parser: Disallow static member var in nested UDT (#748)

Author: dkl

changelog.txt

@@ -66,6 +66,7 @@ Version 1.01.0
 - #760: RETURN and FUNCTION= couldn't be used together in byref functions returning an UDT with constructor. This check is now only applied to functions returning byval.
 - #755: If no result is set in byref functions, the compiler will now show an error instead of a warning (because a byref function defaults to returning a null reference, most likely causing a crash at runtime)
 - Better error message for function result assignments outside of the function (#754), and for illegal use of Exit Sub|Function|...
+- #748: Static member variables in UDTs inside procedures or scope blocks were allowed without error message (but didn't and cannot fully work in this situation, like methods). The compiler will now show an error in this case.
 
 
 Version 1.00.0 (former 0.91.0):

src/compiler/error.bas

@@ -345,6 +345,7 @@ declare function hMakeParamDesc _
 		@"VIRTUAL used on non-member procedure", _
 		@"Invalid initializer", _
 		@"Objects with default [con|de]structors or methods are only allowed in the module level", _
+		@"Static member variable in nested UDT (only allowed in toplevel UDTs)", _
 		@"Symbol not a CLASS, ENUM, TYPE or UNION type", _
 		@"Too many elements", _
 		@"Only data members supported", _

src/compiler/error.bi

@@ -266,6 +266,7 @@ enum FB_ERRMSG
 	FB_ERRMSG_VIRTUALNONMEMBERPROC
 	FB_ERRMSG_INVALIDINITIALIZER
 	FB_ERRMSG_NOOOPINFUNCTIONS
+	FB_ERRMSG_NOSTATICMEMBERVARINNESTEDUDT
 	FB_ERRMSG_EXPECTEDUDT
 	FB_ERRMSG_TOOMANYELEMENTS
 	FB_ERRMSG_NOTADATAMEMBER

src/compiler/parser-decl-struct.bas

@@ -890,7 +890,7 @@ decl_inner:		'' it's an anonymous inner UDT
 	end if
 end sub
 
-private sub hCheckForCDtorOrMethods( byval sym as FBSYMBOL ptr )
+private sub hDisallowNestedClasses( byval sym as FBSYMBOL ptr )
 	dim as FBSYMBOL ptr member = any
 	'' Not at module level?
 	if( parser.scope > FB_MAINSCOPE ) then
@@ -899,10 +899,14 @@ private sub hCheckForCDtorOrMethods( byval sym as FBSYMBOL ptr )
 		'' (Note: assuming symbStructEnd() was already called,
 		'' thus any implicit members were already added by
 		'' symbUdtDeclareDefaultMembers())
+		'' Similar for static member variables (really Externs); normal
+		'' Externs aren't allowed in scopes either.
 		member = symbGetCompSymbTb( sym ).head
 		while( member )
 			if( symbIsProc( member ) ) then
 				errReportEx( FB_ERRMSG_NOOOPINFUNCTIONS, symbGetName( member ) )
+			elseif( symbIsVar( member ) and symbIsExtern( member ) ) then
+				errReportEx( FB_ERRMSG_NOSTATICMEMBERVARINNESTEDUDT, symbGetName( member ) )
 			end if
 			member = member->next
 		wend
@@ -1031,7 +1035,7 @@ sub cTypeDecl( byval attrib as integer )
 	parser.currblock = currblocksym
 	parser.scope = scope_depth
 
-	hCheckForCDtorOrMethods( sym )
+	hDisallowNestedClasses( sym )
 
 	'' end the compound
 	stk = cCompStmtGetTOS( FB_TK_TYPE )

tests/structs/no-static-member-var-in-nested-udt-1.bas

@@ -0,0 +1,9 @@
+' TEST_MODE : COMPILE_ONLY_FAIL
+
+sub test( )
+	type UDT
+		dummy as integer
+
+		static i as integer
+	end type
+end sub

tests/structs/no-static-member-var-in-nested-udt-2.bas

@@ -0,0 +1,9 @@
+' TEST_MODE : COMPILE_ONLY_FAIL
+
+scope
+	type UDT
+		dummy as integer
+
+		static i as integer
+	end type
+end scope