[mlir] Start moving some builtin type formats to the dialectusers/zero9178/simplify-builtin-parsing

Most types and attributes in the builtin dialect are parsed and printed using special-purpose printers and parsers for that type. They also use the low-level `Printer` rather than the `AsmPrinter`, making the implementations inconsistent compared to all other dialects in MLIR.

This PR starts moving some builtin types to be parsed using the usual `print` and `parse` methods like all other MLIR dialects. This has the following advantages:
* The implementation now looks like any other dialect's types
* It is now possible to use `assemblyFormat` for builtin types and attributes
* The code can be easily moved to other dialects if desired
* Arguably better layering and less code
* As a side-effect, it is now also possible to write `!builtin.<type>` for any types moved

A future benefit would include being able to print types and attributes in stripped format as well (e.g. `<f32>` vs `complex<f32>`), just like all other dialect types and attributes. This is currently explicitly disabled as it causes a LOT of changes in IR syntax and I believe some ambiguities in the parser.

For the purpose of reviewing and incremental development, this PR only moves `tuple`, `tensor`, `none`, `memref` and `complex`. The plan is to eventually move all attributes and types where the current syntax can be implemented within the dialect.

For backwards compatibility with the existing syntax, the builtin dialect is special-cased in the printer where the `builtin.` prefix is omitted.

1 files changed, 14 insertions, 58 deletions

diff --git a/mlir/lib/IR/AsmPrinter.cpp b/mlir/lib/IR/AsmPrinter.cpp
index 6b8b747..0679d41 100644
--- a/mlir/lib/IR/AsmPrinter.cpp
+++ b/mlir/lib/IR/AsmPrinter.cpp
@@ -2132,6 +2132,13 @@ static bool isDialectSymbolSimpleEnoughForPrettyForm(StringRef symName) {
 /// Print the given dialect symbol to the stream.
 static void printDialectSymbol(raw_ostream &os, StringRef symPrefix,
                                StringRef dialectName, StringRef symString) {
+  // Treat the builtin dialect special by eliding the '<symPrefix>builtin'
+  // prefix.
+  if (dialectName == "builtin") {
+    os << symString;
+    return;
+  }
+
   os << symPrefix << dialectName;
 
   // If this symbol name is simple enough, print it directly in pretty form,
@@ -2599,64 +2606,6 @@ void AsmPrinter::Impl::printTypeImpl(Type type) {
         printType(vectorTy.getElementType());
         os << '>';
       })
-      .Case<RankedTensorType>([&](RankedTensorType tensorTy) {
-        os << "tensor<";
-        printDimensionList(tensorTy.getShape());
-        if (!tensorTy.getShape().empty())
-          os << 'x';
-        printType(tensorTy.getElementType());
-        // Only print the encoding attribute value if set.
-        if (tensorTy.getEncoding()) {
-          os << ", ";
-          printAttribute(tensorTy.getEncoding());
-        }
-        os << '>';
-      })
-      .Case<UnrankedTensorType>([&](UnrankedTensorType tensorTy) {
-        os << "tensor<*x";
-        printType(tensorTy.getElementType());
-        os << '>';
-      })
-      .Case<MemRefType>([&](MemRefType memrefTy) {
-        os << "memref<";
-        printDimensionList(memrefTy.getShape());
-        if (!memrefTy.getShape().empty())
-          os << 'x';
-        printType(memrefTy.getElementType());
-        MemRefLayoutAttrInterface layout = memrefTy.getLayout();
-        if (!llvm::isa<AffineMapAttr>(layout) || !layout.isIdentity()) {
-          os << ", ";
-          printAttribute(memrefTy.getLayout(), AttrTypeElision::May);
-        }
-        // Only print the memory space if it is the non-default one.
-        if (memrefTy.getMemorySpace()) {
-          os << ", ";
-          printAttribute(memrefTy.getMemorySpace(), AttrTypeElision::May);
-        }
-        os << '>';
-      })
-      .Case<UnrankedMemRefType>([&](UnrankedMemRefType memrefTy) {
-        os << "memref<*x";
-        printType(memrefTy.getElementType());
-        // Only print the memory space if it is the non-default one.
-        if (memrefTy.getMemorySpace()) {
-          os << ", ";
-          printAttribute(memrefTy.getMemorySpace(), AttrTypeElision::May);
-        }
-        os << '>';
-      })
-      .Case<ComplexType>([&](ComplexType complexTy) {
-        os << "complex<";
-        printType(complexTy.getElementType());
-        os << '>';
-      })
-      .Case<TupleType>([&](TupleType tupleTy) {
-        os << "tuple<";
-        interleaveComma(tupleTy.getTypes(),
-                        [&](Type type) { printType(type); });
-        os << '>';
-      })
-      .Case<NoneType>([&](Type) { os << "none"; })
       .Default([&](Type type) { return printDialectType(type); });
 }
 
@@ -2799,6 +2748,13 @@ void AsmPrinter::printAttributeWithoutType(Attribute attr) {
   impl->printAttribute(attr, Impl::AttrTypeElision::Must);
 }
 
+void AsmPrinter::printAttributeWithoutDefaultType(Attribute attr) {
+  assert(
+      impl &&
+      "expected AsmPrinter::printAttributeWithoutDefaultType to be overriden");
+  impl->printAttribute(attr, Impl::AttrTypeElision::May);
+}
+
 void AsmPrinter::printKeywordOrString(StringRef keyword) {
   assert(impl && "expected AsmPrinter::printKeywordOrString to be overriden");
   ::printKeywordOrString(keyword, impl->getStream());