[llvm] add tool to verify mustache library

llvm/CMakeLists.txt

@@ -1276,6 +1276,7 @@ if( LLVM_INCLUDE_UTILS )
   add_subdirectory(utils/yaml-bench)
   add_subdirectory(utils/split-file)
   add_subdirectory(utils/mlgo-utils)
+  add_subdirectory(utils/llvm-mustachespec)
   if( LLVM_INCLUDE_TESTS )
     set(LLVM_SUBPROJECT_TITLE "Third-Party/Google Test")
     add_subdirectory(${LLVM_THIRD_PARTY_DIR}/unittest ${CMAKE_CURRENT_BINARY_DIR}/third-party/unittest)

llvm/docs/CommandGuide/index.rst

@@ -90,6 +90,7 @@ Developer Tools
    llvm-pdbutil
    llvm-profgen
    llvm-tli-checker
+   llvm-mustachespec
 
 Remarks Tools
 ~~~~~~~~~~~~~~

llvm/docs/CommandGuide/llvm-mustachespec.rst

@@ -0,0 +1,12 @@
+llvm-mustachespec - LLVM tool to test Mustache Compliance Library
+=================================================================
+
+llvm-mustachespec test the mustache spec conformance of the LLVM
+mustache library. The spec can be found here https://github.com/mustache/spec
+
+    $ llvm-mustachespec input-file
+
+.. program:: llvm-mustachespec
+
+Outputs the number of tests failures and success in the spec
+

llvm/utils/llvm-mustachespec/CMakeLists.txt

@@ -0,0 +1,5 @@
+add_llvm_utility(llvm-mustachespec
+  llvm-mustachespec.cpp
+  )
+
+target_link_libraries(llvm-mustachespec PRIVATE LLVMSupport)

llvm/utils/llvm-mustachespec/llvm-mustachespec.cpp

@@ -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");
+  size_t Total = 0;
+  size_t Success = 0;
+  for (Value V : *Obj) {
+    Object *TestCase = V.getAsObject();
+    StringRef TemplateStr = TestCase->getString("template").value();
+    StringRef ExpectedStr = TestCase->getString("expected").value();
+    StringRef Name = TestCase->getString("name").value();
+    Value *Data = TestCase->get("data");
+    Value *Partials = TestCase->get("partials");
+
+    if (!Data)
+      continue;
+
+    Template T = Template(TemplateStr);
+    if (Partials) {
+      for (auto &PartialPairs : *Partials->getAsObject()) {
+        const auto &[Partial, Str] = PartialPairs;
+        T.registerPartial((*Str.getAsString()).str(), Partial.str());
+      }
+    }
+    std::string ActualStr;
+    llvm::raw_string_ostream OS(ActualStr);
+    T.render(*Data, OS);
+    if (ExpectedStr == ActualStr) {
+      Success++;
+    } else {
+      llvm::outs() << "Test Failed: " << Name << "\n";
+    }
+    Total++;
+  }
+
+  llvm::outs() << "Result " << Success << "/" << Total << " succeeded\n";
+}
+
+int main(int argc, char **argv) {
+  llvm::cl::ParseCommandLineOptions(argc, argv);
+  for (const auto &FileName : InputFiles) {
+    runThroughTest(FileName);
+  }
+  return 0;
+}