Try to boil down special cases in nested.cpp

gen/functions.cpp

@@ -605,13 +605,10 @@ void DtoDeclareFunction(FuncDeclaration *fdecl) {
       continue;
     }
 
-    Dsymbol *const argsym = (*fdecl->parameters)[arg->parametersIdx];
-    VarDeclaration *argvd = argsym->isVarDeclaration();
-    assert(argvd);
+    auto *const vd = (*fdecl->parameters)[arg->parametersIdx];
+    iarg->setName(vd->ident->toChars() + llvm::Twine("_arg"));
 
-    iarg->setName(argvd->ident->toChars() + llvm::Twine("_arg"));
-
-    IrParameter *irParam = getIrParameter(argvd, true);
+    IrParameter *irParam = getIrParameter(vd, true);
     irParam->arg = arg;
     irParam->value = &(*iarg);
   }
@@ -908,10 +905,7 @@ void DtoDefineFunction(FuncDeclaration *fd) {
     // index in the IrFuncTy args array separately.
     size_t llArgIdx = 0;
     for (size_t i = 0; i < fd->parameters->dim; ++i) {
-      Dsymbol *const argsym = (*fd->parameters)[i];
-      VarDeclaration *const vd = argsym->isVarDeclaration();
-      assert(vd);
-      const bool refout = vd->storage_class & (STCref | STCout);
+      auto *const vd = (*fd->parameters)[i];
 
       IrParameter *irparam = getIrParameter(vd);
       Type *debugInfoType = vd->type;
@@ -922,9 +916,7 @@ void DtoDefineFunction(FuncDeclaration *fd) {
         irparam = getIrParameter(vd, true);
         irparam->value = DtoAlloca(vd, vd->ident->toChars());
       } else {
-        const bool lazy = vd->storage_class & STClazy;
-        const bool firstClassVal = !refout && (!irparam->arg->byref || lazy);
-        if (firstClassVal) {
+        if (!irparam->arg->byref) {
           // alloca a stack slot for this first class value arg
           LLValue *mem = DtoAlloca(irparam->arg->type, vd->ident->toChars());
 
@@ -939,13 +931,10 @@ void DtoDefineFunction(FuncDeclaration *fd) {
         ++llArgIdx;
       }
 
-      if (global.params.symdebug &&
-          !(isaArgument(irparam->value) &&
-            isaArgument(irparam->value)->hasByValAttr())) {
+      if (global.params.symdebug)
         gIR->DBuilder.EmitLocalVariable(irparam->value, vd, debugInfoType);
     }
   }
-  }
 
   {
     ScopeStack scopeStack(gIR);

gen/nested.cpp

@@ -19,23 +19,6 @@
 #include "ir/irtypeaggr.h"
 #include "llvm/Analysis/ValueTracking.h"
 
-static void storeVariable(VarDeclaration *vd, LLValue *dst) {
-  LLValue *value = getIrLocal(vd)->value;
-  int ty = vd->type->ty;
-  FuncDeclaration *fd = getParentFunc(vd, true);
-  assert(fd && "No parent function for nested variable?");
-  if (fd->needsClosure() && !vd->isRef() && (ty == Tstruct || ty == Tsarray) &&
-      isaPointer(value->getType())) {
-    // Copy structs and static arrays
-    LLValue *mem = DtoGcMalloc(vd->loc, DtoType(vd->type), ".gc_mem");
-    DtoMemCpy(mem, value);
-    DtoAlignedStore(mem, dst);
-  } else {
-    // Store the address into the frame
-    DtoAlignedStore(value, dst);
-  }
-}
-
 static unsigned getVthisIdx(AggregateDeclaration *ad) {
   return getFieldGEPIndex(ad, ad->vthis);
 }
@@ -161,8 +144,7 @@ DValue *DtoNestedVariable(Loc &loc, Type *astype, VarDeclaration *vd,
     Logger::cout() << "Addr: " << *val << '\n';
     Logger::cout() << "of type: " << *val->getType() << '\n';
   }
-  if (byref || (vd->isParameter() && getIrParameter(vd)->arg &&
-                getIrParameter(vd)->arg->byref)) {
+  if (!isSpecialRefVar(vd) && (byref || vd->isRef() || vd->isOut())) {
     val = DtoAlignedLoad(val);
     // dwarfOpDeref(dwarfAddr);
     IF_LOG {
@@ -402,31 +384,12 @@ static void DtoCreateNestedContextType(FuncDeclaration *fd) {
     irLocal.nestedDepth = depth;
 
     LLType *t = nullptr;
-    if (vd->isParameter() && getIrParameter(vd)->arg) {
-      // Parameters that are part of the LLVM signature will have
-      // storage associated with them (to handle byref etc.), so
-      // handle those cases specially by storing a pointer instead
-      // of a value.
-      const IrParameter *irparam = getIrParameter(vd);
-      const bool refout = vd->storage_class & (STCref | STCout);
-      const bool lazy = vd->storage_class & STClazy;
-      const bool byref = irparam->arg->byref;
-      const bool isVthisPtr = irparam->isVthis && !byref;
-      if (!(refout || (byref && !lazy)) || isVthisPtr) {
-        // This will be copied to the nesting frame.
-        if (lazy) {
-          t = irparam->value->getType()->getContainedType(0);
-        } else {
-          t = DtoMemType(vd->type);
-        }
-      } else {
-        t = irparam->value->getType();
-      }
-    } else if (isSpecialRefVar(vd)) {
+    if (vd->isRef() || vd->isOut())
       t = DtoType(vd->type->pointerTo());
-    } else {
+    else if (vd->isParameter() && (vd->storage_class & STClazy))
+      t = getIrParameter(vd)->value->getType()->getContainedType(0);
+    else
       t = DtoMemType(vd->type);
-    }
 
     builder.addType(t, getTypeAllocSize(t));
 
@@ -517,9 +480,12 @@ void DtoCreateNestedContext(FuncDeclaration *fd) {
         IF_LOG Logger::println("nested param: %s", vd->toChars());
         LOG_SCOPE
         IrParameter *parm = getIrParameter(vd);
+        assert(parm->value);
+        assert(parm->value->getType()->isPointerTy());
 
-        if (parm->arg && parm->arg->byref) {
-          storeVariable(vd, gep);
+        if (vd->isRef() || vd->isOut()) {
+          Logger::println("Captured by reference, copying pointer to nested frame");
+          DtoAlignedStore(parm->value, gep);
         } else {
           Logger::println("Copying to nested frame");
           // The parameter value is an alloca'd stack slot.

ir/irvar.h

@@ -58,11 +58,6 @@ struct IrLocal : IrVar {
 // represents a function parameter
 struct IrParameter : IrLocal {
   explicit IrParameter(VarDeclaration *v) : IrLocal(v) {}
-  IrParameter(VarDeclaration *v, llvm::Value *value) : IrLocal(v, value) {}
-  IrParameter(VarDeclaration *v, llvm::Value *value, IrFuncTyArg *arg,
-              bool isVthis = false)
-      : IrLocal(v, value), arg(arg), isVthis(isVthis) {}
-
   IrFuncTyArg *arg = nullptr;
   bool isVthis = false; // true, if it is the 'this' parameter
 };