val: Use the metal API to validate MSL shaders, if available

Roughly 4x faster than validating with the MSL executable.

Change-Id: I6566fa29622475c459eb3a988a842a9e19d4be6f
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/53680
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>

src/val/hlsl.cc

@@ -89,45 +89,5 @@ Result Hlsl(const std::string& dxc_path,
   return result;
 }
 
-Result Msl(const std::string& xcrun_path, const std::string& source) {
-  Result result;
-
-  auto xcrun = utils::Command(xcrun_path);
-  if (!xcrun.Found()) {
-    result.output = "xcrun not found at '" + std::string(xcrun_path) + "'";
-    result.failed = true;
-    return result;
-  }
-
-  result.source = source;
-
-  utils::TmpFile file(".metal");
-  file << result.source;
-
-#ifdef _WIN32
-  // On Windows, we should actually be running metal.exe from the Metal
-  // Developer Tools for Windows
-  auto res = xcrun("-x", "metal", "-c", "-o", "NUL", file.Path());
-#else
-  auto res =
-      xcrun("-sdk", "macosx", "metal", "-o", "/dev/null", "-c", file.Path());
-#endif
-  if (!res.out.empty()) {
-    if (!result.output.empty()) {
-      result.output += "\n";
-    }
-    result.output += res.out;
-  }
-  if (!res.err.empty()) {
-    if (!result.output.empty()) {
-      result.output += "\n";
-    }
-    result.output += res.err;
-  }
-  result.failed = (res.error_code != 0);
-
-  return result;
-}
-
 }  // namespace val
 }  // namespace tint

src/val/msl.cc

@@ -0,0 +1,66 @@
+// Copyright 2021 The Tint Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "src/val/val.h"
+
+#include "src/ast/module.h"
+#include "src/program.h"
+#include "src/utils/io/command.h"
+#include "src/utils/io/tmpfile.h"
+
+namespace tint {
+namespace val {
+
+Result Msl(const std::string& xcrun_path, const std::string& source) {
+  Result result;
+
+  auto xcrun = utils::Command(xcrun_path);
+  if (!xcrun.Found()) {
+    result.output = "xcrun not found at '" + std::string(xcrun_path) + "'";
+    result.failed = true;
+    return result;
+  }
+
+  result.source = source;
+
+  utils::TmpFile file(".metal");
+  file << result.source;
+
+#ifdef _WIN32
+  // On Windows, we should actually be running metal.exe from the Metal
+  // Developer Tools for Windows
+  auto res = xcrun("-x", "metal", "-c", "-o", "NUL", file.Path());
+#else
+  auto res =
+      xcrun("-sdk", "macosx", "metal", "-o", "/dev/null", "-c", file.Path());
+#endif
+  if (!res.out.empty()) {
+    if (!result.output.empty()) {
+      result.output += "\n";
+    }
+    result.output += res.out;
+  }
+  if (!res.err.empty()) {
+    if (!result.output.empty()) {
+      result.output += "\n";
+    }
+    result.output += res.err;
+  }
+  result.failed = (res.error_code != 0);
+
+  return result;
+}
+
+}  // namespace val
+}  // namespace tint

src/val/msl_metal.mm

@@ -0,0 +1,58 @@
+// Copyright 2021 The Tint Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifdef TINT_ENABLE_MSL_VALIDATION_USING_METAL_API
+
+@import Metal;
+
+// Disable: error: treating #include as an import of module 'std.string'
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wauto-import"
+#include "src/val/val.h"
+#pragma clang diagnostic pop
+
+namespace tint {
+namespace val {
+
+Result MslUsingMetalAPI(const std::string& src) {
+  tint::val::Result result;
+
+  NSError* error = nil;
+
+  id<MTLDevice> device = MTLCreateSystemDefaultDevice();
+  if (!device) {
+    result.output = "MTLCreateSystemDefaultDevice returned null";
+    result.failed = true;
+    return result;
+  }
+
+  NSString* source = [NSString stringWithCString:src.c_str()
+                                        encoding:NSUTF8StringEncoding];
+
+  id<MTLLibrary> library = [device newLibraryWithSource:source
+                                                options:nil
+                                                  error:&error];
+  if (!library) {
+    NSString* output = [error localizedDescription];
+    result.output = [output UTF8String];
+    result.failed = true;
+  }
+
+  return result;
+}
+
+}  // namespace val
+}  // namespace tint
+
+#endif  // TINT_ENABLE_MSL_VALIDATION_USING_METAL_API

src/val/val.h

@@ -52,6 +52,14 @@ Result Hlsl(const std::string& dxc_path,
 /// @return the result of the compile
 Result Msl(const std::string& xcrun_path, const std::string& source);
 
+#ifdef TINT_ENABLE_MSL_VALIDATION_USING_METAL_API
+/// Msl attempts to compile the shader with the runtime Metal Shader Compiler
+/// API, verifying that the shader compiles successfully.
+/// @param source the generated MSL source
+/// @return the result of the compile
+Result MslUsingMetalAPI(const std::string& source);
+#endif  // TINT_ENABLE_MSL_VALIDATION_USING_METAL_API
+
 }  // namespace val
 }  // namespace tint