Expand - cfg!/#[cfg]/#[cfg_attr] hacked up

3 files changed, 73 insertions, 14 deletions

diff --git a/src/expand/cfg.cpp b/src/expand/cfg.cpp
index 546bb690..d178b9ae 100644
--- a/src/expand/cfg.cpp
+++ b/src/expand/cfg.cpp
@@ -2,6 +2,13 @@
 #include <synext.hpp>
 #include <parse/tokentree.hpp>
 #include <parse/lex.hpp>
+#include <parse/common.hpp>
+
+bool check_cfg(const ::AST::MetaItem& mi) {
+    // TODO: Handle cfg conditions
+    throw ::std::runtime_error("TODO: Handle #[cfg] or cfg! conditions");
+    return true;
+}
 
 class CCfgExpander:
     public ExpandProcMacro
@@ -14,13 +21,51 @@ class CCfgExpander:
             ERROR(sp, E0000, "cfg! doesn't take an identifier");
         }
         
-        DEBUG("cfg!()");
-        
-        // TODO: Handle cfg!()
+        auto lex = TTStreamO(tt);
+        auto attrs = Parse_MetaItem(lex);
+        DEBUG("cfg!() - " << attrs);
         
-        return box$( TTStreamO(TokenTree(TOK_RWORD_FALSE)) );
+        if( check_cfg(attrs) ) {
+            return box$( TTStreamO(TokenTree(TOK_RWORD_TRUE )) );
+        }
+        else {
+            return box$( TTStreamO(TokenTree(TOK_RWORD_FALSE)) );
+        }
+    }
+};
+
+
+class CCfgHandler:
+    public ExpandDecorator
+{
+    AttrStage   stage() const override { return AttrStage::EarlyPre; }
+    
+    
+    void handle(const AST::MetaItem& mi, AST::Crate& crate, AST::MacroInvocation& mac) const override {
+        if( check_cfg(mi) ) {
+            // Leave as is
+        }
+        else {
+            mac.clear();
+        }
+    }
+    void handle(const AST::MetaItem& mi, AST::Crate& crate, const AST::Path& path, AST::Module& mod, AST::Item&i) const override {
+        if( check_cfg(mi) ) {
+            // Leave
+        }
+        else {
+            i = AST::Item::make_None({});
+        }
+    }
+    void handle(const AST::MetaItem& mi, ::std::unique_ptr<AST::ExprNode>& expr) const override {
+        if( check_cfg(mi) ) {
+            // Leave
+        }
+        else {
+            expr.reset();
+        }
     }
 };
 
 STATIC_MACRO("cfg", CCfgExpander);
-//STATIC_DECORATOR("cfg", CCfgHandler);
+STATIC_DECORATOR("cfg", CCfgHandler);
diff --git a/src/expand/mod.cpp b/src/expand/mod.cpp
index 33f982da..8eb6dd87 100644
--- a/src/expand/mod.cpp
+++ b/src/expand/mod.cpp
@@ -9,6 +9,9 @@
 #include "../parse/common.hpp"  // For reparse from macros
 #include <ast/expr.hpp>
 
+
+extern bool check_cfg(const ::AST::MetaItem& mi);
+
 ::std::map< ::std::string, ::std::unique_ptr<ExpandDecorator> >  g_decorators;
 ::std::map< ::std::string, ::std::unique_ptr<ExpandProcMacro> >  g_macros;
 
@@ -28,18 +31,29 @@ namespace {
     }
 }
 
+void Expand_Attr(const ::AST::MetaItem& a, AttrStage stage,  ::std::function<void(const ExpandDecorator& d,const ::AST::MetaItem& a)> f)
+{
+    for( auto& d : g_decorators ) {
+        if( d.first == a.name() ) {
+            DEBUG("#[" << d.first << "] " << (int)d.second->stage() << "-" << (int)stage);
+            if( d.second->stage() == stage ) {
+                f(*d.second, a);
+            }
+        }
+    }
+}
 void Expand_Attrs(const ::AST::MetaItems& attrs, AttrStage stage,  ::std::function<void(const ExpandDecorator& d,const ::AST::MetaItem& a)> f)
 {
     for( auto& a : attrs.m_items )
     {
-        for( auto& d : g_decorators ) {
-            if( d.first == a.name() ) {
-                DEBUG("#[" << d.first << "] " << (int)d.second->stage() << "-" << (int)stage);
-                if( d.second->stage() == stage ) {
-                    f(*d.second, a);
-                }
+        if( a.name() == "cfg_attr" ) {
+            if( check_cfg(a.items().m_items.at(0)) ) {
+                Expand_Attr(a.items().m_items.at(1), stage, f);
             }
         }
+        else {
+            Expand_Attr(a, stage, f);
+        }
     }
 }
 void Expand_Attrs(const ::AST::MetaItems& attrs, AttrStage stage,  ::AST::Crate& crate, const ::AST::Path& path, ::AST::Module& mod, ::AST::Item& item)
@@ -118,7 +132,7 @@ void Expand_Expr(bool is_early, ::AST::Crate& crate, LList<const AST::Module*> m
         
         void visit(::std::unique_ptr<AST::ExprNode>& cnode) {
             if(cnode.get())
-                Expand_Attrs(cnode->attrs(), stage_pre(is_early),  [&](const auto& d, const auto& a){ d.handle(a, *cnode); });
+                Expand_Attrs(cnode->attrs(), stage_pre(is_early),  [&](const auto& d, const auto& a){ d.handle(a, cnode); });
             if(cnode.get())
             {
                 cnode->visit(*this);
@@ -128,7 +142,7 @@ void Expand_Expr(bool is_early, ::AST::Crate& crate, LList<const AST::Module*> m
             }
             
             if(cnode.get())
-                Expand_Attrs(cnode->attrs(), stage_post(is_early),  [&](const auto& d, const auto& a){ d.handle(a, *cnode); });
+                Expand_Attrs(cnode->attrs(), stage_post(is_early),  [&](const auto& d, const auto& a){ d.handle(a, cnode); });
         }
         void visit_nodelete(const ::AST::ExprNode& parent, ::std::unique_ptr<AST::ExprNode>& cnode) {
             if( cnode.get() != nullptr )
diff --git a/src/include/synext.hpp b/src/include/synext.hpp
index cd1fc3b5..3ab594a5 100644
--- a/src/include/synext.hpp
+++ b/src/include/synext.hpp
@@ -44,7 +44,7 @@ public:
     virtual void    handle(const AST::MetaItem& mi, AST::Crate& crate) const {}
     virtual void    handle(const AST::MetaItem& mi, AST::Crate& crate, AST::MacroInvocation& mac) const {}
     virtual void    handle(const AST::MetaItem& mi, AST::Crate& crate, const AST::Path& path, AST::Module& mod, AST::Item&i) const {}
-    virtual void    handle(const AST::MetaItem& mi, AST::ExprNode& expr) const {};
+    virtual void    handle(const AST::MetaItem& mi, ::std::unique_ptr<AST::ExprNode>& expr) const {};
 };
 
 enum class MacroPosition