symbol_table: implicit declarations

Signed-off-by: Lukasz Dalek <[email protected]>
chipsalliance · Mar 23, 2021 · 17e69b4 · 17e69b4
1 parent f7939bd
commit 17e69b4
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Showing 2 changed files with 53 additions and 2 deletions.
diff --git a/verilog/analysis/symbol_table.cc b/verilog/analysis/symbol_table.cc
@@ -266,6 +266,9 @@ class SymbolTable::Builder : public TreeContextVisitor {
       case NodeEnum::kEnumType:
         DescendEnumType(node);
         break;
+      case NodeEnum::kLPValue:
+        HandlePossibleImplicitDeclaration(node);
+        break;
       default:
         Descend(node);
         break;
@@ -508,6 +511,44 @@ class SymbolTable::Builder : public TreeContextVisitor {
     }
   }
 
+  void HandlePossibleImplicitDeclaration(const SyntaxTreeNode& node) {
+    VLOG(2) << __FUNCTION__;
+
+    // Only left-hand side of continuous assignment statements are allowed to
+    // implicitly declare nets (LRM 6.10: Implicit declarations).
+    if (Context().DirectParentsAre({NodeEnum::kNetVariableAssignment,
+                                    NodeEnum::kAssignmentList,
+                                    NodeEnum::kContinuousAssignmentStatement})) {
+      CHECK(node.MatchesTag(NodeEnum::kLPValue));
+      const absl::string_view anon_name =
+          current_scope_->Value().CreateAnonymousScope("implicit");
+      DeclareScopedElementAndDescend(node, anon_name,
+                                     SymbolMetaType::kDataNetVariableInstance);
+
+      // Declare possible implicit declaration
+      //EmplaceElementInCurrentScope(node, "/implicit/",
+      //                             SymbolMetaType::kDataNetVariableInstance);
+
+      //CHECK_EQ(declaration_type_info_, nullptr);
+      //DeclarationTypeInfo decl_type_info;
+      //const ValueSaver<DeclarationTypeInfo*> save_type(&declaration_type_info_,
+      //                                                 &decl_type_info);
+      //
+      //const ReferenceComponent ref{
+      //    .identifier = "/implict/";
+      //    .ref_type = ReferenceType::kImmediate,
+      //};
+      //const CaptureDependentReference cap(this);
+      //cap.Ref().PushReferenceComponent(ref);
+
+      //decl_type_info.implicit_declaration_type = cap.Ref().LastLeaf();
+
+      //Descend(node);
+    } else {
+      Descend(node);
+    }
+  }
+
   void HandleIdentifier(const SyntaxTreeLeaf& leaf) {
     const absl::string_view text = leaf.get().text();
     VLOG(2) << __FUNCTION__ << ": " << text;
@@ -632,8 +673,11 @@ class SymbolTable::Builder : public TreeContextVisitor {
             NodeEnum::kLocalRoot,
             NodeEnum::kReference,
             NodeEnum::kReferenceCallBase,
+            //
             NodeEnum::kLPValue,
-            NodeEnum::kNetVariableAssignment}) ||
+            NodeEnum::kNetVariableAssignment,
+            NodeEnum::kAssignmentList,
+            NodeEnum::kContinuousAssignmentStatement}) ||
         Context().DirectParentsAre({
             NodeEnum::kUnqualifiedId,
             NodeEnum::kLocalRoot,
@@ -642,8 +686,11 @@ class SymbolTable::Builder : public TreeContextVisitor {
             NodeEnum::kExpression,
             NodeEnum::kOpenRangeList,
             NodeEnum::kBraceGroup,
+            //
             NodeEnum::kLPValue,
-            NodeEnum::kNetVariableAssignment});
+            NodeEnum::kNetVariableAssignment,
+            NodeEnum::kAssignmentList,
+            NodeEnum::kContinuousAssignmentStatement});
 
 
     const ReferenceComponent new_ref{

diff --git a/verilog/analysis/symbol_table.h b/verilog/analysis/symbol_table.h
@@ -252,6 +252,10 @@ struct DeclarationTypeInfo {
   // advance, and only ever moving ReferenceComponents, never copying them.
   const ReferenceComponentNode* user_defined_type = nullptr;
 
+  // FIXME(ldk): ...
+  //const ReferenceComponentNode* implicit_declaration_type = nullptr;
+  bool implicit_declaration = false;
+
  public:
   DeclarationTypeInfo() = default;