Remove deprecated registration APIs (NFC)

[mehdi_amini]

Summary

In D104421, we changed the API for pass registration.
Before you would write:

void registerPass("my-pass", "My Pass Description.",
                  [] { return createMyPass(); });

while now you’d only write:

void registerPass([] { return createMyPass(); });

If you’re using TableGen to define your pass registration, you shouldn’t have anything to do. If you’re using directly the C++ API here are some changes.
Your project may also be broken even if you use TableGen and you call the
generated registration API in case your pass implementation didn’t inherit from
the MyPassBase class generated by TableGen.

If you don't use TableGen, the "my-pass" and "My Pass Description." fields must
be provided by overriding methods on the pass itself:

llvm::StringRef getArgument() const final { return "my-pass"; }
llvm::StringRef getDescription() const final {
  return "My Pass Description.";
}

[rriddle]

Can you fix the description?

mlir/lib/Pass/PassRegistry.cpp

122

This can use pass-> now.

[mehdi_amini]

Rebase and update

mlir/include/mlir/Pass/PassRegistry.h

 /// typically used through the PassPipelineRegistration template.
 void registerPassPipeline(
     StringRef arg, StringRef description, const PassRegistryFunction &function,
     std::function<void(function_ref<void(const detail::PassOptions &)>)>
         optHandler);
 
 /// Register a specific dialect pass allocator function with the system,
 /// typically used through the PassRegistration template.
-/// Deprecated: please use the alternate version below.
-void registerPass(StringRef arg, StringRef description,
-                  const PassAllocatorFunction &function);
-
-/// Register a specific dialect pass allocator function with the system,
-/// typically used through the PassRegistration template.
 void registerPass(const PassAllocatorFunction &function);
 
 /// PassRegistration provides a global initializer that registers a Pass
 /// allocation routine for a concrete pass instance. The argument is
 /// optional and provides a callback to construct a pass that does not have
 /// a default constructor.
 ///
 /// Usage:
 ///
 ///   /// At namespace scope.
 ///   static PassRegistration<MyPass> reg;
 ///
 template <typename ConcretePass> struct PassRegistration {
   PassRegistration(const PassAllocatorFunction &constructor) {
     registerPass(constructor);
   }
   PassRegistration()
       : PassRegistration([] { return std::make_unique<ConcretePass>(); }) {}
-
-  /// Constructor below are deprecated.
-
-  PassRegistration(StringRef arg, StringRef description,
-                   const PassAllocatorFunction &constructor) {
-    registerPass(arg, description, constructor);
-  }
-
-  PassRegistration(StringRef arg, StringRef description)
-      : PassRegistration(arg, description,
-                         [] { return std::make_unique<ConcretePass>(); }) {}
 };
 
 /// PassPipelineRegistration provides a global initializer that registers a Pass
 /// pipeline builder routine.
 ///
 /// Usage:
 ///
 ///   // At namespace scope.

mlir/lib/Pass/PassRegistry.cpp

PassInfo::PassInfo(StringRef arg, StringRef description,
                    const PassAllocatorFunction &allocator)
     : PassRegistryEntry(
           arg, description, buildDefaultRegistryFn(allocator),
           // Use a temporary pass to provide an options instance.
           [=](function_ref<void(const PassOptions &)> optHandler) {
             optHandler(allocator()->passOptions);
           }) {}
 
-void mlir::registerPass(StringRef arg, StringRef description,
-                        const PassAllocatorFunction &function) {
+void mlir::registerPass(const PassAllocatorFunction &function) {
+  std::unique_ptr<Pass> pass = function();
+  StringRef arg = pass->getArgument();
+  if (arg.empty())
+    llvm::report_fatal_error(
+        "Trying to register a pass that does not override `getArgument()`");
+  StringRef description = pass->getDescription();
   PassInfo passInfo(arg, description, function);
   passRegistry->try_emplace(arg, passInfo);
 
   // Verify that the registered pass has the same ID as any registered to this
   // arg before it.
   TypeID entryTypeID = function()->getTypeID();
   auto it = passRegistryTypeIDs->try_emplace(arg, entryTypeID).first;
   if (it->second != entryTypeID) {
     llvm_unreachable("pass allocator creates a different pass than previously "
                      "registered");
   }
 }
 
-void mlir::registerPass(const PassAllocatorFunction &function) {
-  std::unique_ptr<Pass> pass = function();
-  StringRef arg = pass->getArgument();
-  if (arg.empty())
-    llvm::report_fatal_error(
-        "Trying to register a pass that does not override `getArgument()`");
-  registerPass(arg, pass->getDescription(), function);
-}
-
 /// Returns the pass info for the specified pass argument or null if unknown.
 const PassInfo *mlir::Pass::lookupPassInfo(StringRef passArg) {
   auto it = passRegistry->find(passArg);
   return it == passRegistry->end() ? nullptr : &it->second;
 }
 
 //===----------------------------------------------------------------------===//
 // PassOptions