mark file parameters as used in reads/writes

diff --git a/lang/pc/comp/readwrite.c b/lang/pc/comp/readwrite.c
index 8b32995..e38c161 100644 (file)
--- a/lang/pc/comp/readwrite.c
+++ b/lang/pc/comp/readwrite.c
@@ -36,6 +36,7 @@ ChkRead(arg)
                        error("\"%s\": variable-access expected", name);
                        return;
                }
+               MarkUsed(file);
        }
        else if( !(file = ChkStdInOut(name, 0)) )
                return;
@@ -112,6 +113,7 @@ ChkReadln(arg)
                else    {
                        file = arg->nd_left;
                        arg = arg->nd_right;
+                       MarkUsed(file);
                }
        }
        else if( !(file = ChkStdInOut(name, 0)) )
@@ -159,6 +161,7 @@ ChkWrite(arg)
                        return;
                }
                file = expp;
+               MarkUsed(file);
                arg = arg->nd_right;
                if( !arg )      {
                        error("\"%s\": expression expected", name);
@@ -211,6 +214,7 @@ ChkWriteln(arg)
                        return;
                }
                file = expp;
+               MarkUsed(file);
                arg = arg->nd_right;
        }
        else if( !(file = ChkStdInOut(name, 1)) )