feat(library)!: replace #LIB with __LIB source regions

Track library mode by original source line, including deferred template bodies
and automatic object cleanup. Update call lines from ordinary code and migrate
the embedded standard library to PP_DEFINE __LIB.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

4 files changed, 9 insertions, 5 deletions

diff --git a/include/cps/CodeGen.h b/include/cps/CodeGen.h
index 0962753..c3a7b19 100644
--- a/include/cps/CodeGen.h
+++ b/include/cps/CodeGen.h
@@ -106,6 +106,7 @@ class CodeGen {
         llvm::AllocaInst *Alive;
         llvm::AllocaInst *Count; // Non-null for an array; Addr then holds its buffer pointer.
         int Line;
+        size_t OwnerUnit;
         bool Temporary = false;
     };
     std::vector<StackObject> StackObjects;
diff --git a/include/cps/Lexer.h b/include/cps/Lexer.h
index 05fb857..3d057a3 100644
--- a/include/cps/Lexer.h
+++ b/include/cps/Lexer.h
@@ -128,7 +128,6 @@ class Lexer {
     int CurrentLine = 1;
     int TokenLine = 1;
     bool HadError = false;
-    bool Library = false;
     bool LineStart = true;
     struct TokenData {
         int Kind, Line;
@@ -158,7 +157,6 @@ public:
     int peekToken(unsigned Offset = 0);
     int peekLine(unsigned Offset = 0);
     int getLine() const { return TokenLine; }
-    bool isLibrary() const { return Library; }
     bool hadError() const { return HadError; }
     // Human-readable spelling of Tok for diagnostics; Lex supplies identifier text.
     static std::string tokenSpelling(int Tok, const Lexer &Lex);
diff --git a/include/cps/RuntimeCheck.h b/include/cps/RuntimeCheck.h
index d2ee1ea..71943d4 100644
--- a/include/cps/RuntimeCheck.h
+++ b/include/cps/RuntimeCheck.h
@@ -3,6 +3,8 @@
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Module.h"
 #include <cstdint>
+#include <functional>
+#include <utility>
 #include <string>
 
 namespace cps {
@@ -18,7 +20,7 @@ class RuntimeCheck {
     llvm::FunctionCallee StderrFunc;   // Windows: __acrt_iob_func(2)
     llvm::GlobalVariable *StderrVar;   // elsewhere: the C library's stderr
     ExceptionHandler &Exceptions;
-    bool LibraryMode = false;
+    std::function<bool(int)> LibraryLookup;
     llvm::GlobalVariable *UserLine;
     llvm::Value *DivZeroMsg;
     llvm::Value *OutOfBoundsMsg;
@@ -33,7 +35,7 @@ public:
     RuntimeCheck(llvm::Module &M, llvm::LLVMContext &C, llvm::IRBuilder<> &B,
                  ExceptionHandler &EH);
 
-    void setLibraryMode(bool Enabled) { LibraryMode = Enabled; }
+    void setLibraryLookup(std::function<bool(int)> Lookup) { LibraryLookup = std::move(Lookup); }
     llvm::Value *lineValue(int Line);
     void setUserLine(int Line);
 
diff --git a/include/cps/SourceUnit.h b/include/cps/SourceUnit.h
index 34266ac..153d020 100644
--- a/include/cps/SourceUnit.h
+++ b/include/cps/SourceUnit.h
@@ -9,6 +9,9 @@ struct SourceUnit {
     std::string Path;
     const std::vector<std::unique_ptr<StmtAST>> &Statements;
     std::vector<bool> Visible;
-    bool IsLibrary = false;
+    std::vector<bool> LibraryLines;
+    bool isLibrary(int Line) const {
+        return Line > 0 && static_cast<size_t>(Line) <= LibraryLines.size() && LibraryLines[Line - 1];
+    }
 };
 }