cfg: convert lambdas to function defs

src/analysis/function_analysis.cpp

@@ -98,12 +98,6 @@ public:
         return true;
     }
 
-    bool visit_lambda(AST_Lambda* node) {
-        for (auto* d : node->args->defaults)
-            d->accept(this);
-        return true;
-    }
-
     bool visit_name(AST_Name* node) {
         if (node->vreg == -1)
             return true;

src/analysis/type_analysis.cpp

@@ -391,8 +391,6 @@ private:
 
     void* visit_index(AST_Index* node) override { return getType(node->value); }
 
-    void* visit_lambda(AST_Lambda* node) override { return typeFromClass(function_cls); }
-
     void* visit_langprimitive(AST_LangPrimitive* node) override {
         switch (node->opcode) {
             case AST_LangPrimitive::CHECK_EXC_MATCH:

src/codegen/ast_interpreter.cpp

@@ -103,7 +103,6 @@ private:
     Value visit_expr(AST_Expr* node);
     Value visit_extslice(AST_ExtSlice* node);
     Value visit_index(AST_Index* node);
-    Value visit_lambda(AST_Lambda* node);
     Value visit_list(AST_List* node);
     Value visit_name(AST_Name* node);
     Value visit_num(AST_Num* node);
@@ -1481,8 +1480,6 @@ Value ASTInterpreter::visit_expr(AST_expr* node) {
             return visit_compare((AST_Compare*)node);
         case AST_TYPE::Dict:
             return visit_dict((AST_Dict*)node);
-        case AST_TYPE::Lambda:
-            return visit_lambda((AST_Lambda*)node);
         case AST_TYPE::List:
             return visit_list((AST_List*)node);
         case AST_TYPE::Name:
@@ -1640,15 +1637,6 @@ Value ASTInterpreter::visit_repr(AST_Repr* node) {
     return Value(repr(v.o), jit ? jit->emitRepr(v) : NULL);
 }
 
-Value ASTInterpreter::visit_lambda(AST_Lambda* node) {
-    AST_Return* expr = new AST_Return();
-    expr->value = node->body;
-    expr->lineno = node->body->lineno;
-
-    std::vector<AST_stmt*> body = { expr };
-    return createFunction(node, node->args, body);
-}
-
 Value ASTInterpreter::visit_dict(AST_Dict* node) {
     RELEASE_ASSERT(node->keys.size() == node->values.size(), "not implemented");
 

src/codegen/irgen/hooks.cpp

@@ -122,8 +122,8 @@ BORROWED(BoxedString*) SourceInfo::getName() noexcept {
         case AST_TYPE::ClassDef:
             return ast_cast<AST_ClassDef>(ast)->name.getBox();
         case AST_TYPE::FunctionDef:
-            return ast_cast<AST_FunctionDef>(ast)->name.getBox();
-        case AST_TYPE::Lambda:
+            if (ast_cast<AST_FunctionDef>(ast)->name != InternedString())
+                return ast_cast<AST_FunctionDef>(ast)->name.getBox();
             return lambda_name;
         case AST_TYPE::Module:
         case AST_TYPE::Expression:

src/codegen/irgen/irgenerator.cpp

@@ -1281,18 +1281,6 @@ private:
 
     CompilerVariable* evalIndex(AST_Index* node, const UnwindInfo& unw_info) { return evalExpr(node->value, unw_info); }
 
-    CompilerVariable* evalLambda(AST_Lambda* node, const UnwindInfo& unw_info) {
-        AST_Return* expr = new AST_Return();
-        expr->value = node->body;
-        expr->lineno = node->body->lineno;
-
-        std::vector<AST_stmt*> body = { expr };
-        CompilerVariable* func = _createFunction(node, unw_info, node->args, body);
-        ConcreteCompilerVariable* converted = func->makeConverted(emitter, func->getBoxType());
-
-        return converted;
-    }
-
 
     CompilerVariable* evalList(AST_List* node, const UnwindInfo& unw_info) {
         std::vector<CompilerVariable*> elts;
@@ -1844,9 +1832,6 @@ private:
             case AST_TYPE::Dict:
                 rtn = evalDict(ast_cast<AST_Dict>(node), unw_info);
                 break;
-            case AST_TYPE::Lambda:
-                rtn = evalLambda(ast_cast<AST_Lambda>(node), unw_info);
-                break;
             case AST_TYPE::List:
                 rtn = evalList(ast_cast<AST_List>(node), unw_info);
                 break;

src/core/ast.cpp

@@ -1405,7 +1405,12 @@ bool PrintVisitor::visit_functiondef(AST_FunctionDef* node) {
         printIndent();
     }
 
-    stream << "def " << node->name.s() << "(";
+    stream << "def ";
+    if (node->name != InternedString())
+        stream << node->name.s();
+    else
+        stream << "<lambda>";
+    stream << "(";
     node->args->accept(this);
     stream << ")";
 

src/core/ast.h

@@ -542,7 +542,7 @@ class AST_FunctionDef : public AST_stmt {
 public:
     std::vector<AST_stmt*> body;
     std::vector<AST_expr*> decorator_list;
-    InternedString name;
+    InternedString name; // if the name is not set this is a lambda
     AST_arguments* args;
 
     virtual void accept(ASTVisitor* v);

src/core/cfg.cpp

@@ -1199,14 +1199,25 @@ private:
     }
 
     AST_expr* remapLambda(AST_Lambda* node) {
-        auto rtn = new AST_Lambda();
-        rtn->body = node->body; // don't remap now; will be CFG'ed later
-        rtn->args = remapArguments(node->args);
-        rtn->lineno = node->lineno;
-        rtn->col_offset = node->col_offset;
-        // lambdas create scope, need to register as replacement
-        scoping_analysis->registerScopeReplacement(node, rtn);
-        return rtn;
+        // we convert lambdas into normal functions (but don't give it a name)
+        auto def = new AST_FunctionDef();
+        def->lineno = node->lineno;
+        def->col_offset = node->col_offset;
+
+        auto stmt = new AST_Return;
+        stmt->lineno = node->lineno;
+        stmt->col_offset = node->col_offset;
+        stmt->value = node->body; // don't remap now; will be CFG'ed later
+
+        def->body = { stmt };
+        def->args = remapArguments(node->args);
+
+        scoping_analysis->registerScopeReplacement(node, def);
+
+        auto tmp = nodeName();
+        pushAssign(tmp, new AST_MakeFunction(def));
+
+        return makeLoad(tmp, def, /* is_kill */ false);
     }
 
     AST_expr* remapLangPrimitive(AST_LangPrimitive* node) {

src/core/stringpool.h

@@ -75,6 +75,7 @@ public:
         // assert(this->pool == rhs.pool || this->pool == invalidPool() || rhs.pool == invalidPool());
         return this->_str == rhs._str;
     }
+    bool operator!=(InternedString rhs) const { return !(*this == rhs); }
 
     // This function compares the actual string contents
     bool operator<(InternedString rhs) const { return this->s().compare(rhs.s()) == -1; }