Bug 1946226 - Don't parse TOML multiple times. r=janerik,tthibaud

We currently parse `Cargo.lock` for every single Gradle project. This is unnecessary: once is enough. Moreover, this can be a parallelizable and build-cache friendly task. This patch places the task in the :geckoview project, since that's where the version of native Glean is most relevant

Differential Revision: https://phabricator.services.mozilla.com/D234384

build.gradle

@@ -55,35 +55,55 @@ def tryInt = { string ->
     return string
 }
 
-// Parses the Cargo.lock and returns the version for the given package name.
-def getRustVersionFor(packageName) {
-    String version = null;
-    TomlParseResult result = Toml.parse(file("Cargo.lock").getText());
-    for (object in result.getArray("package").toList()) {
-        def table = (TomlTable) object
-        if (table.getString("name") == packageName) {
-            if (version != null) {
-                throw new StopExecutionException("Multiple versions for '${packageName}' found." +
-                        " Ensure '${packageName}' is only included once.")
+abstract class VerifyGleanVersionTask extends DefaultTask {
+    @InputFile
+    final RegularFileProperty source = project.objects.fileProperty().convention(project.layout.projectDirectory.file("Cargo.lock"))
+
+    @Input
+    String expectedVersion = Versions.mozilla_glean
+
+    @OutputFiles
+    FileCollection outputFiles = project.objects.fileCollection()
+
+    @TaskAction
+    void verifyGleanVersion() {
+        def foundVersion = getRustVersionFor(source.get().asFile, "glean")
+        if (expectedVersion != foundVersion) {
+          throw new GradleException("Mismatched Glean version, expected: '${expectedVersion}'," +
+              " found '${foundVersion}'")
+        } else {
+            logger.lifecycle("verifyGleanVersion> expected version matches found version '${foundVersion}'")
+        }
+    }
+
+    // Parses the Cargo.lock and returns the version for the given package name.
+    static String getRustVersionFor(file, packageName) {
+        String version = null;
+        TomlParseResult result = Toml.parse(file.getText());
+        for (object in result.getArray("package").toList()) {
+            def table = (TomlTable) object
+            if (table.getString("name") == packageName) {
+                if (version != null) {
+                    throw new GradleException("Multiple versions for '${packageName}' found." +
+                                                     " Ensure '${packageName}' is only included once.")
+                }
+                version = table.getString("version")
             }
-            version = table.getString("version")
         }
+        return version
     }
-    return version
 }
 
+tasks.register("verifyGleanVersion", VerifyGleanVersionTask)
+
 allprojects {
     // Expose the per-object-directory configuration to all projects.
     ext {
         mozconfig = gradle.mozconfig
         topsrcdir = gradle.mozconfig.topsrcdir
         topobjdir = gradle.mozconfig.topobjdir
 
-        gleanVersion = Versions.mozilla_glean
-        if (gleanVersion != getRustVersionFor("glean")) {
-          throw new StopExecutionException("Mismatched Glean version, expected: ${gleanVersion}," +
-              " found ${getRustVersionFor("glean")}")
-        }
+        gleanVersion = Versions.mozilla_glean // Verification done in verifyGleanVersion task
 
         artifactSuffix = getArtifactSuffix()
         versionName = getVersionName()

mobile/android/geckoview/build.gradle

@@ -510,6 +510,8 @@ task("generateSDKBindings", type: JavaExec) {
     dependsOn project(':annotations').jar
 }
 
+preBuild.dependsOn(":verifyGleanVersion")
+
 apply plugin: 'org.mozilla.apilint'
 
 apiLint {