Simplify built-ins import/export in the stack graph

crates/solidity/inputs/language/bindings/rules.msgb

@@ -34,30 +34,10 @@ inherit .parent_scope
 
  ;; Automatically import language built-ins
  if (not (eq FILE_PATH BUILT_INS_FILE_PATH)) {
- ;; All built-in symbols are defined in an internal contract named
- ;; '$BuiltIns$' (see __SLANG_SOLIDITY_BUILT_INS_CONTRACT_NAME__) so we need
- ;; to construct an equivalent import path to reach them. We should have
- ;; access to both type members (eg. defined enums & structs) as well as
- ;; functions and state variables (see special case below), hence why we're
- ;; introducing a path through `@typeof`.
  node built_ins
  attr (built_ins) push_symbol = BUILT_INS_FILE_PATH
 
- node built_in_contract
- ; __SLANG_SOLIDITY_BUILT_INS_CONTRACT_NAME__ keep in sync with built-ins generation
- attr (built_in_contract) push_symbol = "$BuiltIns$"
-
- node built_in_typeof
- attr (built_in_typeof) push_symbol = "@typeof"
-
- node built_in_member
- attr (built_in_member) push_symbol = "."
-
- edge @source_unit.lexical_scope -> built_in_member
- edge built_in_member -> built_in_contract
- edge built_in_member -> built_in_typeof
- edge built_in_typeof -> built_in_contract
- edge built_in_contract -> built_ins
+ edge @source_unit.lexical_scope -> built_ins
  edge built_ins -> ROOT_NODE
  }
 
@@ -89,6 +69,21 @@ inherit .parent_scope
  edge @source_unit.defs -> @unit_member.def
 }
 
+;; Special case for built-ins: we want to export all symbols in the contract:
+;; functions, types and state variables. All built-in symbols are defined in an
+;; internal contract named '$BuiltIns$' so we need to export all its members and
+;; type members directly as a source unit definition.
+;; __SLANG_SOLIDITY_BUILT_INS_CONTRACT_NAME__ keep in sync with built-ins generation.
+@source_unit [SourceUnit [SourceUnitMembers
+ [SourceUnitMember @contract [ContractDefinition name: ["$BuiltIns$"]]]
+]] {
+ if (eq FILE_PATH BUILT_INS_FILE_PATH) {
+ edge @source_unit.defs -> @contract.members
+ edge @source_unit.defs -> @contract.type_members
+ edge @source_unit.defs -> @contract.state_vars
+ }
+}
+
 @source_unit [SourceUnit [SourceUnitMembers [SourceUnitMember @using [UsingDirective]]]] {
  let @using.lexical_scope = @source_unit.lexical_scope
  edge @source_unit.lexical_scope -> @using.def
@@ -288,9 +283,11 @@ inherit .parent_scope
  node @contract.members
  node @contract.type_members
  node @contract.modifiers
+ node @contract.state_vars
 
  edge @contract.lexical_scope -> @contract.members
  edge @contract.lexical_scope -> @contract.type_members
+ edge @contract.lexical_scope -> @contract.state_vars
 
  ;; Modifiers are available as a contract type members through a special '@modifier' symbol
  node modifier
@@ -422,13 +419,7 @@ inherit .parent_scope
  | [StateVariableDefinition]
  )]
 ]] {
- edge @contract.lexical_scope -> @member.def
-
- ;; Special case: for the built-ins file, export state variables in the
- ;; contract's members so they can be seen as globals
- if (eq FILE_PATH BUILT_INS_FILE_PATH) {
- edge @contract.members -> @member.def
- }
+ edge @contract.state_vars -> @member.def
 }
 
 ;; Public state variables are also exposed as external member functions
@@ -1551,7 +1542,6 @@ inherit .parent_scope
  attr (@state_var.def) node_definition = @name
  attr (@state_var.def) definiens_node = @state_var
 
- edge @state_var.def -> @state_var.def
  edge @type_name.type_ref -> @state_var.lexical_scope
 
  node typeof