Fixed #10276 (FP: (style) Variable '((uint8_t*)(uint16_t)0x1000)[0]' is assigned a value that is never used.)

lib/astutils.cpp

@@ -2405,8 +2405,11 @@ bool isNullOperand(const Token *expr)
 bool isGlobalData(const Token *expr, bool cpp)
 {
     bool globalData = false;
+    bool var = false;
     visitAstNodes(expr,
-    [&](const Token *tok) {
+    [expr, cpp, &globalData, &var](const Token *tok) {
+        if (tok->varId())
+            var = true;
         if (tok->varId() && !tok->variable()) {
             // Bailout, this is probably global
             globalData = true;
@@ -2467,7 +2470,7 @@ bool isGlobalData(const Token *expr, bool cpp)
             return ChildrenToVisit::op1;
         return ChildrenToVisit::op1_and_op2;
     });
-    return globalData;
+    return globalData || !var;
 }
 
 struct FwdAnalysis::Result FwdAnalysis::checkRecursive(const Token *expr, const Token *startToken, const Token *endToken, const std::set<nonneg int> &exprVarIds, bool local, bool inInnerClass, int depth)

test/testunusedvar.cpp

@@ -220,6 +220,7 @@ private:
         TEST_CASE(argumentClass);
         TEST_CASE(escapeAlias); // #9150
         TEST_CASE(volatileData); // #9280
+        TEST_CASE(globalData);
     }
 
     void checkStructMemberUsage(const char code[], const std::list<Directive> *directives=nullptr) {
@@ -5809,6 +5810,15 @@ private:
             "}");
         ASSERT_EQUALS("", errout.str());
     }
+
+    void globalData() {
+        // #10276
+        functionVariableUsage(
+            "void f(void) {\n"
+            "    ((uint8_t *) (uint16_t)0x1000)[0] = 0x42;\n"
+            "}");
+        ASSERT_EQUALS("", errout.str());
+    }
 };
 
 REGISTER_TEST(TestUnusedVar)