Expand - Macro cleanup, add cfg! macro (stubbed)

7 files changed, 109 insertions, 16 deletions

diff --git a/Makefile b/Makefile
index c97be0e0..f34e5e01 100644
--- a/Makefile
+++ b/Makefile
@@ -29,7 +29,7 @@ OBJ += ast/ast.o ast/crate.o ast/path.o ast/expr.o ast/pattern.o
 OBJ += ast/provided_module.o
 OBJ += parse/parseerror.o parse/lex.o
 OBJ += parse/root.o parse/paths.o parse/types.o parse/expr.o parse/pattern.o parse/macro_rules.o
-OBJ += expand/mod.o expand/macro_rules.o
+OBJ += expand/mod.o expand/macro_rules.o expand/cfg.o
 OBJ += dump_as_rust.o
 OBJ += convert/ast_iterate.o
 #OBJ += convert/decorators.o
diff --git a/src/expand/cfg.cpp b/src/expand/cfg.cpp
new file mode 100644
index 00000000..546bb690
--- /dev/null
+++ b/src/expand/cfg.cpp
@@ -0,0 +1,26 @@
+
+#include <synext.hpp>
+#include <parse/tokentree.hpp>
+#include <parse/lex.hpp>
+
+class CCfgExpander:
+    public ExpandProcMacro
+{
+    bool    expand_early() const override { return true; }
+    
+    ::std::unique_ptr<TokenStream> expand(Span sp, const ::std::string& ident, const TokenTree& tt, AST::Module& mod) override
+    {
+        if( ident != "" ) {
+            ERROR(sp, E0000, "cfg! doesn't take an identifier");
+        }
+        
+        DEBUG("cfg!()");
+        
+        // TODO: Handle cfg!()
+        
+        return box$( TTStreamO(TokenTree(TOK_RWORD_FALSE)) );
+    }
+};
+
+STATIC_MACRO("cfg", CCfgExpander);
+//STATIC_DECORATOR("cfg", CCfgHandler);
diff --git a/src/expand/macro_rules.cpp b/src/expand/macro_rules.cpp
index 5a8e02c4..fac987ff 100644
--- a/src/expand/macro_rules.cpp
+++ b/src/expand/macro_rules.cpp
@@ -10,19 +10,17 @@ class CMacroRulesExpander:
 {
     bool    expand_early() const override { return true; }
     
-    ::std::unique_ptr<TokenStream> expand(const ::std::string& ident, const TokenTree& tt, AST::Module& mod) override
+    ::std::unique_ptr<TokenStream> expand(Span sp, const ::std::string& ident, const TokenTree& tt, AST::Module& mod) override
     {
-        if( ident == "" ) {
-            throw ::std::runtime_error( "ERROR: macro_rules! requires an identifier" );
-        }
+        if( ident == "" )
+            ERROR(sp, E0000, "macro_rules! requires an identifier" );
         
         TTStream    lex(tt);
         auto mac = Parse_MacroRules(lex);
         // TODO: Place into current module using `ident` as the name
         mod.add_macro( false, ident, mac );
         
-        static TokenTree    empty_tt;
-        return box$( TTStream(empty_tt) );
+        return box$( TTStreamO(TokenTree()) );
     }
 };
 
diff --git a/src/expand/mod.cpp b/src/expand/mod.cpp
index d77650d0..33f982da 100644
--- a/src/expand/mod.cpp
+++ b/src/expand/mod.cpp
@@ -56,7 +56,7 @@ void Expand_Attrs(const ::AST::MetaItems& attrs, AttrStage stage,  ::AST::Crate&
     {
         if( name == m.first && m.second->expand_early() == is_early )
         {
-            auto e = m.second->expand(input_ident, input_tt, mod);
+            auto e = m.second->expand(mi_span, input_ident, input_tt, mod);
             return e;
         }
     }
@@ -155,16 +155,19 @@ void Expand_Expr(bool is_early, ::AST::Crate& crate, LList<const AST::Module*> m
         
         void visit(::AST::ExprNode_Macro& node) override {
             auto ttl = Expand_Macro(
-                false, modstack, *(::AST::Module*)(modstack.m_item),
+                is_early, modstack, *(::AST::Module*)(modstack.m_item),
                 Span(node.get_pos()),
                 node.m_name, node.m_ident, node.m_tokens
                 );
-            // Reparse as expression / item
-            auto newexpr = Parse_Expr0(*ttl);
-            // Then call visit on it again
-            this->visit(newexpr);
-            // And schedule it to replace the previous
-            replacement = mv$(newexpr);
+            if( ttl.get() != nullptr && ttl->lookahead(0) != TOK_EOF )
+            {
+                // Reparse as expression / item
+                auto newexpr = Parse_Expr0(*ttl);
+                // Then call visit on it again
+                this->visit(newexpr);
+                // And schedule it to replace the previous
+                replacement = mv$(newexpr);
+            }
         }
         
         void visit(::AST::ExprNode_Block& node) override {
diff --git a/src/include/synext.hpp b/src/include/synext.hpp
index 05020c8c..cd1fc3b5 100644
--- a/src/include/synext.hpp
+++ b/src/include/synext.hpp
@@ -5,6 +5,7 @@
 #define _SYNEXT_HPP_
 
 #include "../ast/item.hpp"
+#include <span.hpp>
 
 namespace AST {
     class Crate;
@@ -60,7 +61,7 @@ class ExpandProcMacro
 public:
     virtual bool    expand_early() const = 0;
     
-    virtual ::std::unique_ptr<TokenStream>  expand(const ::std::string& ident, const TokenTree& tt, AST::Module& mod) = 0;
+    virtual ::std::unique_ptr<TokenStream>  expand(Span sp, const ::std::string& ident, const TokenTree& tt, AST::Module& mod) = 0;
 };
 
 #define STATIC_DECORATOR(ident, _handler_class) \
diff --git a/src/parse/lex.cpp b/src/parse/lex.cpp
index a3e8c0d0..0e928bf2 100644
--- a/src/parse/lex.cpp
+++ b/src/parse/lex.cpp
@@ -1205,6 +1205,53 @@ Position TTStream::getPosition() const
     return Position("TTStream", 0,0);
 }
 
+
+TTStreamO::TTStreamO(TokenTree input_tt):
+    m_input_tt( mv$(input_tt) )
+{
+    m_stack.push_back( ::std::make_pair(0, nullptr) );
+}
+TTStreamO::~TTStreamO()
+{
+}
+Token TTStreamO::realGetToken()
+{
+    while(m_stack.size() > 0)
+    {
+        // If current index is above TT size, go up
+        unsigned int& idx = m_stack.back().first;
+        const TokenTree& tree = *( m_stack.back().second ? m_stack.back().second : &m_input_tt );
+
+        if(idx == 0 && tree.is_token()) {
+            idx ++;
+            m_last_pos = tree.tok().get_pos();
+            return tree.tok();
+        }
+
+        if(idx < tree.size())
+        {
+            const TokenTree&    subtree = tree[idx];
+            idx ++;
+            if( subtree.size() == 0 ) {
+                m_last_pos = subtree.tok().get_pos();
+                return subtree.tok();
+            }
+            else {
+                m_stack.push_back( ::std::make_pair(0, &subtree ) );
+            }
+        }
+        else {
+            m_stack.pop_back();
+        }
+    }
+    return Token(TOK_EOF);
+}
+Position TTStreamO::getPosition() const
+{
+    return m_last_pos;
+}
+
+
 TokenStream::TokenStream():
     m_cache_valid(false)
 {
diff --git a/src/parse/tokentree.hpp b/src/parse/tokentree.hpp
index 6b54e66e..257bd6ad 100644
--- a/src/parse/tokentree.hpp
+++ b/src/parse/tokentree.hpp
@@ -60,6 +60,24 @@ protected:
     virtual Token realGetToken() override;

 };

 

+class TTStreamO:

+    public TokenStream

+{

+    Position    m_last_pos;

+    const TokenTree m_input_tt;

+    ::std::vector< ::std::pair<unsigned int, const TokenTree*> > m_stack;

+public:

+    TTStreamO(const TokenTree input_tt);

+    ~TTStreamO();

+

+    TTStreamO& operator=(const TTStreamO& x) { m_stack = x.m_stack; return *this; }

+    

+    virtual Position getPosition() const override;

+

+protected:

+    virtual Token realGetToken() override;

+};

+

 // unwrapped = Exclude the enclosing brackets (used by macro parse code)

 extern TokenTree Parse_TT(TokenStream& lex, bool unwrapped);

 extern TokenTree Parse_TT_Pattern(TokenStream& lex);