feat: TYPE-system front end — tokens, designators, ParamDecl grammar

- Reserve TYPE/ENDTYPE/SET/DEFINE (-600 token block); SET/DEFINE parse to
  dedicated not-implemented errors (RANDOM precedent).
- New TypeAST.h: enum/pointer/record decl nodes, designator chain
  (DesignatorExprAST + Index/Field/Deref accessors), AddrOfExprAST,
  DesignatorAssignStmtAST. Bare-name and single-index shapes degrade to
  their legacy nodes, so existing programs produce identical ASTs.
- ParserType.cc: TYPE declarations (top-level only, enforced via a
  ParseBlock depth counter), DECLARE-only record bodies with local
  field-level error recovery.
- Postfix [ ] . ^ chain in ParseIdentifierExpr; prefix ^ (address-of,
  designator operand only) in ParseUnary; assignment targets rebuilt on
  the same suffix parser.
- Parameters: ParamDecl{name, type, mode, array rank/bounds} replaces the
  (name, type, byref) tuple. Pass mode is sticky across parameters and
  BYREF is rejected in FUNCTIONs, both per guide §8.3 (the old per-param
  reset made the guide's own SWAP example pass Y by value). ARRAY OF T /
  ARRAY[l:u,...] OF T parameter syntax parses; codegen rejects it until
  the parameter-passing phase lands.
- CodeGen stubs report clear not-implemented errors for the new nodes so
  nothing is silently ignored.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/lib/CodeGen/CodeGen.cc b/lib/CodeGen/CodeGen.cc
index 4b9ebfb..8940e63 100644
--- a/lib/CodeGen/CodeGen.cc
+++ b/lib/CodeGen/CodeGen.cc
@@ -3,6 +3,7 @@
 #include "cps/FileAST.h"
 #include "cps/FileHandler.h"
 #include "cps/Lexer.h"
+#include "cps/TypeAST.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/Verifier.h"
 #include <cstdarg>
@@ -619,6 +620,12 @@ Value *CodeGen::emitExpr(ExprAST *Expr) {
         return FuncGen->emitCallExpr(Call, Args);
     }
 
+    // TYPE-system stubs: parsed but not yet wired (phases C/D/E of the TYPE work).
+    if (dynamic_cast<DesignatorExprAST*>(Expr) || dynamic_cast<AddrOfExprAST*>(Expr)) {
+        reportError("Record field / pointer expressions are not implemented yet");
+        return nullptr;
+    }
+
     return nullptr;
 }
 
@@ -1039,4 +1046,15 @@ void CodeGen::emitStmt(StmtAST *Stmt) {
         emitForStmt(ForStmt);
         return;
     }
+
+    // TYPE-system stubs: parsed but not yet wired (phases C/D of the TYPE work).
+    if (dynamic_cast<EnumTypeDeclAST*>(Stmt) || dynamic_cast<PointerTypeDeclAST*>(Stmt) ||
+        dynamic_cast<RecordTypeDeclAST*>(Stmt)) {
+        reportError("TYPE declarations are not implemented yet");
+        return;
+    }
+    if (dynamic_cast<DesignatorAssignStmtAST*>(Stmt)) {
+        reportError("Assignment to record fields / pointer targets is not implemented yet");
+        return;
+    }
 }