[wpimath] Use jinja for codegen (#3574)

While not really needed for wpimath, it will make more complex codegen
in the future significantly easier.

.github/workflows/cmake.yml

@@ -10,7 +10,7 @@ jobs:
         include:
           - os: ubuntu-latest
             name: Linux
-            container: wpilib/roborio-cross-ubuntu:2021-18.04
+            container: wpilib/roborio-cross-ubuntu:2021-20.04
             flags: ""
           - os: macos-latest
             name: macOS
@@ -26,6 +26,12 @@ jobs:
           if [ "$RUNNER_OS" == "macOS" ]; then
             brew install opencv
           fi
+      - name: Set up Python 3.8
+        uses: actions/setup-python@v2
+        with:
+          python-version: 3.8
+      - name: Install jinja
+        run: python -m pip install jinja2
       - name: configure
         run: mkdir build && cd build && cmake ${{ matrix.flags }} ..
       - name: build

.github/workflows/lint-format.yml

@@ -63,6 +63,8 @@ jobs:
           sudo apt-get install -y clang-tidy-12 clang-format-12
       - name: Install wpiformat
         run: pip3 install wpiformat
+      - name: Install jinja
+        run: python -m pip install jinja2
       - name: Create compile_commands.json
         run: mkdir build-cmake && cd build-cmake && cmake -DWITH_OLD_COMMANDS=ON -DWITH_EXAMPLES=ON -DCMAKE_EXPORT_COMPILE_COMMANDS=YES ..
       - name: List changed files

.github/workflows/sanitizers.yml

@@ -16,7 +16,7 @@ jobs:
             flags: "-DCMAKE_BUILD_TYPE=Ubsan"
     name: "${{ matrix.name }}"
     runs-on: ubuntu-latest
-    container: wpilib/roborio-cross-ubuntu:2021-18.04
+    container: wpilib/roborio-cross-ubuntu:2021-20.04
     steps:
       - uses: actions/checkout@v2
       - name: Install Dependencies
@@ -27,6 +27,12 @@ jobs:
             --install /usr/bin/gcc gcc /usr/bin/gcc-11 11 \
             --slave /usr/bin/g++ g++ /usr/bin/g++-11
           sudo update-alternatives --set gcc /usr/bin/gcc-11
+      - name: Set up Python 3.8
+        uses: actions/setup-python@v2
+        with:
+          python-version: 3.8
+      - name: Install jinja
+        run: python -m pip install jinja2
       - name: configure
         run: mkdir build && cd build && cmake ${{ matrix.flags }} ..
       - name: build

build.gradle

@@ -1,5 +1,14 @@
 import edu.wpi.first.toolchain.*
 
+buildscript {
+    repositories {
+        mavenCentral()
+    }
+    dependencies {
+        classpath 'com.hubspot.jinjava:jinjava:2.5.8'
+    }
+}
+
 plugins {
     id 'base'
     id 'edu.wpi.first.wpilib.versioning.WPILibVersioningPlugin' version '4.1.0'

wpimath/build.gradle

@@ -1,3 +1,6 @@
+import com.hubspot.jinjava.Jinjava;
+import com.hubspot.jinjava.JinjavaConfig;
+
 ext {
     useJava = true
     useCpp = true
@@ -66,9 +69,8 @@ dependencies {
     api "com.fasterxml.jackson.core:jackson-databind:2.10.0"
 }
 
-def wpilibNumberFileInput = file("src/generate/GenericNumber.java.in")
-def natFileInput = file("src/generate/Nat.java.in")
-def natGetterInput = file("src/generate/NatGetter.java.in")
+def wpilibNumberFileInput = file("src/generate/GenericNumber.java.jinja")
+def natFileInput = file("src/generate/Nat.java.jinja")
 def wpilibNumberFileOutputDir = file("$buildDir/generated/java/edu/wpi/first/math/numbers")
 def wpilibNatFileOutput = file("$buildDir/generated/java/edu/wpi/first/math/Nat.java")
 def maxNum = 20
@@ -86,10 +88,17 @@ task generateNumbers() {
         }
         wpilibNumberFileOutputDir.mkdirs()
 
+        def config = new JinjavaConfig()
+        def jinjava = new Jinjava(config)
+
+        def template = wpilibNumberFileInput.text
+
         for(i in 0..maxNum) {
             def outputFile = new File(wpilibNumberFileOutputDir, "N${i}.java")
-            def read = wpilibNumberFileInput.text.replace('${num}', i.toString())
-            outputFile.write(read)
+            def replacements = new HashMap<String,?>()
+            replacements.put("num", i)
+            def output = jinjava.render(template, replacements)
+            outputFile.write(output)
         }
     }
 }
@@ -97,7 +106,7 @@ task generateNumbers() {
 task generateNat() {
     description = "Generates Nat.java"
     group = "WPILib"
-    inputs.files([natFileInput, natGetterInput])
+    inputs.file natFileInput
     outputs.file wpilibNatFileOutput
     dependsOn generateNumbers
 
@@ -106,19 +115,16 @@ task generateNat() {
             wpilibNatFileOutput.delete()
         }
 
-        def template = natFileInput.text + "\n"
+        def config = new JinjavaConfig()
+        def jinjava = new Jinjava(config)
 
-        def importsString = "";
+        def template = natFileInput.text
 
-        for(i in 0..maxNum) {
-            importsString += "import edu.wpi.first.math.numbers.N${i};\n"
-            template += natGetterInput.text.replace('${num}', i.toString()) + "\n"
-        }
-        template += "}\n" // Close the class body
+        def replacements = new HashMap<String,?>()
+        replacements.put("nums", 0..maxNum)
 
-        template = template.replace('{{REPLACEWITHIMPORTS}}', importsString)
-
-        wpilibNatFileOutput.write(template)
+        def output = jinjava.render(template, replacements)
+        wpilibNatFileOutput.write(output)
     }
 }
 

wpimath/generate_numbers.py

@@ -1,5 +1,26 @@
+# Copyright (c) FIRST and other WPILib contributors.
+# Open Source Software; you can modify and/or share it under the terms of
+# the WPILib BSD license file in the root directory of this project.
+
 import os
 import sys
+from jinja2 import Environment, FileSystemLoader
+
+
+def output(outPath, outfn, contents):
+    if not os.path.exists(outPath):
+        os.makedirs(outPath)
+
+    outpathname = f"{outPath}/{outfn}"
+
+    if os.path.exists(outpathname):
+        with open(outpathname, "r") as f:
+            if f.read() == contents:
+                return
+
+    # File either doesn't exist or has different contents
+    with open(outpathname, "w") as f:
+        f.write(contents)
 
 
 def main():
@@ -8,51 +29,21 @@ def main():
     dirname, _ = os.path.split(os.path.abspath(__file__))
     cmake_binary_dir = sys.argv[1]
 
-    with open(f"{dirname}/src/generate/GenericNumber.java.in",
-              "r") as templateFile:
-        template = templateFile.read()
-        rootPath = f"{cmake_binary_dir}/generated/main/java/edu/wpi/first/math/numbers"
+    env = Environment(loader=FileSystemLoader(f"{dirname}/src/generate"),
+                      autoescape=False,
+                      keep_trailing_newline=True)
 
-        if not os.path.exists(rootPath):
-            os.makedirs(rootPath)
+    template = env.get_template("GenericNumber.java.jinja")
+    rootPath = f"{cmake_binary_dir}/generated/main/java/edu/wpi/first/math/numbers"
 
-        for i in range(MAX_NUM + 1):
-            new_contents = template.replace("${num}", str(i))
+    for i in range(MAX_NUM + 1):
+        contents = template.render(num=i)
+        output(rootPath, f"N{i}.java", contents)
 
-            if os.path.exists(f"{rootPath}/N{i}.java"):
-                with open(f"{rootPath}/N{i}.java", "r") as f:
-                    if f.read() == new_contents:
-                        continue
-
-            # File either doesn't exist or has different contents
-            with open(f"{rootPath}/N{i}.java", "w") as f:
-                f.write(new_contents)
-
-    with open(f"{dirname}/src/generate/Nat.java.in", "r") as templateFile:
-        template = templateFile.read()
-        outputPath = f"{cmake_binary_dir}/generated/main/java/edu/wpi/first/math/Nat.java"
-        with open(f"{dirname}/src/generate/NatGetter.java.in",
-                  "r") as getterFile:
-            getter = getterFile.read()
-
-        importsString = ""
-
-        for i in range(MAX_NUM + 1):
-            importsString += f"import edu.wpi.first.math.numbers.N{i};\n"
-            template += getter.replace("${num}", str(i))
-
-        template += "}\n"
-
-        template = template.replace('{{REPLACEWITHIMPORTS}}', importsString)
-
-        if os.path.exists(outputPath):
-            with open(outputPath, "r") as f:
-                if f.read() == template:
-                    return 0
-
-        # File either doesn't exist or has different contents
-        with open(outputPath, "w") as f:
-            f.write(template)
+    template = env.get_template("Nat.java.jinja")
+    rootPath = f"{cmake_binary_dir}/generated/main/java/edu/wpi/first/math"
+    contents = template.render(nums=range(MAX_NUM + 1))
+    output(rootPath, "Nat.java", contents)
 
 
 if __name__ == "__main__":

wpimath/src/generate/GenericNumber.java.in

@@ -1,34 +0,0 @@
-/*----------------------------------------------------------------------------*/
-/* Copyright (c) 2019 FIRST. All Rights Reserved.                             */
-/* Open Source Software - may be modified and shared by FRC teams. The code   */
-/* must be accompanied by the FIRST BSD license file in the root directory of */
-/* the project.                                                               */
-/*----------------------------------------------------------------------------*/
-
-package edu.wpi.first.math.numbers;
-
-import edu.wpi.first.math.Nat;
-import edu.wpi.first.math.Num;
-
-/**
- * A class representing the number ${num}.
-*/
-public final class N${num} extends Num implements Nat<N${num}> {
-  private N${num}() {
-  }
-
-  /**
-   * The integer this class represents.
-   *
-   * @return The literal number ${num}.
-  */
-  @Override
-  public int getNum() {
-    return ${num};
-  }
-
-  /**
-   * The singleton instance of this class.
-  */
-  public static final N${num} instance = new N${num}();
-}

wpimath/src/generate/GenericNumber.java.jinja

@@ -0,0 +1,31 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+package edu.wpi.first.math.numbers;
+
+import edu.wpi.first.math.Nat;
+import edu.wpi.first.math.Num;
+
+/**
+ * A class representing the number {{ num }}.
+*/
+public final class N{{ num }} extends Num implements Nat<N{{ num }}> {
+  private N{{ num }}() {
+  }
+
+  /**
+   * The integer this class represents.
+   *
+   * @return The literal number {{ num }}.
+  */
+  @Override
+  public int getNum() {
+    return {{ num }};
+  }
+
+  /**
+   * The singleton instance of this class.
+  */
+  public static final N{{ num }} instance = new N{{ num }}();
+}

wpimath/src/generate/Nat.java.in

@@ -1,27 +0,0 @@
-/*----------------------------------------------------------------------------*/
-/* Copyright (c) 2019 FIRST. All Rights Reserved.                             */
-/* Open Source Software - may be modified and shared by FRC teams. The code   */
-/* must be accompanied by the FIRST BSD license file in the root directory of */
-/* the project.                                                               */
-/*----------------------------------------------------------------------------*/
-
-package edu.wpi.first.math;
-
-//CHECKSTYLE.OFF: ImportOrder
-{{REPLACEWITHIMPORTS}}
-//CHECKSTYLE.ON
-
-/**
- * A natural number expressed as a java class.
- * The counterpart to {@link Num} that should be used as a concrete value.
- *
- * @param <T> The {@link Num} this represents.
- */
-@SuppressWarnings({"MethodName", "unused"})
-public interface Nat<T extends Num> {
-  /**
-   * The number this interface represents.
-   *
-   * @return The number backing this value.
-   */
-  int getNum();

wpimath/src/generate/Nat.java.jinja

@@ -0,0 +1,32 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+package edu.wpi.first.math;
+
+//CHECKSTYLE.OFF: ImportOrder
+{% for num in nums %}
+import edu.wpi.first.math.numbers.N{{ num }};
+{%- endfor %}
+//CHECKSTYLE.ON
+
+/**
+ * A natural number expressed as a java class.
+ * The counterpart to {@link Num} that should be used as a concrete value.
+ *
+ * @param <T> The {@link Num} this represents.
+ */
+@SuppressWarnings({"MethodName", "unused"})
+public interface Nat<T extends Num> {
+  /**
+   * The number this interface represents.
+   *
+   * @return The number backing this value.
+   */
+  int getNum();
+{% for num in nums %}
+  static Nat<N{{ num }}> N{{ num }}() {
+    return N{{ num }}.instance;
+  }
+{% endfor %}
+}

wpimath/src/generate/NatGetter.java.in

@@ -1,3 +0,0 @@
-  static Nat<N${num}> N${num}() {
-    return N${num}.instance;
-  }