/*

* Cppcheck - A tool for static C/C++ code analysis

* Copyright (C) 2007-2012 Daniel Marjamäki and Cppcheck team.

*

* This program is free software: you can redistribute it and/or modify

* it under the terms of the GNU General Public License as published by

* the Free Software Foundation, either version 3 of the License, or

* (at your option) any later version.

*

* This program is distributed in the hope that it will be useful,

* but WITHOUT ANY WARRANTY; without even the implied warranty of

* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

* GNU General Public License for more details.

*

* You should have received a copy of the GNU General Public License

* along with this program. If not, see <http://www.gnu.org/licenses/>.

*/

#include "tokenize.h"

#include "checknullpointer.h"

#include "testsuite.h"

#include <sstream>

extern std::ostringstream errout;

class TestNullPointer : public TestFixture {

public:

TestNullPointer() : TestFixture("TestNullPointer")

{ }

private:

void run() {

TEST_CASE(nullpointerAfterLoop);

TEST_CASE(nullpointer1);

TEST_CASE(nullpointer2);

TEST_CASE(structDerefAndCheck); // dereferencing struct and then checking if it's null

TEST_CASE(pointerDerefAndCheck);

TEST_CASE(nullpointer5); // References should not be checked

TEST_CASE(nullpointerExecutionPaths);

TEST_CASE(nullpointerExecutionPathsLoop);

TEST_CASE(nullpointer7);

TEST_CASE(nullpointer8);

TEST_CASE(nullpointer9);

TEST_CASE(nullpointer10);

TEST_CASE(nullpointer11); // ticket #2812

TEST_CASE(nullpointer12); // ticket #2470

TEST_CASE(nullpointer13); // ticket #1708

TEST_CASE(nullpointer14);

TEST_CASE(nullpointer15); // #3560 (fp: return p ? f(*p) : f(0))

TEST_CASE(nullpointer16); // #3591

TEST_CASE(nullpointer17); // #3567

TEST_CASE(nullpointer18); // #1927

TEST_CASE(pointerCheckAndDeRef); // check if pointer is null and then dereference it

TEST_CASE(nullConstantDereference); // Dereference NULL constant

TEST_CASE(gcc_statement_expression); // Don't crash

TEST_CASE(snprintf_with_zero_size);

TEST_CASE(snprintf_with_non_zero_size);

TEST_CASE(printf_with_invalid_va_argument);

TEST_CASE(scanf_with_invalid_va_argument);

TEST_CASE(nullpointer_in_return);

TEST_CASE(nullpointer_in_typeid);

TEST_CASE(nullpointer_in_for_loop);

TEST_CASE(nullpointerDelete);

TEST_CASE(nullpointerExit);

TEST_CASE(nullpointerStdString);

TEST_CASE(nullpointerStdStream);

TEST_CASE(functioncall);

TEST_CASE(crash1);

}

void check(const char code[], bool inconclusive = false, bool cpp11 = false) {

// Clear the error buffer..

errout.str("");

Settings settings;

settings.addEnabled("style");

settings.inconclusive = inconclusive;

settings.standards.cpp11 = cpp11;

// Tokenize..

Tokenizer tokenizer(&settings, this);

std::istringstream istr(code);

tokenizer.tokenize(istr, "test.cpp");

// Check for redundant code..

CheckNullPointer checkNullPointer(&tokenizer, &settings, this);

checkNullPointer.nullPointer();

tokenizer.simplifyTokenList();

checkNullPointer.nullConstantDereference();

checkNullPointer.executionPaths();

}

void nullpointerAfterLoop() {

check("int foo(const Token *tok)\n"

"{\n"

" while (tok);\n"

" tok = tok->next();\n"

"}\n");

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());

// #2681

{

const char code[] = "void foo(const Token *tok)\n"

"{\n"

" while (tok && tok->str() == \"=\")\n"

" tok = tok->next();\n"

"\n"

" if (tok->str() != \";\")\n"

" ;\n"

"}\n";

check(code, false); // inconclusive=false => no error

ASSERT_EQUALS("", errout.str());

check(code, true); // inconclusive=true => error

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());

}

check("void foo()\n"

"{\n"

" for (const Token *tok = tokens; tok; tok = tok->next())\n"

" {\n"

" while (tok && tok->str() != \";\")\n"

" tok = tok->next();\n"

" }\n"

"}\n");

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());

check("void foo(Token &tok)\n"

"{\n"

" for (int i = 0; i < tok.size(); i++ )\n"

" {\n"

" while (!tok)\n"

" char c = tok.read();\n"

" }\n"

"}\n");

ASSERT_EQUALS("", errout.str());

check("void foo()\n"

"{\n"

" for (const Token *tok = tokens; tok; tok = tok->next())\n"

" {\n"

" while (tok && tok->str() != \";\")\n"

" tok = tok->next();\n"

" if( !tok ) break;\n"

" }\n"

"}\n");

ASSERT_EQUALS("", errout.str());

check("void foo()\n"

"{\n"

" for (const Token *tok = tokens; tok; tok = tok ? tok->next() : NULL)\n"

" {\n"

" while (tok && tok->str() != \";\")\n"

" tok = tok->next();\n"

" }\n"

"}\n");

ASSERT_EQUALS("", errout.str());

check("void foo(A*a)\n"

"{\n"

" switch (a->b()) {\n"

" case 1:\n"

" while( a ){\n"

" a = a->next;\n"

" }\n"

" break;\n"

" case 2:\n"

" a->b();\n"

" break;\n"

" }\n"

"}\n");

ASSERT_EQUALS("", errout.str());

// dereference in outer scope..

{

const char code[] = "void foo(int x, const Token *tok) {\n"

" if (x == 123) {\n"

" while (tok) tok = tok->next();\n"

" }\n"

" tok->str();\n"

"}\n";

check(code, false);

ASSERT_EQUALS("", errout.str());

check(code, true);

ASSERT_EQUALS("[test.cpp:5]: (error) Possible null pointer dereference: tok - otherwise it is redundant to check if tok is null at line 3\n", errout.str());

}

check("int foo(const Token *tok)\n"

"{\n"

" while (tok){;}\n"

"}\n", true);

ASSERT_EQUALS("", errout.str());

check("int foo(const Token *tok)\n"

"{\n"

" while (tok){;}\n"

" char a[2] = {0,0};\n"

"}\n", true);

ASSERT_EQUALS("", errout.str());

}

void nullpointer1() {

// ticket #1923 - no false positive when using else if

check("void f(A *a)\n"

"{\n"

" if (a->x == 1)\n"

" {\n"

" a = a->next;\n"

" }\n"

" else if (a->x == 2) { }\n"

" if (a) { }\n"

"}\n");

ASSERT_EQUALS("", errout.str());

// ticket #2134 - sizeof doesn't dereference

check("void f() {\n"

" int c = 1;\n"

" int *list = NULL;\n"

" sizeof(*list);\n"

" if (!list)\n"

" ;\n"

"}\n");

ASSERT_EQUALS("", errout.str());

// ticket #2245 - sizeof doesn't dereference

check("void f(Bar *p) {\n"

" if (!p) {\n"

" int sz = sizeof(p->x);\n"

" }\n"

"}\n");

ASSERT_EQUALS("", errout.str());

}

void nullpointer2() {

// Null pointer dereference can only happen with pointers

check("void foo()\n"

"{\n"

" Fred fred;\n"

" while (fred);\n"

" fred.hello();\n"

"}\n");

ASSERT_EQUALS("", errout.str());

}

// Dereferencing a struct and then checking if it is null

// This is checked by this function:

// CheckOther::nullPointerStructByDeRefAndChec

void structDerefAndCheck() {

// errors..

check("void foo(struct ABC *abc)\n"

"{\n"

" int a = abc->a;\n"

" if (!abc)\n"

" ;\n"

"}\n");

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());

check("void foo(struct ABC *abc) {\n"

" bar(abc->a);\n"

" if (!abc)\n"

" ;\n"

"}\n");

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());

check("void foo(ABC *abc) {\n"

" if (abc->a == 3) {\n"

" return;\n"

" }\n"

" if (abc) {}\n"

"}");

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());

check("void f(ABC *abc) {\n"

" if (abc->x == 0) {\n"

" return;\n"

" }\n"

" if (!abc);\n"

"}");

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());

// TODO: False negative if member of member is dereferenced

check("void foo(ABC *abc) {\n"

" abc->next->a = 0;\n"

" if (abc->next)\n"

" ;\n"

"}\n");

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());

check("void foo(ABC *abc) {\n"

" abc->a = 0;\n"

" if (abc && abc->b == 0)\n"

" ;\n"

"}\n");

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());

// ok dereferencing in a condition

check("void foo(struct ABC *abc)\n"

"{\n"

" if (abc && abc->a);\n"

" if (!abc)\n"

" ;\n"

"}\n");

ASSERT_EQUALS("", errout.str());

check("void f(struct ABC *abc) {\n"

" int x = abc && a(abc->x);\n"

" if (abc) { }\n"

"}");

ASSERT_EQUALS("", errout.str());

// ok to use a linked list..

check("void foo(struct ABC *abc)\n"

"{\n"

" abc = abc->next;\n"

" if (!abc)\n"

" ;\n"

"}\n");

ASSERT_EQUALS("", errout.str());

check("void f(struct ABC *abc) {\n"

" abc = (ABC *)(abc->_next);\n"

" if (abc) { }"

"}\n");

ASSERT_EQUALS("", errout.str());

// reassign struct..

check("void foo(struct ABC *abc)\n"

"{\n"

" int a = abc->a;\n"

" abc = abc->next;\n"

" if (!abc)\n"

" ;\n"

"}\n");

ASSERT_EQUALS("", errout.str());

check("void foo(struct ABC *abc)\n"

"{\n"

" int a = abc->a;\n"

" f(&abc);\n"

" if (!abc)\n"

" ;\n"

"}\n");

ASSERT_EQUALS("", errout.str());

// goto..

check("void foo(struct ABC *abc)\n"

"{\n"

" int a;\n"

" if (!abc)\n"

" goto out;"

" a = abc->a;\n"

" return;\n"

"out:\n"

" if (!abc)\n"

" ;\n"

"}\n");

ASSERT_EQUALS("", errout.str());

// loops..

check("void foo(struct ABC *abc)\n"

"{\n"

" int a = abc->a;"

" do\n"

" {\n"

" if (abc)\n"

" abc = abc->next;\n"

" --a;\n"

" }\n"

" while (a > 0);\n"

"}\n");

ASSERT_EQUALS("", errout.str());

check("void f()\n"

"{\n"

" for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())\n"

" {\n"

" while (tok && tok->str() != \"{\")\n"

" tok = tok->next();\n"

" if (!tok)\n"

" return;\n"

" }\n"

"}\n");

ASSERT_EQUALS("", errout.str());

// dynamic_cast..

check("void foo(ABC *abc)\n"

"{\n"

" int a = abc->a;\n"

" if (!dynamic_cast<DEF *>(abc))\n"

" ;\n"

"}\n");

ASSERT_EQUALS("", errout.str());

// #2641 - global pointer, function call

check("ABC *abc;\n"

"void f() {\n"

" abc->a = 0;\n"

" do_stuff();\n"

" if (abc) { }\n"

"}");

ASSERT_EQUALS("",errout.str());

check("Fred *fred;\n"

"void f() {\n"

" fred->foo();\n"

" if (fred) { }\n"

"}");

ASSERT_EQUALS("",errout.str());

// #2641 - local pointer, function call

check("void f() {\n"

" ABC *abc;\n"

" abc->a = 0;\n"

" do_stuff();\n"

" if (abc) { }\n"

"}");

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());

// #2641 - local pointer, function call

check("void f(ABC *abc) {\n"

" abc->a = 0;\n"

" do_stuff();\n"

" if (abc) { }\n"

"}");

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());

// #2691 - switch/break

check("void f(ABC *abc) {\n"

" switch ( x ) {\n"

" case 14:\n"

" sprintf(buf, \"%d\", abc->a);\n"

" break;\n"

" case 15:\n"

" if ( abc ) {}\n"

" break;\n"

" }\n"

"}");

ASSERT_EQUALS("", errout.str());

// #3128

check("void f(ABC *abc) {\n"

" x(!abc || y(abc->a));\n"

" if (abc) {}\n"

"}");

ASSERT_EQUALS("", errout.str());

// #3228 - calling function with null object

{

const char code[] = "void f(Fred *fred) {\n"

" fred->x();\n"

" if (fred) { }\n"

"}";

check(code);

ASSERT_EQUALS("", errout.str());

check(code, true);

ASSERT_EQUALS("[test.cpp:2]: (error) Possible null pointer dereference: fred - otherwise it is redundant to check if fred is null at line 3\n", errout.str());

}

// false positives when there are macros

check("void f(struct FRED *fred) {\n"

" fred->x = 0;\n"

" $if(!fred){}\n"

"}");

ASSERT_EQUALS("", errout.str());

}

// Dereferencing a pointer and then checking if it is null

void pointerDerefAndCheck() {

// errors..

check("void foo(int *p)\n"

"{\n"

" *p = 0;\n"

" if (!p)\n"

" ;\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 4\n", errout.str());

check("void foo(int *p)\n"

"{\n"

" *p = 0;\n"

" if (p) { }\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 4\n", errout.str());

check("void foo(int *p)\n"

"{\n"

" *p = 0;\n"

" if (p || q) { }\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 4\n", errout.str());

check("void foo(int *p)\n"

"{\n"

" bar(*p);\n"

" if (!p)\n"

" ;\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 4\n", errout.str());

check("void foo(char *p)\n"

"{\n"

" strcpy(p, \"abc\");\n"

" if (!p)\n"

" ;\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 4\n", errout.str());

check("void foo(char *p)\n"

"{\n"

" if (*p == 0) { }\n"

" if (!p) { }\n"

"}\n");

TODO_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());

// no error

check("void foo()\n"

"{\n"

" int *p;\n"

" f(&p);\n"

" if (!p)\n"

" ;\n"

"}\n");

ASSERT_EQUALS("", errout.str());

check("void foo()\n"

"{\n"

" int **p = f();\n"

" if (!p)\n"

" ;\n"

"}\n");

ASSERT_EQUALS("", errout.str());

check("void foo(int *p)\n"

"{\n"

" if (x)\n"

" p = 0;\n"

" else\n"

" *p = 0;\n"

" if (!p)\n"

" ;\n"

"}\n");

ASSERT_EQUALS("", errout.str());

check("void foo(int x)\n"

"{\n"

" int a = 2 * x;"

" if (x == 0)\n"

" ;\n"

"}\n");

ASSERT_EQUALS("", errout.str());

check("void foo(int *p)\n"

"{\n"

" int var1 = p ? *p : 0;\n"

" if (!p)\n"

" ;\n"

"}\n");

ASSERT_EQUALS("", errout.str());

check("void foo(int *p)\n"

"{\n"

" int var1 = x ? *p : 5;\n"

" if (!p)\n"

" ;\n"

"}\n");

TODO_ASSERT_EQUALS("error", "", errout.str());

// Ticket #3125

check("void foo(ABC *p)\n"

"{\n"

" int var1 = p ? (p->a) : 0;\n"

" if (!p)\n"

" ;\n"

"}\n");

ASSERT_EQUALS("", errout.str());

check("void foo(ABC *p)\n"

"{\n"

" int var1 = p ? (1 + p->a) : 0;\n"

" if (!p)\n"

" ;\n"

"}\n");

ASSERT_EQUALS("", errout.str());

check("void foo(P *p)\n"

"{\n"

" while (p)\n"

" if (p->check())\n"

" break;\n"

" else\n"

" p = p->next();\n"

"}\n");

ASSERT_EQUALS("", errout.str());

check("void f(Document *doc) {\n"

" int x = doc && doc->x;\n"

" if (!doc) {\n"

" return;\n"

" }\n"

"}");

ASSERT_EQUALS("", errout.str());

// #3128 - false positive

check("void f(int *p) {\n"

" assert(!p || (*p<=6));\n"

" if (p) { *p = 0; }\n"

"}");

ASSERT_EQUALS("", errout.str());

check("void f(int *p) {\n"

" assert(p && (*p<=6));\n"

" if (p) { *p = 0; }\n"

"}");

ASSERT_EQUALS("", errout.str());

check("void f(int *p) {\n"

" *p = 12;\n"

" assert(p && (*p<=6));\n"

" if (p) { *p = 0; }\n"

"}");

ASSERT_EQUALS("[test.cpp:2]: (error) Possible null pointer dereference: p - otherwise it is redundant to check if p is null at line 4\n", errout.str());

check("void foo(x *p)\n"

"{\n"

" p = p->next;\n"

" if (!p)\n"

" ;\n"

"}\n");

ASSERT_EQUALS("", errout.str());

check("void foo(x *p)\n"

"{\n"

" p = bar(p->next);\n"

" if (!p)\n"

" ;\n"

"}\n");

ASSERT_EQUALS("", errout.str());

check("void foo(x *p)\n"

"{\n"

" p = aa->bar(p->next);\n"

" if (!p)\n"

" ;\n"

"}\n");

ASSERT_EQUALS("", errout.str());

check("void foo(struct ABC *abc)\n"

"{\n"

" abc = abc ? abc->next : 0;\n"

" if (!abc)\n"

" ;\n"

"}\n");

ASSERT_EQUALS("", errout.str());

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());

// #3023 - checked deref

check("void f(struct ABC *abc) {\n"

" WARN_ON(!abc || abc->x == 0);\n"

" if (!abc) { }\n"

"}");

ASSERT_EQUALS("", errout.str());

check("void f(struct ABC *abc) {\n"

" WARN_ON(!abc || abc->x == 7);\n"

" if (!abc) { }\n"

"}");

ASSERT_EQUALS("", errout.str());

// false positives when there are macros

check("void f(int *p) {\n"

" *p = 0;\n"

" $if(!p){}\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());

{

const char code[] = "static void foo(int x)\n"

"{\n"

" Foo<int> *abc = 0;\n"

" abc->a();\n"

"}\n";

// inconclusive=false => no error

check(code,false);

ASSERT_EQUALS("", errout.str());

// inconclusive=true => error

check(code, true);

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 #3220: calling member function

check("void f() {\n"

" Fred *fred = NULL;\n"

" fred->do_something();\n"

"}");

ASSERT_EQUALS("", errout.str());

// ticket #3570 - parsing of conditions

{

check("void f() {\n"

" int *p = NULL;\n"

" if (x)\n"

" p = q;\n"

" if (p && *p) { }\n"

"}");

ASSERT_EQUALS("", errout.str());

check("void f() {\n"

" int *p = NULL;\n"

" if (x)\n"

" p = q;\n"

" if (!p || *p) { }\n"

"}");