Fixed #10547 (False positive: constVariable, buffer written by stream read)

danmar · danmar · commit 921f5c18182a · 2021-10-18T19:38:53.000+02:00
diff --git a/lib/checkother.cpp b/lib/checkother.cpp
@@ -1525,8 +1525,13 @@ void CheckOther::checkConstPointer()
             if (!p->scope() || !p->scope()->function || p->scope()->function->isImplicitlyVirtual(true) || p->scope()->function->hasVirtualSpecifier())
                 continue;
         }
-        if (nonConstPointers.find(p) == nonConstPointers.end())
+        if (nonConstPointers.find(p) == nonConstPointers.end()) {
+            const Token *start = (p->isArgument()) ? p->scope()->bodyStart : p->nameToken()->next();
+            const int indirect = p->isArray() ? p->dimensions().size() : 1;
+            if (isVariableChanged(start, p->scope()->bodyEnd, indirect, p->declarationId(), false, mSettings, mTokenizer->isCPP()))
+                continue;
             constVariableError(p, nullptr);
+        }
     }
 }
 void CheckOther::constVariableError(const Variable *var, const Function *function)
diff --git a/test/testother.cpp b/test/testother.cpp
@@ -2764,6 +2764,13 @@ class TestOther : public TestFixture {
               "    memcpy(data.buf, &a, sizeof(a));\n"
               "}");
         ASSERT_EQUALS("", errout.str());
+
+        // #10547
+        check("void foo(std::istream &istr) {\n"
+              "  unsigned char x[2];\n"
+              "  istr >> x[0];\n"
+              "}");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void switchRedundantAssignmentTest() {

Original file line number	Diff line number	Diff line change
`@@ -1525,8 +1525,13 @@ void CheckOther::checkConstPointer()`
`1525`	`1525`	`if (!p->scope() \|\| !p->scope()->function \|\| p->scope()->function->isImplicitlyVirtual(true) \|\| p->scope()->function->hasVirtualSpecifier())`
`1526`	`1526`	`continue;`
`1527`	`1527`	`}`
`1528`		`- if (nonConstPointers.find(p) == nonConstPointers.end())`
	`1528`	`+ if (nonConstPointers.find(p) == nonConstPointers.end()) {`
	`1529`	`+ const Token *start = (p->isArgument()) ? p->scope()->bodyStart : p->nameToken()->next();`
	`1530`	`+ const int indirect = p->isArray() ? p->dimensions().size() : 1;`
	`1531`	`+ if (isVariableChanged(start, p->scope()->bodyEnd, indirect, p->declarationId(), false, mSettings, mTokenizer->isCPP()))`
	`1532`	`+ continue;`
`1529`	`1533`	`constVariableError(p, nullptr);`
	`1534`	`+ }`
`1530`	`1535`	`}`
`1531`	`1536`	`}`
`1532`	`1537`	`void CheckOther::constVariableError(const Variable var, const Function function)`