From 502cc9c8dc1941877b35e45d742a3e36264671ca Mon Sep 17 00:00:00 2001
From: John Hodge <tpg@mutabah.net>
Date: Thu, 9 Jun 2016 09:54:57 +0800
Subject: HIR - Save and use paths to #[lang] items

---
 src/ast/crate.hpp        |  2 +-
 src/expand/lang_item.cpp | 22 ++++++++++++++--------
 src/hir/from_ast.cpp     |  6 ++++++
 src/hir/hir.cpp          | 31 +++++--------------------------
 src/hir/hir.hpp          |  3 +++
 5 files changed, 29 insertions(+), 35 deletions(-)

diff --git a/src/ast/crate.hpp b/src/ast/crate.hpp
index 79a5d57f..24106bfa 100644
--- a/src/ast/crate.hpp
+++ b/src/ast/crate.hpp
@@ -19,7 +19,7 @@ public:
 
     ::AST::MetaItems    m_attrs;
     
-    AST::Path   m_lang_item_PhantomFn;
+    ::std::map< ::std::string, ::AST::Path> m_lang_items;
 public:
     Module  m_root_module;
     ::std::map< ::std::string, ExternCrate> m_extern_crates;
diff --git a/src/expand/lang_item.cpp b/src/expand/lang_item.cpp
index c34642db..6d90370a 100644
--- a/src/expand/lang_item.cpp
+++ b/src/expand/lang_item.cpp
@@ -11,17 +11,18 @@
 #include "../ast/crate.hpp"
 
 
-void handle_lang_item(AST::Crate& crate, const AST::Path& path, const ::std::string& name, AST::eItemType type)
+void handle_lang_item(const Span& sp, AST::Crate& crate, const AST::Path& path, const ::std::string& name, AST::eItemType type)
 {
     if(name == "phantom_fn") {
-        crate.m_lang_item_PhantomFn = AST::Path(path);
-        crate.m_lang_item_PhantomFn.nodes().back().args().m_types = { TypeRef("A"), TypeRef("B") };
+        // - Just save path
     }
     else if( name == "send" ) {
         // Don't care, Send is fully library in mrustc
+        // - Needed for `static`
     }
     else if( name == "sync" ) {
         // Don't care, Sync is fully library in mrustc
+        // - Needed for `static`
     }
     else if( name == "sized" ) {
         DEBUG("Bind 'sized' to " << path);
@@ -90,10 +91,13 @@ void handle_lang_item(AST::Crate& crate, const AST::Path& path, const ::std::str
     else if( name == "str_eq" ) { }
     
     else {
-        throw CompileError::Generic(FMT("Unknown lang item '" << name << "'"));
+        ERROR(sp, E0000, "Unknown language item '" << name << "'");
     }
 
-    
+    auto rv = crate.m_lang_items.insert( ::std::make_pair( name, ::AST::Path(path) ) );
+    if( !rv.second ) {
+        ERROR(sp, E0000, "Duplicate definition of language item '" << name << "'");
+    }
 }
 
 class Decorator_LangItem:
@@ -108,13 +112,13 @@ public:
             TODO(sp, "Unknown item type with #[lang=\""<<attr<<"\"] attached at " << path);
             ),
         (Function,
-            handle_lang_item(crate, path, attr.string(), AST::ITEM_FN);
+            handle_lang_item(sp, crate, path, attr.string(), AST::ITEM_FN);
             ),
         (Struct,
-            handle_lang_item(crate, path, attr.string(), AST::ITEM_STRUCT);
+            handle_lang_item(sp, crate, path, attr.string(), AST::ITEM_STRUCT);
             ),
         (Trait,
-            handle_lang_item(crate, path, attr.string(), AST::ITEM_TRAIT);
+            handle_lang_item(sp, crate, path, attr.string(), AST::ITEM_TRAIT);
             )
         )
     }
@@ -137,6 +141,8 @@ public:
         else {
             ERROR(sp, E0000, "Unknown lang item '" << name << "' on impl");
         }
+        
+        // TODO: Somehow annotate these impls to allow them to provide inherents?
     }
 };
 
diff --git a/src/hir/from_ast.cpp b/src/hir/from_ast.cpp
index 3f297e89..6c873e1e 100644
--- a/src/hir/from_ast.cpp
+++ b/src/hir/from_ast.cpp
@@ -1028,6 +1028,12 @@ public:
     
     LowerHIR_Module_Impls(crate.m_root_module,  rv);
     
+    auto sp = Span();
+    for( const auto& lang_item_path : crate.m_lang_items )
+    {
+        rv.m_lang_items.insert( ::std::make_pair(lang_item_path.first, LowerHIR_SimplePath(sp, lang_item_path.second)) );
+    }
+    
     // Set all pointers in the HIR to the correct (now fixed) locations
     IndexVisitor(rv).visit_crate( rv );
     
diff --git a/src/hir/hir.cpp b/src/hir/hir.cpp
index 1dce63f8..d9f85a53 100644
--- a/src/hir/hir.cpp
+++ b/src/hir/hir.cpp
@@ -153,33 +153,12 @@ bool ::HIR::MarkerImpl::matches_type(const ::HIR::TypeRef& type, ::HIR::t_cb_res
 
 const ::HIR::SimplePath& ::HIR::Crate::get_lang_item_path(const Span& sp, const char* name) const
 {
-    if( ::std::strcmp(name, "index") == 0 ) {
-        static ::HIR::SimplePath    lang_index { "", {"ops", "Index"} };
-        return lang_index;
-    }
-    else if( ::std::strcmp(name, "unsize") == 0 ) {
-        static ::HIR::SimplePath lang_unsize { "", {"marker", "Unsize"} };
-        return lang_unsize;
-    }
-    else if( ::std::strcmp(name, "add") == 0 ) {
-        static ::HIR::SimplePath lang_path { "", {"ops", "Add"} };
-        return lang_path;
-    }
-    else if( ::std::strcmp(name, "ord") == 0 ) {
-        static ::HIR::SimplePath lang_path { "", {"cmp", "PartialOrd"} };
-        return lang_path;
-    }
-    else if( ::std::strcmp(name, "eq") == 0 ) {
-        static ::HIR::SimplePath lang_path { "", {"cmp", "PartialEq"} };
-        return lang_path;
-    }
-    else if( ::std::strcmp(name, "fn_once") == 0 ) {
-        static ::HIR::SimplePath lang_path { "", {"ops", "FnOnce"} };
-        return lang_path;
-    }
-    else {
-        ERROR(sp, E0000, "Unknown language item '" << name << "' encountered");
+    // TODO: have map stored in crate populated by (or from) the #[lang] attribute handler
+    auto it = this->m_lang_items.find( name );
+    if( it == this->m_lang_items.end() ) {
+        ERROR(sp, E0000, "Undefined language item '" << name << "' required");
     }
+    return it->second;
 }
 
 const ::HIR::TypeItem& ::HIR::Crate::get_typeitem_by_path(const Span& sp, const ::HIR::SimplePath& path) const
diff --git a/src/hir/hir.hpp b/src/hir/hir.hpp
index 3447aaa0..a938579a 100644
--- a/src/hir/hir.hpp
+++ b/src/hir/hir.hpp
@@ -263,6 +263,9 @@ public:
     /// Macros exported by this crate
     ::std::unordered_map< ::std::string, ::MacroRules >   m_exported_macros;
     
+    /// Language items avaliable through this crate (includes ones from loaded externs)
+    ::std::unordered_map< ::std::string, ::HIR::SimplePath> m_lang_items;
+    
     const ::HIR::SimplePath& get_lang_item_path(const Span& sp, const char* name) const;
     
     const ::HIR::TypeItem& get_typeitem_by_path(const Span& sp, const ::HIR::SimplePath& path) const;
-- 
cgit v1.2.3