1238 lines
40 KiB
C++
1238 lines
40 KiB
C++
/*
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* Cppcheck - A tool for static C/C++ code analysis
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* Copyright (C) 2007-2011 Daniel Marjamäki and Cppcheck team.
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include "tokenize.h"
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#include "checknullpointer.h"
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#include "testsuite.h"
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#include <sstream>
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extern std::ostringstream errout;
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class TestNullPointer : public TestFixture
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{
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public:
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TestNullPointer() : TestFixture("TestNullPointer")
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{ }
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private:
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void run()
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{
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TEST_CASE(nullpointer1);
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TEST_CASE(nullpointer2);
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TEST_CASE(structDerefAndCheck); // dereferencing struct and then checking if it's null
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TEST_CASE(pointerDerefAndCheck);
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TEST_CASE(nullpointer5); // References should not be checked
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TEST_CASE(nullpointerExecutionPaths);
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TEST_CASE(nullpointerExecutionPathsLoop);
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TEST_CASE(nullpointer7);
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TEST_CASE(nullpointer8);
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TEST_CASE(nullpointer9);
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TEST_CASE(nullpointer10);
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TEST_CASE(nullpointer11); // ticket #2812
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TEST_CASE(pointerCheckAndDeRef); // check if pointer is null and then dereference it
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TEST_CASE(nullConstantDereference); // Dereference NULL constant
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TEST_CASE(gcc_statement_expression); // Don't crash
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TEST_CASE(snprintf_with_zero_size);
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TEST_CASE(snprintf_with_non_zero_size);
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}
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void check(const char code[])
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{
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// Clear the error buffer..
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errout.str("");
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Settings settings;
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settings._checkCodingStyle = true;
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// Tokenize..
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Tokenizer tokenizer(&settings, this);
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std::istringstream istr(code);
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tokenizer.tokenize(istr, "test.cpp");
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// Check for redundant code..
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CheckNullPointer checkNullPointer(&tokenizer, &settings, this);
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checkNullPointer.nullPointer();
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tokenizer.simplifyTokenList();
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checkNullPointer.nullConstantDereference();
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checkNullPointer.executionPaths();
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}
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void nullpointer1()
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{
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check("int foo(const Token *tok)\n"
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"{\n"
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" while (tok);\n"
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" tok = tok->next();\n"
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"}\n");
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ASSERT_EQUALS("[test.cpp:4]: (error) Possible null pointer dereference: tok - otherwise it is redundant to check if tok is null at line 3\n", errout.str());
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// #2681
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check("void foo(const Token *tok)\n"
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"{\n"
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" while (tok && tok->str() == \"=\")\n"
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" tok = tok->next();\n"
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"\n"
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" if (tok->str() != \";\")\n"
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" ;\n"
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"}\n");
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ASSERT_EQUALS("[test.cpp:6]: (error) Possible null pointer dereference: tok - otherwise it is redundant to check if tok is null at line 3\n", errout.str());
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check("void foo()\n"
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"{\n"
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" for (const Token *tok = tokens; tok; tok = tok->next())\n"
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" {\n"
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" while (tok && tok->str() != \";\")\n"
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" tok = tok->next();\n"
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" }\n"
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"}\n");
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ASSERT_EQUALS("[test.cpp:3]: (error) Possible null pointer dereference: tok - otherwise it is redundant to check if tok is null at line 5\n", errout.str());
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check("void foo(Token &tok)\n"
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"{\n"
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" for (int i = 0; i < tok.size(); i++ )\n"
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" {\n"
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" while (!tok)\n"
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" char c = tok.read();\n"
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" }\n"
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"}\n");
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ASSERT_EQUALS("", errout.str());
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check("void foo()\n"
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"{\n"
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" for (const Token *tok = tokens; tok; tok = tok->next())\n"
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" {\n"
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" while (tok && tok->str() != \";\")\n"
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" tok = tok->next();\n"
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" if( !tok ) break;\n"
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" }\n"
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"}\n");
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ASSERT_EQUALS("", errout.str());
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check("void foo()\n"
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"{\n"
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" for (const Token *tok = tokens; tok; tok = tok ? tok->next() : NULL)\n"
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" {\n"
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" while (tok && tok->str() != \";\")\n"
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" tok = tok->next();\n"
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" }\n"
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"}\n");
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ASSERT_EQUALS("", errout.str());
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check("void foo(A*a)\n"
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"{\n"
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" switch (a->b()) {\n"
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" case 1:\n"
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" while( a ){\n"
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" a = a->next;\n"
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" }\n"
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" break;\n"
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" case 2:\n"
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" a->b();\n"
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" break;\n"
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" }\n"
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"}\n");
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ASSERT_EQUALS("", errout.str());
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// ticket #1923 - no false positive when using else if
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check("void f(A *a)\n"
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"{\n"
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" if (a->x == 1)\n"
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" {\n"
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" a = a->next;\n"
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" }\n"
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" else if (a->x == 2) { }\n"
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" if (a) { }\n"
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"}\n");
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ASSERT_EQUALS("", errout.str());
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// ticket #2134 - sizeof doesn't dereference
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check("void f() {\n"
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" int c = 1;\n"
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" int *list = NULL;\n"
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" sizeof(*list);\n"
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" if (!list)\n"
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" ;\n"
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"}\n");
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ASSERT_EQUALS("", errout.str());
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// ticket #2245 - sizeof doesn't dereference
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check("void f(Bar *p) {\n"
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" if (!p) {\n"
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" int sz = sizeof(p->x);\n"
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" }\n"
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"}\n");
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ASSERT_EQUALS("", errout.str());
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}
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void nullpointer2()
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{
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// Null pointer dereference can only happen with pointers
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check("void foo()\n"
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"{\n"
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" Fred fred;\n"
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" while (fred);\n"
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" fred.hello();\n"
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"}\n");
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ASSERT_EQUALS("", errout.str());
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}
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// Dereferencing a struct and then checking if it is null
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// This is checked by this function:
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// CheckOther::nullPointerStructByDeRefAndChec
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void structDerefAndCheck()
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{
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// errors..
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check("void foo(struct ABC *abc)\n"
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"{\n"
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" int a = abc->a;\n"
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" if (!abc)\n"
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" ;\n"
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"}\n");
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ASSERT_EQUALS("[test.cpp:3]: (error) Possible null pointer dereference: abc - otherwise it is redundant to check if abc is null at line 4\n", errout.str());
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check("void foo(struct ABC *abc) {\n"
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" bar(abc->a);\n"
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" if (!abc)\n"
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" ;\n"
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"}\n");
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ASSERT_EQUALS("[test.cpp:2]: (error) Possible null pointer dereference: abc - otherwise it is redundant to check if abc is null at line 3\n", errout.str());
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check("void foo(ABC *abc) {\n"
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" abc->do_something();\n"
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" if (abc)\n"
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" ;\n"
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"}\n");
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ASSERT_EQUALS("[test.cpp:2]: (error) Possible null pointer dereference: abc - otherwise it is redundant to check if abc is null at line 3\n", errout.str());
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check("void foo(ABC *abc) {\n"
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" if (abc->a == 3) {\n"
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" return;\n"
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" }\n"
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" if (abc) {}\n"
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"}");
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ASSERT_EQUALS("[test.cpp:2]: (error) Possible null pointer dereference: abc - otherwise it is redundant to check if abc is null at line 5\n", errout.str());
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// TODO: False negative if member of member is dereferenced
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check("void foo(ABC *abc) {\n"
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" abc->next->a = 0;\n"
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" if (abc->next)\n"
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" ;\n"
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"}\n");
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TODO_ASSERT_EQUALS("[test.cpp:2]: (error) Possible null pointer dereference: abc - otherwise it is redundant to check if abc is null at line 3\n", "", errout.str());
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check("void foo(ABC *abc) {\n"
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" abc->a = 0;\n"
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" if (abc && abc->b == 0)\n"
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" ;\n"
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"}\n");
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ASSERT_EQUALS("[test.cpp:2]: (error) Possible null pointer dereference: abc - otherwise it is redundant to check if abc is null at line 3\n", errout.str());
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// ok dereferencing in a condition
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check("void foo(struct ABC *abc)\n"
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"{\n"
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" if (abc && abc->a);\n"
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" if (!abc)\n"
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" ;\n"
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"}\n");
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ASSERT_EQUALS("", errout.str());
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// ok to use a linked list..
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check("void foo(struct ABC *abc)\n"
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"{\n"
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" abc = abc->next;\n"
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" if (!abc)\n"
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" ;\n"
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"}\n");
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ASSERT_EQUALS("", errout.str());
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// reassign struct..
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check("void foo(struct ABC *abc)\n"
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"{\n"
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" int a = abc->a;\n"
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" abc = abc->next;\n"
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" if (!abc)\n"
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" ;\n"
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"}\n");
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ASSERT_EQUALS("", errout.str());
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check("void foo(struct ABC *abc)\n"
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"{\n"
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" int a = abc->a;\n"
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" f(&abc);\n"
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" if (!abc)\n"
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" ;\n"
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"}\n");
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ASSERT_EQUALS("", errout.str());
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// goto..
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check("void foo(struct ABC *abc)\n"
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"{\n"
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" int a;\n"
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" if (!abc)\n"
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" goto out;"
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" a = abc->a;\n"
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" return;\n"
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"out:\n"
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" if (!abc)\n"
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" ;\n"
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"}\n");
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ASSERT_EQUALS("", errout.str());
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// loops..
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check("void freeAbc(struct ABC *abc)\n"
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"{\n"
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" while (abc)\n"
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" {\n"
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" struct ABC *next = abc->next;\n"
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" if (abc) delete abc;\n"
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" abc = next;\n"
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" }\n"
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"}\n");
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ASSERT_EQUALS("", errout.str());
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check("void foo(struct ABC *abc)\n"
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"{\n"
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" int a = abc->a;"
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" do\n"
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" {\n"
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" if (abc)\n"
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" abc = abc->next;\n"
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" --a;\n"
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" }\n"
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" while (a > 0);\n"
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"}\n");
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ASSERT_EQUALS("", errout.str());
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check("void f()\n"
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"{\n"
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" for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())\n"
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" {\n"
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" while (tok && tok->str() != \"{\")\n"
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" tok = tok->next();\n"
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" if (!tok)\n"
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" return;\n"
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" }\n"
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"}\n");
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ASSERT_EQUALS("", errout.str());
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// dynamic_cast..
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check("void foo(ABC *abc)\n"
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"{\n"
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" int a = abc->a;\n"
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" if (!dynamic_cast<DEF *>(abc))\n"
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" ;\n"
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"}\n");
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ASSERT_EQUALS("", errout.str());
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// #2641 - global pointer, function call
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check("ABC *abc;\n"
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"void f() {\n"
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" abc->a = 0;\n"
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" do_stuff();\n"
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" if (abc) { }\n"
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"}");
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ASSERT_EQUALS("",errout.str());
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check("Fred *fred;\n"
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"void f() {\n"
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" fred->foo();\n"
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" if (fred) { }\n"
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"}");
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ASSERT_EQUALS("",errout.str());
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// #2641 - local pointer, function call
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check("void f() {\n"
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" ABC *abc;\n"
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" abc->a = 0;\n"
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" do_stuff();\n"
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" if (abc) { }\n"
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"}");
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ASSERT_EQUALS("[test.cpp:3]: (error) Possible null pointer dereference: abc - otherwise it is redundant to check if abc is null at line 5\n",errout.str());
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// #2641 - local pointer, function call
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check("void f(ABC *abc) {\n"
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" abc->a = 0;\n"
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" do_stuff();\n"
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" if (abc) { }\n"
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"}");
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ASSERT_EQUALS("[test.cpp:2]: (error) Possible null pointer dereference: abc - otherwise it is redundant to check if abc is null at line 4\n",errout.str());
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// #2691 - switch/break
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check("void f(ABC *abc) {\n"
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" switch ( x ) {\n"
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" case 14:\n"
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" sprintf(buf, \"%d\", abc->a);\n"
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" break;\n"
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" case 15:\n"
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" if ( abc ) {}\n"
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" break;\n"
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" }\n"
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"}");
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ASSERT_EQUALS("", errout.str());
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}
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// Dereferencing a pointer and then checking if it is null
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void pointerDerefAndCheck()
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{
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// errors..
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check("void foo(int *p)\n"
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"{\n"
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" *p = 0;\n"
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" if (!p)\n"
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" ;\n"
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"}\n");
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ASSERT_EQUALS("[test.cpp:3]: (error) Possible null pointer dereference: p - otherwise it is redundant to check if p is null at line 4\n", errout.str());
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check("void foo(int *p)\n"
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"{\n"
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" bar(*p);\n"
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" if (!p)\n"
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" ;\n"
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"}\n");
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ASSERT_EQUALS("[test.cpp:3]: (error) Possible null pointer dereference: p - otherwise it is redundant to check if p is null at line 4\n", errout.str());
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check("void foo(char *p)\n"
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"{\n"
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" strcpy(p, \"abc\");\n"
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" if (!p)\n"
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" ;\n"
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"}\n");
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ASSERT_EQUALS("[test.cpp:3]: (error) Possible null pointer dereference: p - otherwise it is redundant to check if p is null at line 4\n", errout.str());
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// no error
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check("void foo()\n"
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"{\n"
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" int *p;\n"
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" f(&p);\n"
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" if (!p)\n"
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" ;\n"
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"}\n");
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ASSERT_EQUALS("", errout.str());
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check("void foo()\n"
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"{\n"
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" int **p = f();\n"
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" if (!p)\n"
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" ;\n"
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"}\n");
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ASSERT_EQUALS("", errout.str());
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check("void foo(int *p)\n"
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"{\n"
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" if (x)\n"
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" p = 0;\n"
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" else\n"
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" *p = 0;\n"
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" if (!p)\n"
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" ;\n"
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"}\n");
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ASSERT_EQUALS("", errout.str());
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check("void foo(int x)\n"
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"{\n"
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" int a = 2 * x;"
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" if (x == 0)\n"
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" ;\n"
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"}\n");
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ASSERT_EQUALS("", errout.str());
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check("void foo(int *p)\n"
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"{\n"
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" int var1 = p ? *p : 0;\n"
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" if (!p)\n"
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" ;\n"
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"}\n");
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ASSERT_EQUALS("", errout.str());
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check("void foo(P *p)\n"
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"{\n"
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" while (p)\n"
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" if (p->check())\n"
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" break;\n"
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" else\n"
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" p = p->next();\n"
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"}\n");
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ASSERT_EQUALS("", errout.str());
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check("void f(Document *doc) {\n"
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" int x = doc && doc->x;\n"
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" if (!doc) {\n"
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" return;\n"
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" }\n"
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"}");
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ASSERT_EQUALS("", errout.str());
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check("void foo(x *p)\n"
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"{\n"
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" p = p->next;\n"
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" if (!p)\n"
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" ;\n"
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"}\n");
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ASSERT_EQUALS("", errout.str());
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check("void foo(x *p)\n"
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"{\n"
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" p = bar(p->next);\n"
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" if (!p)\n"
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" ;\n"
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"}\n");
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ASSERT_EQUALS("", errout.str());
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check("void foo(x *p)\n"
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"{\n"
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" p = aa->bar(p->next);\n"
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" if (!p)\n"
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" ;\n"
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"}\n");
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ASSERT_EQUALS("", errout.str());
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check("void foo(struct ABC *abc)\n"
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"{\n"
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" abc = abc ? abc->next : 0;\n"
|
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" if (!abc)\n"
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" ;\n"
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"}\n");
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ASSERT_EQUALS("", errout.str());
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check("int f(Item *item) {\n"
|
|
" x = item ? ab(item->x) : 0;\n"
|
|
" if (item) { }\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
check("int f(Item *item) {\n"
|
|
" item->x = 0;\n"
|
|
" a = b ? c : d;\n"
|
|
" if (item) { }\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:2]: (error) Possible null pointer dereference: item - otherwise it is redundant to check if item is null at line 4\n", errout.str());
|
|
|
|
check("BOOL GotoFlyAnchor()\n" // #2243
|
|
"{\n"
|
|
" const SwFrm* pFrm = GetCurrFrm();\n"
|
|
" do {\n"
|
|
" pFrm = pFrm->GetUpper();\n"
|
|
" } while( pFrm && !pFrm->IsFlyFrm() );\n"
|
|
"\n"
|
|
" if( !pFrm )\n"
|
|
" return FALSE;\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
// Ticket #2463
|
|
check("struct A \n"
|
|
"{\n"
|
|
" B* W;\n"
|
|
"\n"
|
|
" void f() {\n"
|
|
" switch (InData) {\n"
|
|
" case 2:\n"
|
|
" if (!W) return;\n"
|
|
" W->foo();\n"
|
|
" break;\n"
|
|
" case 3:\n"
|
|
" f();\n"
|
|
" if (!W) return;\n"
|
|
" break;\n"
|
|
" }\n"
|
|
" }\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
// #2525 - sizeof
|
|
check("void f() {\n"
|
|
" int *test = NULL;\n"
|
|
" int c = sizeof(test[0]);\n"
|
|
" if (!test)\n"
|
|
" ;\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("", errout.str());
|
|
}
|
|
|
|
void nullpointer5()
|
|
{
|
|
// errors..
|
|
check("void foo(A &a)\n"
|
|
"{\n"
|
|
" char c = a.c();\n"
|
|
" if (!a)\n"
|
|
" return;\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("", errout.str());
|
|
}
|
|
|
|
// Execution paths..
|
|
void nullpointerExecutionPaths()
|
|
{
|
|
// errors..
|
|
check("static void foo()\n"
|
|
"{\n"
|
|
" Foo *p = 0;\n"
|
|
" if (a == 1)\n"
|
|
" p = new FooBar;\n"
|
|
" else if (a == 2)\n"
|
|
" p = new FooCar;\n"
|
|
" p->abcd();\n"
|
|
"}\n");
|
|
TODO_ASSERT_EQUALS("[test.cpp:8]: (error) Possible null pointer dereference: p\n",
|
|
"", errout.str());
|
|
|
|
check("static void foo()\n"
|
|
"{\n"
|
|
" int *p = 0;\n"
|
|
" int *q = p;\n"
|
|
" q[0] = 0;\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:5]: (error) Possible null pointer dereference: q\n", errout.str());
|
|
|
|
check("static void foo()\n"
|
|
"{\n"
|
|
" int *p = 0;\n"
|
|
" int &r = *p;\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:4]: (error) Null pointer dereference\n", errout.str());
|
|
|
|
check("static void foo(int x)\n"
|
|
"{\n"
|
|
" int *p = 0;\n"
|
|
" int y = 5 + *p;\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:4]: (error) Null pointer dereference\n", errout.str());
|
|
|
|
check("static void foo(int x)\n"
|
|
"{\n"
|
|
" Foo<int> *abc = 0;\n"
|
|
" abc->a();\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:4]: (error) Possible null pointer dereference: abc\n", errout.str());
|
|
|
|
check("static void foo()\n"
|
|
"{\n"
|
|
" int *p(0);\n"
|
|
" std::cout << *p;"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:4]: (error) Null pointer dereference\n", errout.str());
|
|
|
|
check("void f()\n"
|
|
"{\n"
|
|
" char *c = 0;\n"
|
|
" {\n"
|
|
" delete c;\n"
|
|
" }\n"
|
|
" c[0] = 0;\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:7]: (error) Possible null pointer dereference: c\n", errout.str());
|
|
|
|
check("static void foo()\n"
|
|
"{\n"
|
|
" int *p = 0;\n"
|
|
" if (3 > *p);\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:4]: (error) Null pointer dereference\n", errout.str());
|
|
|
|
check("void f()\n"
|
|
"{\n"
|
|
" if (x) {\n"
|
|
" char *c = 0;\n"
|
|
" *c = 0;\n"
|
|
" }\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:5]: (error) Null pointer dereference\n", errout.str());
|
|
|
|
// no false positive..
|
|
check("static void foo()\n"
|
|
"{\n"
|
|
" Foo *p = 0;\n"
|
|
" p = new Foo;\n"
|
|
" p->abcd();\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
check("static void foo()\n"
|
|
"{\n"
|
|
" Foo *p = 0;\n"
|
|
" if (!p)\n"
|
|
" return;\n"
|
|
" p->abcd();\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
check("static void foo()\n"
|
|
"{\n"
|
|
" int *p = 0;\n"
|
|
" exit();\n"
|
|
" *p = 0;\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
check("static void foo(int a)\n"
|
|
"{\n"
|
|
" Foo *p = 0;\n"
|
|
" if (a && p)\n"
|
|
" p->do_something();\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
check("void f() {\n"
|
|
" Foo *p = 0;\n"
|
|
" bool b = (p && (p->type() == 1));\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
check("void foo()\n"
|
|
"{\n"
|
|
" int sz = sizeof((*(struct dummy *)0).x);\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
check("void get_offset(long &offset)\n"
|
|
"{\n"
|
|
" mystruct * temp; temp = 0;\n"
|
|
" offset = (long)(&(temp->z));\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
// Ticket #1893 - try/catch inside else
|
|
check("int *test(int *Z)\n"
|
|
"{\n"
|
|
" int *Q=NULL;\n"
|
|
" if (Z) {\n"
|
|
" Q = Z;\n"
|
|
" }\n"
|
|
" else {\n"
|
|
" Z = new int;\n"
|
|
" try {\n"
|
|
" } catch(...) {\n"
|
|
" }\n"
|
|
" Q = Z;\n"
|
|
" }\n"
|
|
" *Q=1;\n"
|
|
" return Q;\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
check("int *test(int *Z)\n"
|
|
"{\n"
|
|
" int *Q=NULL;\n"
|
|
" if (Z) {\n"
|
|
" Q = Z;\n"
|
|
" }\n"
|
|
" else {\n"
|
|
" try {\n"
|
|
" } catch(...) {\n"
|
|
" }\n"
|
|
" }\n"
|
|
" *Q=1;\n"
|
|
" return Q;\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:12]: (error) Possible null pointer dereference: Q\n", errout.str());
|
|
|
|
// Ticket #2052 (false positive for 'else continue;')
|
|
check("void f() {\n"
|
|
" for (int x = 0; x < 5; ++x) {"
|
|
" int *p = 0;\n"
|
|
" if (a(x)) p=b(x);\n"
|
|
" else continue;\n"
|
|
" *p = 0;\n"
|
|
" }\n"
|
|
"}");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
// function pointer..
|
|
check("void foo()\n"
|
|
"{\n"
|
|
" void (*f)();\n"
|
|
" f = 0;\n"
|
|
" f();\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:5]: (error) Possible null pointer dereference: f\n", errout.str());
|
|
|
|
check("static void foo()\n"
|
|
"{\n"
|
|
" int *p = 0;\n"
|
|
" int *p2 = 0;\n"
|
|
" int r = *p;\n"
|
|
" int r2 = *p2;\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:5]: (error) Null pointer dereference\n"
|
|
"[test.cpp:6]: (error) Null pointer dereference\n", errout.str());
|
|
|
|
// loops..
|
|
check("void f() {\n"
|
|
" int *p = 0;\n"
|
|
" for (int i = 0; i < 10; ++i) {\n"
|
|
" int x = *p + 1;\n"
|
|
" }\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:4]: (error) Possible null pointer dereference: p\n", errout.str());
|
|
|
|
check("void f(int a) {\n"
|
|
" const char *p = 0;\n"
|
|
" if (a) {\n"
|
|
" p = \"abcd\";\n"
|
|
" }\n"
|
|
" for (int i = 0; i < 3; i++) {\n"
|
|
" if (a && (p[i] == '1'));\n"
|
|
" }\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
// ticket #2251: taking the address of member
|
|
check("void f() {\n"
|
|
" Fred *fred = 0;\n"
|
|
" int x = &fred->x;\n"
|
|
"}");
|
|
ASSERT_EQUALS("", errout.str());
|
|
}
|
|
|
|
// Ticket #2350
|
|
void nullpointerExecutionPathsLoop()
|
|
{
|
|
// No false positive:
|
|
check("void foo() {\n"
|
|
" int n;\n"
|
|
" int *argv32;\n"
|
|
" if (x) {\n"
|
|
" n = 0;\n"
|
|
" argv32 = 0;\n"
|
|
" }\n"
|
|
"\n"
|
|
" for (int i = 0; i < n; i++) {\n"
|
|
" argv32[i] = 0;\n"
|
|
" }\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
// No false negative:
|
|
check("void foo() {\n"
|
|
" int n;\n"
|
|
" int *argv32;\n"
|
|
" if (x) {\n"
|
|
" n = 10;\n"
|
|
" argv32 = 0;\n"
|
|
" }\n"
|
|
"\n"
|
|
" for (int i = 0; i < n; i++) {\n"
|
|
" argv32[i] = 0;\n"
|
|
" }\n"
|
|
"}\n");
|
|
TODO_ASSERT_EQUALS("error",
|
|
"", errout.str());
|
|
|
|
// #2231 - error if assignment in loop is not used
|
|
check("void f() {\n"
|
|
" char *p = 0;\n"
|
|
"\n"
|
|
" for (int x = 0; x < 3; ++x) {\n"
|
|
" if (y[x] == 0) {\n"
|
|
" p = malloc(10);\n"
|
|
" break;\n"
|
|
" }\n"
|
|
" }\n"
|
|
"\n"
|
|
" *p = 0;\n"
|
|
"}");
|
|
ASSERT_EQUALS("[test.cpp:11]: (error) Possible null pointer dereference: p\n", errout.str());
|
|
}
|
|
|
|
void nullpointer7()
|
|
{
|
|
check("void foo()\n"
|
|
"{\n"
|
|
" wxLongLong x = 0;\n"
|
|
" int y = x.GetValue();\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("", errout.str());
|
|
}
|
|
|
|
void nullpointer8()
|
|
{
|
|
check("void foo()\n"
|
|
"{\n"
|
|
" const char * x = 0;\n"
|
|
" strdup(x);\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:4]: (error) Possible null pointer dereference: x\n", errout.str());
|
|
check("void foo()\n"
|
|
"{\n"
|
|
" char const * x = 0;\n"
|
|
" strdup(x);\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:4]: (error) Possible null pointer dereference: x\n", errout.str());
|
|
}
|
|
|
|
void nullpointer9() //#ticket 1778
|
|
{
|
|
check("void foo()\n"
|
|
"{\n"
|
|
" std::string * x = 0;\n"
|
|
" *x = \"test\";\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:4]: (error) Null pointer dereference\n", errout.str());
|
|
}
|
|
|
|
void nullpointer10()
|
|
{
|
|
check("void foo()\n"
|
|
"{\n"
|
|
" struct my_type* p = 0;\n"
|
|
" p->x = 0;\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:4]: (error) Possible null pointer dereference: p\n", errout.str());
|
|
|
|
check("void foo()\n"
|
|
"{\n"
|
|
" struct my_type* p;\n"
|
|
" p = 0; \n"
|
|
" p->x = 0;\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:5]: (error) Possible null pointer dereference: p\n", errout.str());
|
|
}
|
|
|
|
void nullpointer11() // ticket #2812
|
|
{
|
|
check("int foo()\n"
|
|
"{\n"
|
|
" my_type* p = 0;\n"
|
|
" return p->x;\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:4]: (error) Possible null pointer dereference: p\n", errout.str());
|
|
|
|
check("int foo()\n"
|
|
"{\n"
|
|
" struct my_type* p = 0;\n"
|
|
" return p->x;\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:4]: (error) Possible null pointer dereference: p\n", errout.str());
|
|
|
|
check("int foo()\n"
|
|
"{\n"
|
|
" my_type* p;\n"
|
|
" p = 0; \n"
|
|
" return p->x;\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:5]: (error) Possible null pointer dereference: p\n", errout.str());
|
|
|
|
check("int foo()\n"
|
|
"{\n"
|
|
" struct my_type* p;\n"
|
|
" p = 0; \n"
|
|
" return p->x;\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:5]: (error) Possible null pointer dereference: p\n", errout.str());
|
|
}
|
|
|
|
// Check if pointer is null and the dereference it
|
|
void pointerCheckAndDeRef()
|
|
{
|
|
check("void foo(char *p) {\n"
|
|
" if (!p) {\n"
|
|
" }\n"
|
|
" *p = 0;\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:4]: (error) Possible null pointer dereference: p - otherwise it is redundant to check if p is null at line 2\n", errout.str());
|
|
|
|
check("void foo(char *p) {\n"
|
|
" if (NULL == p) {\n"
|
|
" }\n"
|
|
" *p = 0;\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:4]: (error) Possible null pointer dereference: p - otherwise it is redundant to check if p is null at line 2\n", errout.str());
|
|
|
|
check("void foo(char *p) {\n"
|
|
" if (p == NULL) {\n"
|
|
" }\n"
|
|
" *p = 0;\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:4]: (error) Possible null pointer dereference: p - otherwise it is redundant to check if p is null at line 2\n", errout.str());
|
|
|
|
check("void foo(char *p) {\n"
|
|
" if (p == NULL) {\n"
|
|
" }\n"
|
|
" printf(\"%c\", *p);\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:4]: (error) Possible null pointer dereference: p - otherwise it is redundant to check if p is null at line 2\n", errout.str());
|
|
|
|
check("void foo(char *p) {\n"
|
|
" if (p && *p == 0) {\n"
|
|
" }\n"
|
|
" printf(\"%c\", *p);\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:4]: (error) Possible null pointer dereference: p - otherwise it is redundant to check if p is null at line 2\n", errout.str());
|
|
|
|
check("void foo(char *p) {\n"
|
|
" if (p && *p == 0) {\n"
|
|
" } else { *p = 0; }\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:3]: (error) Possible null pointer dereference: p - otherwise it is redundant to check if p is null at line 2\n", errout.str());
|
|
|
|
check("void foo(char *p) {\n"
|
|
" if (p) {\n"
|
|
" }\n"
|
|
" strcpy(p, \"abc\");\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:4]: (error) Possible null pointer dereference: p - otherwise it is redundant to check if p is null at line 2\n", errout.str());
|
|
|
|
check("void foo(char *p) {\n"
|
|
" if (p) {\n"
|
|
" }\n"
|
|
" bar();\n"
|
|
" strcpy(p, \"abc\");\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:5]: (error) Possible null pointer dereference: p - otherwise it is redundant to check if p is null at line 2\n", errout.str());
|
|
|
|
check("void foo(abc *p) {\n"
|
|
" if (!p) {\n"
|
|
" }\n"
|
|
" else if (!p->x) {\n"
|
|
" }\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
check("void foo(char *p) {\n"
|
|
" if (!p) {\n"
|
|
" abort();\n"
|
|
" }\n"
|
|
" *p = 0;\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
check("void foo(char *p) {\n"
|
|
" if (!p) {\n"
|
|
" (*bail)();\n"
|
|
" }\n"
|
|
" *p = 0;\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
check("void foo(char *p) {\n"
|
|
" if (!p) {\n"
|
|
" throw x;\n"
|
|
" }\n"
|
|
" *p = 0;\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
check("void foo(char *p) {\n"
|
|
" if (!p) {\n"
|
|
" switch (x) { }\n"
|
|
" }\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
check("void foo(char *p) {\n"
|
|
" if (!p) {\n"
|
|
" }\n"
|
|
" return *x;\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
// operator!
|
|
check("void f() {\n"
|
|
" A a;\n"
|
|
" if (!a) {\n"
|
|
" a.x();\n"
|
|
" }\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
// This is why this check can't be used on the simplified token list
|
|
check("void f(Foo *foo) {\n"
|
|
" if (!dynamic_cast<bar *>(foo)) {\n"
|
|
" *foo = 0;\n"
|
|
" }\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
// ticket: #2300 - calling unknown function that may initialize the pointer
|
|
check("Fred *fred;\n"
|
|
"void a() {\n"
|
|
" if (!fred) {\n"
|
|
" initfred();\n"
|
|
" fred->x = 0;\n"
|
|
" }\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
// ticket #1219
|
|
check("void foo(char *p) {\n"
|
|
" if (p) {\n"
|
|
" return;\n"
|
|
" }\n"
|
|
" *p = 0;\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:5]: (error) Possible null pointer dereference: p - otherwise it is redundant to check if p is null at line 2\n", errout.str());
|
|
|
|
// #2467 - unknown macro may terminate the application
|
|
check("void f(Fred *fred) {\n"
|
|
" if (fred == NULL) {\n"
|
|
" MACRO;\n"
|
|
" }\n"
|
|
" fred->a();\n"
|
|
"}");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
// #2493 - switch
|
|
check("void f(Fred *fred) {\n"
|
|
" if (fred == NULL) {\n"
|
|
" x = 0;\n"
|
|
" }\n"
|
|
" switch (x) {\n"
|
|
" case 1:\n"
|
|
" fred->a();\n"
|
|
" break;\n"
|
|
" };\n"
|
|
"}");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
// #2582 - segmentation fault
|
|
check("if()");
|
|
|
|
// #2674 - different functions
|
|
check("class Fred {\n"
|
|
"public:\n"
|
|
" Wilma *wilma;\n"
|
|
" void a();\n"
|
|
" void b();\n"
|
|
"};\n"
|
|
"\n"
|
|
"void Fred::a() {\n"
|
|
" if ( wilma ) { }\n"
|
|
"}\n"
|
|
"\n"
|
|
"void Fred::b() {\n"
|
|
" wilma->Reload();\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
check("void test(int *i) {\n"
|
|
" if(i == NULL) {\n"
|
|
" int b = 1;\n"
|
|
" } else {\n"
|
|
" int b = *i;\n"
|
|
" }\n"
|
|
"}");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
// #2696 - false positives nr 1
|
|
check("void f()\n"
|
|
"{\n"
|
|
" struct foo *pFoo = NULL;\n"
|
|
" size_t len;\n"
|
|
"\n"
|
|
" len = sizeof(*pFoo) - sizeof(pFoo->data);\n"
|
|
"\n"
|
|
" if (pFoo)\n"
|
|
" bar();\n"
|
|
"}");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
// #2696 - false positives nr 2
|
|
check("void f()\n"
|
|
"{\n"
|
|
" struct foo *pFoo = NULL;\n"
|
|
" size_t len;\n"
|
|
"\n"
|
|
" while (pFoo)\n"
|
|
" pFoo = pFoo->next;\n"
|
|
"\n"
|
|
" len = sizeof(pFoo->data);\n"
|
|
"}");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
// #2696 - false positives nr 3
|
|
check("void f()\n"
|
|
"{\n"
|
|
" struct foo *pFoo = NULL;\n"
|
|
" size_t len;\n"
|
|
"\n"
|
|
" while (pFoo)\n"
|
|
" pFoo = pFoo->next;\n"
|
|
"\n"
|
|
" len = decltype(*pFoo);\n"
|
|
"}");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
check("int foo(struct Fred *fred) {\n"
|
|
" if (fred) { int a = 0; }\n"
|
|
" return fred->a;\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:3]: (error) Possible null pointer dereference: fred - otherwise it is redundant to check if fred is null at line 2\n", errout.str());
|
|
|
|
// #2789 - assign and check pointer
|
|
check("void f() {\n"
|
|
" char *p;\n"
|
|
" if (!(p=x())) { }\n"
|
|
" *p = 0;\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:4]: (error) Possible null pointer dereference: p - otherwise it is redundant to check if p is null at line 3\n", errout.str());
|
|
}
|
|
|
|
// Test CheckNullPointer::nullConstantDereference
|
|
void nullConstantDereference()
|
|
{
|
|
// Ticket #2090
|
|
check("void foo() {\n"
|
|
" char *p = 0;\n"
|
|
" strcpy(p, \"abcd\");\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("[test.cpp:3]: (error) Null pointer dereference\n", errout.str());
|
|
|
|
// Ticket #2413 - it's ok to pass NULL to fflush
|
|
check("void foo() {\n"
|
|
" fflush(NULL);\n"
|
|
"}\n");
|
|
ASSERT_EQUALS("", errout.str());
|
|
|
|
}
|
|
|
|
void gcc_statement_expression()
|
|
{
|
|
// Ticket #2621
|
|
check("void f(struct ABC *abc) {\n"
|
|
" ({ if (abc) dbg(); })\n"
|
|
"}");
|
|
ASSERT_EQUALS("", errout.str());
|
|
}
|
|
|
|
void snprintf_with_zero_size()
|
|
{
|
|
// Ticket #2840
|
|
check("void f() {\n"
|
|
" int bytes = snprintf(0, 0, \"%u\", 1);\n"
|
|
"}");
|
|
ASSERT_EQUALS("", errout.str());
|
|
}
|
|
|
|
void snprintf_with_non_zero_size()
|
|
{
|
|
// Ticket #2840
|
|
check("void f() {\n"
|
|
" int bytes = snprintf(0, 10, \"%u\", 1);\n"
|
|
"}");
|
|
ASSERT_EQUALS("[test.cpp:2]: (error) Null pointer dereference\n", errout.str());
|
|
}
|
|
};
|
|
|
|
REGISTER_TEST(TestNullPointer)
|
|
|