From 1c28457d2c2317070af45f0650d9586f85a13b76 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Sat, 10 Jun 2023 15:22:17 +0200
Subject: [PATCH] ValueFlow: Fix uninitvar false positive after initialization
 '*((int*)&x) = ..' (#5142)

---
 lib/valueflow.cpp      |  8 ++++++++
 test/testvalueflow.cpp | 12 ++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/lib/valueflow.cpp b/lib/valueflow.cpp
index 16dfc2725..7e5f9f667 100644
--- a/lib/valueflow.cpp
+++ b/lib/valueflow.cpp
@@ -7924,6 +7924,14 @@ static Token* findStartToken(const Variable* var, Token* start, const Library* l
     Token* first = uses.front();
     if (Token::findmatch(start, "goto|asm|setjmp|longjmp", first))
         return start;
+    if (first != var->nameToken()) {
+        // if this is lhs in assignment then set first to the first token in LHS expression
+        Token* temp = first;
+        while (Token::Match(temp->astParent(), "[&*(]") && precedes(temp->astParent(), temp))
+            temp = temp->astParent();
+        if (Token::simpleMatch(temp->astParent(), "=") && precedes(temp, temp->astParent()))
+            first = temp;
+    }
     // If there is only one usage
     if (uses.size() == 1)
         return first->previous();
diff --git a/test/testvalueflow.cpp b/test/testvalueflow.cpp
index 17e4278d9..1f5cb95a8 100644
--- a/test/testvalueflow.cpp
+++ b/test/testvalueflow.cpp
@@ -5292,6 +5292,18 @@ private:
                "}";
         ASSERT_EQUALS(0U, tokenValues(code, "x )").size());
 
+        // initialization
+        code = "int foo() {\n"
+               "  int x;\n"
+               "  *((int *)(&x)) = 12;"
+               "  a = x + 1;\n"
+               "}";
+        values = tokenValues(code, "x +");
+        ASSERT_EQUALS(true, values.empty());
+        // ASSERT_EQUALS(1U, values.size());
+        // ASSERT(values.front().isIntValue());
+        // ASSERT_EQUALS(12, values.front().intvalue);
+
         // #8036
         code = "void foo() {\n"
                "    int x;\n"