[clang-tools-extra] [llvm] [llvm] add tool to verify mustache library (PR #111487)

[Nikita Popov via llvm-commits]

================
@@ -0,0 +1,104 @@
+//===- llvm-mustachespec.cpp - The LLVM Modular Optimizer
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Simple drivers to test the mustache spec found here
+// https://github.com/mustache/
+// It is used to verify that the current implementation conforms to the spec
+// simply download the spec and pass the test files to the driver
+//
+// Currently Triple Mustache is not supported we expect the following spec
+// test to fail:
+//    Triple Mustache
+//    Triple Mustache Integer Interpolation
+//    Triple Mustache Decimal Interpolation
+//    Triple Mustache Null Interpolation
+//    Triple Mustache Context Miss Interpolation
+//    Dotted Names - Triple Mustache Interpolation
+//    Implicit Iterators - Triple Mustache
+//    Triple Mustache - Surrounding Whitespace
+//    Triple Mustache - Standalone
+//    Triple Mustache With Padding
+//    Standalone Indentation
+//    Implicit Iterator - Triple mustache
+//
+// Usage:
+//  mustache path/to/test/file/test.json path/to/test/file/test2.json ...
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/Mustache.h"
+#include <string>
+
+using namespace llvm;
+using namespace llvm::json;
+using namespace llvm::mustache;
+
+cl::list<std::string> InputFiles(cl::Positional, cl::desc("<input files>"),
+                                 cl::OneOrMore);
+
+void runThroughTest(StringRef InputFile) {
+  llvm::outs() << "Running Tests: " << InputFile << "\n";
+  ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> BufferOrError =
+      MemoryBuffer::getFile(InputFile);
+
+  if (auto EC = BufferOrError.getError()) {
+    return;
+  }
+  std::unique_ptr<llvm::MemoryBuffer> Buffer = std::move(BufferOrError.get());
+  llvm::StringRef FileContent = Buffer->getBuffer();
+  Expected<Value> Json = parse(FileContent);
+
+  if (auto E = Json.takeError()) {
+    errs() << "Parsing error: " << toString(std::move(E)) << "\n";
+    return;
+  }
+  // Get test
+  Array *Obj = (*Json).getAsObject()->getArray("tests");
----------------
nikic wrote:

```suggestion
  Array *Obj = Json->getAsObject()->getArray("tests");
```
This looks a bit odd, does this work?

https://github.com/llvm/llvm-project/pull/111487