Add support for nested symbol references.

This change allows for adding additional nested references to a SymbolRefAttr to allow for further resolving a symbol if that symbol also defines a SymbolTable. If a referenced symbol also defines a symbol table, a nested reference can be used to refer to a symbol within that table. Nested references are printed after the main reference in the following form:

  symbol-ref-attribute ::= symbol-ref-id (`::` symbol-ref-id)*

Example:

  module @reference {
    func @nested_reference()
  }

  my_reference_op @reference::@nested_reference

Given that SymbolRefAttr is now more general, the existing functionality centered around a single reference is moved to a derived class FlatSymbolRefAttr. Followup commits will add support to lookups, rauw, etc. for scoped references.

PiperOrigin-RevId: 279860501

1 files changed, 5 insertions, 5 deletions

diff --git a/mlir/lib/Dialect/StandardOps/Ops.cpp b/mlir/lib/Dialect/StandardOps/Ops.cpp
index 12029248168..8c08868bc7a 100644
--- a/mlir/lib/Dialect/StandardOps/Ops.cpp
+++ b/mlir/lib/Dialect/StandardOps/Ops.cpp
@@ -528,7 +528,7 @@ void BranchOp::getCanonicalizationPatterns(OwningRewritePatternList &results,
 //===----------------------------------------------------------------------===//
 
 static ParseResult parseCallOp(OpAsmParser &parser, OperationState &result) {
-  SymbolRefAttr calleeAttr;
+  FlatSymbolRefAttr calleeAttr;
   FunctionType calleeType;
   SmallVector<OpAsmParser::OperandType, 4> operands;
   auto calleeLoc = parser.getNameLoc();
@@ -555,7 +555,7 @@ static void print(OpAsmPrinter &p, CallOp op) {
 
 static LogicalResult verify(CallOp op) {
   // Check that the callee attribute was specified.
-  auto fnAttr = op.getAttrOfType<SymbolRefAttr>("callee");
+  auto fnAttr = op.getAttrOfType<FlatSymbolRefAttr>("callee");
   if (!fnAttr)
     return op.emitOpError("requires a 'callee' symbol reference attribute");
   auto fn =
@@ -608,8 +608,8 @@ struct SimplifyIndirectCallWithKnownCallee
     // Replace with a direct call.
     SmallVector<Type, 8> callResults(indirectCall.getResultTypes());
     SmallVector<Value *, 8> callOperands(indirectCall.getArgOperands());
-    rewriter.replaceOpWithNewOp<CallOp>(indirectCall, calledFn.getValue(),
-                                        callResults, callOperands);
+    rewriter.replaceOpWithNewOp<CallOp>(indirectCall, calledFn, callResults,
+                                        callOperands);
     return matchSuccess();
   }
 };
@@ -1206,7 +1206,7 @@ static LogicalResult verify(ConstantOp &op) {
   }
 
   if (type.isa<FunctionType>()) {
-    auto fnAttr = value.dyn_cast<SymbolRefAttr>();
+    auto fnAttr = value.dyn_cast<FlatSymbolRefAttr>();
     if (!fnAttr)
       return op.emitOpError("requires 'value' to be a function reference");