Check for containers that modify the size using square bracket

pfultz2 · pfultz2 · commit 71c228a01a26 · 2020-08-10T22:07:22.000-05:00
diff --git a/lib/valueflow.cpp b/lib/valueflow.cpp
@@ -2391,7 +2391,7 @@ struct ValueFlowForwardAnalyzer : ForwardAnalyzer {
             return Action::Invalid;
         if (match(tok)) {
             const Token* parent = tok->astParent();
-            if ((Token::Match(parent, "*|[") || (parent && parent->originalName() == "->")) && getIndirect(tok) <= 0)
+            if (astIsPointer(tok) && (Token::Match(parent, "*|[") || (parent && parent->originalName() == "->")) && getIndirect(tok) <= 0)
                 return Action::Read;
 
             // Action read = Action::Read;
diff --git a/test/testvalueflow.cpp b/test/testvalueflow.cpp
@@ -4471,6 +4471,14 @@ class TestValueFlow : public TestFixture {
                "  ints.front();\n"
                "}";
         ASSERT_EQUALS("", isKnownContainerSizeValue(tokenValues(code, "ints . front", ValueFlow::Value::CONTAINER_SIZE), 2));
+
+        code = "int f(bool b) {\n"
+               "    std::map<int, int> m;\n"
+               "    if (b)\n"
+               "        m[0] = 1;\n"
+               "    return m.at(0);\n"
+               "}\n";
+        ASSERT_EQUALS("", isPossibleContainerSizeValue(tokenValues(code, "m . at", ValueFlow::Value::CONTAINER_SIZE), 0));
     }
 
     void valueFlowDynamicBufferSize() {
