Add support for hierarchical configurations

include/slang/ast/Compilation.h

@@ -46,7 +46,9 @@ class Symbol;
 class SystemSubroutine;
 class ValueDriver;
 struct AssertionInstanceDetails;
+struct ConfigCellId;
 struct ConfigRule;
+struct ResolvedConfig;
 
 using DriverIntervalMap = IntervalMap<uint64_t, const ValueDriver*>;
 using UnrollIntervalMap = IntervalMap<uint64_t, std::monostate>;
@@ -211,12 +213,6 @@ struct HierarchyOverrideNode {
 
     /// A list of bind directives to apply in this scope.
     std::vector<const syntax::BindDirectiveSyntax*> binds;
-
-    /// A config rule that should be applied to this hierarchy instance.
-    const ConfigRule* configRule = nullptr;
-
-    /// Set to true if any direct child nodes have config rules supplied.
-    bool anyChildConfigRules = false;
 };
 
 /// A centralized location for creating and caching symbols. This includes
@@ -336,6 +332,11 @@ class SLANG_EXPORT Compilation : public BumpAllocator {
                                 const ConfigRule& configRule, SourceRange sourceRange,
                                 DiagCode code) const;
 
+    /// Gets the definition indicated by the given config and cell ID, or nullptr
+    /// if it does not exist. If no definition is found an appropriate diagnostic will be issued.
+    const DefinitionSymbol* getDefinition(const ConfigBlockSymbol& config,
+                                          const ConfigCellId& cell) const;
+
     /// Gets a list of all definitions (including primitives) in the design.
     std::vector<const Symbol*> getDefinitions() const;
 
@@ -683,7 +684,8 @@ class SLANG_EXPORT Compilation : public BumpAllocator {
                                std::span<const Symbol* const> instTargets,
                                const DefinitionSymbol* defTarget);
     std::pair<const Symbol*, bool> resolveConfigRules(std::string_view name, const Scope& scope,
-                                                      const ConfigRule& configRule,
+                                                      const ResolvedConfig* parentConfig,
+                                                      const ConfigRule* configRule,
                                                       const std::vector<Symbol*>& defList) const;
     Diagnostic* errorMissingDef(std::string_view name, const Scope& scope, SourceRange sourceRange,
                                 DiagCode code) const;

include/slang/ast/symbols/CompilationUnitSymbols.h

@@ -229,6 +229,9 @@ struct ConfigCellId {
     /// The source range where this cell id was declared.
     SourceRange sourceRange;
 
+    /// If true, this ID targets a config block specifically.
+    bool targetConfig = false;
+
     ConfigCellId() = default;
     ConfigCellId(std::string_view lib, std::string_view name, SourceRange sourceRange) :
         lib(lib), name(name), sourceRange(sourceRange) {}
@@ -242,13 +245,28 @@ struct ConfigRule {
     /// A specific cell to use for this instance or definition lookup.
     ConfigCellId useCell;
 
-    /// A specific config block to use for this instance and child instances.
-    const ConfigBlockSymbol* useConfig = nullptr;
-
     /// The source range where this rule was declared.
     SourceRange sourceRange;
 };
 
+/// Contains information about a resolved configuration rule
+/// that affects an instance and the hierarchy underneath it.
+struct ResolvedConfig {
+    /// A specific configuration to use for this hierarchy.
+    const ConfigBlockSymbol& useConfig;
+
+    /// The root instance of this particular configuration hierarchy.
+    const InstanceSymbol& rootInstance;
+
+    /// A list of libraries to use to look up definitions.
+    std::span<const SourceLibrary* const> liblist;
+
+    /// The original rule that was resolved.
+    const ConfigRule* configRule = nullptr;
+
+    ResolvedConfig(const ConfigBlockSymbol& useConfig, const InstanceSymbol& rootInstance);
+};
+
 /// Represents a config block declaration.
 class SLANG_EXPORT ConfigBlockSymbol : public Symbol, public Scope {
 public:

include/slang/ast/symbols/InstanceSymbols.h

@@ -19,6 +19,7 @@ class AssertionExpr;
 class AttributeSymbol;
 class CheckerSymbol;
 class CheckerInstanceBodySymbol;
+class ConfigBlockSymbol;
 class DefinitionSymbol;
 class Expression;
 class InstanceBodySymbol;
@@ -30,7 +31,7 @@ class PortConnection;
 class PortSymbol;
 class PrimitiveSymbol;
 class TimingControl;
-struct ConfigRule;
+struct ResolvedConfig;
 struct HierarchyOverrideNode;
 enum class DriveStrength : int;
 
@@ -56,13 +57,14 @@ class SLANG_EXPORT InstanceSymbolBase : public Symbol {
     using Symbol::Symbol;
 };
 
+/// Represents an instance of a module, interface, or program.
 class SLANG_EXPORT InstanceSymbol : public InstanceSymbolBase {
 public:
     const InstanceBodySymbol& body;
 
     /// A config rule that applies to this instance, or a pointer to
     /// the parent instance's config rule if there is one up the stack.
-    const ConfigRule* configRule = nullptr;
+    const ResolvedConfig* resolvedConfig = nullptr;
 
     InstanceSymbol(std::string_view name, SourceLocation loc, InstanceBodySymbol& body);