[mlir][spirv] Enable serializer to write SPIR-V modules into separate files

mlir/include/mlir/Target/SPIRV/Serialization.h

@@ -34,7 +34,17 @@ struct SerializationOptions {
   /// tool. This saved file is later used for validation.
   bool saveModuleForValidation = false;
   /// A prefix prepended to the file used when `saveModuleForValidation`
-  /// is set to `true`.
+  /// is set to `true`. This can either be a file prefix, or a relative or
+  /// or an absolute path followed by the prefix. For example:
+  ///
+  ///   * "foo" - Create files with a `foo` prefix in the current working
+  ///     directory. For example: `foo0`, `foo1` ... `fooN`.
+  ///
+  ///   * "my/dir/foo" - Create files in `my/dir` with a `foo` prefix. The
+  ///     `my/dir` need to exists. For example: `foo0`, `foo1` ... `fooN`
+  ///     will be created and stored in `/my/dir`.
+  ///
+  ///   * "/home/user/my/dir" - Same as above but using an absolute path.
   std::string validationFilePrefix = "";
 };
 

mlir/lib/Target/SPIRV/TranslateRegistration.cpp

@@ -79,10 +79,6 @@ void registerFromSPIRVTranslation() {
 // Serialization registration
 //===----------------------------------------------------------------------===//
 
-// Static variable is probably not ideal, but it lets us have unique files names
-// without taking additional parameters from `mlir-translate`.
-static size_t validationFileCounter = 0;
-
 static LogicalResult
 serializeModule(spirv::ModuleOp moduleOp, raw_ostream &output,
                 const spirv::SerializationOptions &options) {
@@ -106,18 +102,22 @@ serializeModule(spirv::ModuleOp moduleOp, raw_ostream &output,
         return failure();
       }
     }
-    std::string errorMessage;
-    std::string filename =
-        options.validationFilePrefix + std::to_string(validationFileCounter++);
-    std::unique_ptr<llvm::ToolOutputFile> validationOutput =
-        openOutputFile(filename, &errorMessage);
-    if (!validationOutput) {
-      llvm::errs() << errorMessage << "\n";
+
+    SmallString<128> filename;
+    int fd;
+
+    std::error_code errorCode = llvm::sys::fs::createUniqueFile(
+        options.validationFilePrefix + "%%%%%%", fd, filename);
+    if (errorCode) {
+      llvm::errs() << "error creating validation output file: "
+                   << errorCode.message() << "\n";
       return failure();
     }
-    validationOutput->os().write(reinterpret_cast<char *>(binary.data()),
-                                 sizeInBytes);
-    validationOutput->keep();
+
+    llvm::raw_fd_ostream validationOutput(fd, /*shouldClose=*/true);
+    validationOutput.write(reinterpret_cast<char *>(binary.data()),
+                           sizeInBytes);
+    validationOutput.flush();
   }
 
   return mlir::success();
@@ -133,8 +133,7 @@ void registerToSPIRVTranslation() {
           "is used to generate separate binaries for validation, where "
           "`--split-input-file` normally combines all outputs into one. The "
           "one combined output (`-o`) is still written. Created files need to "
-          "be "
-          "removed manually once processed."),
+          "be removed manually once processed."),
       llvm::cl::init(""));
 
   TranslateFromMLIRRegistration toBinary(

mlir/test/Target/SPIRV/mlir-translate.mlir

@@ -0,0 +1,29 @@
+// COM: Check that `--spirv-save-validation-files-with-prefix` generates
+// COM: a correct number of files.
+
+// REQUIRES: shell
+// RUN: rm -rf %t
+// RUN: mkdir %t
+// RUN: mlir-translate --serialize-spirv --no-implicit-module --split-input-file --spirv-save-validation-files-with-prefix=%t/foo %s
+// RUN: ls %t | wc -l | FileCheck %s
+// RUN: rm -rf %t
+
+// CHECK: 4
+
+spirv.module Logical GLSL450 requires #spirv.vce<v1.0, [Shader, Linkage], []> {
+}
+
+// -----
+
+spirv.module Logical GLSL450 requires #spirv.vce<v1.0, [Shader, Linkage], []> {
+}
+
+// -----
+
+spirv.module Logical GLSL450 requires #spirv.vce<v1.0, [Shader, Linkage], []> {
+}
+
+// -----
+
+spirv.module Logical GLSL450 requires #spirv.vce<v1.0, [Shader, Linkage], []> {
+}