All - Ensure that all files have a header comment, remove some dead code

78 files changed, 520 insertions, 320 deletions

diff --git a/Makefile b/Makefile
index 1aafecc3..0d34be43 100644
--- a/Makefile
+++ b/Makefile
@@ -95,7 +95,7 @@ OBJ += resolve/use.o resolve/index.o resolve/absolute.o
 OBJ += hir/from_ast.o hir/from_ast_expr.o
 OBJ +=  hir/dump.o
 OBJ +=  hir/hir.o hir/generic_params.o
-OBJ +=  hir/crate_ptr.o hir/type_ptr.o hir/expr_ptr.o
+OBJ +=  hir/crate_ptr.o hir/expr_ptr.o
 OBJ +=  hir/type.o hir/path.o hir/expr.o hir/pattern.o
 OBJ +=  hir/visitor.o hir/crate_post_load.o
 OBJ += hir_conv/expand_type.o hir_conv/constant_evaluation.o hir_conv/resolve_ufcs.o hir_conv/bind.o hir_conv/markings.o
diff --git a/src/ast/ast.cpp b/src/ast/ast.cpp
index 4fdf8f9d..e4fe49da 100644
--- a/src/ast/ast.cpp
+++ b/src/ast/ast.cpp
@@ -1,4 +1,9 @@
 /*
+ * MRustC - Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * ast/ast.cpp
+ * - Implementation of the various AST classes
  */
 #include "ast.hpp"
 #include "crate.hpp"
@@ -236,16 +241,6 @@ bool Impl::has_named_item(const ::std::string& name) const
     return os << impl.m_def;
 }
 
-::rust::option<char> ImplRef::find_named_item(const ::std::string& name) const
-{
-    if( this->impl.has_named_item(name) ) {
-        return ::rust::Some(' ');
-    }
-    else {
-        return ::rust::None<char>();
-    }
-}
-
 ::std::ostream& operator<<(::std::ostream& os, const UseStmt& x)
 {
     os << "Use(" << x.path << ")";
@@ -311,7 +306,7 @@ void Module::add_macro(bool is_exported, ::std::string name, MacroRulesPtr macro
     m_macros.push_back( Named<MacroRulesPtr>( mv$(name), mv$(macro), is_exported ) );
 }
 void Module::add_macro_import(::std::string name, const MacroRules& mr) {
-    m_macro_import_res.push_back( NamedNS<const MacroRules*>( mv$(name), &mr, false ) );
+    m_macro_import_res.push_back( Named<const MacroRules*>( mv$(name), &mr, false ) );
 }
 
 Item Item::clone() const
diff --git a/src/ast/ast.hpp b/src/ast/ast.hpp
index 241b51d7..0a43cc71 100644
--- a/src/ast/ast.hpp
+++ b/src/ast/ast.hpp
@@ -505,7 +505,7 @@ class Module
     // --- Runtime caches and state ---
     ::std::vector< ::std::shared_ptr<Module> >  m_anon_modules;
 
-    ::std::vector< NamedNS<const MacroRules*> > m_macro_import_res; // Vec of imported macros (not serialised)
+    ::std::vector< Named<const MacroRules*> >   m_macro_import_res;
     ::std::vector< Named<MacroRulesPtr> >  m_macros;
 
 public:
@@ -570,7 +570,7 @@ public:
 
           NamedList<MacroRulesPtr>&    macros()        { return m_macros; }
     const NamedList<MacroRulesPtr>&    macros()  const { return m_macros; }
-    const ::std::vector<NamedNS<const MacroRules*> >  macro_imports_res() const { return m_macro_import_res; }
+    const ::std::vector<Named<const MacroRules*> >  macro_imports_res() const { return m_macro_import_res; }
 
 private:
     void resolve_macro_import(const Crate& crate, const ::std::string& modname, const ::std::string& macro_name);
@@ -612,20 +612,6 @@ TAGGED_UNION_EX(Item, (), None,
     )
     );
 
-
-struct ImplRef
-{
-    const Impl& impl;
-    ::std::vector<TypeRef>  params;
-
-    ImplRef(const Impl& impl, ::std::vector<TypeRef> params):
-        impl(impl),
-        params( mv$(params) )
-    {}
-
-    ::rust::option<char> find_named_item(const ::std::string& name) const;
-};
-
 } // namespace AST
 
 class GenericResolveClosure
diff --git a/src/ast/crate.cpp b/src/ast/crate.cpp
index 9e4ed2ad..3db09f1b 100644
--- a/src/ast/crate.cpp
+++ b/src/ast/crate.cpp
@@ -1,4 +1,9 @@
 /*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * ast/crate.cpp
+ * - Helper functions for the AST::Crate type (includes loading `extern crate`s)
  */
 #include "crate.hpp"
 #include "ast.hpp"
diff --git a/src/ast/crate.hpp b/src/ast/crate.hpp
index bf1758d7..87a9f867 100644
--- a/src/ast/crate.hpp
+++ b/src/ast/crate.hpp
@@ -1,4 +1,10 @@
-
+/*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * ast/crate.hpp
+ * - AST::Crate type, and other top-level AST definitions
+ */
 #pragma once
 
 #include "ast.hpp"
diff --git a/src/ast/expr.cpp b/src/ast/expr.cpp
index 1142b763..32295c8e 100644
--- a/src/ast/expr.cpp
+++ b/src/ast/expr.cpp
@@ -1,4 +1,9 @@
 /*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * ast/expr.cpp
+ * - AST Expression nodes
  */
 #include "expr.hpp"
 #include "ast.hpp"
diff --git a/src/ast/expr_ptr.hpp b/src/ast/expr_ptr.hpp
index 1d68af15..cae519cc 100644
--- a/src/ast/expr_ptr.hpp
+++ b/src/ast/expr_ptr.hpp
@@ -1,4 +1,9 @@
 /*
+  * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * ast/expr_ptr.hpp
+ * - Pointer type wrapping AST::ExprNode (prevents need to know the full definition)
  */
 #include <memory>
 
diff --git a/src/ast/item.hpp b/src/ast/item.hpp
index 2137090d..0074ce9a 100644
--- a/src/ast/item.hpp
+++ b/src/ast/item.hpp
@@ -1,4 +1,10 @@
-
+/*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * ast/item.hpp
+ * - AST named item wrapper
+ */
 #pragma once
 
 #include <string>
@@ -7,19 +13,19 @@
 namespace AST {
 
 template <typename T>
-struct NamedNS
+struct Named
 {
     ::std::string   name;
     T   data;
     bool    is_pub;
 
-    NamedNS():
+    Named():
         is_pub(false)
     {}
-    NamedNS(NamedNS&&) = default;
-    NamedNS(const NamedNS&) = default;
-    NamedNS& operator=(NamedNS&&) = default;
-    NamedNS(::std::string name, T data, bool is_pub):
+    Named(Named&&) = default;
+    Named(const Named&) = default;
+    Named& operator=(Named&&) = default;
+    Named(::std::string name, T data, bool is_pub):
         name( ::std::move(name) ),
         data( ::std::move(data) ),
         is_pub( is_pub )
@@ -28,21 +34,6 @@ struct NamedNS
 };
 
 template <typename T>
-struct Named:
-    public NamedNS<T>
-{
-    Named():
-        NamedNS<T>()
-    {}
-    Named(Named&&) = default;
-    Named(const Named&) = default;
-    Named& operator=(Named&&) = default;
-    Named(::std::string name, T data, bool is_pub):
-        NamedNS<T>( ::std::move(name), ::std::move(data), is_pub )
-    {}
-};
-
-template <typename T>
 using NamedList = ::std::vector<Named<T> >;
 
 }   // namespace AST
diff --git a/src/ast/macro.hpp b/src/ast/macro.hpp
index 84baa5a3..5b2223ce 100644
--- a/src/ast/macro.hpp
+++ b/src/ast/macro.hpp
@@ -1,4 +1,10 @@
-
+/*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * ast/macro.hpp
+ * - AST representation of a macro invocation
+ */
 #ifndef _AST_MACRO_HPP_
 #define _AST_MACRO_HPP_
 
diff --git a/src/ast/path.cpp b/src/ast/path.cpp
index 690bc9eb..6fdf1e40 100644
--- a/src/ast/path.cpp
+++ b/src/ast/path.cpp
@@ -1,4 +1,9 @@
 /*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * ast/path.cpp
+ * - AST::Path and friends
  */
 #include "path.hpp"
 #include "ast.hpp"
diff --git a/src/ast/path.hpp b/src/ast/path.hpp
index 0cb6fcc8..c2d13d73 100644
--- a/src/ast/path.hpp
+++ b/src/ast/path.hpp
@@ -1,4 +1,9 @@
 /*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * ast/path.hpp
+ * - AST::Path and helper types
  */
 #ifndef AST_PATH_HPP_INCLUDED
 #define AST_PATH_HPP_INCLUDED
diff --git a/src/ast/types.hpp b/src/ast/types.hpp
index b6d9d6f5..af07ba2d 100644
--- a/src/ast/types.hpp
+++ b/src/ast/types.hpp
@@ -1,3 +1,10 @@
+/*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * ast/types.hpp
+ * - AST Type reference (and helpers)
+ */
 #ifndef TYPES_HPP_INCLUDED
 #define TYPES_HPP_INCLUDED
 
diff --git a/src/common.hpp b/src/common.hpp
index 3c99e57b..f46f93fd 100644
--- a/src/common.hpp
+++ b/src/common.hpp
@@ -1,4 +1,9 @@
 /*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * common.hpp
+ * - Compiler-global common header
  */
 #ifndef COMMON_HPP_INCLUDED
 #define COMMON_HPP_INCLUDED
@@ -22,7 +27,6 @@
 #define rc_new$(...) ::make_shared_ptr(::std::move(__VA_ARGS__))
 
 #include "include/debug.hpp"
-#include "include/rustic.hpp"   // slice and option
 #include "include/compile_error.hpp"
 
 template<typename T>
diff --git a/src/coretypes.hpp b/src/coretypes.hpp
index 67e32f79..7665f5ba 100644
--- a/src/coretypes.hpp
+++ b/src/coretypes.hpp
@@ -1,3 +1,10 @@
+/*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * coretypes.hpp
+ * - AST-level builtin types
+ */
 #ifndef CORETYPES_HPP_INCLUDED
 #define CORETYPES_HPP_INCLUDED
 
diff --git a/src/debug.cpp b/src/debug.cpp
index d460c3cb..43e2795e 100644
--- a/src/debug.cpp
+++ b/src/debug.cpp
@@ -1,4 +1,10 @@
-
+/*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * debug.cpp
+ * - Debug printing (with indenting)
+ */
 #include <debug.hpp>
 
 TraceLog::TraceLog(const char* tag, ::std::function<void(::std::ostream&)> info_cb, ::std::function<void(::std::ostream&)> ret):
diff --git a/src/expand/cfg.hpp b/src/expand/cfg.hpp
index 7c7785bb..5050a229 100644
--- a/src/expand/cfg.hpp
+++ b/src/expand/cfg.hpp
@@ -1,3 +1,10 @@
+/*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * expand/cfg.hpp
+ * - Handling of `#[cfg]` and `cfg!` conditions
+ */
 
 #pragma once
 
diff --git a/src/expand/macro_rules.cpp b/src/expand/macro_rules.cpp
index 5aa15a46..89f394e1 100644
--- a/src/expand/macro_rules.cpp
+++ b/src/expand/macro_rules.cpp
@@ -15,7 +15,6 @@
 #include "../parse/common.hpp"
 #include "../parse/ttstream.hpp"
 #include <ast/crate.hpp>
-#include "macro_rules.hpp"
 #include <macro_rules/macro_rules.hpp>
 #include <hir/hir.hpp>  // for HIR::Crate
 
diff --git a/src/expand/macro_rules.hpp b/src/expand/macro_rules.hpp
deleted file mode 100644
index 00332dd5..00000000
--- a/src/expand/macro_rules.hpp
+++ /dev/null
@@ -1,14 +0,0 @@
-/**
- * Binding header for the macro_rules syntax extension
- */
-#pragma once
-
-#include <synext.hpp>
-
-namespace AST {
-    class Expr;
-    class Module;
-}
-class TokenTree;
-class TokenStream;
-class MacroRules;
diff --git a/src/expand/mod.cpp b/src/expand/mod.cpp
index 8e052dfe..5d6d3234 100644
--- a/src/expand/mod.cpp
+++ b/src/expand/mod.cpp
@@ -10,7 +10,6 @@
 #include <main_bindings.hpp>
 #include <synext.hpp>
 #include <map>
-#include "macro_rules.hpp"
 #include "../macro_rules/macro_rules.hpp"
 #include "../parse/common.hpp"  // For reparse from macros
 #include <ast/expr.hpp>
diff --git a/src/expand/std_prelude.cpp b/src/expand/std_prelude.cpp
index 6b81b71e..d6022959 100644
--- a/src/expand/std_prelude.cpp
+++ b/src/expand/std_prelude.cpp
@@ -1,4 +1,9 @@
 /*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * expand/std_prelude.cpp
+ * - Handling of no_std/no_core/no_prelude
  */
 #include <synext.hpp>
 #include <ast/crate.hpp>
diff --git a/src/hir/crate_ptr.cpp b/src/hir/crate_ptr.cpp
index bc0287b3..e5cb8bf1 100644
--- a/src/hir/crate_ptr.cpp
+++ b/src/hir/crate_ptr.cpp
@@ -1,4 +1,9 @@
 /*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * hir/crate_ptr.cpp
+ * - Implementation of HIR::CratePtr
  */
 #include "crate_ptr.hpp"
 #include "hir.hpp"
diff --git a/src/hir/crate_ptr.hpp b/src/hir/crate_ptr.hpp
index c870b1ea..bdbff1b2 100644
--- a/src/hir/crate_ptr.hpp
+++ b/src/hir/crate_ptr.hpp
@@ -1,5 +1,9 @@
 /*
- * High-level intermediate representation
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * hir/crate_ptr.hpp
+ * - Pointer type to the HIR version of a crate
  */
 #pragma once
 
diff --git a/src/hir/expr.hpp b/src/hir/expr.hpp
index 33726093..37efac31 100644
--- a/src/hir/expr.hpp
+++ b/src/hir/expr.hpp
@@ -1,4 +1,9 @@
 /*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * hir/expr.hpp
+ * - HIR Expression nodes
  */
 #pragma once
 
diff --git a/src/hir/generic_params.cpp b/src/hir/generic_params.cpp
index 984d8a3a..381277fc 100644
--- a/src/hir/generic_params.cpp
+++ b/src/hir/generic_params.cpp
@@ -1,4 +1,9 @@
 /*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * hir/generic_params.hpp
+ * - HIR version of generic definition blocks
  */
 #include "generic_params.hpp"
 
diff --git a/src/hir/generic_params.hpp b/src/hir/generic_params.hpp
index 8753ae7e..ef83bda7 100644
--- a/src/hir/generic_params.hpp
+++ b/src/hir/generic_params.hpp
@@ -1,4 +1,9 @@
 /*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * hir/generic_params.hpp
+ * - HIR version of generic definition blocks
  */
 #pragma once
 #include <string>
diff --git a/src/hir/path.hpp b/src/hir/path.hpp
index 206b5d5b..f2bec6ee 100644
--- a/src/hir/path.hpp
+++ b/src/hir/path.hpp
@@ -11,11 +11,11 @@
 
 #include <common.hpp>
 #include <tagged_union.hpp>
-#include <hir/type_ptr.hpp>
 #include <span.hpp>
 
 namespace HIR {
 
+class TypeRef;
 class Trait;
 
 enum Compare {
diff --git a/src/hir/type_ptr.cpp b/src/hir/type_ptr.cpp
deleted file mode 100644
index b4814e41..00000000
--- a/src/hir/type_ptr.cpp
+++ /dev/null
@@ -1,18 +0,0 @@
-
-#include <hir/type_ptr.hpp>
-#include <hir/type.hpp>
-
-::HIR::TypeRefPtr::TypeRefPtr(TypeRef tr):
-    m_ptr( new TypeRef(mv$(tr)) )
-{
-}
-::HIR::TypeRefPtr::TypeRefPtr(TypeRefPtr&& other):
-    m_ptr( other.m_ptr )
-{
-    other.m_ptr = nullptr;
-}
-::HIR::TypeRefPtr::~TypeRefPtr()
-{
-    delete m_ptr, m_ptr = nullptr;
-}
-
diff --git a/src/hir/type_ptr.hpp b/src/hir/type_ptr.hpp
deleted file mode 100644
index b3e1bcc7..00000000
--- a/src/hir/type_ptr.hpp
+++ /dev/null
@@ -1,16 +0,0 @@
-/*
- */
-#pragma once
-
-namespace HIR {
-
-class TypeRef;
-class TypeRefPtr {
-    TypeRef*    m_ptr;
-public:
-    TypeRefPtr(TypeRef _);
-    TypeRefPtr(TypeRefPtr&& _);
-    ~TypeRefPtr();
-};
-
-}   // namespace HIR
diff --git a/src/hir_conv/main_bindings.hpp b/src/hir_conv/main_bindings.hpp
index fe99b859..37488dae 100644
--- a/src/hir_conv/main_bindings.hpp
+++ b/src/hir_conv/main_bindings.hpp
@@ -1,4 +1,9 @@
 /*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * hir_conv/main_bindings.hpp
+ * - Functions in the "HIR Conversion" group called by main
  */
 #pragma once
 
diff --git a/src/hir_typeck/expr_visit.cpp b/src/hir_typeck/expr_visit.cpp
index b82e8f23..123f51b3 100644
--- a/src/hir_typeck/expr_visit.cpp
+++ b/src/hir_typeck/expr_visit.cpp
@@ -1,4 +1,9 @@
 /*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * hir_typeck/expr_visit.cpp
+ * - Wrapper around HIR typecheck that visits all expressions
  */
 #include <hir/hir.hpp>
 #include <hir/expr.hpp>
diff --git a/src/hir_typeck/expr_visit.hpp b/src/hir_typeck/expr_visit.hpp
index 3fe601e4..2263a66f 100644
--- a/src/hir_typeck/expr_visit.hpp
+++ b/src/hir_typeck/expr_visit.hpp
@@ -1,3 +1,10 @@
+/*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * hir_typeck/expr_visit.hpp
+ * - Helpers for the HIR typecheck expression visiting
+ */
 
 namespace typeck {
     struct ModuleState
diff --git a/src/hir_typeck/impl_ref.hpp b/src/hir_typeck/impl_ref.hpp
index 126daeda..b1190c61 100644
--- a/src/hir_typeck/impl_ref.hpp
+++ b/src/hir_typeck/impl_ref.hpp
@@ -1,4 +1,9 @@
 /*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * hir_typeck/impl_ref.hpp
+ * - Reference to a specific impl block (or the concept of one)
  */
 #pragma once
 
diff --git a/src/hir_typeck/main_bindings.hpp b/src/hir_typeck/main_bindings.hpp
index fe2920b9..12872fe6 100644
--- a/src/hir_typeck/main_bindings.hpp
+++ b/src/hir_typeck/main_bindings.hpp
@@ -1,4 +1,9 @@
 /*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * hir_typeck/main_bindings.hpp
+ * - Functions in HIR typecheck called by main
  */
 #pragma once
 
diff --git a/src/include/compile_error.hpp b/src/include/compile_error.hpp
index f88cbe58..d813d83a 100644
--- a/src/include/compile_error.hpp
+++ b/src/include/compile_error.hpp
@@ -1,4 +1,9 @@
 /*
+ * MRustC - Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * include/compile_error.hpp
+ * - Front-end compiler error exception classes
  */
 #ifndef _COMPILE_ERROR_H_
 #define _COMPILE_ERROR_H_
diff --git a/src/include/cpp_unpack.h b/src/include/cpp_unpack.h
index 69417589..801d5619 100644
--- a/src/include/cpp_unpack.h
+++ b/src/include/cpp_unpack.h
@@ -1,4 +1,10 @@
-
+/*
+ * MRustC - Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * include/cpp_unpack.hpp
+ * - Macro that performs variadic unpacking and calls a function/macro with the unpacked values
+ */
 #ifndef _CPP_UNAPCK_H_
 #define _CPP_UNAPCK_H_
 
diff --git a/src/include/main_bindings.hpp b/src/include/main_bindings.hpp
index ee8f4c54..c9e573d4 100644
--- a/src/include/main_bindings.hpp
+++ b/src/include/main_bindings.hpp
@@ -1,4 +1,9 @@
 /*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * include/main_bindings.hpp
+ * - General bindings of AST passes for main to call
  */
 #ifndef _MAIN_BINDINGS_HPP_
 #define _MAIN_BINDINGS_HPP_
@@ -8,25 +13,16 @@
 
 namespace AST {
     class Crate;
-    class Flat;
 }
 
 /// Parse a crate from the given file
 extern AST::Crate Parse_Crate(::std::string mainfile);
 
-
 extern void Expand(::AST::Crate& crate);
 extern void Expand_TestHarness(::AST::Crate& crate);
 extern void Expand_ProcMacro(::AST::Crate& crate);
 
-/// Process #[] decorators
-extern void Process_Decorators(AST::Crate& crate);
-
-/// Convert the AST to a flat tree
-extern AST::Flat Convert_Flatten(const AST::Crate& crate);
-
-
-/// Dump the crate as annotated rust
+/// Dump the crate AST as annotated rust
 extern void Dump_Rust(const char *Filename, const AST::Crate& crate);
 
 #endif
diff --git a/src/include/rc_string.hpp b/src/include/rc_string.hpp
index fd230062..eec47d80 100644
--- a/src/include/rc_string.hpp
+++ b/src/include/rc_string.hpp
@@ -1,4 +1,9 @@
 /*
+ * MRustC - Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * include/rc_string.hpp
+ * - Reference-counted string (used for spans)
  */
 #pragma once
 
diff --git a/src/include/rustic.hpp b/src/include/rustic.hpp
deleted file mode 100644
index 93992f61..00000000
--- a/src/include/rustic.hpp
+++ /dev/null
@@ -1,152 +0,0 @@
-/*
- */
-#pragma once
-
-template<typename T>
-class slice
-{
-    T*  m_first;
-    unsigned int    m_len;
-public:
-    slice():
-        m_first(nullptr),
-        m_len(0)
-    {}
-    slice(const ::std::vector<T>& v):
-        m_first(&v[0]),
-        m_len(v.size())
-    {}
-    slice(::std::vector<T>& v):
-        m_first(&v[0]),
-        m_len(v.size())
-    {}
-    slice(T* ptr, unsigned int len):
-        m_first(ptr),
-        m_len(len)
-    {}
-
-    ::std::vector<T> to_vec() const {
-        return ::std::vector<T>(begin(), end());
-    }
-
-    unsigned int size() const {
-        return m_len;
-    }
-    T& operator[](unsigned int i) const {
-        assert(i < m_len);
-        return m_first[i];
-    }
-    slice<T> subslice(unsigned int ofs, unsigned int len) const {
-        assert(ofs < m_len);
-        assert(len <= m_len);
-        assert(ofs + len <= m_len);
-        return slice { m_first + ofs, len };
-    }
-
-    T* begin() const { return m_first; }
-    T* end() const { return m_first + m_len; }
-
-    T& front() const { return m_first[0]; }
-    T& back() const { return m_first[m_len-1]; }
-};
-
-template<typename T>
-::std::ostream& operator<<(::std::ostream& os, slice<T> s) {
-    if( s.size() > 0 )
-    {
-        bool is_first = true;
-        for( const auto& i : s )
-        {
-            if(!is_first)
-                os << ", ";
-            is_first = false;
-            os << i;
-        }
-    }
-    return os;
-}
-
-namespace rust {
-
-template<typename T>
-class option
-{
-    char    m_data[ sizeof(T) ];
-    bool    m_set;
-
-          void* data_ptr()       { return m_data; }
-    const void* data_ptr() const { return m_data; }
-public:
-    option(T ent):
-        m_set(true)
-    {
-        new (m_data) T(::std::move(ent));
-    }
-    option():
-        m_set(false)
-    {}
-    ~option() {
-        if( m_set ) {
-            reinterpret_cast<T*>(data_ptr())->~T();
-        }
-    }
-
-    bool is_none() const { return !m_set; }
-    bool is_some() const { return m_set; }
-
-    const T& unwrap() const {
-        assert(is_some());
-        return *reinterpret_cast<const T*>(m_data);
-    }
-
-    void if_set(::std::function<void (const T&)> f) const {
-        if( m_set ) {
-            return f(m_data);
-        }
-    }
-    //template<typename U/*, class FcnSome, class FcnNone*/>
-    //U match(::std::function<U(const T&)> if_some, ::Std::function<U()> if_none) const {
-    //    if( m_set ) {
-    //        return if_some(m_data);
-    //    }
-    //    else {
-    //        return if_none();
-    //    }
-    //}
-};
-template<typename T>
-class option<T&>
-{
-    T* m_ptr;
-public:
-    option(T& ent):
-        m_ptr(&ent)
-    {}
-    option():
-        m_ptr(nullptr)
-    {}
-
-    bool is_none() const { return m_ptr == nullptr; }
-    bool is_some() const { return m_ptr != nullptr; }
-    T& unwrap() const {
-        assert(is_some());
-        return *m_ptr;
-    }
-    void if_set(::std::function<void (const T&)> f) const {
-        if( m_ptr ) {
-            return f(*m_ptr);
-        }
-    }
-};
-template<typename T>
-option<T> Some(T data) {
-    return option<T>( ::std::move(data) );
-}
-template<typename T>
-option<T> None() {
-    return option<T>( );
-}
-
-#define IF_OPTION_SOME(bind, var, ...)    { auto __v = (var); if( var.is_some() ) { auto bind = __v.unwrap(); (void)&bind; __VA_ARGS__ } }
-
-};
diff --git a/src/include/stdspan.hpp b/src/include/stdspan.hpp
new file mode 100644
index 00000000..0d574cfc
--- /dev/null
+++ b/src/include/stdspan.hpp
@@ -0,0 +1,78 @@
+/*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * include/stdspan.hpp
+ * - Clone of the C++20 span class
+ */
+#pragma once
+#include <vector>
+#include <iostream> // ostream
+
+namespace std {
+
+template<typename T>
+class span
+{
+    T*  m_first;
+    unsigned int    m_len;
+public:
+    span():
+        m_first(nullptr),
+        m_len(0)
+    {}
+    span(const ::std::vector<T>& v):
+        m_first(&v[0]),
+        m_len(v.size())
+    {}
+    span(::std::vector<T>& v):
+        m_first(&v[0]),
+        m_len(v.size())
+    {}
+    span(T* ptr, unsigned int len):
+        m_first(ptr),
+        m_len(len)
+    {}
+
+    ::std::vector<T> to_vec() const {
+        return ::std::vector<T>(begin(), end());
+    }
+
+    unsigned int size() const {
+        return m_len;
+    }
+    T& operator[](unsigned int i) const {
+        assert(i < m_len);
+        return m_first[i];
+    }
+    span<T> subspan(unsigned int ofs, unsigned int len) const {
+        assert(ofs < m_len);
+        assert(len <= m_len);
+        assert(ofs + len <= m_len);
+        return span { m_first + ofs, len };
+    }
+
+    T* begin() const { return m_first; }
+    T* end() const { return m_first + m_len; }
+
+    T& front() const { return m_first[0]; }
+    T& back() const { return m_first[m_len-1]; }
+};
+
+template<typename T>
+::std::ostream& operator<<(::std::ostream& os, span<T> s) {
+    if( s.size() > 0 )
+    {
+        bool is_first = true;
+        for( const auto& i : s )
+        {
+            if(!is_first)
+                os << ", ";
+            is_first = false;
+            os << i;
+        }
+    }
+    return os;
+}
+
+}
diff --git a/src/include/synext.hpp b/src/include/synext.hpp
index 67f3b87b..6a8e74b6 100644
--- a/src/include/synext.hpp
+++ b/src/include/synext.hpp
@@ -1,4 +1,9 @@
 /*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * include/synext.hpp
+ * - Generic syntax extension support
  */
 #pragma once
 #ifndef _SYNEXT_HPP_
diff --git a/src/include/synext_decorator.hpp b/src/include/synext_decorator.hpp
index 049a28b0..eaed3154 100644
--- a/src/include/synext_decorator.hpp
+++ b/src/include/synext_decorator.hpp
@@ -1,4 +1,9 @@
 /*
+ * MRustC - Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * include/synext_decorator.hpp
+ * - Decorator syntax extensions (#[foo])
  */
 #pragma once
 #ifndef _SYNEXT_DECORATOR_HPP_
diff --git a/src/include/synext_macro.hpp b/src/include/synext_macro.hpp
index 0359d508..d414ceb0 100644
--- a/src/include/synext_macro.hpp
+++ b/src/include/synext_macro.hpp
@@ -1,4 +1,9 @@
 /*
+ * MRustC - Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * include/synext_macro.hpp
+ * - Macro-style syntax extensions ( `foo!()` )
  */
 #pragma once
 #ifndef _SYNEXT_MACRO_HPP_
diff --git a/src/include/tagged_union.hpp b/src/include/tagged_union.hpp
index 478953b9..bcc9eb3d 100644
--- a/src/include/tagged_union.hpp
+++ b/src/include/tagged_union.hpp
@@ -1,4 +1,11 @@
 /*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * include/tagged_union.hpp
+ * - Macro that allows construction of a tagged union (with various helper methods)
+ *
+ *
  * The most evil CPP abuse I have ever written
  *
  * Constructs a tagged union that correctly handles objects.
@@ -169,11 +176,11 @@
  *
  * ```
  * TAGGED_UNION(Inner, Any,
- *     (Any, (bool flag)),
- *     (Tuple, (::std::vector<Pattern> subpats)),
- *     (TupleStruct, (Path path; ::std::vector<Pattern> sub_patterns;)),
- *     (Value, (::std::unique_ptr<ExprNode> val )),
- *     (Range, (::std::unique_ptr<ExprNode> left; ::std::unique_ptr<ExprNode> right;))
+ *     (Any, (struct { bool match_multiple; })),
+ *     (Tuple, (::std::vector<Pattern> )),
+ *     (TupleStruct, (struct { Path path; ::std::vector<Pattern> sub_patterns; })),
+ *     (Value, (::std::unique_ptr<ExprNode> )),
+ *     (Range, (struct { ::std::unique_ptr<ExprNode> left; ::std::unique_ptr<ExprNode> right; }))
  *     );
  * ```
  */
diff --git a/src/macro_rules/mod.cpp b/src/macro_rules/mod.cpp
index 2613a0b4..6410d334 100644
--- a/src/macro_rules/mod.cpp
+++ b/src/macro_rules/mod.cpp
@@ -1,4 +1,9 @@
 /*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * macro_rules/mod.cpp
+ * - Top-level handling for macro_rules macros
  */
 #include <common.hpp>
 #include "macro_rules.hpp"
diff --git a/src/macro_rules/pattern_checks.hpp b/src/macro_rules/pattern_checks.hpp
index 138f11a3..4ebbe915 100644
--- a/src/macro_rules/pattern_checks.hpp
+++ b/src/macro_rules/pattern_checks.hpp
@@ -1,4 +1,9 @@
 /*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * macro_rules/pattern_checks.hpp
+ * - Checking helpers for the fragement patterns
  */
 #pragma once
 
diff --git a/src/parse/eTokenType.enum.h b/src/parse/eTokenType.enum.h
index 1e46721f..5104142b 100644
--- a/src/parse/eTokenType.enum.h
+++ b/src/parse/eTokenType.enum.h
@@ -1,3 +1,10 @@
+/*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * parse/eTokenType.enum.h
+ * - Multi-include file for defining the eTokenType enum
+ */
 _(TOK_NULL)
 _(TOK_EOF)
 
diff --git a/src/parse/interpolated_fragment.cpp b/src/parse/interpolated_fragment.cpp
index 9b7979f3..d8a8bc43 100644
--- a/src/parse/interpolated_fragment.cpp
+++ b/src/parse/interpolated_fragment.cpp
@@ -1,4 +1,9 @@
 /*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * parse/interpolated_fragment.cpp
+ * - An "interpolated fragment", result of parsing e.g. :expr in a macro invocation
  */
 #include <iostream>
 #include "interpolated_fragment.hpp"
diff --git a/src/parse/interpolated_fragment.hpp b/src/parse/interpolated_fragment.hpp
index 857e77aa..36539fb0 100644
--- a/src/parse/interpolated_fragment.hpp
+++ b/src/parse/interpolated_fragment.hpp
@@ -1,4 +1,9 @@
 /*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * parse/interpolated_fragment.hpp
+ * - An "interpolated fragment", result of parsing e.g. :expr in a macro invocation
  */
 #pragma once
 
diff --git a/src/parse/parseerror.hpp b/src/parse/parseerror.hpp
index d6bcab6b..d6e2b03e 100644
--- a/src/parse/parseerror.hpp
+++ b/src/parse/parseerror.hpp
@@ -1,3 +1,10 @@
+/*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * parse/parseerror.hpp
+ * - Exception classes for parsing/lexing errors
+ */
 #ifndef PARSEERROR_HPP_INCLUDED
 #define PARSEERROR_HPP_INCLUDED
 
diff --git a/src/rc_string.cpp b/src/rc_string.cpp
index 59534d28..46f36923 100644
--- a/src/rc_string.cpp
+++ b/src/rc_string.cpp
@@ -1,4 +1,9 @@
 /*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * rc_string.cpp
+ * - Reference-counted string
  */
 #include <rc_string.hpp>
 #include <cstring>
diff --git a/src/resolve/absolute.cpp b/src/resolve/absolute.cpp
index c51cac72..19da5820 100644
--- a/src/resolve/absolute.cpp
+++ b/src/resolve/absolute.cpp
@@ -1,6 +1,11 @@
 /*
- * Convert all paths in AST into absolute form (or to the relevant local item)
- * - NOTE: This is the core of the 'resolve' pass.
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * resolve/absolute.cpp
+ * - Convert all paths in AST into absolute form (or to the relevant local item)
+ *
+ * NOTE: This is the core of the 'resolve' pass.
  *
  * After complete there should be no:
  * - Relative/super/self paths
diff --git a/src/resolve/index.cpp b/src/resolve/index.cpp
index 458aed5e..659bded4 100644
--- a/src/resolve/index.cpp
+++ b/src/resolve/index.cpp
@@ -1,5 +1,9 @@
 /*
- * Build up a name index in all modules (optimising lookups in later stages)
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * resolve/index.cpp
+ * - Build up a name index in all modules (optimising lookups in later stages)
  */
 #include <ast/ast.hpp>
 #include <ast/crate.hpp>
diff --git a/src/resolve/main_bindings.hpp b/src/resolve/main_bindings.hpp
index cc6c74d7..f843a99e 100644
--- a/src/resolve/main_bindings.hpp
+++ b/src/resolve/main_bindings.hpp
@@ -1,6 +1,10 @@
 /*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * resolve/main_bindings.hpp
+ * - Functions in the resolve pass called by main
  */
-
 #pragma once
 
 namespace AST {
diff --git a/src/resolve/use.cpp b/src/resolve/use.cpp
index e36e40a0..23f7e70c 100644
--- a/src/resolve/use.cpp
+++ b/src/resolve/use.cpp
@@ -10,6 +10,7 @@
 #include <ast/ast.hpp>
 #include <ast/expr.hpp>
 #include <hir/hir.hpp>
+#include <stdspan.hpp>  // std::span
 
 enum class Lookup
 {
@@ -20,8 +21,8 @@ enum class Lookup
 };
 
 ::AST::Path Resolve_Use_AbsolutisePath(const ::AST::Path& base_path, ::AST::Path path);
-void Resolve_Use_Mod(const ::AST::Crate& crate, ::AST::Module& mod, ::AST::Path path, slice< const ::AST::Module* > parent_modules={});
-::AST::PathBinding Resolve_Use_GetBinding(const Span& span, const ::AST::Crate& crate, const ::AST::Path& path, slice< const ::AST::Module* > parent_modules, Lookup allow=Lookup::Any);
+void Resolve_Use_Mod(const ::AST::Crate& crate, ::AST::Module& mod, ::AST::Path path, ::std::span< const ::AST::Module* > parent_modules={});
+::AST::PathBinding Resolve_Use_GetBinding(const Span& span, const ::AST::Crate& crate, const ::AST::Path& path, ::std::span< const ::AST::Module* > parent_modules, Lookup allow=Lookup::Any);
 ::AST::PathBinding Resolve_Use_GetBinding__ext(const Span& span, const ::AST::Crate& crate, const ::AST::Path& path,  const ::HIR::Module& hmodr, unsigned int start,  Lookup allow);
 
 
@@ -101,7 +102,7 @@ void Resolve_Use(::AST::Crate& crate)
     throw "BUG: Reached end of Resolve_Use_AbsolutisePath";
 }
 
-void Resolve_Use_Mod(const ::AST::Crate& crate, ::AST::Module& mod, ::AST::Path path, slice< const ::AST::Module* > parent_modules)
+void Resolve_Use_Mod(const ::AST::Crate& crate, ::AST::Module& mod, ::AST::Path path, ::std::span< const ::AST::Module* > parent_modules)
 {
     TRACE_FUNCTION_F("path = " << path);
 
@@ -267,7 +268,7 @@ void Resolve_Use_Mod(const ::AST::Crate& crate, ::AST::Module& mod, ::AST::Path
         const Span& span,
         const ::AST::Crate& crate, const ::AST::Module& mod,
         const ::std::string& des_item_name,
-        slice< const ::AST::Module* > parent_modules,
+        ::std::span< const ::AST::Module* > parent_modules,
         Lookup allow
     )
 {
@@ -476,7 +477,7 @@ void Resolve_Use_Mod(const ::AST::Crate& crate, ::AST::Module& mod, ::AST::Path
 
     if( mod.path().nodes().size() > 0 && mod.path().nodes().back().name()[0] == '#' ) {
         assert( parent_modules.size() > 0 );
-        return Resolve_Use_GetBinding_Mod(span, crate, *parent_modules.back(), des_item_name, parent_modules.subslice(0, parent_modules.size()-1), allow);
+        return Resolve_Use_GetBinding_Mod(span, crate, *parent_modules.back(), des_item_name, parent_modules.subspan(0, parent_modules.size()-1), allow);
     }
     else {
         if( allow == Lookup::Any )
@@ -691,7 +692,7 @@ namespace {
     return Resolve_Use_GetBinding__ext(span, crate, path, ec.m_hir->m_root_module, start, allow);
 }
 
-::AST::PathBinding Resolve_Use_GetBinding(const Span& span, const ::AST::Crate& crate, const ::AST::Path& path, slice< const ::AST::Module* > parent_modules, Lookup allow)
+::AST::PathBinding Resolve_Use_GetBinding(const Span& span, const ::AST::Crate& crate, const ::AST::Path& path, ::std::span< const ::AST::Module* > parent_modules, Lookup allow)
 {
     TRACE_FUNCTION_F(path);
     //::AST::Path rv;
diff --git a/src/trans/allocator.cpp b/src/trans/allocator.cpp
index ce4b3340..5f61093d 100644
--- a/src/trans/allocator.cpp
+++ b/src/trans/allocator.cpp
@@ -1,4 +1,10 @@
-
+/*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * trans/allocator.cpp
+ * - Handling for switchable allocator backends
+ */
 
 #include "allocator.hpp"
 
diff --git a/src/trans/allocator.hpp b/src/trans/allocator.hpp
index 67d56c11..8a4e5186 100644
--- a/src/trans/allocator.hpp
+++ b/src/trans/allocator.hpp
@@ -1,4 +1,9 @@
 /*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * trans/allocator.hpp
+ * - Handling for switchable allocator backends
  */
 #include <cstddef>
 
diff --git a/src/trans/codegen_c.hpp b/src/trans/codegen_c.hpp
index 094cc264..77ac5d5c 100644
--- a/src/trans/codegen_c.hpp
+++ b/src/trans/codegen_c.hpp
@@ -1,4 +1,9 @@
 /*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * trans/codegen_c.hpp
+ * - C codegen backend (internal header)
  */
 #pragma once
 #include <vector>
diff --git a/src/trans/codegen_mmir.cpp b/src/trans/codegen_mmir.cpp
index 3347606c..b2c5282a 100644
--- a/src/trans/codegen_mmir.cpp
+++ b/src/trans/codegen_mmir.cpp
@@ -1,6 +1,12 @@
-//
-//
-//
+/*
+ * MRustC - Mutabah's Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * trans/codegen_mmir.cpp
+ * - Monomorphised MIR Backend
+ *
+ * Saves the MIR in a loadable form, used by the `standalone_miri` tool
+ */
 #include "codegen.hpp"
 #include <hir_typeck/static.hpp>
 #include <mir/helpers.hpp>
diff --git a/tools/common/debug.h b/tools/common/debug.h
index 86c88de9..6935bfb9 100644
--- a/tools/common/debug.h
+++ b/tools/common/debug.h
@@ -1,3 +1,10 @@
+/*
+ * mrustc common tools
+ * - by John Hodge (Mutabah)
+ *
+ * tools/common/debug.h
+ * - Generic debug interface (used by minicargo/standalone_miri)
+ */
 #pragma once
 
 #include <functional>
diff --git a/tools/common/helpers.h b/tools/common/helpers.h
index 8111483a..a1250847 100644
--- a/tools/common/helpers.h
+++ b/tools/common/helpers.h
@@ -1,3 +1,11 @@
+/*
+ * mrustc common tools
+ * - by John Hodge (Mutabah)
+ *
+ * tools/common/helpers.h
+ * - General helper classes
+ */
+// TODO: Replace this header with src/includ/string_view.hpp
 #pragma once
 
 #include <string>
diff --git a/tools/common/path.cpp b/tools/common/path.cpp
index 12e505bb..4967a1d5 100644
--- a/tools/common/path.cpp
+++ b/tools/common/path.cpp
@@ -1,4 +1,9 @@
 /*
+ * mrustc common code
+ * - by John Hodge (Mutabah)
+ *
+ * tools/common/path.cpp
+ * - Generic representation of a filesystem path
  */
 #include "path.h"
 #if _WIN32
diff --git a/tools/common/path.h b/tools/common/path.h
index dd97f9be..eae4951f 100644
--- a/tools/common/path.h
+++ b/tools/common/path.h
@@ -1,3 +1,10 @@
+/*
+ * mrustc common code
+ * - by John Hodge (Mutabah)
+ *
+ * tools/common/path.h
+ * - Generic representation of a filesystem path (HEADER)
+ */
 #pragma once
 
 #include <string>
diff --git a/tools/common/toml.cpp b/tools/common/toml.cpp
index 75a93810..489f32b6 100644
--- a/tools/common/toml.cpp
+++ b/tools/common/toml.cpp
@@ -1,13 +1,17 @@
 /*
- * A very bad streaming TOML parser
+ * mrustc common tools
+ * - by John Hodge (Mutabah)
+ *
+ * tools/common/toml.cpp
+ * - A very basic (and probably incomplete) streaming TOML parser
  */
-#define NOLOG
+#define NOLOG   // Disable logging
 #include "toml.h"
 #include "debug.h"
 #include <cassert>
 #include <string>
 
-
+// Representation of a syntatic token in a TOML file
 struct Token
 {
     enum class Type
diff --git a/tools/common/toml.h b/tools/common/toml.h
index a2c03bf1..4c97e7f2 100644
--- a/tools/common/toml.h
+++ b/tools/common/toml.h
@@ -1,3 +1,10 @@
+/*
+ * mrustc common tools
+ * - by John Hodge (Mutabah)
+ *
+ * tools/common/toml.h
+ * - A very basic (and probably incomplete) streaming TOML parser
+ */
 #pragma once
 
 #include <fstream>
@@ -31,6 +38,7 @@ public:
     TomlFileIter begin();
     TomlFileIter end();
 
+    // Obtain the next value in the file
     TomlKeyValue get_next_value();
 };
 
@@ -38,11 +46,14 @@ struct TomlValue
 {
     enum class Type
     {
+        // A true/false, 1/0, yes/no value
         Boolean,
+        // A double-quoted string
         String,
+        // Integer
         Integer,
+        // A list of other values
         List,
-
     };
     friend ::std::ostream& operator<<(::std::ostream& os, const Type& e) {
         switch(e)
@@ -146,7 +157,10 @@ struct TomlValue
 
 struct TomlKeyValue
 {
+    // Path to the value (last node is the value name)
+    // TODO: How are things like `[[bin]]` handled?
     ::std::vector<::std::string>    path;
+    // Relevant value
     TomlValue   value;
 };
 
diff --git a/tools/minicargo/build.h b/tools/minicargo/build.h
index 54d03575..bba22964 100644
--- a/tools/minicargo/build.h
+++ b/tools/minicargo/build.h
@@ -1,3 +1,10 @@
+/*
+ * minicargo - MRustC-specific clone of `cargo`
+ * - By John Hodge (Mutabah)
+ *
+ * build.h
+ * - Definitions relating to building the crate (and dependencies)
+ */
 #pragma once
 
 #include "manifest.h"
@@ -21,7 +28,7 @@ class BuildList
     struct Entry
     {
         const PackageManifest*  package;
-	bool	is_host;
+        bool    is_host;
         ::std::vector<unsigned> dependents;   // Indexes into the list
     };
     const PackageManifest&  m_root_manifest;
diff --git a/tools/minicargo/main.cpp b/tools/minicargo/main.cpp
index b185881b..b96a8a03 100644
--- a/tools/minicargo/main.cpp
+++ b/tools/minicargo/main.cpp
@@ -1,5 +1,6 @@
 /*
- * Mini version of cargo 
+ * mrustc "minicargo" (minimal cargo clone)
+ * - By John Hodge (Mutabah)
  *
  * main.cpp
  * - Entrypoint
diff --git a/tools/minicargo/manifest.cpp b/tools/minicargo/manifest.cpp
index 687c3e2a..bbaa24f6 100644
--- a/tools/minicargo/manifest.cpp
+++ b/tools/minicargo/manifest.cpp
@@ -1,4 +1,9 @@
 /*
+ * mrustc "minicargo" (minimal cargo clone)
+ * - By John Hodge (Mutabah)
+ *
+ * manifest.cpp
+ * - Cargo.toml manifest loading and manipulation code
  */
 #include "manifest.h"
 #include "toml.h"
@@ -9,7 +14,7 @@
 #include <cctype>   // toupper
 #include "repository.h"
 
-// TODO: Extract this from the target at runtime
+// TODO: Extract this from the target at runtime (by invoking the compiler on the passed target)
 #ifdef _WIN32
 # define TARGET_NAME    "i586-windows-msvc"
 # define CFG_UNIX   false
diff --git a/tools/minicargo/manifest.h b/tools/minicargo/manifest.h
index e48e7f2a..4bb8b843 100644
--- a/tools/minicargo/manifest.h
+++ b/tools/minicargo/manifest.h
@@ -1,3 +1,10 @@
+/*
+ * mrustc "minicargo" (minimal cargo clone)
+ * - By John Hodge (Mutabah)
+ *
+ * manifest.h
+ * - Cargo.toml package manifests
+ */
 #pragma once
 
 #include <string>
diff --git a/tools/minicargo/repository.cpp b/tools/minicargo/repository.cpp
index ebe660f1..f5ff5ea8 100644
--- a/tools/minicargo/repository.cpp
+++ b/tools/minicargo/repository.cpp
@@ -1,4 +1,9 @@
 /*
+ * minicargo - MRustC-specific clone of `cargo`
+ * - By John Hodge (Mutabah)
+ *
+ * repository.cpp
+ * - Handling of (vendored) crates.io dependencies
  */
 #include "repository.h"
 #include "debug.h"
diff --git a/tools/minicargo/repository.h b/tools/minicargo/repository.h
index 0b186077..ca481166 100644
--- a/tools/minicargo/repository.h
+++ b/tools/minicargo/repository.h
@@ -1,3 +1,10 @@
+/*
+ * minicargo - MRustC-specific clone of `cargo`
+ * - By John Hodge (Mutabah)
+ *
+ * repository.h
+ * - Handling (vendored) crates.io dependencies
+ */
 #pragma once
 
 #include <string>
diff --git a/tools/standalone_miri/hir/type.hpp b/tools/standalone_miri/hir/type.hpp
index 2e566691..6a0abd8f 100644
--- a/tools/standalone_miri/hir/type.hpp
+++ b/tools/standalone_miri/hir/type.hpp
@@ -1 +1,8 @@
-#include "../hir_sim.hpp"
\ No newline at end of file
+/*
+ * mrustc Standalone MIRI
+ * - by John Hodge (Mutabah)
+ *
+ * hir/type.hpp
+ * - Forwarding header so mrustc's mir.hpp can be imported
+ */
+#include "../hir_sim.hpp"
diff --git a/tools/standalone_miri/hir_sim.hpp b/tools/standalone_miri/hir_sim.hpp
index 7730ac48..62248fe9 100644
--- a/tools/standalone_miri/hir_sim.hpp
+++ b/tools/standalone_miri/hir_sim.hpp
@@ -1,6 +1,10 @@
-//
-//
-//
+/*
+ * mrustc Standalone MIRI
+ * - by John Hodge (Mutabah)
+ *
+ * hir_sim.hpp
+ * - Clones of the mrustc HIR types (HEADER)
+ */
 #pragma once
 #include <string>
 #include <vector>
diff --git a/tools/standalone_miri/lex.cpp b/tools/standalone_miri/lex.cpp
index 8fc77f7a..07427bde 100644
--- a/tools/standalone_miri/lex.cpp
+++ b/tools/standalone_miri/lex.cpp
@@ -1,6 +1,10 @@
-//
-//
-//
+/*
+ * mrustc Standalone MIRI
+ * - by John Hodge (Mutabah)
+ *
+ * lex.cpp
+ * - MIR file lexer (very simple)
+ */
 #include "lex.hpp"
 #include <cctype>
 #include <iostream>
diff --git a/tools/standalone_miri/lex.hpp b/tools/standalone_miri/lex.hpp
index cc1429f7..1d1b5c2a 100644
--- a/tools/standalone_miri/lex.hpp
+++ b/tools/standalone_miri/lex.hpp
@@ -1,6 +1,10 @@
-//
-//
-//
+/*
+ * mrustc Standalone MIRI
+ * - by John Hodge (Mutabah)
+ *
+ * lex.hpp
+ * - Simple lexer for MIR files (HEADER)
+ */
 #pragma once
 #include <string>
 #include <fstream>
diff --git a/tools/standalone_miri/miri.hpp b/tools/standalone_miri/miri.hpp
index 09d92a9b..6f02ffee 100644
--- a/tools/standalone_miri/miri.hpp
+++ b/tools/standalone_miri/miri.hpp
@@ -1,4 +1,10 @@
-
+/*
+ * mrustc Standalone MIRI
+ * - by John Hodge (Mutabah)
+ *
+ * miri.hpp
+ * - MIR Interpreter State (HEADER)
+ */
 #pragma once
 #include "module_tree.hpp"
 #include "value.hpp"
@@ -35,10 +41,10 @@ class InterpreterThread
         ::std::vector<Value>    args;
         ::std::vector<Value>    locals;
         ::std::vector<bool>     drop_flags;
-        
+
         unsigned    bb_idx;
         unsigned    stmt_idx;
-        
+
         StackFrame(const Function& fcn, ::std::vector<Value> args);
         static StackFrame make_wrapper(::std::function<bool(Value&,Value)> cb) {
             static Function f;
@@ -51,14 +57,14 @@ class InterpreterThread
     ModuleTree& m_modtree;
     ThreadState m_thread;
     ::std::vector<StackFrame>   m_stack;
-    
+
 public:
     InterpreterThread(ModuleTree& modtree):
         m_modtree(modtree)
     {
     }
     ~InterpreterThread();
-    
+
     void start(const ::HIR::Path& p, ::std::vector<Value> args);
     // Returns `true` if the call stack empties
     bool step_one(Value& out_thread_result);
diff --git a/tools/standalone_miri/module_tree.cpp b/tools/standalone_miri/module_tree.cpp
index 8beba018..eb6b6b9e 100644
--- a/tools/standalone_miri/module_tree.cpp
+++ b/tools/standalone_miri/module_tree.cpp
@@ -1,11 +1,16 @@
-//
-//
-//
+/*
+ * mrustc Standalone MIRI
+ * - by John Hodge (Mutabah)
+ *
+ * module_tree.cpp
+ * - In-memory representation of a Monomorphised MIR executable
+ * - Also handles parsing the .mir files
+ */
 #include "module_tree.hpp"
 #include "lex.hpp"
 #include "value.hpp"
 #include <iostream>
-#include <algorithm>	// std::find
+#include <algorithm>    // std::find
 #include "debug.hpp"
 
 ModuleTree::ModuleTree()
diff --git a/tools/standalone_miri/module_tree.hpp b/tools/standalone_miri/module_tree.hpp
index 5479d9ef..efa0a034 100644
--- a/tools/standalone_miri/module_tree.hpp
+++ b/tools/standalone_miri/module_tree.hpp
@@ -1,6 +1,10 @@
-//
-//
-//
+/*
+ * mrustc Standalone MIRI
+ * - by John Hodge (Mutabah)
+ *
+ * module_tree.hpp
+ * - In-memory representation of a Monomorphised MIR executable (HEADER)
+ */
 #pragma once
 #include <string>
 #include <vector>
@@ -27,6 +31,7 @@ struct Function
 struct Static
 {
     ::HIR::TypeRef  ty;
+    // TODO: Should this value be stored in the program state (making the entire `ModuleTree` const)
     Value   val;
 };
 
diff --git a/tools/testrunner/main.cpp b/tools/testrunner/main.cpp
index f21dc7fa..4dafe508 100644
--- a/tools/testrunner/main.cpp
+++ b/tools/testrunner/main.cpp
@@ -1,6 +1,13 @@
-///
-///
-///
+/*
+ * mrustc test runner
+ * - by John Hodge (Mutabah)
+ *
+ * tools/testrunner/main.cpp
+ * - Clone of rustc's integration test runner
+ *
+ *
+ * Runs all .rs files in a directory, parsing test options out of comments in the file
+ */
 #define _CRT_SECURE_NO_WARNINGS
 #include <iostream>
 #include <string>