New pass - Optimise2 (runs on the Jar) built with R8. Reduces JAR size in the tests from ~1M to ~300K.

Author: IntegralPilot

CompareSize.py

@@ -1,7 +1,7 @@
 # === Phony Targets ===
 .PHONY: all help clean rust-components rust clean-rust java-linker clean-java-linker \
-        shim-metadata-gen clean-shim-metadata-gen asm-processor clean-asm-processor \
-        library clean-library gen-files clean-gen-files ci
+        shim-metadata-gen clean-shim-metadata-gen stackmapadder clean-stackmapadder \
+        library clean-library gen-files clean-gen-files ci optimise2 clean-optimise2
 
 # === Terminal Colors ===
 GREEN  := \033[1;32m
@@ -11,17 +11,18 @@ RESET  := \033[0m
 # === Directory Variables ===
 JAVA_LINKER_DIR := java-linker
 SHIM_METADATA_GEN_DIR := shim-metadata-gen
-ASM_PROCESSOR_DIR := asm-processor
+STACKMAPADDER_DIR := stackmapadder
+OPTIMISE2_DIR := optimise2
 LIBRARY_DIR := library
 LIBRARY_JAR := $(LIBRARY_DIR)/build/libs/library-0.1.0.jar
 RUST_SOURCES := $(shell find $(SHIM_METADATA_GEN_DIR)/src -type f -name '*.rs')
 
 # === Default Target ===
 ifeq ($(IS_CI),1)
-all: rust java-linker asm-processor
+all: rust java-linker stackmapadder optimise2
 	@echo "$(GREEN)✨ Build complete in CI mode! ✨$(RESET)"
 else
-all: rust gen-files java-linker asm-processor
+all: rust gen-files java-linker stackmapadder optimise2
 	@echo "$(GREEN)✨ Build complete! ✨$(RESET)"
 endif
 
@@ -40,7 +41,7 @@ help:
 	@echo "  make rust-components      - Install needed Rust components"
 	@echo "  make rust                 - Build the Rust root project"
 	@echo "  make java-linker          - Build the Java Linker subproject"
-	@echo "  make asm-processor        - Build the ASM processor"
+	@echo "  make stackmapadder        - Build the ASM processor"
 	@echo "  make library              - Build the standard library shim"
 	@echo "  make gen-files            - Generate necessary files from templates"
 	@echo "  make clean-*              - Clean individual components"
@@ -95,21 +96,37 @@ clean-shim-metadata-gen-json-files:
 	    rm -f $(SHIM_METADATA_GEN_DIR)/*.json; \
 	fi
 
-# === ASM Processor (Gradle) ===
-asm-processor:
-	@echo "$(CYAN)⚙️  Building ASM processor...$(RESET)"
+# === ASM Processors (Gradle) ===
+stackmapadder:
+	@echo "$(CYAN)⚙️  Building Stack map adder...$(RESET)"
 ifeq ($(IS_CI),1)
-	cd $(ASM_PROCESSOR_DIR) && gradle --no-daemon shadowJar
+	cd $(STACKMAPADDER_DIR) && gradle --no-daemon shadowJar
 else
-	cd $(ASM_PROCESSOR_DIR) && gradle shadowJar
+	cd $(STACKMAPADDER_DIR) && gradle shadowJar
 endif
 
-clean-asm-processor:
+clean-stackmapadder:
 	@echo "$(CYAN)🧹 Cleaning ASM processor...$(RESET)"
 ifeq ($(IS_CI),1)
-	cd $(ASM_PROCESSOR_DIR) && gradle --no-daemon clean
+	cd $(STACKMAPADDER_DIR) && gradle --no-daemon clean
 else
-	cd $(ASM_PROCESSOR_DIR) && gradle clean
+	cd $(STACKMAPADDER_DIR) && gradle clean
+endif
+
+optimise2:
+	@echo "$(CYAN)⚙️  Building optimise2...$(RESET)"
+ifeq ($(IS_CI),1)
+	cd $(OPTIMISE2_DIR) && gradle --no-daemon shadowJar
+else
+	cd $(OPTIMISE2_DIR) && gradle shadowJar
+endif
+
+clean-optimise2:
+	@echo "$(CYAN)🧹 Cleaning optimise2...$(RESET)
+ifeq ($(IS_CI),1)
+	cd $(OPTIMISE2_DIR) && gradle --no-daemon clean
+else
+	cd $(OPTIMISE2_DIR) && gradle clean
 endif
 
 # === Standard Library Shim (Gradle) ===
@@ -142,5 +159,5 @@ clean-gen-files:
 	rm -f jvm-unknown-unknown.json config.toml
 
 # === Clean All ===
-clean: clean-rust clean-java-linker clean-asm-processor clean-library clean-shim-metadata-gen clean-gen-files
+clean: clean-rust clean-java-linker clean-stackmapadder clean-library clean-shim-metadata-gen clean-gen-files
 	@echo "$(GREEN)🧼 All clean!$(RESET)"

Makefile

@@ -72,7 +72,9 @@ All examples live in `tests/binary` and are compiled to JVM bytecode & run/teste
    Translate to `.class` files using `ristretto_classfile`.  
    _(see `src/lower2.rs`)_  
 5. **Post‑Process Stack Map Frames**  
-   Kotlin `asm-processor` (ASM library) adds verification frames.  
+   Kotlin `stackmapadder` (built with ASM library) adds verification frames and applys some further optimisations to the class files.
+6. **JAR Optimisation**
+   `optimise2` (based on `r8`) optimises the final jar file.
 6. **Link & Package**  
    `java-linker` bundles `.class` files into a runnable `.jar` with `META-INF/MANIFEST.MF`.
 
@@ -102,7 +104,8 @@ This will compile:
 
 - `rustc_codegen_jvm` backend library  
 - `java-linker`  
-- `asm-processor`  
+- `stackmapadder` 
+- `optimise2`
 - Kotlin shim for `core` (once core support is reached, this will no longer be needed)  
 - Generate `config.toml` & `jvm-unknown-unknown.json`  
 
@@ -162,7 +165,8 @@ Look for `✅ All tests passed!` or inspect `.generated` files on failure.
 │   ├── lower2.rs          # OOMIR → JVM bytecode
 │   └── oomir.rs           # OOMIR definitions
 ├── java-linker/           # Bundles .class files into .jar
-├── asm-processor/         # Kotlin ASM post‑processor
+├── stackmapadder/         # Kotlin StackMapFrame generator
+├── optimise2/             # Jar optimiser
 ├── tests/binary/          # Integration tests
 ├── library/               # Kotlin shim for Rust core library
 ├── shim-metadata-gen/     # Generates core.json metadata

Readme.md

@@ -2,7 +2,7 @@
 rustflags = [
   "-Z", "codegen-backend=../../../target/debug/librustc_codegen_jvm.dylib",
   "-C", "linker=../../../java-linker/target/debug/java-linker",
-  "-C", "link-args=../../../library/build/distributions/library-0.1.0/lib/library-0.1.0.jar ../../../library/build/distributions/library-0.1.0/lib/kotlin-stdlib-2.1.20.jar --asm-processor ../../../asm-processor/build/libs/asm-processor-1.0-SNAPSHOT-all.jar --known-good kotlin-stdlib"
+  "-C", "link-args=../../../library/build/distributions/library-0.1.0/lib/library-0.1.0.jar ../../../library/build/distributions/library-0.1.0/lib/kotlin-stdlib-2.1.20.jar --stackmapadder ../../../stackmapadder/build/libs/stackmapadder-1.0-SNAPSHOT-all.jar --known-good kotlin-stdlib --optimizer ../../../optimise2/build/libs/optimise2-1.0-SNAPSHOT-all.jar --proguard-config ../../../proguard/default.pro"
 ]
 
 # Throwing a JVM exception will unwind and give a stack trace, no need for rust to handle unwinding.