[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

@@ -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], []> {
+}