Ticket #270: pinvoke.patch

Source/Members.cobra

@@ -701 +701 @@
 
     get statements from _stmts
 
+    get isExtern as bool
+        return 'extern' in _isNames
+
     def findLocal(name as String) as AbstractLocalVar?
         # TODO: should this use a dictionary lookup?
         for local in _locals, if local.name==name, return local
@@ -1204 +1207 @@
         if _implementsTypeNode
             _implementsType = _implementsTypeNode.realType
             # TODO: make sure the type is among the interfaces of the box
-        if .compiler.errors.count==numErrors and _returnType not in [.compiler.voidType to IType, .compiler.passThroughType to IType] and not .hasReturnStmt and not .hasYieldStmt and not .hasThrowStmt and not .isAbstract and not .parentBox.isExtern and not .parentBox inherits Interface
+        if .compiler.errors.count==numErrors and _returnType not in [.compiler.voidType to IType, .compiler.passThroughType to IType] and not .hasReturnStmt and not .hasYieldStmt and not .hasThrowStmt and not .isAbstract and not .parentBox.isExtern and not .parentBox inherits Interface and not .isExtern
             .throwError('Missing return statement for method "[_name]" which returns [_returnType.name].')
         # check for `return` and `yield` in the same method
         if .resultType is not .compiler.voidType

Source/BackEndClr/SharpGenerator.cobra

@@ -1572 +1572 @@
         pass
     
     def writeSharpImp(sw as CurlyWriter, skipFirst as bool)
+        if .isExtern 
+            sw.write(';\n')
+            return
         .compiler.codeMemberStack.push(this)
         try
             sw.writeAndIndent('{\n')

Source/CobraParser.cobra

@@ -1447 +1447 @@
         if method.statements.count
             if 'abstract' in isNames
                 .throwError('Cannot have statements for an abstract method.')
+            if 'extern' in isNames
+                .throwError('Cannot have statements for a method declared extern.')
             if not curBox.canHaveStatements
                 .throwError('Cannot have statements for a method in an [curBox.englishName].')
         else
-            if not 'abstract' in isNames and not curBox inherits Interface
+            if not 'abstract' in isNames and not 'extern' in isNames and not curBox inherits Interface
                 .throwError('Missing statements. Use "pass" or other statements.')
 
     def _endMethodDecl(didIndent as bool) as bool   

Tests/320-misc-two/850-pinvoke-test.cobra

@@ +1 @@
+#simple, silent PInvoke test
+use System.Runtime.InteropServices
+
+class PInvokeTst
+    
+    #PInvoke entry point
+    def isCharLower(ch as char) as bool is shared, extern 
+        has DllImport("user32.dll")
+        
+    def main is shared
+        assert .isCharLower(c'a') 
+        assert not .isCharLower(c'A') 
+        print .isCharLower(c'!') 

Tests/320-misc-two/852-pinvoke-test.cobra

@@ +1 @@
+# Slightly more complicated pInvoke call/test
+
+use System.Runtime.InteropServices
+
+class PInvokeTst
+    
+    #PInvoke entry point
+    def getUserName(lpBuffer as uint8[] has MarshalAs(UnmanagedType.LPArray), nSize as int32[] has MarshalAs(UnmanagedType.LPArray)) as bool is shared, extern
+        has DllImport("Advapi32.dll", setLastError = true, entryPoint = "GetUserName", exactSpelling=false)
+        
+    def main is shared
+        userNameBytes = uint8[](256)
+        len = int[](1)
+        len[0] = 256
+        .getUserName(userNameBytes,len)
+        userName = System.Text.Encoding.ascii.getString(userNameBytes).trim(c'\0')
+        #print userName
+        #For confirmation: alternative .Net approach:
+        userCred = System.Security.Principal.WindowsIdentity.getCurrent.name.toString
+        #print userCred
+        if userCred.contains('\\') 
+            userCred = userCred.split(c'\\')[1]
+        assert userCred == userName, "WinAPI call doesn't match the .Net Principal call"