ===
 asm-processor:
+	@echo "$(CYAN)⚙️  Building ASM processor...$(RESET)"
 	cd asm-processor && gradle shadowJar
 
 clean-asm-processor:
+	@echo "$(CYAN)🧹 Cleaning ASM processor...$(RESET)"
 	cd asm-processor && gradle clean
 
-# --- Standard Library Shim (Gradle) ---
+# === Standard Library Shim (Gradle) ===
 library:
+	@echo "$(CYAN)📚 Building standard library shim...$(RESET)"
 	cd library && gradle build
+
 clean-library:
+	@echo "$(CYAN)🧹 Cleaning library shim...$(RESET)"
 	cd library && gradle clean
 
-# --- Clean everything ---
-clean: clean-rust clean-java-linker clean-asm-processor clean-library
+# === Clean All ===
+clean: clean-rust clean-java-linker clean-asm-processor clean-library clean-shim-metadata-gen
+	@echo "$(GREEN)🧼 All clean!$(RESET)"

Makefile

@@ -29,14 +29,15 @@ This backend currently supports a subset of Rust features:
 
 *   ✅ Compiling minimal `no_std` & `no_core` Rust programs (like an empty `main`) using the `jvm-unknown-unknown` target.
 *   ✅ Compiling simple programs using basic `core` features (like the `is_even_plus_one` test) using the host target.
-*   ✅ Basic integer arithmetic operations on `i32`:
+*   ✅ Basic integer arithmetic operations on all types of numbers:
     *   Addition (`+`), Subtraction (`-`), Multiplication (`*`), Division (`/`), Remainder (`%`).
     *   Checked addition and subtraction (`checked_add`, `checked_sub`) returning `(result, overflowed_bool)` tuples.
 *   ✅ Comparisons (`==`, `!=`, `<`, `<=`, `>`, `>=`).
 *   ✅ Bitwise operations (`&`, `|`, `^`, `<<`, `>>`).
 *   ✅ Basic control flow: `if`/`else` statements, `panic!` / `assert!` (with simple string messages).
 *   ✅ Calling other `static` functions within the same crate (including recursion).
 *   ✅ Basic variable assignment (`let x = y;`).
+*   ✅ Arrays and slices.
 *   ✅ Generating executable `.jar` files for binary crates.
 
 ### Next Milestone:
@@ -62,10 +63,6 @@ This backend currently supports a subset of Rust features:
       ```bash
       # Using Make
       make all
-
-      # OR Using the build script
-      chmod +x build.sh
-      ./build.sh
       ```
     *   This will:
         *   Build the main `rustc_codegen_jvm` library (`target/debug/librustc_codegen_jvm.dylib`).
@@ -113,7 +110,7 @@ To compile *your own* Rust project using this backend:
 
 This project includes integration tests managed by a Python script.
 
-1.  **Ensure Toolchain is Built:** Build the project using `make all` or `./build.sh`.
+1.  **Ensure Toolchain is Built:** Build the project using `make all`.
 2.  **Check Target JSON:** Make sure the `jvm-unknown-unknown.json` file in the *root* of this repository has the **relative paths** starting with `../../../` for the linker and backend, as the tester expects this structure when running tests from subdirectories. If you changed them to absolute paths for external use, change them back temporarily.
 3.  **Run the Tester:**
     ```bash
@@ -135,9 +132,11 @@ This project includes integration tests managed by a Python script.
 *   `tests/`: Integration tests.
     *   `binary/`: Tests for compiling executable Rust crates.
 *   `library/`: Source code for a minimal Kotlin-based implementation of the Rust core library. This serves as a temporary substitute to bootstrap the project until the backend can fully compile the Rust core library itself.
+*   `shim-metadata-gen`: A tool for generating metadata for the Kotlin core library, called at compiletime to provide nessecary info (descriptors) to the codegen backend. It's generated metadata is embedded in the generated library, so not needed at runtime.
+    *   `core.json`: Metadata for the core library, generated by this tool.
 *   `jvm-unknown-unknown.json`: The Rust target specification file.
 *   `Tester.py`: Python script for running integration tests.
-*   `Makefile`, `build.sh`: Scripts for building the entire toolchain.
+*   `Makefile` Scripts for building the entire toolchain.
 *   `setup.sh`: Script to install Rust components.
 *   `Cargo.toml`, `Cargo.lock`: Rust package definition and dependencies for the backend.
 *   `LICENSE`, `LICENSE-Apache`: Project licenses.

Readme.md

@@ -6,13 +6,16 @@ package org.rustlang.core
 public object Core {
 
     @JvmStatic // Ensures static JVM methods are generated
-    public fun rust_panic_fmt(message: String?) {
+    public fun panic_fmt(message: String?) {
         // note to future self: consider using a more specific Rust exception type if needed
         throw RuntimeException("Rust panic: " + (message ?: "<no message>"))
     }
 
     @JvmStatic
-    public fun rust_fmt_arguments_new_const_stub(messagePiece: String?): String? {
-        return messagePiece
+    public fun arguments_new_const(pieces: Array<String>): String {
+        // Concatenate all the string pieces together.
+        // This mimics the simplest formatting scenario where pieces are just joined.
+        // If the array is empty, it correctly returns an empty string.
+        return pieces.joinToString("")
     }
 }