Merge pull request chapel-lang#6498 from Spartee/fwDec_c2chap

implemented a fix for Struct forward declarations in c2chapel. Added testing to empty struct and typedef structs.

reviewer = [Ben Harshbarger]

Author: Spartee

tools/c2chapel/c2chapel.py

@@ -314,6 +314,11 @@ def genStruct(struct, name=""):
 
     ret = "extern record " + name + " {"
     foundTypes.add(name)
+
+    # Forward Declaration
+    if not struct.decls:
+        print()
+        return
 
     members = ""
     warnKeyword = False

tools/c2chapel/test/miscTypedef.chpl

@@ -17,6 +17,13 @@ extern proc retStruct(a : my_int, b : my_int, r : renamedStruct) : fancyStruct;
 
 extern proc tdPointer(ref a : fancyStruct, ref b : c_ptr(renamedStruct)) : void;
 
+
+
+extern record forwardStruct {
+  var a : c_int;
+  var b : c_int;
+}
+
 // ==== c2chapel typedefs ====
 
 extern record fancyStruct {
@@ -26,6 +33,8 @@ extern record fancyStruct {
   var d : simpleStruct;
 }
 
+extern type fwdStruct = forwardStruct;
+
 extern type my_int = c_int;
 
 extern type my_string = c_string;

tools/c2chapel/test/miscTypedef.h

@@ -30,3 +30,14 @@ typedef struct {
   int i;
   char c;
 } *recp;
+
+struct empty_struct;
+
+struct forwardStruct;
+typedef struct forwardStruct fwdStruct;
+
+struct forwardStruct {
+  int a;
+  int b;
+};
+