[mlir] Add traits, interfaces, effects to generated docs

[jpienaar]

Summary

Simply emit traits, interfaces & effects (with some minimal formatting) to the
generated docs to make this information easier to find in the docs.

mlir/test/mlir-tblgen/gen-dialect-doc.td

 // RUN: mlir-tblgen -gen-dialect-doc -I %S/../../include %s | FileCheck %s
 
 include "mlir/IR/OpBase.td"
+include "mlir/Interfaces/SideEffectInterfaces.td"
 
 def Test_Dialect : Dialect {
   let name = "test";
   let summary = "Dialect of ops to test";
   let description = [{
     Dialect without a [TOC] here.
     TOC added by tool.
   }];
   let cppNamespace = "NS";
 }
-def AOp : Op<Test_Dialect, "a", []>;
+def AOp : Op<Test_Dialect, "a", [NoSideEffect, SingleBlockImplicitTerminator<"YieldOp">]>;
 
 // CHECK: Dialect without a [TOC] here.
 // CHECK: TOC added by tool.
 // CHECK: [TOC]
 // CHECK-NOT: [TOC]
+// CHECK: Traits: SingleBlockImplicitTerminator<YieldOp>
+// CHECK: Interfaces: NoSideEffect (MemoryEffectOpInterface)
+// CHECK: Effects: MemoryEffects::Effect{}
 
 def Toc_Dialect : Dialect {
   let name = "test_toc";
   let summary = "Dialect of ops to test";
   let description = [{
     Dialect with
 
     [TOC]

mlir/tools/mlir-tblgen/OpDocGen.cpp

if (!str.empty()) {
     os << "\n";
   }
 }
 
 /// Emit the given named constraint.
 template <typename T>
 static void emitNamedConstraint(const T &it, raw_ostream &os) {
   if (!it.name.empty())
-    os << "`" << it.name << "`";
+    os << "| `" << it.name << "`";
   else
     os << "&laquo;unnamed&raquo;";
   os << " | " << it.constraint.getSummary() << "\n";
 }
 
 //===----------------------------------------------------------------------===//
 // Operation Documentation
 //===----------------------------------------------------------------------===//
do {
     split = split.second.split('\n');
     StringRef formatChunk = split.first.trim();
     if (!formatChunk.empty())
       os.indent(indent) << formatChunk << "\n";
   } while (!split.second.empty());
   os << "```\n\n";
 }
 
+static void emitOpTraitsDoc(Operator op, raw_ostream &os) {
+  // TODO: We should link to the trait/documentation of it. That also means we
+  // should add descriptions to traits that can be queried.
+  // Collect using set to sort effects, interfaces & traits.
+  std::set<std::string> effects, interfaces, traits;
+  for (auto &trait : op.getTraits()) {
+    if (auto *nt = dyn_cast<PredTrait>(&trait))
+      continue;
+
+    std::string name = trait.getDef().getName().str();
+    StringRef ref = name;
+    StringRef traitName = trait.getDef().getValueAsString("trait");
+    traitName.consume_back("::Trait");
+    traitName.consume_back("::Impl");
+    if (ref.startswith("anonymous_"))
+      name = traitName.str();
+    if (auto *nt = dyn_cast<InterfaceTrait>(&trait)) {
+      if (trait.getDef().isSubClassOf("SideEffectsTraitBase")) {
+        auto effectName = trait.getDef().getValueAsString("baseEffectName");
+        effectName.consume_front("::");
+        effectName.consume_front("mlir::");
+        std::string effectStr;
+        llvm::raw_string_ostream os(effectStr);
+        os << effectName << "{";
+        auto list = trait.getDef().getValueAsListOfDefs("effects");
+        llvm::interleaveComma(list, os, [&](Record *rec) {
+          StringRef effect = rec->getValueAsString("effect");
+          effect.consume_front("::");
+          effect.consume_front("mlir::");
+          os << effect << " on " << rec->getValueAsString("resource");
+        });
+        os << "}";
+        effects.insert(os.str());
+        name.append(llvm::formatv(" ({0})", traitName).str());
+      }
+      interfaces.insert(name);
+      continue;
+    }
+
+    traits.insert(name);
+  }
+  if (!traits.empty()) {
+    llvm::interleaveComma(traits, os << "\nTraits: ");
+    os << "\n";
+  }
+  if (!interfaces.empty()) {
+    llvm::interleaveComma(interfaces, os << "\nInterfaces: ");
+    os << "\n";
+  }
+  if (!effects.empty()) {
+    llvm::interleaveComma(effects, os << "\nEffects: ");
+    os << "\n";
+  }
+}
+
 static void emitOpDoc(Operator op, raw_ostream &os) {
   os << llvm::formatv("### `{0}` ({1})\n", op.getOperationName(),
                       op.getQualCppClassName());
 
   // Emit the summary, syntax, and description if present.
   if (op.hasSummary())
     os << "\n" << op.getSummary() << "\n\n";
   if (op.hasAssemblyFormat())
     emitAssemblyFormat(op.getOperationName(), op.getAssemblyFormat().trim(),
                        os);
   if (op.hasDescription())
     mlir::tblgen::emitDescription(op.getDescription(), os);
 
+  emitOpTraitsDoc(op, os);
+
   // Emit attributes.
   if (op.getNumAttributes() != 0) {
     // TODO: Attributes are only documented by TableGen name, with no further
     // info. This should be improved.
     os << "\n#### Attributes:\n\n";
     os << "| Attribute | MLIR Type | Description |\n"
        << "| :-------: | :-------: | ----------- |\n";
     for (const auto &it : op.getAttributes()) {
       StringRef storageType = it.attr.getStorageType();
-      os << "`" << it.name << "` | " << storageType << " | "
+      os << "| `" << it.name << "` | " << storageType << " | "
          << it.attr.getSummary() << "\n";
     }
   }
 
   // Emit each of the operands.
   if (op.getNumOperands() != 0) {
     os << "\n#### Operands:\n\n";
     os << "| Operand | Description |\n"