cast-conv-ptr: add -w funcptr option

- '-w funcptr' check function pointer casts inside CAST()/CPTR()
- '-w constness' implies '-w funcptr'
- AST_CONVOPT_DONTWARNFUNCPTR conversion option

Author: jayrm

src/compiler/ast-node-conv.bas

@@ -492,22 +492,36 @@ function astNewCONV _
 
 		n->cast.convconst = ( symbCheckConstAssign( to_dtype, ldtype, to_subtype, l->subtype, , , wrnmsg ) = FALSE )
 
+		'' -w funcptr  -w constness
+		''    no           no          don't warn anything         
+		''    yes          yes         warn everything
+		''    yes          no          warn if wrnmsg<>0
+		''    no           yes         warn everything (-w constness implies -w funcptr)
+
 		'' else check if const conversion
 		if( n->cast.convconst ) then
-			if( (options and AST_CONVOPT_DONTWARNCONST) = 0 ) then
-				if( fbPdCheckIsSet( FB_PDCHECK_CONSTNESS ) ) then
-					'' specific warning message takes priority over const warning
-					if( wrnmsg = 0 ) then
-						wrnmsg = FB_WARNINGMSG_CONSTQUALIFIERDISCARDED
+
+			'' wrnmsg is <> 0 only if funcptr check failed
+			'' specific warning message takes priority over const warning
+			if( wrnmsg <> 0 ) then
+				if( (options and AST_CONVOPT_DONTWARNFUNCPTR) = 0 ) then
+					errReportWarn( wrnmsg )
+				end if
+
+			'' else, must be const warning
+			else
+
+				if( (options and AST_CONVOPT_DONTWARNCONST) = 0 ) then
+					if( fbPdCheckIsSet( FB_PDCHECK_CONSTNESS ) ) then
+						errReportWarn( FB_WARNINGMSG_CONSTQUALIFIERDISCARDED )
 					end if
 				end if
+
 			end if
+
 		end if
 
-		'' warning? show it now
-		if( wrnmsg <> 0 ) then
-			errReportWarn( wrnmsg )
-		end if
+
 	end if
 
 	if( env.clopt.backend = FB_BACKEND_GAS ) then

src/compiler/ast.bi

@@ -531,6 +531,7 @@ enum AST_CONVOPT
 	AST_CONVOPT_PTRONLY  = &h4
 	AST_CONVOPT_DONTCHKPTR = &h8
 	AST_CONVOPT_DONTWARNCONST = &h10
+	AST_CONVOPT_DONTWARNFUNCPTR = &h20
 end enum
 
 declare function astNewCONV _

src/compiler/fb.bi

@@ -106,11 +106,12 @@ enum FB_PDCHECK
 	FB_PDCHECK_NEXTVAR      = &h00000008
 	FB_PDCHECK_CASTTONONPTR = &h00000010
 	FB_PDCHECK_SIGNEDNESS   = &h00000020
-	FB_PDCHECK_CONSTNESS    = &h00000040
+	FB_PDCHECK_CASTFUNCPTR  = &h00000040
+	FB_PDCHECK_CONSTNESS    = &h00000080
 
 	FB_PDCHECK_ALL          = &hffffffff
 
-	FB_PDCHECK_DEFAULT      = FB_PDCHECK_ALL xor ( FB_PDCHECK_NEXTVAR or FB_PDCHECK_SIGNEDNESS or FB_PDCHECK_CONSTNESS )
+	FB_PDCHECK_DEFAULT      = FB_PDCHECK_ALL xor ( FB_PDCHECK_NEXTVAR or FB_PDCHECK_SIGNEDNESS or FB_PDCHECK_CASTFUNCPTR or FB_PDCHECK_CONSTNESS )
 end enum
 
 '' cpu types

src/compiler/fbc.bas

@@ -1842,6 +1842,10 @@ private sub handleOpt(byval optid as integer, byref arg as string)
 			fbSetOption( FB_COMPOPT_PEDANTICCHK, _
 						 fbGetOption( FB_COMPOPT_PEDANTICCHK ) or FB_PDCHECK_CONSTNESS )
 
+		case "funcptr"
+			fbSetOption( FB_COMPOPT_PEDANTICCHK, _
+						 fbGetOption( FB_COMPOPT_PEDANTICCHK ) or FB_PDCHECK_CASTFUNCPTR )
+
 		case "pedantic"
 			fbSetOption( FB_COMPOPT_PEDANTICCHK, FB_PDCHECK_DEFAULT )
 			value = -1

src/compiler/parser-expr-unary.bas

@@ -362,6 +362,13 @@ private function hCast( byval options as AST_CONVOPT ) as ASTNODE ptr
 	end if
 
 	options or= AST_CONVOPT_CHECKSTR
+
+	'' -w constness implies -w funcptr
+	if( (fbPdCheckIsSet( FB_PDCHECK_CASTFUNCPTR ) = FALSE) _
+		and (fbPdCheckIsSet( FB_PDCHECK_CONSTNESS ) = FALSE) ) then
+		options or= AST_CONVOPT_DONTWARNFUNCPTR
+	end if
+
 	expr = astNewCONV( dtype, subtype, expr, options, @errmsg )
 	if( expr = NULL ) then
 		if( errmsg = FB_ERRMSG_OK ) then

src/compiler/symb.bas

@@ -2086,8 +2086,6 @@ function symbCheckConstAssign _
 
 	dim ret as integer = any
 
-	wrnmsg = 0            '' FB_WARNINGMSG
-	
 	'' check top-level const
 	ret = symbCheckConstAssignTopLevel( ldtype, rdtype, lsubtype, rsubtype, mode, matches )