From 8e3e634ce0e99e8808790bed67f82b5f1005dd70 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <danielm77@spray.se>
Date: Wed, 14 Dec 2011 18:28:30 +0100
Subject: [PATCH] Uninitialized variables: Detect more errors. Ticket: #3369

---
 lib/checkuninitvar.cpp | 25 ++++++++++++++++++++-----
 lib/checkuninitvar.h   |  1 +
 test/testuninitvar.cpp | 13 +++++++++++++
 3 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/lib/checkuninitvar.cpp b/lib/checkuninitvar.cpp
index 4d8a7cc4b..8f6bc787f 100644
--- a/lib/checkuninitvar.cpp
+++ b/lib/checkuninitvar.cpp
@@ -1078,7 +1078,8 @@ bool CheckUninitVar::checkScopeForVariable(const Token *tok, const unsigned int
             const Token * const endToken = tok->next()->link();
             for (const Token *tok2 = tok->tokAt(2); tok2 != endToken; tok2 = tok2->next()) {
                 if (tok2->varId() == varid) {
-                    // TODO: better checks if this is initialization or usage
+                    if (isVariableUsage(tok2))
+                        uninitvarError(tok2, tok2->str());
                     return true;
                 }
             }
@@ -1124,10 +1125,7 @@ bool CheckUninitVar::checkScopeForVariable(const Token *tok, const unsigned int
                 return true;
 
             // Use variable
-            if (tok->previous()->str() == "return")
-                uninitvarError(tok, tok->str());
-
-            else if (Token::Match(tok->next(), "++|--|%op%"))
+            if (isVariableUsage(tok))
                 uninitvarError(tok, tok->str());
 
             else
@@ -1139,6 +1137,23 @@ bool CheckUninitVar::checkScopeForVariable(const Token *tok, const unsigned int
     return ret;
 }
 
+bool CheckUninitVar::isVariableUsage(const Token *vartok) const
+{
+    if (vartok->previous()->str() == "return")
+        return true;
+
+    if (Token::Match(vartok->next(), "++|--|%op%"))
+        return true;
+
+    if (Token::Match(vartok->previous(), "++|--|%op%")) {
+        if (vartok->previous()->str() != "&" || !Token::Match(vartok->tokAt(-2), "[(,]")) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
 
 void CheckUninitVar::uninitstringError(const Token *tok, const std::string &varname, bool strncpy_)
 {
diff --git a/lib/checkuninitvar.h b/lib/checkuninitvar.h
index 734487b0a..ce756a272 100644
--- a/lib/checkuninitvar.h
+++ b/lib/checkuninitvar.h
@@ -61,6 +61,7 @@ public:
     /** Check for uninitialized variables */
     void check();
     bool checkScopeForVariable(const Token *tok, const unsigned int varid);
+    bool isVariableUsage(const Token *vartok) const;
 
     /**
      * @brief Uninitialized variables: analyse functions to see how they work with uninitialized variables
diff --git a/test/testuninitvar.cpp b/test/testuninitvar.cpp
index e6fef5f26..91d77bafc 100644
--- a/test/testuninitvar.cpp
+++ b/test/testuninitvar.cpp
@@ -1713,6 +1713,19 @@ private:
                         "}");
         ASSERT_EQUALS("[test.cpp:3]: (error) Uninitialized variable: x\n", errout.str());
 
+        checkUninitVar2("void f() {\n"
+                        "    int x;\n"
+                        "    int y = 3 & x;\n"
+                        "}");
+        ASSERT_EQUALS("[test.cpp:3]: (error) Uninitialized variable: x\n", errout.str());
+
+        // using uninit var in condition
+        checkUninitVar2("void f() {\n"
+                        "    int x;\n"
+                        "    if (1 == (3 & x)) { }\n"
+                        "}");
+        ASSERT_EQUALS("[test.cpp:3]: (error) Uninitialized variable: x\n", errout.str());
+
         // conditional initialization
         checkUninitVar2("void f() {\n"
                         "    int x;\n"