Enhance overflow handling in arithmetic operations and implement an asm-processor that creates stack frames (so we can use Java 8)

Author: IntegralPilot

.gitignore

@@ -1,6 +1,16 @@
+# Ignores relvant to Rust projects within this tree
 **/target/*
-**/*.class
-**/*.txt
+
+# Ignores relevant to Kotlin projects within this tree
+**/.gradle/*
+**/build/*
+**/.kotlin/*
+
+# Files generated by Tester.py
 **/*.generated
-**/*.bc
-**/*.jar
+
+# ICE files generated by Rustc
+**/*.txt
+
+# Crash logs generated by the JVM
+**/*.log

Makefile

@@ -0,0 +1,29 @@
+# Makefile
+
+.PHONY: all rust java-linker asm-processor clean clean-rust clean-java-linker clean-asm-processor
+
+all: rust java-linker asm-processor
+
+# --- Rust root project ---
+rust:
+	cargo build
+
+clean-rust:
+	cargo clean
+
+# --- Java Linker Rust Subproject ---
+java-linker:
+	cd java-linker && cargo build
+
+clean-java-linker:
+	cd java-linker && cargo clean
+
+# --- ASM Processor (Gradle) ---
+asm-processor:
+	cd asm-processor && gradle shadowJar
+
+clean-asm-processor:
+	cd asm-processor && gradle clean
+
+# --- Clean everything ---
+clean: clean-rust clean-java-linker clean-asm-processor

Tester.py

@@ -2,6 +2,7 @@
 import os
 import subprocess
 import sys
+import argparse
 
 def read_from_file(path: str) -> str:
     with open(path, "r") as f:
@@ -19,7 +20,7 @@ def write_to_file(path: str, content: str):
     with open(path, "w") as f:
         f.write(content)
 
-def process_test(test_dir: str):
+def process_test(test_dir: str, release_mode: bool):
     test_name = os.path.basename(test_dir)
     normalized = normalize_name(test_name)
     print(f"|-- Test '{test_name}' ({normalized})")
@@ -36,14 +37,14 @@ def process_test(test_dir: str):
 
     # Run cargo build.
     print("|--- ⚒️ Building with Cargo...")
-    # see if the file no_jvm_target.flag exists in the test directory
+    build_cmd = ["cargo", "build", "--release"] if release_mode else ["cargo", "build"]
     no_jvm_target = os.path.join(test_dir, "no_jvm_target.flag")
     if os.path.exists(no_jvm_target):
         print("|---- ⚠️ Skipping JVM target build due to no_jvm_target.flag")
-        proc = run_command(["cargo", "build"], cwd=test_dir)
     else:
         print("|---- 🛠️ Building with JVM target...")
-        proc = run_command(["cargo", "build", "--target", "../../../jvm-unknown-unknown.json"], cwd=test_dir)
+        build_cmd.extend(["--target", "../../../jvm-unknown-unknown.json"])
+    proc = run_command(build_cmd, cwd=test_dir)
     if proc.returncode != 0:
         fail_path = os.path.join(test_dir, "cargo-build-fail.generated")
         output = f"STDOUT:\n{proc.stdout}\n\nSTDERR:\n{proc.stderr}"
@@ -53,26 +54,22 @@ def process_test(test_dir: str):
 
     # Run java with the generated jar.
     print("|--- 🤖 Running with Java...")
-    # if no_jvm_target flag is set, we first need to move target/debug/deps/{test_name}-{hash}.jar to target/jvm-unknown-unknown/debug/{test_name}.jar
-    # we might need to make the directory first
+    target_dir = "release" if release_mode else "debug"
     if os.path.exists(no_jvm_target):
         print("|---- ⚠️ Doing some needed moving around due to no_jvm_target.flag")
-        # move the jar file to the target/jvm-unknown-unknown/debug directory
-        jar_path = os.path.join(test_dir, "target", "debug", "deps", f"{test_name}-*.jar")
-        # find the jar file
+        jar_path = os.path.join(test_dir, "target", target_dir, "deps", f"{test_name}-*.jar")
         jar_file = None
-        for file in os.listdir(os.path.join(test_dir, "target", "debug", "deps")):
+        for file in os.listdir(os.path.join(test_dir, "target", target_dir, "deps")):
             if file.startswith(test_name) and file.endswith(".jar"):
                 jar_file = file
                 break
         if jar_file is None:
-            print("|---- ❌ No jar file found in target/debug/deps")
+            print("|---- ❌ No jar file found in target/{target_dir}/deps")
             return False
-        # move the file
-        os.makedirs(os.path.join(test_dir, "target", "jvm-unknown-unknown", "debug"), exist_ok=True)
-        os.rename(os.path.join(test_dir, "target", "debug", "deps", jar_file), os.path.join(test_dir, "target", "jvm-unknown-unknown", "debug", f"{test_name}.jar"))
-    jar_path = os.path.join(test_dir, "target", "jvm-unknown-unknown", "debug", f"{test_name}.jar")
-    proc = run_command(["java", "-jar", jar_path])
+        os.makedirs(os.path.join(test_dir, "target", "jvm-unknown-unknown", target_dir), exist_ok=True)
+        os.rename(os.path.join(test_dir, "target", target_dir, "deps", jar_file), os.path.join(test_dir, "target", "jvm-unknown-unknown", target_dir, f"{test_name}.jar"))
+    jar_path = os.path.join(test_dir, "target", "jvm-unknown-unknown", target_dir, f"{test_name}.jar")
+    proc = run_command(["java", "-jar", jar_path]) 
     if proc.returncode != 0:
         fail_path = os.path.join(test_dir, "java-fail.generated")
         output = f"STDOUT:\n{proc.stdout}\n\nSTDERR:\n{proc.stderr}"
@@ -100,9 +97,16 @@ def process_test(test_dir: str):
     return True
 
 def main():
+    parser = argparse.ArgumentParser(description="Tester for Rustc's JVM Codegen Backend")
+    parser.add_argument("--release", action="store_true", help="Run cargo in release mode")
+    args = parser.parse_args()
+
     print("🧪 Tester for Rustc's JVM Codegen Backend started!")
     overall_success = True
 
+    if args.release:
+        print("|- ⚒️ Running in release mode")
+
     print(" ")
 
     # Process binary tests.
@@ -113,7 +117,7 @@ def main():
         binary_tests = []
     print(f"|- 📦 Running {len(binary_tests)} binary build tests...")
     for idx, test_dir in enumerate(binary_tests):
-        if not process_test(test_dir):
+        if not process_test(test_dir, args.release):
             overall_success = False
 
     print("")

asm-processor/build.gradle.kts

@@ -0,0 +1,30 @@
+plugins {
+    kotlin("jvm") version "2.1.20"
+    id("com.gradleup.shadow") version "8.3.6"
+    application
+}
+
+group = "com.integralpilot"
+version = "1.0-SNAPSHOT"
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    // ASM Core library
+    implementation("org.ow2.asm:asm:9.8")
+
+    testImplementation(kotlin("test"))
+}
+
+application {
+    mainClass.set("asmprocessor.ProcessorKt")
+}
+
+tasks.test {
+    useJUnitPlatform()
+}
+kotlin {
+    jvmToolchain(21) // latest LTS. note to self: update when they release a new LTS.
+}

asm-processor/src/main/kotlin/asmprocessor/Processor.kt

@@ -0,0 +1,46 @@
+package asmprocessor
+
+import org.objectweb.asm.ClassReader
+import org.objectweb.asm.ClassWriter
+import java.nio.file.Files
+import java.nio.file.Paths
+import java.nio.file.StandardOpenOption
+import kotlin.system.exitProcess
+
+fun main(args: Array<String>) {
+    if (args.size != 2) {
+        System.err.println("Usage: kotlin asmprocessor.ProcessorKt <input.class> <output.class>")
+        exitProcess(1)
+    }
+    val inputFile = args[0]
+    val outputFile = args[1]
+
+    try {
+        println("Reading: $inputFile")
+        val originalBytecode: ByteArray = Files.readAllBytes(Paths.get(inputFile))
+
+        val cr = ClassReader(originalBytecode)
+        // Combine COMPUTE_FRAMES and COMPUTE_MAXS to generate new frames and adjust max values.
+        val cw = ClassWriter(ClassWriter.COMPUTE_FRAMES or ClassWriter.COMPUTE_MAXS)
+
+        // Use ClassReader.EXPAND_FRAMES to ensure full frame expansion before computing new frames.
+        cr.accept(cw, ClassReader.EXPAND_FRAMES)
+
+        val modifiedBytecode: ByteArray = cw.toByteArray()
+
+        println("Writing processed bytecode to: $outputFile")
+        Files.write(
+            Paths.get(outputFile),
+            modifiedBytecode,
+            StandardOpenOption.CREATE,
+            StandardOpenOption.TRUNCATE_EXISTING
+        )
+
+        println("Done.")
+
+    } catch (e: Exception) {
+        System.err.println("Error processing class file: ${e.message}")
+        e.printStackTrace() // Print full stack trace for debugging
+        exitProcess(1)
+    }
+}

build.sh

@@ -1,4 +1,10 @@
+cargo clean
+cargo build
 pushd java-linker
+cargo clean
 cargo build
 popd
-cargo build
+pushd asm-processor
+gradle clean
+gradle shadowJar
+popd