From d40f4e4a554cd181cbce79bb82934c6cccbed785 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Mon, 21 Nov 2016 17:26:36 +0100
Subject: [PATCH] Fixed #7778 (valueFlowAfterAssign: alias)

---
 lib/valueflow.cpp      |  9 +++++++++
 test/testvalueflow.cpp | 11 +++++++++++
 2 files changed, 20 insertions(+)

diff --git a/lib/valueflow.cpp b/lib/valueflow.cpp
index 6d45d1aa3..d87be4b77 100644
--- a/lib/valueflow.cpp
+++ b/lib/valueflow.cpp
@@ -1800,8 +1800,15 @@ static void valueFlowAfterAssign(TokenList *tokenlist, SymbolDatabase* symboldat
 {
     const std::size_t functions = symboldatabase->functionScopes.size();
     for (std::size_t i = 0; i < functions; ++i) {
+        std::set<unsigned int> aliased;
         const Scope * scope = symboldatabase->functionScopes[i];
         for (Token* tok = const_cast<Token*>(scope->classStart); tok != scope->classEnd; tok = tok->next()) {
+            // Alias
+            if (tok->str() == "&" && !tok->astOperand2() && tok->astOperand1()) {
+                aliased.insert(tok->astOperand1()->varId());
+                continue;
+            }
+
             // Assignment
             if ((tok->str() != "=") || (tok->astParent()))
                 continue;
@@ -1810,6 +1817,8 @@ static void valueFlowAfterAssign(TokenList *tokenlist, SymbolDatabase* symboldat
             if (!tok->astOperand1() || !tok->astOperand1()->varId())
                 continue;
             const unsigned int varid = tok->astOperand1()->varId();
+            if (aliased.find(varid) != aliased.end())
+                continue;
             const Variable *var = tok->astOperand1()->variable();
             if (!var || (!var->isLocal() && !var->isArgument()))
                 continue;
diff --git a/test/testvalueflow.cpp b/test/testvalueflow.cpp
index df5ee8bff..4d82e39d2 100644
--- a/test/testvalueflow.cpp
+++ b/test/testvalueflow.cpp
@@ -1342,6 +1342,17 @@ private:
                "  }\n"
                "}\n";
         ASSERT_EQUALS(false, testValueOfX(code, 3U, 0));
+
+        // alias
+        code = "void f() {\n" // #7778
+               "  int x = 0;\n"
+               "  int *p = &x;\n"
+               "  x = 3;\n"
+               "  *p = 2;\n"
+               "  a = x;\n"
+               "}\n";
+        ASSERT_EQUALS(false, testValueOfX(code, 6U, 3));
+        TODO_ASSERT_EQUALS(true, false, testValueOfX(code, 6U, 2));
     }
 
     void valueFlowAfterCondition() {