test moving out anon struct for case branches

compiler/cbuilderdecls.nim

@@ -594,22 +594,29 @@ template addStruct(obj: var Builder; m: BModule; typ: PType; name: string; baseT
   body
   finishStruct(obj, m, typ, info)
 
-template addFieldWithStructType(obj: var Builder; m: BModule; parentTyp: PType; fieldName: string, body: typed) =
-  ## adds a field with a `struct { ... }` type, building the fields according to `body`
-  obj.add('\t')
-  if tfPacked in parentTyp.flags:
-    if hasAttribute in CC[m.config.cCompiler].props:
-      obj.add("struct __attribute__((__packed__)) {\n")
-    else:
-      obj.add("#pragma pack(push, 1)\nstruct {")
+proc addFieldStruct(obj: var Builder; m: BModule; parentTyp: PType; name: string, fields: Snippet) =
+  ## see `genRecordFieldsAux` for use
+  when buildNifc:
+    # XXX packed not implemented in nifc
+    obj.addTypedef(name):
+      obj.add(fields)
   else:
-    obj.add("struct {\n")
-  body
-  obj.add("} ")
-  obj.add(fieldName)
-  obj.add(";\n")
-  if tfPacked in parentTyp.flags and hasAttribute notin CC[m.config.cCompiler].props:
-    obj.add("#pragma pack(pop)\n")
+    obj.add('\t')
+    if tfPacked in parentTyp.flags:
+      if hasAttribute in CC[m.config.cCompiler].props:
+        obj.add("typedef struct __attribute__((__packed__)) ")
+      else:
+        obj.add("#pragma pack(push, 1)\ntypedef struct ")
+    else:
+      obj.add("typedef struct ")
+    obj.add(name)
+    obj.add(" {\n")
+    obj.add(fields)
+    obj.add("} ")
+    obj.add(name)
+    obj.add(";\n")
+    if tfPacked in parentTyp.flags and hasAttribute notin CC[m.config.cCompiler].props:
+      obj.add("#pragma pack(pop)\n")
 
 template addAnonUnion(obj: var Builder; body: typed) =
   ## adds an anonymous union i.e. `union { ... };` with fields according to `body`

compiler/ccgtypes.nim

@@ -673,6 +673,8 @@ proc genCppInitializer(m: BModule, prc: BProc; typ: PType; didGenTemp: var bool)
 proc genRecordFieldsAux(m: BModule; n: PNode,
                         rectype: PType,
                         check: var IntSet; result: var Builder; unionPrefix = "") =
+  template maybeDotField(a, b: Snippet): Snippet =
+    if a.len != 0: dotField(a, b) else: b
   case n.kind
   of nkRecList:
     for i in 0..<n.len:
@@ -688,12 +690,14 @@ proc genRecordFieldsAux(m: BModule; n: PNode,
       of nkOfBranch, nkElse:
         let k = lastSon(n[i])
         if k.kind != nkSym:
-          let structName = "_" & mangleRecFieldName(m, n[0].sym) & "_" & $i
+          let fieldName = "_" & mangleRecFieldName(m, n[0].sym) & "_" & $i
           var a = newBuilder("")
-          genRecordFieldsAux(m, k, rectype, check, a, unionPrefix & $structName & ".")
+          genRecordFieldsAux(m, k, rectype, check, a, maybeDotField(unionPrefix, $fieldName))
           if a.buf.len != 0:
-            unionBody.addFieldWithStructType(m, rectype, structName):
-              unionBody.add(extract(a))
+            let tmp = getTempName(m)
+            let structName = tmp & "_" & fieldName & "_Struct"
+            m.s[cfsTypes].addFieldStruct(m, rectype, structName, extract(a))
+            unionBody.addField(name = fieldName, typ = structName)
         else:
           genRecordFieldsAux(m, k, rectype, check, unionBody, unionPrefix)
       else: internalError(m.config, "genRecordFieldsAux(record case branch)")
@@ -706,7 +710,7 @@ proc genRecordFieldsAux(m: BModule; n: PNode,
     if field.typ.kind == tyVoid: return
     #assert(field.ast == nil)
     let sname = mangleRecFieldName(m, field)
-    fillLoc(field.loc, locField, n, unionPrefix & sname, OnUnknown)
+    fillLoc(field.loc, locField, n, maybeDotField(unionPrefix, sname), OnUnknown)
     # for importcpp'ed objects, we only need to set field.loc, but don't
     # have to recurse via 'getTypeDescAux'. And not doing so prevents problems
     # with heavily templatized C++ code: