feat: implement CIE 9.1 text file handling (OPENFILE/READFILE/WRITEFILE/CLOSEFILE/EOF)

Front end: OPENFILE/READFILE/WRITEFILE/CLOSEFILE plus reserved mode
keywords READ/WRITE/APPEND (RANDOM reserved with a dedicated
not-implemented error); statement nodes in new FileAST.h, parsing in new
ParserFile.cc; EOF joins the Builtins table as the 12th builtin and
CallExprAST now carries a line number for its runtime diagnostics.

Runtime: new FileHandler (StringHandler-shaped leaf) lazily synthesizes
internal __cps_file_* helper functions and a 16-slot open-file table
keyed by filename content (strcmp — STRING '=' is pointer identity).
EOF is an fgetc/ungetc peek; READFILE grows a malloc/realloc line buffer
and strips a trailing CR; fopen uses text modes so mingw-w64 line
translation works. File-free programs get byte-identical IR. All misuse
(not open, wrong mode, reopen, fopen failure, read past EOF, table full)
dies with the existing "[Fatal] line N:" pattern via a new
RuntimeCheck::emitErrorAndExit overload taking runtime printf args.

Also fixes a pre-existing ArithmeticHandler hole surfaced by adversarial
review: mixed-width integer operands (i1 BOOLEAN / i8 CHAR vs i64) now
widen via ZExt instead of emitting invalid IR, and remaining type
mismatches get a clean diagnostic; -EOF(f) and -IS_NUM(x) compile.

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

1 files changed, 3 insertions, 0 deletions

diff --git a/include/cps/CodeGen.h b/include/cps/CodeGen.h
index 140d1f5..43d3a32 100644
--- a/include/cps/CodeGen.h
+++ b/include/cps/CodeGen.h
@@ -18,6 +18,7 @@
 namespace cps {
 
 class ArrayHandler;
+class FileHandler;
 
 class CodeGen {
     std::unique_ptr<llvm::LLVMContext> TheContext;
@@ -33,6 +34,7 @@ class CodeGen {
     std::unique_ptr<ArithmeticHandler> ArithHandler;
     std::unique_ptr<StringHandler> StrHandler;
     std::unique_ptr<StringConversionHandler> StrConvHandler;
+    std::unique_ptr<FileHandler> Files;
 
     llvm::FunctionCallee PrintfFunc;
     llvm::FunctionCallee ScanfFunc;
@@ -59,6 +61,7 @@ class CodeGen {
 
     void registerSymbol(const std::string &Name, llvm::Value *Storage, const std::string &TypeName, bool IsArray = false);
     const SymbolInfo *getSymbolInfo(const std::string &Name) const;
+    bool isWholeArrayVar(ExprAST *Expr) const;
     const TypeInfo *getExprTypeInfo(ExprAST *Expr) const;
     llvm::Value *coerceValueToType(llvm::Value *Val, const TypeInfo *TargetInfo);
     bool marshalCallArgs(const std::string &Callee,