From a7d487f6db4a35045a1f91c71be8f7fea048d1e8 Mon Sep 17 00:00:00 2001
From: chrchr-github <78114321+chrchr-github@users.noreply.github.com>
Date: Fri, 11 Aug 2023 18:45:58 +0200
Subject: [PATCH] Fix  #11805 FP uninitvar for stringstream into deref pointer
 to uninit var / #11804 FP uninitvar for array in struct in struct (#5311)

---
 lib/astutils.cpp       |  7 +++++--
 lib/checkuninitvar.cpp |  2 +-
 test/testuninitvar.cpp | 42 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 48 insertions(+), 3 deletions(-)

diff --git a/lib/astutils.cpp b/lib/astutils.cpp
index ca7c08af3..b1dc9900a 100644
--- a/lib/astutils.cpp
+++ b/lib/astutils.cpp
@@ -3142,11 +3142,14 @@ ExprUsage getExprUsage(const Token* tok, int indirect, const Settings* settings)
             return getExprUsage(tok->astParent()->astParent(), indirect, settings);
     }
     if (indirect == 0) {
-        if (Token::Match(tok->astParent(), "%cop%|%assign%|++|--") && !Token::simpleMatch(tok->astParent(), "=") &&
+        if (Token::Match(tok->astParent(), "%cop%|%assign%|++|--") && !Token::Match(tok->astParent(), "=|>>") &&
             !tok->astParent()->isUnaryOp("&"))
             return ExprUsage::Used;
-        if (Token::simpleMatch(tok->astParent(), "=") && astIsRHS(tok))
+        if (Token::simpleMatch(tok->astParent(), "=") && astIsRHS(tok)) {
+            if (tok->astParent()->astOperand1() && tok->astParent()->astOperand1()->variable() && tok->astParent()->astOperand1()->variable()->isReference())
+                return ExprUsage::NotUsed;
             return ExprUsage::Used;
+        }
         // Function call or index
         if (((Token::simpleMatch(tok->astParent(), "(") && !tok->astParent()->isCast()) || (Token::simpleMatch(tok->astParent(), "[") && tok->valueType())) &&
             (astIsLHS(tok) || Token::simpleMatch(tok->astParent(), "( )")))
diff --git a/lib/checkuninitvar.cpp b/lib/checkuninitvar.cpp
index e30dfebc1..887e38b61 100644
--- a/lib/checkuninitvar.cpp
+++ b/lib/checkuninitvar.cpp
@@ -1579,7 +1579,7 @@ static bool isLeafDot(const Token* tok)
     const Token * parent = tok->astParent();
     if (!Token::simpleMatch(parent, "."))
         return false;
-    if (parent->astOperand2() == tok)
+    if (parent->astOperand2() == tok && !Token::simpleMatch(parent->astParent(), "."))
         return true;
     return isLeafDot(parent);
 }
diff --git a/test/testuninitvar.cpp b/test/testuninitvar.cpp
index 924ebcaa6..fdaad7eb1 100644
--- a/test/testuninitvar.cpp
+++ b/test/testuninitvar.cpp
@@ -6127,6 +6127,48 @@ private:
                         "  int *q = 1 ? &y : 0;\n"
                         "}\n");
         ASSERT_EQUALS("", errout.str());
+
+        valueFlowUninit("void f(std::stringstream& ss) {\n" // #11805
+                        "    int x;\n"
+                        "    int* p = &x;\n"
+                        "    ss >> *p;\n"
+                        "}\n"
+                        "void g() {\n"
+                        "    int x;\n"
+                        "    int* p = &x;\n"
+                        "    int& r = *p;\n"
+                        "}\n");
+        ASSERT_EQUALS("", errout.str());
+
+        valueFlowUninit("void f(std::stringstream& ss) {\n" // #11805
+                        "    int x;\n"
+                        "    int* p = &x;\n"
+                        "    ss >> *p;\n"
+                        "}\n"
+                        "void g() {\n"
+                        "    int x;\n"
+                        "    int* p = &x;\n"
+                        "    int& r = *p;\n"
+                        "}\n");
+        ASSERT_EQUALS("", errout.str());
+
+        valueFlowUninit("struct S1 { char a[10]; };\n" // #11804
+                        "struct S2 { struct S1 s1; };\n"
+                        "void init(char* c);\n"
+                        "void f() {\n"
+                        "    struct S2 s2;\n"
+                        "    init(s2.s1.a);\n"
+                        "}\n");
+        ASSERT_EQUALS("", errout.str());
+
+        valueFlowUninit("struct S { int i; };\n" // #11731
+                        "void f(const S*& p);\n"
+                        "int g() {\n"
+                        "   const S* s;\n"
+                        "   f(s);\n"
+                        "   return s->i;\n"
+                        "}\n");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void valueFlowUninitBreak() { // Do not show duplicate warnings about the same uninitialized value