From 2e45df3b72d1fda2dd3058e44608d9df7e7bbb50 Mon Sep 17 00:00:00 2001
From: orbitcowboy <ettl.martin78@gmail.com>
Date: Wed, 17 Dec 2014 17:43:31 +0100
Subject: [PATCH] Fixed #6341: false negative uninitvar pattern "return foo (
 %var%"

---
 cfg/posix.cfg          |  9 +++++++++
 lib/checkuninitvar.cpp |  9 ++++++---
 test/testuninitvar.cpp | 10 ++++++++++
 3 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/cfg/posix.cfg b/cfg/posix.cfg
index 0a7a888ea..db63a3e29 100644
--- a/cfg/posix.cfg
+++ b/cfg/posix.cfg
@@ -1,5 +1,14 @@
 <?xml version="1.0"?>
 <def format="1">
+  <!-- wint_t btowc (int c); -->
+  <!-- A function to convert a single byte character to a wide character. -->
+  <function name="btowc">
+    <noreturn>false</noreturn>
+    <arg nr="1">
+      <not-uninit/>
+    </arg>
+    <leak-ignore/>
+  </function>
   <function name="usleep">
     <noreturn>false</noreturn>
     <arg nr="1">
diff --git a/lib/checkuninitvar.cpp b/lib/checkuninitvar.cpp
index 7b8e29ceb..eb90e1bcf 100644
--- a/lib/checkuninitvar.cpp
+++ b/lib/checkuninitvar.cpp
@@ -1449,9 +1449,7 @@ bool CheckUninitVar::checkScopeForVariable(const Scope* scope, const Token *tok,
                             uninitdataError(tok, tok->str());
                         else
                             uninitvarError(tok, tok->str());
-                    }
-
-                    else
+                    } else
                         // assume that variable is assigned
                         return true;
                 }
@@ -1666,6 +1664,11 @@ bool CheckUninitVar::isVariableUsage(const Token *vartok, bool pointer, bool all
     if (!alloc && vartok->previous()->str() == "return")
         return true;
 
+    // code like: return foo( variable
+    if (vartok->tokAt(-3) && vartok->tokAt(-3)->str() == "return"
+        && vartok->tokAt(-1) && vartok->tokAt(-1)->str() == "(")
+        return true;
+
     // Passing variable to typeof/__alignof__
     if (Token::Match(vartok->tokAt(-3), "typeof|__alignof__ ( * %var%"))
         return false;
diff --git a/test/testuninitvar.cpp b/test/testuninitvar.cpp
index 49f4e2d63..b8616ad3e 100644
--- a/test/testuninitvar.cpp
+++ b/test/testuninitvar.cpp
@@ -73,6 +73,7 @@ private:
         TEST_CASE(syntax_error); // Ticket #5073
 
         // Test that the functions from std.cfg are configured correctly
+        TEST_CASE(stdcfg_btowc);
         TEST_CASE(stdcfg_clearerr);
         TEST_CASE(stdcfg_fclose);
         TEST_CASE(stdcfg_fopen);
@@ -3610,6 +3611,15 @@ private:
         ASSERT_EQUALS("[test.cpp:6]: (debug) assertion failed '} while ('\n", errout.str());
     }
 
+    // Test that the btowc function, defined in std.cfg is configured correctly.
+    void stdcfg_btowc() {
+        checkUninitVar2("wchar_t f() { int i; return btowc(i); }");
+        ASSERT_EQUALS("[test.cpp:1]: (error) Uninitialized variable: i\n", errout.str());
+
+        checkUninitVar2("wchar_t f(int i) { return btowc(i); }");
+        ASSERT_EQUALS("", errout.str());
+    }
+
     // Test that the clearerr function, defined in std.cfg is configured correctly.
     void stdcfg_clearerr() {
         checkUninitVar("void f() {\n"