Fixed #1799 (false positive: Variable is assigned a value that is never used)

lib/checkother.cpp

@@ -983,7 +983,20 @@ void CheckOther::functionVariableUsage()
                 if (tok->tokAt(4)->varId() != 0)
                     variables.read(tok->tokAt(4)->varId());
 
-                tok = tok->tokAt(5);
+                // look at initializers
+                if (Token::Match(tok->tokAt(6), "= {"))
+                {
+                    tok = tok->tokAt(8);
+                    while (tok && tok->str() != "}")
+                    {
+                        if (Token::Match(tok, "%var%"))
+                            variables.read(tok->varId());
+                        tok = tok->next();
+                    }
+                    tok = tok->next();
+                }
+                else
+                    tok = tok->tokAt(5);
             }
 
             // pointer or reference declaration with possible initialization
@@ -1310,11 +1323,13 @@ void CheckOther::functionVariableUsage()
             // function parameter
             else if (Token::Match(tok, "[(,] %var% ["))
                 variables.use(tok->next()->varId());   // use = read + write
-
-            // function parameter
             else if (Token::Match(tok, "[(,] %var% [,)]") && tok->previous()->str() != "*")
                 variables.use(tok->next()->varId());   // use = read + write
 
+            // function
+            else if (Token::Match(tok, " %var% ("))
+                variables.read(tok->varId());
+
             else if (Token::Match(tok, " %var% ."))
                 variables.use(tok->varId());   // use = read + write
 

test/testunusedvar.cpp

@@ -65,6 +65,7 @@ private:
         TEST_CASE(localvar17); // ticket #1720
         TEST_CASE(localvar18); // ticket #1723
         TEST_CASE(localvar19); // ticket #1776
+        TEST_CASE(localvar20); // ticket #1799
         TEST_CASE(localvaralias1);
         TEST_CASE(localvaralias2); // ticket #1637
         TEST_CASE(localvaralias3); // ticket #1639
@@ -89,6 +90,7 @@ private:
         TEST_CASE(localvarCast);
         TEST_CASE(localvarClass);
         TEST_CASE(localvarUnused);
+        TEST_CASE(localvarFunction); // ticket #1799
     }
 
     void checkStructMemberUsage(const char code[])
@@ -1164,6 +1166,17 @@ private:
                       "[test.cpp:3]: (style) Variable 'c' is assigned a value that is never used\n", errout.str());
     }
 
+    void localvar20() // ticket #1799
+    {
+        functionVariableUsage("void foo()\n"
+                              "{\n"
+                              "    char c1 = 'c';\n"
+                              "    char c2[] = { c1 };\n"
+                              "    a(c2);\n"
+                              "}");
+        ASSERT_EQUALS("", errout.str());
+    }
+
     void localvaralias1()
     {
         functionVariableUsage("void foo()\n"
@@ -1921,6 +1934,18 @@ private:
                               "}\n");
         ASSERT_EQUALS("", errout.str());
     }
+
+    void localvarFunction()
+    {
+        functionVariableUsage("void check_dlsym(void*& h)\n"
+                              "{\n"
+                              "  typedef void (*function_type) (void);\n"
+                              "  function_type fn;\n"
+                              "  fn = reinterpret_cast<function_type>(dlsym(h, \"try_allocation\"));\n"
+                              "  fn();\n"
+                              "}");
+        ASSERT_EQUALS("", errout.str());
+    }
 };
 
 REGISTER_TEST(TestUnusedVar)