Squashed commits form PRs chipsalliance#675, chipsalliance#745 and ch…

…ipsalliance#746

Signed-off-by: Lukasz Dalek <[email protected]>

verilog/analysis/symbol_table.cc

@@ -78,6 +78,8 @@ static const verible::EnumNameMap<SymbolMetaType> kSymbolMetaTypeNames({
     {"function", SymbolMetaType::kFunction},
     {"task", SymbolMetaType::kTask},
     {"struct", SymbolMetaType::kStruct},
+    {"enum", SymbolMetaType::kEnumType},
+    {"<enum constant>", SymbolMetaType::kEnumConstant},
     {"interface", SymbolMetaType::kInterface},
     {"<unspecified>", SymbolMetaType::kUnspecified},
     {"<callable>", SymbolMetaType::kCallable},
@@ -159,6 +161,9 @@ static absl::Status DiagnoseMemberSymbolResolutionFailure(
                    context_name, "."));
 }
 
+static const SymbolTableNode* LookupSymbolUpwards(
+    const SymbolTableNode& context, absl::string_view symbol);
+
 class SymbolTable::Builder : public TreeContextVisitor {
  public:
   Builder(const VerilogSourceFile& source, SymbolTable* symbol_table,
@@ -261,6 +266,12 @@ class SymbolTable::Builder : public TreeContextVisitor {
       case NodeEnum::kStructType:
         DescendStructType(node);
         break;
+      case NodeEnum::kEnumType:
+        DescendEnumType(node);
+		break;
+      case NodeEnum::kLPValue:
+        HandlePossibleImplicitDeclaration(node);
+        break;
       default:
         Descend(node);
         break;
@@ -455,6 +466,83 @@ class SymbolTable::Builder : public TreeContextVisitor {
     }
   }
 
+  void DescendEnumType(const SyntaxTreeNode& enum_type) {
+    CHECK(enum_type.MatchesTag(NodeEnum::kEnumType));
+    const absl::string_view anon_name =
+        current_scope_->Value().CreateAnonymousScope("enum");
+    SymbolTableNode& new_enum = DeclareScopedElementAndDescend(
+        enum_type, anon_name, SymbolMetaType::kEnumType);
+
+    const ReferenceComponent anon_type_ref{
+        .identifier = anon_name,
+        .ref_type = ReferenceType::kImmediate,
+        .required_metatype = SymbolMetaType::kEnumType,
+        // pre-resolve this symbol immediately
+        .resolved_symbol = &new_enum,
+    };
+
+    const CaptureDependentReference capture(this);
+    capture.Ref().PushReferenceComponent(anon_type_ref);
+
+    if (declaration_type_info_ != nullptr) {
+      declaration_type_info_->user_defined_type = capture.Ref().LastLeaf();
+    }
+
+    // Iterate over enumeration constants
+    for (const auto& itr : new_enum) {
+      const auto enum_constant_name = itr.first;
+      const auto& symbol = itr.second;
+      const auto& syntax_origin =
+          *ABSL_DIE_IF_NULL(symbol.Value().syntax_origin);
+
+      const ReferenceComponent itr_ref{
+          .identifier = enum_constant_name,
+          .ref_type = ReferenceType::kImmediate,
+          .required_metatype = SymbolMetaType::kEnumConstant,
+          // pre-resolve this symbol immediately
+          .resolved_symbol = &symbol,
+      };
+
+      // CaptureDependentReference class doesn't support
+      // copy constructor
+      const CaptureDependentReference cap(this);
+      cap.Ref().PushReferenceComponent(anon_type_ref);
+      cap.Ref().PushReferenceComponent(itr_ref);
+
+      // Create default DeclarationTypeInfo
+      DeclarationTypeInfo decl_type_info;
+      const ValueSaver<DeclarationTypeInfo*> save_type(&declaration_type_info_,
+                                                       &decl_type_info);
+      declaration_type_info_->syntax_origin = &syntax_origin;
+      declaration_type_info_->user_defined_type = cap.Ref().LastLeaf();
+
+      // Constants should be visible in current scope so we create
+      // variable instances with references to enum constants
+      EmplaceTypedElementInCurrentScope(syntax_origin, enum_constant_name,
+                                        SymbolMetaType::kTypeAlias);
+    }
+  }
+
+  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));
+
+      DeclarationTypeInfo decl_type_info;
+      const ValueSaver<DeclarationTypeInfo*> save_type(&declaration_type_info_,
+                                                       &decl_type_info);
+      declaration_type_info_->implicit = true;
+      Descend(node);
+    } else {
+      Descend(node);
+    }
+  }
+
   void HandleIdentifier(const SyntaxTreeLeaf& leaf) {
     const absl::string_view text = leaf.get().text();
     VLOG(2) << __FUNCTION__ << ": " << text;
@@ -546,6 +634,13 @@ class SymbolTable::Builder : public TreeContextVisitor {
       return;
     }
 
+    if (Context().DirectParentsAre(
+            {NodeEnum::kEnumName, NodeEnum::kEnumNameList})) {
+      EmplaceTypedElementInCurrentScope(leaf, text,
+                                        SymbolMetaType::kEnumConstant);
+      return;
+    }
+
     // In DeclareInstance(), we already planted a self-reference that is
     // resolved to the instance being declared.
     if (Context().DirectParentIs(NodeEnum::kGateInstance)) return;
@@ -582,6 +677,29 @@ class SymbolTable::Builder : public TreeContextVisitor {
       return;
     }
 
+    // Handle possible implicit declarations here
+    if (declaration_type_info_ != nullptr && declaration_type_info_->implicit) {
+      const SymbolTableNode* resolved =
+          LookupSymbolUpwards(*ABSL_DIE_IF_NULL(current_scope_), text);
+      if (resolved == nullptr) {
+        // No explicit declaration found, declare here
+        SymbolTableNode& implicit_declaration =
+            EmplaceTypedElementInCurrentScope(
+                leaf, text, SymbolMetaType::kDataNetVariableInstance);
+
+        const ReferenceComponent implicit_ref{
+            .identifier = text,
+            .ref_type = InferReferenceType(),
+            .required_metatype = InferMetaType(),
+            // pre-resolve
+            .resolved_symbol = &implicit_declaration,
+        };
+
+        ref.PushReferenceComponent(implicit_ref);
+        return;
+      }
+    }
+
     // For all other cases, grow the reference chain deeper.
     // For type references, which may contained named parameters,
     // when encountering the first unqualified reference, establish its
@@ -1697,6 +1815,10 @@ std::ostream& operator<<(std::ostream& stream,
     stream << "(primitive)";
   }
 
+  if (decl_type_info.implicit) {
+    stream << ", implicit";
+  }
+
   return stream << " }";
 }
 

verilog/analysis/symbol_table.h

@@ -54,6 +54,8 @@ enum class SymbolMetaType {
   kFunction,
   kTask,
   kStruct,
+  kEnumType,
+  kEnumConstant,
   kInterface,
 
   // The following enums represent classes/groups of the above types,
@@ -248,6 +250,11 @@ struct DeclarationTypeInfo {
   // advance, and only ever moving ReferenceComponents, never copying them.
   const ReferenceComponentNode* user_defined_type = nullptr;
 
+  // Indicates that this is implicit declaration.
+  // FIXME(ldk): Check if this could be replaced by user_defined_type pointing
+  //    to default implicit type.
+  bool implicit = false;
+
  public:
   DeclarationTypeInfo() = default;