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, 2 insertions, 2 deletions

diff --git a/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp b/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
index 69f7e933d49..7f3ce5a738f 100644
--- a/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
@@ -52,7 +52,7 @@ llvm::Constant *ModuleTranslation::getLLVMConstant(llvm::Type *llvmType,
     return llvm::ConstantInt::get(llvmType, intAttr.getValue());
   if (auto floatAttr = attr.dyn_cast<FloatAttr>())
     return llvm::ConstantFP::get(llvmType, floatAttr.getValue());
-  if (auto funcAttr = attr.dyn_cast<SymbolRefAttr>())
+  if (auto funcAttr = attr.dyn_cast<FlatSymbolRefAttr>())
     return functionMapping.lookup(funcAttr.getValue());
   if (auto splatAttr = attr.dyn_cast<SplatElementsAttr>()) {
     auto *sequentialType = cast<llvm::SequentialType>(llvmType);
@@ -194,7 +194,7 @@ LogicalResult ModuleTranslation::convertOperation(Operation &opInst,
   auto convertCall = [this, &builder](Operation &op) -> llvm::Value * {
     auto operands = lookupValues(op.getOperands());
     ArrayRef<llvm::Value *> operandsRef(operands);
-    if (auto attr = op.getAttrOfType<SymbolRefAttr>("callee")) {
+    if (auto attr = op.getAttrOfType<FlatSymbolRefAttr>("callee")) {
       return builder.CreateCall(functionMapping.lookup(attr.getValue()),
                                 operandsRef);
     } else {