Fix #12082 FP uninitvar for assignment to array member in conditional (…

…#5570)
danmar · Oct 18, 2023 · 09f426d · 09f426d
1 parent 285ef96
commit 09f426d
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Showing 2 changed files with 12 additions and 2 deletions.
diff --git a/lib/astutils.cpp b/lib/astutils.cpp
@@ -3249,9 +3249,11 @@ static ExprUsage getFunctionUsage(const Token* tok, int indirect, const Settings
 
 ExprUsage getExprUsage(const Token* tok, int indirect, const Settings* settings, bool cpp)
 {
-    const Token* const parent = tok->astParent();
+    const Token* parent = tok->astParent();
     if (indirect > 0 && parent) {
-        if (Token::Match(parent, "%assign%") && astIsRHS(tok))
+        while (Token::simpleMatch(parent, "[") && parent->astParent())
+            parent = parent->astParent();
+        if (Token::Match(parent, "%assign%") && (astIsRHS(tok) || astIsLHS(parent->astOperand1())))
             return ExprUsage::NotUsed;
         if (parent->isConstOp())
             return ExprUsage::NotUsed;

diff --git a/test/testuninitvar.cpp b/test/testuninitvar.cpp
@@ -6289,6 +6289,14 @@ class TestUninitVar : public TestFixture {
                         "    foo(q);\n"
                         "}\n");
         ASSERT_EQUALS("[test.cpp:9]: (error) Uninitialized variable: q\n", errout.str());
+
+        valueFlowUninit("int g();\n" // #12082
+                        "void f() {\n"
+                        "    int a[1], b[1];\n"
+                        "    while (a[0] = g()) {}\n"
+                        "    if ((b[0] = g()) == 0) {}\n"
+                        "}");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void valueFlowUninitBreak() { // Do not show duplicate warnings about the same uninitialized value