1 ## Code Reflection Examples 2 3 List of examples to learn and play with the Code Reflection API. 4 5 - GitHub repo: [https://github.com/openjdk/babylon](https://github.com/openjdk/babylon) 6 7 ### Learning Code Reflection? 8 9 Here's an ordered list of code example to start learning code reflection and some of its features. 10 Each example is self-contained, and it can be used within the IDE to explore and understand how code reflection 11 transforms and executes code. 12 13 1. [`HelloCodeReflection`](https://github.com/openjdk/babylon/blob/code-reflection/cr-examples/samples/src/main/java/oracle/code/samples/HelloCodeReflection.java): Just start using code reflection and lowering code models. 14 2. [`MathOptimizer`](https://github.com/openjdk/babylon/blob/code-reflection/cr-examples/samples/src/main/java/oracle/code/samples/MathOptimizer.java): First code transformations to optimize a math function. 15 3. [`InlineExample`](https://github.com/openjdk/babylon/blob/code-reflection/cr-examples/samples/src/main/java/oracle/code/samples/InliningExample.java): Simple example to illustrate the inlining. 16 4. [`MathOptimizerWithInlining`](https://github.com/openjdk/babylon/blob/code-reflection/cr-examples/samples/src/main/java/oracle/code/samples/MathOptimizerWithInlining.java): Follow up of the [`MathOptimizer`](https://github.com/openjdk/babylon/blob/code-reflection/cr-examples/samples/src/main/java/oracle/code/samples/MathOptimizer.java) to inline optimize calls into the code model. 17 5. [`DialectWithInvoke`](https://github.com/openjdk/babylon/blob/code-reflection/cr-examples/samples/src/main/java/oracle/code/samples/DialectWithInvoke.java): Example of creating a dialect that replaces `Invoke` `Op` with a specific signature with a new `Op`. The dialect is handled as an intrinsic replacement. 18 6. [`DialectFMAOp`](https://github.com/openjdk/babylon/blob/code-reflection/cr-examples/samples/src/main/java/oracle/code/samples/DialectFMAOp.java): Example of how to extend the code reflection `Op` to create a new dialect. It analysis the code for substitution of Add(Mult) to create a new `FMA` Op. 19 7. [`DynamicFunctionBuild`](https://github.com/openjdk/babylon/blob/code-reflection/cr-examples/samples/src/main/java/oracle/code/samples/DynamicFunctionBuild.java): Example of how to create a new function dynamically to compute the inverse of a square root. The code model is built dynamically for a new method and it is evaluated in the `Interpreter`. 20 8. [`CodeReflectionProcessor`](https://github.com/openjdk/babylon/blob/code-reflection/cr-examples/samples/src/main/java/oracle/code/samples/CodeReflectionProcessor.java): A simple code model-based annotation processor 21 22 ### Resources 23 24 1. [Article] [Code Models](https://openjdk.org/projects/babylon/articles/code-models) 25 2. [Article] [Emulating C# LINQ in Java using Code Reflection](https://openjdk.org/projects/babylon/articles/linq) 26 3. [Video] [Project Babylon - Code Reflection @JVMLS 2024](https://www.youtube.com/watch?v=6c0DB2kwF_Q) 27 4. [Video] [Java and GPUs using Code Reflection @JVMLS 2023](https://www.youtube.com/watch?v=lbKBu3lTftc) 28 29 ### How to build with project? 30 31 #### 1. Build Babylon JDK 32 33 We need to use the JDK build that enables the code reflection API (Babylon). 34 35 ```bash 36 git clone https://github.com/openjdk/babylon 37 cd babylon 38 bash configure --with-boot-jdk=${JAVA_HOME} 39 ``` 40 41 Then, we use the built JDK as `JAVA_HOME` 42 43 ```bash 44 export JAVA_HOME=/$HOME/repos/babylon/build/macosx-aarch64-server-release/jdk/ 45 export PATH=$JAVA_HOME/bin:$PATH 46 ``` 47 48 #### 2. Build examples 49 50 ```bash 51 mvn clean package 52 ``` 53 54 #### 3. Run the examples 55 56 57 ##### Run HelloCodeReflection 58 59 ```bash 60 java --add-modules jdk.incubator.code -cp target/crsamples-1.0-SNAPSHOT.jar oracle.code.samples.HelloCodeReflection 61 ``` 62 63 ##### Run MathOptimizer 64 65 ```bash 66 java --add-modules jdk.incubator.code -cp target/crsamples-1.0-SNAPSHOT.jar oracle.code.samples.MathOptimizer 67 ``` 68 69 ##### Run InlineExample 70 71 ```bash 72 java --add-modules jdk.incubator.code -cp target/crsamples-1.0-SNAPSHOT.jar oracle.code.samples.InlineExample 73 ``` 74 75 ##### Run MathOptimizerWithInlining 76 77 ```bash 78 java --add-modules jdk.incubator.code -cp target/crsamples-1.0-SNAPSHOT.jar oracle.code.samples.MathOptimizerWithInlining 79 ``` 80 81 ##### Run DialectWithInvoke 82 83 ```bash 84 java --add-modules jdk.incubator.code -cp target/crsamples-1.0-SNAPSHOT.jar oracle.code.samples.DialectWithInvoke 85 ``` 86 87 ##### Run DialectFMAOp 88 89 ```bash 90 java --add-modules jdk.incubator.code -cp target/crsamples-1.0-SNAPSHOT.jar oracle.code.samples.DialectFMAOp 91 ``` 92 93 ##### Run DynamicFunctionBuild 94 95 ```bash 96 java --add-modules jdk.incubator.code -cp target/crsamples-1.0-SNAPSHOT.jar oracle.code.samples.DynamicFunctionBuild 97 ``` 98 99 ##### Compile with CodeReflectionProcessor 100 101 ```bash 102 javac --add-modules jdk.incubator.code --processor-path target/crsamples-1.0-SNAPSHOT.jar -processor oracle.code.samples.CodeReflectionProcessor <.java files to compile> 103 ```