Make sure that the command for a plugin-generated command is unique by adding the input and output files as well.

Otherwise the llbuild manifest will contain only the last defined command with the same name, leading to build failures.

To avoid having the name be exceedingly long, what we append to the name is a digest of the string and not the string itself.

rdar://79872414

Author: abertelrud

Fixtures/Miscellaneous/Plugins/ContrivedTestPlugin/Package.swift

@@ -9,6 +9,7 @@ let package = Package(
             name: "MyLocalTool",
             plugins: [
                 "MySourceGenBuildToolPlugin",
+                "MyAmbiguouslyNamedCommandPlugin",
             ]
         ),
         // The plugin that generates build tool commands to invoke MySourceGenBuildTool.
@@ -23,5 +24,13 @@ let package = Package(
         .executableTarget(
             name: "MySourceGenBuildTool"
         ),
+        // Plugin that emits commands with a generic name.
+        .plugin(
+            name: "MyAmbiguouslyNamedCommandPlugin",
+            capability: .buildTool(),
+            dependencies: [
+                "MySourceGenBuildTool",
+            ]
+        ),
     ]
 )

Fixtures/Miscellaneous/Plugins/ContrivedTestPlugin/Plugins/MyAmbiguouslyNamedCommandPlugin/plugin.swift

@@ -0,0 +1,26 @@
+import PackagePlugin
+ 
+for inputFile in targetBuildContext.inputFiles.filter({ $0.path.extension == "dat" }) {
+    let inputPath = inputFile.path
+    let outputName = "Ambiguous_" + inputPath.stem + ".swift"
+    let outputPath = targetBuildContext.pluginWorkDirectory.appending(outputName)
+    commandConstructor.addBuildCommand(
+        displayName:
+            "This is a constant name",
+        executable:
+            try targetBuildContext.tool(named: "MySourceGenBuildTool").path,
+        arguments: [
+            "\(inputPath)",
+            "\(outputPath)"
+        ],
+        environment: [
+            "VARIABLE_NAME_PREFIX": "SECOND_PREFIX_"
+        ],
+        inputFiles: [
+            inputPath,
+        ],
+        outputFiles: [
+            outputPath
+        ]
+    )
+}

Fixtures/Miscellaneous/Plugins/ContrivedTestPlugin/Sources/MyLocalTool/bar.dat

@@ -0,0 +1 @@
+I am Bar!

Sources/Build/ManifestBuilder.swift

@@ -586,8 +586,9 @@ extension LLBuildManifestBuilder {
         for command in target.pluginInvocationResults.reduce([], { $0 + $1.buildCommands }) {
             // Create a shell command to invoke the executable. We include the path of the executable as a dependency.
             let execPath = AbsolutePath(command.configuration.executable, relativeTo: buildParameters.buildPath)
+            let uniquedName = ([command.configuration.displayName] + (command.inputFiles + command.outputFiles ).map{ $0.pathString }).joined(separator: "|")
             manifest.addShellCmd(
-                name: command.configuration.displayName,
+                name: command.configuration.displayName + "-" + ByteString(encodingAsUTF8: uniquedName).sha256Checksum,
                 description: command.configuration.displayName,
                 inputs: [.file(execPath)] + command.inputFiles.map{ .file($0) },
                 outputs: command.outputFiles.map{ .file($0) },