Expand - Handle std/core loading (partially)

5 files changed, 88 insertions, 6 deletions

diff --git a/Makefile b/Makefile
index d6009aa6..f6ac536f 100644
--- a/Makefile
+++ b/Makefile
@@ -33,6 +33,7 @@ OBJ += expand/mod.o expand/macro_rules.o expand/cfg.o
 OBJ +=  expand/format_args.o
 OBJ +=  expand/concat.o expand/stringify.o expand/file_line.o
 OBJ +=  expand/derive.o expand/lang_item.o
+OBJ +=  expand/std_prelude.o
 OBJ += dump_as_rust.o
 OBJ += convert/ast_iterate.o
 #OBJ += convert/decorators.o
diff --git a/src/ast/crate.cpp b/src/ast/crate.cpp
index 55f78ad1..135c2ae7 100644
--- a/src/ast/crate.cpp
+++ b/src/ast/crate.cpp
@@ -27,7 +27,7 @@ namespace AST {
 
 Crate::Crate():
     m_root_module(::AST::Path()),
-    m_load_std(true)
+    m_load_std(LOAD_STD)
 {
 }
 
@@ -292,8 +292,15 @@ void Crate::load_extern_crate(::std::string name)
     
     m_extern_crates.insert( make_pair(::std::move(name), ::std::move(ret)) );
 }
-SERIALISE_TYPE_A(Crate::, "AST_Crate", {
-    s.item(m_load_std);
+SERIALISE_TYPE(Crate::, "AST_Crate", {
+    unsigned ls = m_load_std;
+    s.item(ls);
+    s.item(m_extern_crates);
+    s.item(m_root_module);
+},{
+    unsigned ls = m_load_std;
+    s.item(ls);
+    m_load_std = (::AST::Crate::LoadStd)ls;
     s.item(m_extern_crates);
     s.item(m_root_module);
 })
diff --git a/src/ast/crate.hpp b/src/ast/crate.hpp
index cf9e2d10..a25d2480 100644
--- a/src/ast/crate.hpp
+++ b/src/ast/crate.hpp
@@ -26,7 +26,12 @@ public:
     // Mapping filled by searching for (?visible) macros with is_pub=true
     ::std::map< ::std::string, const MacroRules*> m_exported_macros;
     
-    bool    m_load_std;
+    enum LoadStd {
+        LOAD_STD,
+        LOAD_CORE,
+        LOAD_NONE,
+    } m_load_std;
+    AST::Path   m_prelude_path;
 
     Crate();
 
diff --git a/src/expand/mod.cpp b/src/expand/mod.cpp
index f1a9891a..3b46736f 100644
--- a/src/expand/mod.cpp
+++ b/src/expand/mod.cpp
@@ -636,8 +636,9 @@ void Expand_Mod(bool is_early, ::AST::Crate& crate, LList<const AST::Module*> mo
         for( auto& i : impl.items() )
         {
             DEBUG("  - " << i.name << " :: " << i.data.attrs);
+            
             // TODO: Make a path from the impl definition? Requires having the impl def resolved to be correct
-            // - Does it? the namespace is essentially the same
+            // - Does it? the namespace is essentially the same. There may be issues with wherever the path is used though
             //::AST::Path path = modpath + i.name;
             
             auto attrs = mv$(i.data.attrs);
@@ -680,7 +681,22 @@ void Expand(::AST::Crate& crate)
     // 1. Crate attributes
     Expand_Attrs(crate.m_attrs, AttrStage::EarlyPre,  [&](const auto& d, const auto& a){ d.handle(a, crate); });
     
-    // TODO: Load std/core
+    // Load libstd/libcore
+    switch( crate.m_load_std )
+    {
+    case ::AST::Crate::LOAD_STD:
+        if( crate.m_prelude_path != AST::Path() )
+            crate.m_prelude_path = AST::Path("std", {AST::PathNode("prelude"), AST::PathNode("v1")});
+        TODO(Span(), "Load libstd");
+        break;
+    case ::AST::Crate::LOAD_CORE:
+        if( crate.m_prelude_path != AST::Path() )
+            crate.m_prelude_path = AST::Path("core", {AST::PathNode("prelude")});
+        TODO(Span(), "Load libcore");
+        break;
+    case ::AST::Crate::LOAD_NONE:
+        break;
+    }
     
     // 2. Module attributes
     for( auto& a : crate.m_attrs.m_items )
diff --git a/src/expand/std_prelude.cpp b/src/expand/std_prelude.cpp
new file mode 100644
index 00000000..c8ad6471
--- /dev/null
+++ b/src/expand/std_prelude.cpp
@@ -0,0 +1,53 @@
+/*
+ */
+#include <synext.hpp>
+#include <ast/crate.hpp>
+
+class Decorator_NoStd:
+    public ExpandDecorator
+{
+public:
+    AttrStage stage() const override { return AttrStage::EarlyPre; }
+    
+    void handle(const AST::MetaItem& mi, AST::Crate& crate) const override {
+        if( crate.m_load_std != AST::Crate::LOAD_STD ) {
+            ERROR(Span()/*mi.span()*/, E0000, "Invalid use of #![no_std] with itself or #![no_core]");
+        }
+        crate.m_load_std = AST::Crate::LOAD_CORE;
+    }
+};
+class Decorator_NoCore:
+    public ExpandDecorator
+{
+public:
+    AttrStage stage() const override { return AttrStage::EarlyPre; }
+    
+    void handle(const AST::MetaItem& mi, AST::Crate& crate) const override {
+        if( crate.m_load_std != AST::Crate::LOAD_STD ) {
+            ERROR(Span()/*mi.span()*/, E0000, "Invalid use of #![no_core] with itself or #![no_std]");
+        }
+        crate.m_load_std = AST::Crate::LOAD_NONE;
+    }
+};
+//class Decorator_Prelude:
+//    public ExpandDecorator
+//{
+//public:
+//    AttrStage stage() const override { return AttrStage::EarlyPre; }
+//};
+
+class Decorator_NoPrelude:
+    public ExpandDecorator
+{
+public:
+    AttrStage stage() const override { return AttrStage::EarlyPre; }
+};
+
+
+
+STATIC_DECORATOR("no_std", Decorator_NoStd)
+STATIC_DECORATOR("no_core", Decorator_NoCore)
+//STATIC_DECORATOR("prelude", Decorator_Prelude)
+
+STATIC_DECORATOR("no_prelude", Decorator_NoPrelude)
+