fixup! fixup! fixup! fixup! fixup! fixup! Fix #958: warn when feof() is used as a while loop condition

Author: francois-berder

lib/checkio.cpp

@@ -484,14 +484,18 @@ void CheckIO::invalidScanfError(const Token *tok)
 static bool findFileReadCall(const Token *start, const Token *end, int varid)
 {
     const Token* found = Token::findmatch(start, "fgets|fgetc|getc|fread|fscanf (", end);
-    const std::vector<const Token*> args = getArguments(found);
-    if (args.empty())
-        return false;
-
-    if (found->str() == "fscanf")
-        return args.front()->varId() == varid;
-
-    return args.back()->varId() == varid;
+    while (found) {
+        const std::vector<const Token*> args = getArguments(found);
+        if (!args.empty()) {
+            const bool match = (found->str() == "fscanf")
+                               ? args.front()->varId() == varid
+                               : args.back()->varId() == varid;
+            if (match)
+                return true;
+        }
+        found = Token::findmatch(found->next(), "fgets|fgetc|getc|fread|fscanf (", end);
+    }
+    return false;
 }
 
 void CheckIO::checkWrongfeofUsage()
@@ -509,6 +513,10 @@ void CheckIO::checkWrongfeofUsage()
             const Token *endCond = tok->linkAt(1);
             const Token *endBody = endCond->linkAt(1);
             const int fpVarId = tok->tokAt(5)->varId();
+
+            // Bail out if we cannot identify file pointer
+            if (fpVarId == 0)
+                continue;
             if (findFileReadCall(scope->bodyStart, tok, fpVarId) && findFileReadCall(tok, endBody, fpVarId))
                 continue;