[ImportVerilog] Skip bodies for pure virtual non-void methods

Consolidates A11 branches: agent11/pure-virtual-nonvoid-methods

Author: AmurG

.github/workflows/uploadWheels.yml

@@ -83,6 +83,8 @@ jobs:
 
       - name: Setup Python
         uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
+        with:
+          python-version: '3.14'
 
       - name: Install cibuildwheel
         run: python -m pip install cibuildwheel==3.3.0

lib/Conversion/ImportVerilog/Structure.cpp

@@ -1973,6 +1973,10 @@ Context::defineFunction(const slang::ast::SubroutineSymbol &subroutine) {
   // symbol and calls to it are not eliminated.
   if (subroutine.flags.has(slang::ast::MethodFlags::DPIImport))
     return success();
+  // Pure virtual methods only contribute class method declarations and vtable
+  // slots. They have no body to define, including for non-void return types.
+  if (subroutine.flags.has(slang::ast::MethodFlags::Pure))
+    return success();
 
   const bool isMethod = (subroutine.thisVar != nullptr);
 

test/Conversion/ImportVerilog/pure-virtual-nonvoid.sv

@@ -0,0 +1,25 @@
+// RUN: circt-translate --import-verilog %s | FileCheck %s
+// RUN: circt-verilog --ir-moore %s
+// REQUIRES: slang
+// UNSUPPORTED: valgrind
+
+// clang-format off
+// CHECK-LABEL: moore.class.classdecl @StringBase {
+// CHECK:         moore.class.methoddecl @text : (!moore.class<@StringBase>) -> !moore.string
+// CHECK:       }
+virtual class StringBase;
+  pure virtual function string text();
+endclass
+
+// CHECK-LABEL: moore.class.classdecl @StringLeaf extends @StringBase {
+// CHECK:         moore.class.methoddecl @text -> @"StringLeaf::text" : (!moore.class<@StringLeaf>) -> !moore.string
+// CHECK:       }
+// CHECK-LABEL: func.func private @"StringLeaf::text"(%arg0: !moore.class<@StringLeaf>) -> !moore.string {
+// CHECK:         return
+// CHECK:       }
+class StringLeaf extends StringBase;
+  virtual function string text();
+    return "leaf";
+  endfunction
+endclass
+  // clang-format on