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cppcheck/test/testnullpointer.cpp

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/*
* Cppcheck - A tool for static C/C++ code analysis
* Copyright (C) 2007-2019 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 "checknullpointer.h"
#include "checkuninitvar.h"
#include "library.h"
#include "settings.h"
#include "testsuite.h"
#include "token.h"
#include "tokenize.h"
#include <simplecpp.h>
#include <tinyxml2.h>
#include <list>
#include <map>
#include <string>
#include <vector>
class TestNullPointer : public TestFixture {
public:
TestNullPointer() : TestFixture("TestNullPointer") {
}
private:
Settings settings;
void run() OVERRIDE {
LOAD_LIB_2(settings.library, "std.cfg");
settings.addEnabled("warning");
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(nullpointer9);
TEST_CASE(nullpointer10);
TEST_CASE(nullpointer11); // ticket #2812
TEST_CASE(nullpointer12); // ticket #2470
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(nullpointer19); // #3811
TEST_CASE(nullpointer20); // #3807 (fp: return p ? (p->x() || p->y()) : z)
TEST_CASE(nullpointer21); // #4038 (fp: if (x) p=q; else return;)
TEST_CASE(nullpointer23); // #4665 (false positive)
TEST_CASE(nullpointer24); // #5082 fp: chained assignment
TEST_CASE(nullpointer25); // #5061
TEST_CASE(nullpointer26); // #3589
TEST_CASE(nullpointer28); // #6491
TEST_CASE(nullpointer30); // #6392
TEST_CASE(nullpointer31); // #8482
TEST_CASE(nullpointer32); // #8460
TEST_CASE(nullpointer_addressOf); // address of
TEST_CASE(nullpointerSwitch); // #2626
TEST_CASE(nullpointer_cast); // #4692
TEST_CASE(nullpointer_castToVoid); // #3771
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(nullpointerSmartPointer);
TEST_CASE(functioncall);
TEST_CASE(functioncalllibrary); // use Library to parse function call
TEST_CASE(functioncallDefaultArguments);
TEST_CASE(nullpointer_internal_error); // #5080
TEST_CASE(ticket6505);
TEST_CASE(subtract);
TEST_CASE(addNull);
TEST_CASE(ctu);
}
void check(const char code[], bool inconclusive = false, const char filename[] = "test.cpp") {
// Clear the error buffer..
errout.str("");
settings.inconclusive = inconclusive;
// Tokenize..
Tokenizer tokenizer(&settings, this);
std::istringstream istr(code);
if (!tokenizer.tokenize(istr, filename))
return;
// Check for null pointer dereferences..
CheckNullPointer checkNullPointer;
checkNullPointer.runChecks(&tokenizer, &settings, this);
}
void checkP(const char code[]) {
// Clear the error buffer..
errout.str("");
settings.inconclusive = false;
// Raw tokens..
std::vector<std::string> files(1, "test.cpp");
std::istringstream istr(code);
const simplecpp::TokenList tokens1(istr, files, files[0]);
// Preprocess..
simplecpp::TokenList tokens2(files);
std::map<std::string, simplecpp::TokenList*> filedata;
simplecpp::preprocess(tokens2, tokens1, files, filedata, simplecpp::DUI());
// Tokenizer..
Tokenizer tokenizer(&settings, this);
tokenizer.createTokens(&tokens2);
tokenizer.simplifyTokens1("");
// Check for null pointer dereferences..
CheckNullPointer checkNullPointer;
checkNullPointer.runChecks(&tokenizer, &settings, this);
}
void nullpointerAfterLoop() {
check("int foo(const Token *tok)\n"
"{\n"
" while (tok);\n"
" tok = tok->next();\n"
"}", true);
ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:4]: (warning, inconclusive) Either the condition 'tok' is redundant or there is possible null pointer dereference: tok.\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:3] -> [test.cpp:6]: (warning, inconclusive) Either the condition 'tok' is redundant or there is possible null pointer dereference: tok.\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"
"}");
ASSERT_EQUALS("[test.cpp:5] -> [test.cpp:3]: (warning) Either the condition 'while' is redundant or there is possible null pointer dereference: tok.\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"
"}");
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"
"}");
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"
"}");
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"
"}");
ASSERT_EQUALS("", errout.str());
// dereference in outer scope..
check("void foo(int x, const Token *tok) {\n"
" if (x == 123) {\n"
" while (tok) tok = tok->next();\n"
" }\n"
" tok->str();\n"
"}\n");
TODO_ASSERT_EQUALS("[test.cpp:5] -> [test.cpp:3]: (warning, inconclusive) Possible null pointer dereference: tok - otherwise it is redundant to check it against null.\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"
"}");
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"
"}", true);
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"
"}", true);
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"
"}", true);
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"
"}");
ASSERT_EQUALS("[test.cpp:4] -> [test.cpp:3]: (warning) Either the condition '!abc' is redundant or there is possible null pointer dereference: abc.\n", errout.str());
check("void foo(struct ABC *abc) {\n"
" bar(abc->a);\n"
" bar(x, abc->a);\n"
" bar(x, y, abc->a);\n"
" if (!abc)\n"
" ;\n"
"}");
ASSERT_EQUALS("[test.cpp:5] -> [test.cpp:2]: (warning) Either the condition '!abc' is redundant or there is possible null pointer dereference: abc.\n"
"[test.cpp:5] -> [test.cpp:3]: (warning) Either the condition '!abc' is redundant or there is possible null pointer dereference: abc.\n"
"[test.cpp:5] -> [test.cpp:4]: (warning) Either the condition '!abc' is redundant or there is possible null pointer dereference: abc.\n", errout.str());
check("void foo(ABC *abc) {\n"
" if (abc->a == 3) {\n"
" return;\n"
" }\n"
" if (abc) {}\n"
"}");
ASSERT_EQUALS("[test.cpp:5] -> [test.cpp:2]: (warning) Either the condition 'if(abc)' is redundant or there is possible null pointer dereference: abc.\n", errout.str());
check("void f(ABC *abc) {\n"
" if (abc->x == 0) {\n"
" return;\n"
" }\n"
" if (!abc);\n"
"}");
ASSERT_EQUALS("[test.cpp:5] -> [test.cpp:2]: (warning) Either the condition '!abc' is redundant or there is possible null pointer dereference: abc.\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"
"}");
TODO_ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:2]: (warning) Possible null pointer dereference: abc - otherwise it is redundant to check it against null.\n", "", errout.str());
check("void foo(ABC *abc) {\n"
" abc->a = 0;\n"
" if (abc && abc->b == 0)\n"
" ;\n"
"}");
ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:2]: (warning) Either the condition 'if(abc&&abc->b==0)' is redundant or there is possible null pointer dereference: abc.\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"
"}");
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"
"}", true);
ASSERT_EQUALS("", errout.str());
check("void f(struct ABC *abc) {\n"
" abc = (ABC *)(abc->_next);\n"
" if (abc) { }"
"}", true);
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"
"}", true);
ASSERT_EQUALS("", errout.str());
check("void foo(struct ABC *abc)\n"
"{\n"
" int a = abc->a;\n"
" f(&abc);\n"
" if (!abc)\n"
" ;\n"
"}", true);
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"
"}");
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"
"}");
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"
"}");
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"
"}");
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 = abc1;\n"
" abc->a = 0;\n"
" do_stuff();\n"
" if (abc) { }\n"
"}");
ASSERT_EQUALS("[test.cpp:5] -> [test.cpp:3]: (warning) Either the condition 'if(abc)' is redundant or there is possible null pointer dereference: abc.\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:4] -> [test.cpp:2]: (warning) Either the condition 'if(abc)' is redundant or there is possible null pointer dereference: abc.\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());
check("void f(ABC *abc) {\n"
" x(def || !abc || y(def, abc->a));\n"
" if (abc) {}\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(ABC *abc) {\n"
" x(abc && y(def, abc->a));\n"
" if (abc) {}\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(ABC *abc) {\n"
" x(def && abc && y(def, 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:3] -> [test.cpp:2]: (warning, inconclusive) Either the condition 'if(fred)' is redundant or there is possible null pointer dereference: fred.\n", errout.str());
}
// #3425 - false positives when there are macros
checkP("#define IF if\n"
"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"
"}");
ASSERT_EQUALS("[test.cpp:4] -> [test.cpp:3]: (warning) Either the condition '!p' is redundant or there is possible null pointer dereference: p.\n", errout.str());
check("void foo(int *p)\n"
"{\n"
" *p = 0;\n"
" if (p) { }\n"
"}");
ASSERT_EQUALS("[test.cpp:4] -> [test.cpp:3]: (warning) Either the condition 'if(p)' is redundant or there is possible null pointer dereference: p.\n", errout.str());
check("void foo(int *p)\n"
"{\n"
" *p = 0;\n"
" if (p || q) { }\n"
"}");
ASSERT_EQUALS("[test.cpp:4] -> [test.cpp:3]: (warning) Either the condition 'if(p||q)' is redundant or there is possible null pointer dereference: p.\n", errout.str());
check("void foo(int *p)\n"
"{\n"
" bar(*p);\n"
" if (!p)\n"
" ;\n"
"}");
ASSERT_EQUALS("[test.cpp:4] -> [test.cpp:3]: (warning) Either the condition '!p' is redundant or there is possible null pointer dereference: p.\n", errout.str());
check("void foo(char *p)\n"
"{\n"
" strcpy(p, \"abc\");\n"
" if (!p)\n"
" ;\n"
"}");
ASSERT_EQUALS("[test.cpp:4] -> [test.cpp:3]: (warning) Either the condition '!p' is redundant or there is possible null pointer dereference: p.\n", errout.str());
check("void foo(char *p)\n"
"{\n"
" if (*p == 0) { }\n"
" if (!p) { }\n"
"}");
ASSERT_EQUALS("[test.cpp:4] -> [test.cpp:3]: (warning) Either the condition '!p' is redundant or there is possible null pointer dereference: p.\n", errout.str());
// no error
check("void foo()\n"
"{\n"
" int *p;\n"
" f(&p);\n"
" if (!p)\n"
" ;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void foo()\n"
"{\n"
" int **p = f();\n"
" if (!p)\n"
" ;\n"
"}", true);
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"
"}");
ASSERT_EQUALS("", errout.str());
check("void foo(int x)\n"
"{\n"
" int a = 2 * x;"
" if (x == 0)\n"
" ;\n"
"}", true);
ASSERT_EQUALS("", errout.str());
check("void foo(int *p)\n"
"{\n"
" int var1 = p ? *p : 0;\n"
" if (!p)\n"
" ;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void foo(int *p)\n"
"{\n"
" int var1 = x ? *p : 5;\n"
" if (!p)\n"
" ;\n"
"}");
ASSERT_EQUALS("[test.cpp:4] -> [test.cpp:3]: (warning) Either the condition '!p' is redundant or there is possible null pointer dereference: p.\n", errout.str());
// while
check("void f(int *p) {\n"
" *p = 0;\n"
" while (p) { p = 0; }\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(int *p) {\n"
" *p = 0;\n"
" while (p) { }\n"
"}");
ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:2]: (warning) Either the condition 'while(p)' is redundant or there is possible null pointer dereference: p.\n", errout.str());
// Ticket #3125
check("void foo(ABC *p)\n"
"{\n"
" int var1 = p ? (p->a) : 0;\n"
" if (!p)\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"
"}");
ASSERT_EQUALS("", errout.str());
check("void f() {\n"
" int * a=0;\n"
" if (!a) {};\n"
" int c = a ? 0 : 1;\n"
"}\n",true);
ASSERT_EQUALS("", errout.str());
// #3686
check("void f() {\n"
" int * a=0;\n"
" if (!a) {};\n"
" int c = a ? b : b+1;\n"
"}\n",true);
ASSERT_EQUALS("", errout.str());
check("void f() {\n"
" int * a=0;\n"
" if (!a) {};\n"
" int c = (a) ? b : b+1;\n"
"}\n",true);
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"
"}");
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:4] -> [test.cpp:2]: (warning) Either the condition 'if(p)' is redundant or there is possible null pointer dereference: p.\n", errout.str());
check("void foo(x *p)\n"
"{\n"
" p = p->next;\n"
" if (!p)\n"
" ;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void foo(x *p)\n"
"{\n"
" p = bar(p->next);\n"
" if (!p)\n"
" ;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void foo(x *p)\n"
"{\n"
" p = aa->bar(p->next);\n"
" if (!p)\n"
" ;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void foo(x *p)\n"
"{\n"
" p = *p2 = p->next;\n"
" if (!p)\n"
" ;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void foo(struct ABC *abc)\n"
"{\n"
" abc = abc ? abc->next : 0;\n"
" if (!abc)\n"
" ;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(struct ABC *abc) {\n" // #4523
" abc = (*abc).next;\n"
" if (abc) { }\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(struct ABC *abc) {\n" // #4523
" abc = (*abc->ptr);\n"
" if (abc) { }\n"
"}");
ASSERT_EQUALS("", errout.str());
check("int f(Item *item) {\n"
" x = item ? ab(item->x) : 0;\n"
" if (item) { }\n"
"}");
ASSERT_EQUALS("", errout.str());
check("int f(Item *item) {\n"
" item->x = 0;\n"
" a = b ? c : d;\n"
" if (item) { }\n"
"}");
ASSERT_EQUALS("[test.cpp:4] -> [test.cpp:2]: (warning) Either the condition 'if(item)' is redundant or there is possible null pointer dereference: item.\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"
"}");
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"
"}");
ASSERT_EQUALS("", errout.str());
// #2525 - sizeof
check("void f() {\n"
" int *test = NULL;\n"
" int c = sizeof(test[0]);\n"
" if (!test)\n"
" ;\n"
"}", true);
ASSERT_EQUALS("", errout.str());
check("void f(type* p) {\n" // #4983
" x(sizeof p[0]);\n"
" if (!p)\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());
// #3425 - false positives when there are macros
checkP("#define IF if\n"
"void f(int *p) {\n"
" *p = 0;\n"
" IF(!p){}\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f() {\n" // #3914 - false positive
" int *p;\n"
" ((p=ret()) && (x=*p));\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"
"}");
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"
"}");
TODO_ASSERT_EQUALS("[test.cpp:8]: (error) Possible null pointer dereference: p\n",
"", errout.str());
check("static void foo() {\n"
" int &r = *0;\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (error) Null pointer dereference\n", errout.str());
check("static void foo(int x) {\n"
" int y = 5 + *0;\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (error) Null pointer dereference\n", errout.str());
{
const char code[] = "static void foo() {\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:3]: (error, inconclusive) Null pointer dereference: abc\n", errout.str());
}
check("static void foo() {\n"
" std::cout << *0;"
"}");
ASSERT_EQUALS("[test.cpp:2]: (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"
"}");
ASSERT_EQUALS("[test.cpp:7]: (error) Null pointer dereference: c\n", errout.str());
check("static void foo() {\n"
" if (3 > *0);\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (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"
"}");
ASSERT_EQUALS("", errout.str());
check("void foo()\n"
"{\n"
" int sz = sizeof((*(struct dummy *)0).x);\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void get_offset(long &offset)\n"
"{\n"
" mystruct * temp; temp = 0;\n"
" offset = (long)(&(temp->z));\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"
"}");
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"
"}");
ASSERT_EQUALS("[test.cpp:12]: (warning) 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"
"}");
ASSERT_EQUALS("[test.cpp:5]: (error) Null pointer dereference: f\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"
"}");
ASSERT_EQUALS("[test.cpp:4]: (error) 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"
"}", true);
ASSERT_EQUALS("", errout.str());
// ticket #2251: taking the address of member
check("void f() {\n"
" Fred *fred = 0;\n"
" int x = &fred->x;\n"
"}", true);
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"
"}", true);
ASSERT_EQUALS("", errout.str());
check("void f() {\n"
" int *p = NULL;\n"
" if (x)\n"
" p = q;\n"
" if (!p || *p) { }\n"
"}", true);
ASSERT_EQUALS("", errout.str());
check("void f() {\n"
" int *p = NULL;\n"
" if (x)\n"
" p = q;\n"
" if (p || *p) { }\n"
"}");
ASSERT_EQUALS("[test.cpp:5] -> [test.cpp:5]: (warning) Either the condition 'p' is redundant or there is possible null pointer dereference: p.\n", errout.str());
}
// ticket #8831 - FP triggered by if/return/else sequence
{
check("void f(int *p, int *q) {\n"
" if (p == NULL)\n"
" return;\n"
" else if (q == NULL)\n"
" return;\n"
" *q = 0;\n"
"}\n"
"\n"
"void g() {\n"
" f(NULL, NULL);\n"
"}", true);
ASSERT_EQUALS("", errout.str());
}
}
// Ticket #2350
void nullpointerExecutionPathsLoop() {
// No false positive:
check("void foo() {\n"
" int n;\n"
" int *argv32 = p;\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"
"}");
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"
"}");
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]: (warning) Possible null pointer dereference: p\n", errout.str());
}
void nullpointer7() {
check("void foo()\n"
"{\n"
" wxLongLong x = 0;\n"
" int y = x.GetValue();\n"
"}", true);
ASSERT_EQUALS("", errout.str());
}
void nullpointer9() { //#ticket 1778
check("void foo()\n"
"{\n"
" std::string * x = 0;\n"
" *x = \"test\";\n"
"}");
ASSERT_EQUALS("[test.cpp:4]: (error) Null pointer dereference: x\n", errout.str());
}
void nullpointer10() {
check("void foo()\n"
"{\n"
" struct my_type* p = 0;\n"
" p->x = 0;\n"
"}");
ASSERT_EQUALS("[test.cpp:4]: (error) Null pointer dereference: p\n", errout.str());
}
void nullpointer11() { // ticket #2812
check("int foo()\n"
"{\n"
" struct my_type* p;\n"
" p = 0;\n"
" return p->x;\n"
"}");
ASSERT_EQUALS("[test.cpp:5]: (error) Null pointer dereference: p\n", errout.str());
}
void nullpointer12() { // ticket #2470, #4035
const char code[] = "int foo()\n"
"{\n"
" int* i = nullptr;\n"
" return *i;\n"
"}\n";
check(code, false, "test.cpp"); // C++ file => nullptr means NULL
ASSERT_EQUALS("[test.cpp:4]: (error) Null pointer dereference: i\n", errout.str());
check(code, false, "test.c"); // C file => nullptr does not mean NULL
ASSERT_EQUALS("", errout.str());
}
void nullpointer15() { // #3560
check("void f() {\n"
" char *p = 0;\n"
" if (x) p = \"abcd\";\n"
" return p ? f(*p) : f(0);\n"
"}");
ASSERT_EQUALS("", errout.str());
}
void nullpointer16() { // #3591
check("void foo() {\n"
" int *p = 0;\n"
" bar(&p);\n"
" *p = 0;\n"
"}", true);
ASSERT_EQUALS("", errout.str());
}
void nullpointer17() { // #3567
check("int foo() {\n"
" int *p = 0;\n"
" if (x) { return 0; }\n"
" return !p || *p;\n"
"}", true);
ASSERT_EQUALS("", errout.str());
check("int foo() {\n"
" int *p = 0;\n"
" if (x) { return 0; }\n"
" return p && *p;\n"
"}", true);
ASSERT_EQUALS("", errout.str());
}
void nullpointer18() { // #1927
check("void f ()\n"
"{\n"
" int i=0;\n"
" char *str=NULL;\n"
" while (str[i])\n"
" {\n"
" i++;\n"
" };\n"
"}");
ASSERT_EQUALS("[test.cpp:5]: (error) Null pointer dereference: str\n", errout.str());
}
void nullpointer19() { // #3811
check("int foo() {\n"
" perror(0);\n"
"}", true);
ASSERT_EQUALS("", errout.str());
}
void nullpointer20() { // #3807
check("void f(int x) {\n"
" struct xy *p = 0;\n"
" if (x) p = q;\n"
" if (p ? p->x || p->y : 0) { }\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(int x) {\n" // false negative
" struct xy *p = 0;\n"
" if (x) p = q;\n"
" if (y ? p->x : p->y) { }\n"
"}");
ASSERT_EQUALS("[test.cpp:4]: (warning) Possible null pointer dereference: p\n", errout.str());
}
void nullpointer21() { // #4038 - fp: if (x) p=q; else return;
check("void f(int x) {\n"
" int *p = 0;\n"
" if (x) p = q;\n"
" else return;\n"
" *p = 0;\n" // <- p is not NULL
"}");
ASSERT_EQUALS("", errout.str());
}
void nullpointer23() { // #4665
check("void f(){\n"
" char *c = NULL;\n"
" char cBuf[10];\n"
" sprintf(cBuf, \"%s\", c ? c : \"0\" );\n"
"}");
ASSERT_EQUALS("",errout.str());
}
void nullpointer24() { // #5083 - fp: chained assignment
check("void f(){\n"
" char *c = NULL;\n"
" x = c = new char[10];\n"
" *c = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
}
void nullpointer25() { // #5061
check("void f(int *data, int i)\n"
"{\n"
" int *array = NULL;\n"
" if (data == 1 && array[i] == 0)\n"
" std::cout << \"test\";\n"
"}");
ASSERT_EQUALS("[test.cpp:4]: (error) Null pointer dereference: array\n", errout.str());
}
void nullpointer26() { // #3589
check("double foo() {\n"
" sk *t1 = foo();\n"
" sk *t2 = foo();\n"
" if ((!t1) && (!t2))\n"
" return 0.0;\n"
" if (t1 && (!t2))\n"
" return t1->Inter();\n"
" if (t2->GetT() == t)\n"
" return t2->Inter();\n"
" if (t2 && (!t1))\n"
" return 0.0;\n"
" return 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
}
void nullpointer28() { // #6491
check("typedef struct { int value; } S;\n"
"int f(const S *s) { \n"
" int i = s ? s->value + 1 \n"
" : s->value - 1; // <-- null ptr dereference \n"
" return i;\n"
"}\n");
TODO_ASSERT_EQUALS("[test.cpp:4]: (warning) Possible null pointer dereference: s\n", "", errout.str());
}
void nullpointer30() { // #6392
check("void f(std::vector<std::string> *values)\n"
"{\n"
" values->clear();\n"
" if (values) \n"
" {\n"
" for (int i = 0; i < values->size(); ++i)\n"
" {\n"
" values->push_back(\"test\");\n"
" }\n"
" }\n"
"}\n", true);
ASSERT_EQUALS("[test.cpp:4] -> [test.cpp:3]: (warning, inconclusive) Either the condition 'if(values)' is redundant or there is possible null pointer dereference: values.\n", errout.str());
}
void nullpointer31() { // #8482
check("struct F\n"
"{\n"
" int x;\n"
"};\n"
" \n"
"static void foo(F* f)\n"
"{\n"
" if( f ) {}\n"
" else { return; }\n"
" (void)f->x;\n"
"}\n", true);
ASSERT_EQUALS("", errout.str());
}
void nullpointer32() { // #8460
check("int f(int * ptr) {\n"
" if(ptr)\n"
" { return 0;}\n"
" else{\n"
" int *p1 = ptr;\n"
" return *p1;\n"
" }\n"
"}\n", true);
ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:6]: (warning) Either the condition 'ptr' is redundant or there is possible null pointer dereference: p1.\n", errout.str());
}
void nullpointer_addressOf() { // address of
check("void f() {\n"
" struct X *x = 0;\n"
" if (addr == &x->y) {}\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f() {\n"
" struct X *x = 0;\n"
" if (addr == &x->y.z[0]) {}\n"
"}");
ASSERT_EQUALS("", errout.str());
}
void nullpointerSwitch() { // #2626
check("char *f(int x) {\n"
" char *p = do_something();\n"
" switch (x) {\n"
" case 1:\n"
" p = 0;\n"
" case 2:\n"
" *p = 0;\n"
" break;\n"
" }\n"
" return p;\n"
"}", true);
ASSERT_EQUALS("[test.cpp:7]: (warning) Possible null pointer dereference: p\n", errout.str());
}
void nullpointer_cast() { // #4692
check("char *nasm_skip_spaces(const char *p) {\n"
" if (p)\n"
" while (*p && nasm_isspace(*p))\n"
" p++;\n"
" return p;\n"
"}");
ASSERT_EQUALS("", errout.str());
}
void nullpointer_castToVoid() { // #3771
check("void f () {\n"
" int *buf; buf = NULL;\n"
" buf;\n"
"}", true);
ASSERT_EQUALS("", 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"
"}");
ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:4]: (warning) Either the condition '!p' is redundant or there is possible null pointer dereference: p.\n", errout.str());
check("void foo(char *p) {\n"
" if (p && *p == 0) {\n"
" }\n"
" printf(\"%c\", *p);\n"
"}");
ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:4]: (warning) Either the condition 'p' is redundant or there is possible null pointer dereference: p.\n", errout.str());
check("void foo(char *p) {\n"
" if (p && *p == 0) {\n"
" } else { *p = 0; }\n"
"}");
ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (warning) Either the condition 'p' is redundant or there is possible null pointer dereference: p.\n", errout.str());
check("void foo(char *p) {\n"
" if (p) {\n"
" }\n"
" strcpy(p, \"abc\");\n"
"}");
ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:4]: (warning) Either the condition 'p' is redundant or there is possible null pointer dereference: p.\n", errout.str());
check("void foo(char *p) {\n"
" if (p) {\n"
" }\n"
" bar();\n"
" strcpy(p, \"abc\");\n"
"}");
ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:5]: (warning) Either the condition 'p' is redundant or there is possible null pointer dereference: p.\n", errout.str());
check("void foo(abc *p) {\n"
" if (!p) {\n"
" }\n"
" else { if (!p->x) {\n"
" } }\n"
"}");
ASSERT_EQUALS("", errout.str());
{
static const char code[] =
"void foo(char *p) {\n"
" if (!p) {\n"
" abort();\n"
" }\n"
" *p = 0;\n"
"}";
check(code, false);
ASSERT_EQUALS("", errout.str());
check(code, true);
ASSERT_EQUALS("", errout.str());
}
check("void foo(char *p) {\n"
" if (!p) {\n"
" (*bail)();\n"
" }\n"
" *p = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void foo(char *p) {\n"
" if (!p) {\n"
" throw x;\n"
" }\n"
" *p = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void foo(char *p) {\n"
" if (!p) {\n"
" ab.abort();\n"
" }\n"
" *p = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void foo(char *p) {\n"
" if (!p) {\n"
" switch (x) { }\n"
" }\n"
"}", true);
ASSERT_EQUALS("", errout.str());
check("void foo(char *p) {\n"
" if (!p) {\n"
" }\n"
" return *x;\n"
"}", true);
ASSERT_EQUALS("", errout.str());
check("int foo(int *p) {\n"
" if (!p) {\n"
" x = *p;\n"
" return 5+*p;\n"
" }\n"
"}");
ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (warning) Either the condition '!p' is redundant or there is possible null pointer dereference: p.\n"
"[test.cpp:2] -> [test.cpp:4]: (warning) Either the condition '!p' is redundant or there is possible null pointer dereference: p.\n", errout.str());
// operator!
check("void f() {\n"
" A a;\n"
" if (!a) {\n"
" a.x();\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"
"}");
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"
"}");
ASSERT_EQUALS("", errout.str());
// ticket #1219
check("void foo(char *p) {\n"
" if (p) {\n"
" return;\n"
" }\n"
" *p = 0;\n"
"}");
ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:5]: (warning) Either the condition 'p' is redundant or there is possible null pointer dereference: p.\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());
// #4118 - second if
check("void f(char *p) {\n"
" int x = 1;\n"
" if (!p) x = 0;\n"
" if (x) *p = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
// #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"
"}", true);
ASSERT_EQUALS("", errout.str());
check("void test(int *i) {\n"
" if(i == NULL) { }\n"
" else {\n"
" int b = *i;\n"
" }\n"
"}", true);
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"
"}", true);
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"
"}", true);
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"
"}", true);
ASSERT_EQUALS("", errout.str());
check("int foo(struct Fred *fred) {\n"
" if (fred) { }\n"
" return fred->a;\n"
"}");
ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (warning) Either the condition 'fred' is redundant or there is possible null pointer dereference: fred.\n", errout.str());
// #2789 - assign and check pointer
check("void f() {\n"
" char *p; p = x();\n"
" if (!p) { }\n"
" *p = 0;\n"
"}");
ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:4]: (warning) Either the condition '!p' is redundant or there is possible null pointer dereference: p.\n", errout.str());
// check, assign and use
check("void f() {\n"
" char *p;\n"
" if (p == 0 && (p = malloc(10)) != 0) {\n"
" *p = 0;\n"
" }\n"
"}");
ASSERT_EQUALS("", errout.str());
// check, assign and use
check("void f() {\n"
" char *p;\n"
" if (p == 0 && (p = malloc(10)) != a && (*p = a)) {\n"
" *p = 0;\n"
" }\n"
"}");
ASSERT_EQUALS("", errout.str());
// check, and use
check("void f() {\n"
" char *p;\n"
" if (p == 0 && (*p = 0)) {\n"
" return;\n"
" }\n"
"}");
ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:3]: (warning) Either the condition 'p==0' is redundant or there is possible null pointer dereference: p.\n", errout.str());
// check, and use
check("void f() {\n"
" struct foo *p;\n"
" if (p == 0 && p->x == 10) {\n"
" return;\n"
" }\n"
"}");
ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:3]: (warning) Either the condition 'p==0' is redundant or there is possible null pointer dereference: p.\n", errout.str());
// check, and use
check("void f() {\n"
" struct foo *p;\n"
" if (p == 0 || p->x == 10) {\n"
" return;\n"
" }\n"
"}");
ASSERT_EQUALS("", errout.str());
// check, and use
check("void f() {\n"
" char *p; p = malloc(10);\n"
" if (p == NULL && (*p = a)) {\n"
" return;\n"
" }\n"
"}");
ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:3]: (warning) Either the condition 'p==NULL' is redundant or there is possible null pointer dereference: p.\n", errout.str());
// check, and use
check("void f(struct X *p, int x) {\n"
" if (!p && x==1 || p && p->x==0) {\n"
" return;\n"
" }\n"
"}");
ASSERT_EQUALS("", errout.str());
{
const char code[] = "void f(Fred *fred) {\n"
" if (fred == NULL) { }\n"
" fred->x();\n"
"}";
check(code, false); // non-inconclusive
ASSERT_EQUALS("", errout.str());
check(code, true); // inconclusive
ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (warning, inconclusive) Either the condition 'fred==NULL' is redundant or there is possible null pointer dereference: fred.\n", errout.str());
}
check("void f(char *s) {\n" // #3358
" if (s==0);\n"
" strcpy(a, s?b:c);\n"
"}");
ASSERT_EQUALS("", errout.str());
// sizeof
check("void f(struct fred_t *fred) {\n"
" if (!fred)\n"
" int sz = sizeof(fred->x);\n"
"}", true);
ASSERT_EQUALS("", errout.str());
// check in macro
check("void f(int *x) {\n"
" $if (!x) {}\n"
" *x = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
// return ?:
check("int f(ABC *p) {\n" // FP : return ?:
" if (!p) {}\n"
" return p ? p->x : 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("int f(ABC *p) {\n" // no fn
" if (!p) {}\n"
" return q ? p->x : 0;\n"
"}");
ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (warning) Either the condition '!p' is redundant or there is possible null pointer dereference: p.\n", errout.str());
check("int f(ABC *p) {\n" // FP : return &&
" if (!p) {}\n"
" return p && p->x;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(int x, int *p) {\n"
" if (x || !p) {}\n"
" *p = 0;\n"
"}");
ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (warning) Either the condition '!p' is redundant or there is possible null pointer dereference: p.\n", errout.str());
// sizeof
check("void f() {\n"
" int *pointer = NULL;\n"
" pointer = func(sizeof pointer[0]);\n"
"}");
ASSERT_EQUALS("", errout.str());
}
// Test CheckNullPointer::nullConstantDereference
void nullConstantDereference() {
check("void f() {\n"
" int* p = 0;\n"
" return p[4];\n"
"}");
ASSERT_EQUALS("[test.cpp:3]: (error) Null pointer dereference: p\n", errout.str());
check("void f() {\n"
" typeof(*NULL) y;\n"
"}", true);
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"
"}", true);
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());
}
void printf_with_invalid_va_argument() {
check("void f() {\n"
" printf(\"%s\", 0);\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (error) Null pointer dereference\n", errout.str());
check("void f(char* s) {\n"
" printf(\"%s\", s);\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f() {\n"
" char* s = 0;\n"
" printf(\"%s\", s);\n"
"}");
ASSERT_EQUALS("[test.cpp:3]: (error) Null pointer dereference: s\n", errout.str());
check("void f() {\n"
" char *s = 0;\n"
" printf(\"%s\", s == 0 ? a : s);\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f() {\n"
" printf(\"%u%s\", 0, 0);\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (error) Null pointer dereference\n", errout.str());
check("void f(char* s) {\n"
" printf(\"%u%s\", 0, s);\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f() {\n"
" char* s = 0;\n"
" printf(\"%u%s\", 123, s);\n"
"}");
ASSERT_EQUALS("[test.cpp:3]: (error) Null pointer dereference: s\n", errout.str());
check("void f() {\n"
" printf(\"%%%s%%\", 0);\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (error) Null pointer dereference\n", errout.str());
check("void f(char* s) {\n"
" printf(\"text: %s, %s\", s, 0);\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (error) Null pointer dereference\n", errout.str());
check("void f() {\n"
" char* s = \"blabla\";\n"
" printf(\"%s\", s);\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(char* s) {\n"
" printf(\"text: %m%s, %s\", s, 0);\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (error) Null pointer dereference\n", errout.str());
check("void f(char* s) {\n"
" printf(\"text: %*s, %s\", s, 0);\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (error) Null pointer dereference\n", errout.str());
// Ticket #3364
check("void f() {\n"
" printf(\"%-*.*s\", s, 0);\n"
" sprintf(\"%*\", s);\n"
"}");
ASSERT_EQUALS("", errout.str());
}
void scanf_with_invalid_va_argument() {
check("void f(char* s) {\n"
" sscanf(s, \"%s\", 0);\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (error) Null pointer dereference\n", errout.str());
check("void f() {\n"
" scanf(\"%d\", 0);\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (error) Null pointer dereference\n", errout.str());
check("void f(char* foo) {\n"
" char location[200];\n"
" int width, height;\n"
" sscanf(imgInfo, \"%s %d %d\", location, &width, &height);\n"
"}");
ASSERT_EQUALS("", errout.str()); // ticket #3207
check("void f(char *dummy) {\n"
" int iVal;\n"
" sscanf(dummy, \"%d%c\", &iVal);\n"
"}");
ASSERT_EQUALS("", errout.str()); // ticket #3211
check("void f(char *dummy) {\n"
" int* iVal = 0;\n"
" sscanf(dummy, \"%d\", iVal);\n"
"}");
ASSERT_EQUALS("[test.cpp:3]: (error) Null pointer dereference: iVal\n", errout.str());
check("void f(char *dummy) {\n"
" int* iVal;\n"
" sscanf(dummy, \"%d\", foo(iVal));\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(char *dummy) {\n"
" int* iVal = 0;\n"
" sscanf(dummy, \"%d%d\", foo(iVal), iVal);\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(char* dummy) {\n"
" sscanf(dummy, \"%*d%u\", 0);\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (error) Null pointer dereference\n", errout.str());
}
void nullpointer_in_return() {
check("int foo() {\n"
" int* iVal = 0;\n"
" if(g()) iVal = g();\n"
" return iVal[0];\n"
"}");
ASSERT_EQUALS("[test.cpp:4]: (warning) Possible null pointer dereference: iVal\n", errout.str());
check("int foo(int* iVal) {\n"
" return iVal[0];\n"
"}", true);
ASSERT_EQUALS("", errout.str());
}
void nullpointer_in_typeid() {
// Should throw std::bad_typeid
check("struct PolymorphicA { virtual ~A() {} };\n"
"bool foo() {\n"
" PolymorphicA* a = 0;\n"
" return typeid(*a) == typeid(*a);\n"
"}", true);
ASSERT_EQUALS("", errout.str());
check("struct NonPolymorphicA { ~A() {} };\n"
"bool foo() {\n"
" NonPolymorphicA* a = 0;\n"
" return typeid(*a) == typeid(*a);\n"
"}", true);
ASSERT_EQUALS("", errout.str());
check("bool foo() {\n"
" char* c = 0;\n"
" return typeid(*c) == typeid(*c);\n"
"}", true);
ASSERT_EQUALS("", errout.str());
}
void nullpointer_in_for_loop() {
// Ticket #3278
check("void f(int* ptr, int cnt){\n"
" if (!ptr)\n"
" cnt = 0;\n"
" for (int i = 0; i < cnt; ++i)\n"
" *ptr++ = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
}
void nullpointerDelete() {
check("void f() {\n"
" K *k = getK();\n"
" if (k)\n"
" k->doStuff();\n"
" delete k;\n"
"}\n", true);
ASSERT_EQUALS("", errout.str());
check("void f() {\n"
" K *k = getK();\n"
" if (k)\n"
" k[0] = ptr;\n"
" delete [] k;\n"
" k = new K[10];\n"
"}\n", true);
ASSERT_EQUALS("", errout.str());
}
void nullpointerExit() {
check("void f() {\n"
" K *k = getK();\n"
" if (!k)\n"
" exit(1);\n"
" k->f();\n"
"}\n", true);
ASSERT_EQUALS("", errout.str());
}
void nullpointerStdString() {
check("void f(std::string s1) {\n"
" void* p = 0;\n"
" s1 = 0;\n"
" s1 = '\\0';\n"
" std::string s2 = 0;\n"
" std::string s2 = '\\0';\n"
" std::string s3(0);\n"
" foo(std::string(0));\n"
" s1 = p;\n"
" std::string s4 = p;\n"
" std::string s5(p);\n"
" foo(std::string(p));\n"
"}", true);
ASSERT_EQUALS("[test.cpp:9]: (error) Null pointer dereference: p\n"
"[test.cpp:10]: (error) Null pointer dereference: p\n"
"[test.cpp:11]: (error) Null pointer dereference: p\n"
"[test.cpp:12]: (warning, inconclusive) Possible null pointer dereference: p\n"
"[test.cpp:3]: (error) Null pointer dereference\n"
"[test.cpp:5]: (error) Null pointer dereference\n"
"[test.cpp:7]: (error) Null pointer dereference\n"
"[test.cpp:8]: (error) Null pointer dereference\n"
, errout.str());
check("void f(std::string s1) {\n"
" s1 = nullptr;\n"
" std::string s2 = nullptr;\n"
" std::string s3(nullptr);\n"
" foo(std::string(nullptr));\n"
"}", true);
ASSERT_EQUALS("[test.cpp:2]: (error) Null pointer dereference\n"
"[test.cpp:3]: (error) Null pointer dereference\n"
"[test.cpp:4]: (error) Null pointer dereference\n"
"[test.cpp:5]: (error) Null pointer dereference\n"
, errout.str());
check("void f(std::string s1) {\n"
" s1 = NULL;\n"
" std::string s2 = NULL;\n"
" std::string s3(NULL);\n"
" foo(std::string(NULL));\n"
"}", true);
ASSERT_EQUALS("[test.cpp:2]: (error) Null pointer dereference\n"
"[test.cpp:3]: (error) Null pointer dereference\n"
"[test.cpp:4]: (error) Null pointer dereference\n"
"[test.cpp:5]: (error) Null pointer dereference\n"
, errout.str());
check("void f(std::string s1, const std::string& s2, const std::string* s3) {\n"
" void* p = 0;\n"
" if (x) { return; }\n"
" foo(s1 == p);\n"
" foo(s2 == p);\n"
" foo(s3 == p);\n"
" foo(p == s1);\n"
" foo(p == s2);\n"
" foo(p == s3);\n"
"}", true);
ASSERT_EQUALS("[test.cpp:4]: (error) Null pointer dereference: p\n"
"[test.cpp:5]: (error) Null pointer dereference: p\n"
"[test.cpp:7]: (error) Null pointer dereference: p\n"
"[test.cpp:8]: (error) Null pointer dereference: p\n", errout.str());
check("void f(std::string s1, const std::string& s2, const std::string* s3) {\n"
" void* p = 0;\n"
" if (x) { return; }\n"
" foo(0 == s1.size());\n"
" foo(0 == s2.size());\n"
" foo(0 == s3->size());\n"
" foo(s1.size() == 0);\n"
" foo(s2.size() == 0);\n"
" foo(s3->size() == 0);\n"
"}", true);
ASSERT_EQUALS("", errout.str());
check("void f(std::string s1, const std::string& s2) {\n"
" if (x) { return; }\n"
" foo(0 == s1[0]);\n"
" foo(0 == s2[0]);\n"
" foo(s1[0] == 0);\n"
" foo(s2[0] == 0);\n"
"}", true);
ASSERT_EQUALS("", errout.str());
check("void f(std::string s1, const std::string& s2) {\n"
" if (x) { return; }\n"
" foo(s1 == '\\0');\n"
" foo(s2 == '\\0');\n"
" foo('\\0' == s1);\n"
" foo('\\0' == s2);\n"
"}", true);
ASSERT_EQUALS("", errout.str());
check("class Bar {\n"
" std::string s;\n"
" Bar() : s(0) {}\n"
"};\n"
"class Foo {\n"
" std::string s;\n"
" Foo();\n"
"};\n"
"Foo::Foo() : s(0) {}");
ASSERT_EQUALS("[test.cpp:3]: (error) Null pointer dereference\n"
"[test.cpp:9]: (error) Null pointer dereference\n", errout.str());
check("void f() {\n"
" std::string s = 0 == x ? \"a\" : \"b\";\n"
"}", true);
ASSERT_EQUALS("", errout.str());
check("void f() {\n"
" const std::string s = g();\n"
" ASSERT_MESSAGE(\"Error on s\", 0 == s.compare(\"Some text\"));\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void foo(int i, std::string s);\n"
"void bar() {\n"
" foo(0, \"\");\n"
" foo(0, 0);\n"
" foo(var, 0);\n"
" foo(var, NULL);\n"
" foo(var, nullptr);\n"
" foo(0, var);\n"
"}");
ASSERT_EQUALS("[test.cpp:4]: (error) Null pointer dereference\n"
"[test.cpp:5]: (error) Null pointer dereference\n"
"[test.cpp:6]: (error) Null pointer dereference\n"
"[test.cpp:7]: (error) Null pointer dereference\n", errout.str());
}
void nullpointerStdStream() {
check("void f(std::ifstream& is) {\n"
" char* p = 0;\n"
" is >> p;\n"
"}");
TODO_ASSERT_EQUALS("[test.cpp:3]: (error) Possible null pointer dereference: p\n", "", errout.str());
check("void f(const std::ostringstream& oss, char* q) {\n"
" char const* p = 0;\n" // Simplification makes detection of bug difficult
" oss << p;\n"
" oss << foo << p;\n"
" if(q == 0)\n"
" oss << foo << q;\n"
"}", false);
ASSERT_EQUALS("[test.cpp:3]: (error) Null pointer dereference: p\n"
"[test.cpp:4]: (error) Null pointer dereference: p\n"
"[test.cpp:5] -> [test.cpp:6]: (warning) Either the condition 'q==0' is redundant or there is possible null pointer dereference: q.\n", errout.str());
check("void f(const char* p) {\n"
" if(p == 0) {\n"
" std::cout << p;\n"
" std::cerr << p;\n"
" std::cin >> p;\n"
" std::cout << abc << p;\n"
" }\n"
"}", false);
TODO_ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (warning) Either the condition 'p==0' is redundant or there is possible null pointer dereference: p.\n"
"[test.cpp:2] -> [test.cpp:4]: (warning) Either the condition 'p==0' is redundant or there is possible null pointer dereference: p.\n"
"[test.cpp:2] -> [test.cpp:5]: (warning) Either the condition 'p==0' is redundant or there is possible null pointer dereference: p.\n"
"[test.cpp:2] -> [test.cpp:6]: (warning) Either the condition 'p==0' is redundant or there is possible null pointer dereference: p.\n",
"[test.cpp:2] -> [test.cpp:3]: (warning) Either the condition 'p==0' is redundant or there is possible null pointer dereference: p.\n"
"[test.cpp:2] -> [test.cpp:4]: (warning) Either the condition 'p==0' is redundant or there is possible null pointer dereference: p.\n",
errout.str());
check("void f() {\n"
" void* p1 = 0;\n"
" std::cout << p1;\n" // No char*
" char* p2 = 0;\n"
" std::cin >> (int)p;\n" // result casted
" std::cout << (int)p;\n"
"}", true);
ASSERT_EQUALS("", errout.str());
check("void f(const std::string& str) {\n"
" long long ret = 0;\n"
" std::istringstream istr(str);\n"
" istr >> std::hex >> ret;\n" // Read integer
" return ret;\n"
"}", true);
ASSERT_EQUALS("", errout.str());
check("void f(int* i) {\n"
" if(i) return;\n"
" std::cout << i;\n" // Its no char* (#4240)
"}", true);
ASSERT_EQUALS("", errout.str());
// #5811 false positive: (error) Null pointer dereference
check("using namespace std;\n"
"std::string itoip(int ip) {\n"
" stringstream out;\n"
" out << ((ip >> 0) & 0xFF);\n"
" return out.str();\n"
"}n", true);
ASSERT_EQUALS("", errout.str());
// avoid regression from first fix attempt for #5811...
check("void deserialize(const std::string &data) {\n"
"std::istringstream iss(data);\n"
"unsigned int len = 0;\n"
"if (!(iss >> len))\n"
" return;\n"
"}\n", true);
ASSERT_EQUALS("", errout.str());
}
void nullpointerSmartPointer() {
check("struct Fred { int x; };\n"
"void f(std::shared_ptr<Fred> p) {\n"
" if (p) {}\n"
" dostuff(p->x);\n"
"}\n");
ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:4]: (warning) Either the condition 'p' is redundant or there is possible null pointer dereference: p.\n", errout.str());
check("struct Fred { int x; };\n"
"void f(std::shared_ptr<Fred> p) {\n"
" p = nullptr;\n"
" dostuff(p->x);\n"
"}\n");
ASSERT_EQUALS("[test.cpp:4]: (error) Null pointer dereference: p\n", errout.str());
check("struct Fred { int x; };\n"
"void f(std::unique_ptr<Fred> p) {\n"
" if (p) {}\n"
" dostuff(p->x);\n"
"}\n");
ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:4]: (warning) Either the condition 'p' is redundant or there is possible null pointer dereference: p.\n", errout.str());
check("struct Fred { int x; };\n"
"void f(std::unique_ptr<Fred> p) {\n"
" p = nullptr;\n"
" dostuff(p->x);\n"
"}\n");
ASSERT_EQUALS("[test.cpp:4]: (error) Null pointer dereference: p\n", errout.str());
check("struct Fred { int x; };\n"
"void f() {\n"
" std::shared_ptr<Fred> p;\n"
" dostuff(p->x);\n"
"}\n");
ASSERT_EQUALS("[test.cpp:4]: (error) Null pointer dereference: p\n", errout.str());
check("struct Fred { int x; };\n"
"void f(std::shared_ptr<Fred> p) {\n"
" p.reset();\n"
" dostuff(p->x);\n"
"}\n");
ASSERT_EQUALS("[test.cpp:4]: (error) Null pointer dereference: p\n", errout.str());
check("struct Fred { int x; };\n"
"void f(std::shared_ptr<Fred> p) {\n"
" Fred * pp = nullptr;\n"
" p.reset(pp);\n"
" dostuff(p->x);\n"
"}\n");
ASSERT_EQUALS("[test.cpp:5]: (error) Null pointer dereference: p\n", errout.str());
check("struct Fred { int x; };\n"
"void f(Fred& f) {\n"
" std::shared_ptr<Fred> p;\n"
" p.reset(&f);\n"
" dostuff(p->x);\n"
"}\n");
ASSERT_EQUALS("", errout.str());
check("struct Fred { int x; };\n"
"void f(std::shared_ptr<Fred> p) {\n"
" p.release();\n"
" dostuff(p->x);\n"
"}\n");
ASSERT_EQUALS("[test.cpp:4]: (error) Null pointer dereference: p\n", errout.str());
check("struct Fred { int x; };\n"
"void f() {\n"
" std::shared_ptr<Fred> p(nullptr);\n"
" dostuff(p->x);\n"
"}\n");
ASSERT_EQUALS("[test.cpp:4]: (error) Null pointer dereference: p\n", errout.str());
check("struct A {};\n"
"void f(int n) {\n"
" std::unique_ptr<const A*[]> p;\n"
" p.reset(new const A*[n]);\n"
"}\n");
ASSERT_EQUALS("", errout.str());
}
void functioncall() { // #3443 - function calls
// dereference pointer and then check if it's null
{
// function not seen
check("void f(int *p) {\n"
" *p = 0;\n"
" foo(p);\n"
" if (p) { }\n"
"}");
ASSERT_EQUALS("", errout.str());
// function seen (taking pointer parameter)
check("void foo(int *p) { }\n"
"\n"
"void f(int *p) {\n"
" *p = 0;\n"
" foo(p);\n"
" if (p) { }\n"
"}");
ASSERT_EQUALS("[test.cpp:6] -> [test.cpp:4]: (warning) Either the condition 'if(p)' is redundant or there is possible null pointer dereference: p.\n", errout.str());
// function seen (taking reference parameter)
check("void foo(int *&p) { }\n"
"\n"
"void f(int *p) {\n"
" *p = 0;\n"
" foo(p);\n"
" if (p) { }\n"
"}", true);
ASSERT_EQUALS("", errout.str());
// function implementation not seen
check("void foo(int *p);\n"
"\n"
"void f(int *p) {\n"
" *p = 0;\n"
" foo(p);\n"
" if (p) { }\n"
"}");
ASSERT_EQUALS("[test.cpp:6] -> [test.cpp:4]: (warning) Either the condition 'if(p)' is redundant or there is possible null pointer dereference: p.\n", errout.str());
// inconclusive
check("void f(int *p) {\n"
" *p = 0;\n"
" foo(p);\n"
" if (p) { }\n"
"}", true);
ASSERT_EQUALS("[test.cpp:4] -> [test.cpp:2]: (warning, inconclusive) Either the condition 'if(p)' is redundant or there is possible null pointer dereference: p.\n", errout.str());
}
// dereference struct pointer and then check if it's null
{
// function not seen
check("void f(struct ABC *abc) {\n"
" abc->a = 0;\n"
" foo(abc);\n"
" if (abc) { }\n"
"}");
ASSERT_EQUALS("", errout.str());
// function seen (taking pointer parameter)
check("void foo(struct ABC *abc) { }\n"
"\n"
"void f(struct ABC *abc) {\n"
" abc->a = 0;\n"
" foo(abc);\n"
" if (abc) { }\n"
"}");
ASSERT_EQUALS("[test.cpp:6] -> [test.cpp:4]: (warning) Either the condition 'if(abc)' is redundant or there is possible null pointer dereference: abc.\n", errout.str());
// function implementation not seen
check("void foo(struct ABC *abc);\n"
"\n"
"void f(struct ABC *abc) {\n"
" abc->a = 0;\n"
" foo(abc);\n"
" if (abc) { }\n"
"}");
ASSERT_EQUALS("[test.cpp:6] -> [test.cpp:4]: (warning) Either the condition 'if(abc)' is redundant or there is possible null pointer dereference: abc.\n", errout.str());
// inconclusive
check("void f(struct ABC *abc) {\n"
" abc->a = 0;\n"
" foo(abc);\n"
" if (abc) { }\n"
"}", true);
ASSERT_EQUALS("[test.cpp:4] -> [test.cpp:2]: (warning, inconclusive) Either the condition 'if(abc)' is redundant or there is possible null pointer dereference: abc.\n", errout.str());
}
}
void functioncalllibrary() {
Settings settings1;
Tokenizer tokenizer(&settings1,this);
std::istringstream code("void f() { int a,b,c; x(a,b,c); }");
tokenizer.tokenize(code,"test.c");
const Token *xtok = Token::findsimplematch(tokenizer.tokens(), "x");
// nothing bad..
{
Library library;
Library::ArgumentChecks arg;
library.functions["x"].argumentChecks[1] = arg;
library.functions["x"].argumentChecks[2] = arg;
library.functions["x"].argumentChecks[3] = arg;
std::list<const Token *> null;
CheckNullPointer::parseFunctionCall(*xtok, null, &library);
ASSERT_EQUALS(0U, null.size());
}
// for 1st parameter null pointer is not ok..
{
Library library;
Library::ArgumentChecks arg;
library.functions["x"].argumentChecks[1] = arg;
library.functions["x"].argumentChecks[2] = arg;
library.functions["x"].argumentChecks[3] = arg;
library.functions["x"].argumentChecks[1].notnull = true;
std::list<const Token *> null;
CheckNullPointer::parseFunctionCall(*xtok, null, &library);
ASSERT_EQUALS(1U, null.size());
ASSERT_EQUALS("a", null.front()->str());
}
}
void functioncallDefaultArguments() {
check("void f(int *p = 0) {\n"
" *p = 0;\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (warning) Possible null pointer dereference if the default parameter value is used: p\n", errout.str());
check("void f(int *p = 0) {\n"
" if (!p)\n"
" return;\n"
" *p = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(char a, int *p = 0) {\n"
" *p = 0;\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (warning) Possible null pointer dereference if the default parameter value is used: p\n", errout.str());
check("void f(int *p = 0) {\n"
" printf(\"p = %d\", *p);\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (warning) Possible null pointer dereference if the default parameter value is used: p\n", errout.str());
check("void f(int *p = 0) {\n"
" printf(\"p[1] = %d\", p[1]);\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (warning) Possible null pointer dereference if the default parameter value is used: p\n", errout.str());
check("void f(int *p = 0) {\n"
" buf[p] = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(int *p = 0) {\n"
" if (p != 0 && bar())\n"
" *p = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(int *p) {\n"
" *p = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(int *p = 0) {\n"
" if (p != 0)\n"
" *p = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(int *p = 0) {\n"
" int y;\n"
" if (p == 0)\n"
" p = &y;\n"
" *p = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(int *p = 0) {\n"
" if (a != 0)\n"
" *p = 0;\n"
"}", true);
TODO_ASSERT_EQUALS("[test.cpp:3]: (warning) Possible null pointer dereference if the default parameter value is used: p\n", "", errout.str());
check("void f(int *p = 0) {\n"
" p = a;\n"
" *p = 0;\n" // <- don't simplify and verify
"}");
ASSERT_EQUALS("", errout.str());
check("void f(int *p = 0) {\n"
" p += a;\n"
" *p = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("int f(int *p = 0) {\n"
" if (p == 0) {\n"
" return 0;\n"
" }\n"
" return *p;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(int *p = 0) {\n"
" std::cout << p ? *p : 0;\n" // Due to operator precedence, this is equivalent to: (std::cout << p) ? *p : 0;
"}");
ASSERT_EQUALS("[test.cpp:2]: (warning) Possible null pointer dereference if the default parameter value is used: p\n", errout.str()); // Check the first branch of ternary
check("void f(char *p = 0) {\n"
" std::cout << p ? *p : 0;\n" // Due to operator precedence, this is equivalent to: (std::cout << p) ? *p : 0;
"}");
ASSERT_EQUALS("[test.cpp:2]: (warning) Possible null pointer dereference if the default parameter value is used: p\n", errout.str());
check("void f(int *p = 0) {\n"
" std::cout << (p ? *p : 0);\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(int *p = 0) {\n"
" std::cout << p;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(int *p = 0) {\n"
" std::cout << (p && p[0] ? *p : 42);\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void isEmpty(int *p = 0) {\n"
" return p && *p;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void g(int *p = 0) {\n"
" return !p || *p;\n"
"}");
ASSERT_EQUALS("", errout.str());
// bar may initialize p but be can't know for sure without knowing
// if p is passed in by reference and is modified by bar()
check("void f(int *p = 0) {\n"
" bar(p);\n"
" *p = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(int *p = 0) {\n"
" printf(\"%p\", p);\n"
" *p = 0;\n"
"}", true);
ASSERT_EQUALS("[test.cpp:3]: (warning, inconclusive) Possible null pointer dereference if the default parameter value is used: p\n", errout.str());
// The init() function may or may not initialize p, but since the address
// of p is passed in, it's a good bet that p may be modified and
// so we should not report an error.
check("void f(int *p = 0) {\n"
" init(&p);\n"
" *p = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void init(int* &g);\n"
"void f(int *p = 0) {\n"
" init(p);\n"
" *p = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(int *p = 0) {\n"
" if (p == 0) {\n"
" init(&p);\n"
" }\n"
" *p = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(int *p = 0) {\n"
" if (p == 0) {\n"
" throw SomeException;\n"
" }\n"
" *p = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void foo(int *p = 0) {\n"
" int var1 = x ? *p : 5;\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (warning) Possible null pointer dereference if the default parameter value is used: p\n", errout.str());
}
void nullpointer_internal_error() { // ticket #5080
check("struct A { unsigned int size; };\n"
"struct B { struct A *a; };\n"
"void f(struct B *b) {\n"
" unsigned int j;\n"
" for (j = 0; j < b[0].a->size; ++j) {\n"
" }\n"
"}\n");
ASSERT_EQUALS("", errout.str());
}
void ticket6505() {
check("void foo(MythSocket *socket) {\n"
" bool do_write=0;\n"
" if (socket) {\n"
" do_write=something();\n"
" }\n"
" if (do_write) {\n"
" socket->func();\n"
" }\n"
"}\n"
"void bar() {\n"
" foo(0);\n"
"}\n", true, "test.c");
ASSERT_EQUALS("", errout.str());
}
void subtract() {
check("void foo(char *s) {\n"
" p = s - 20;\n"
"}\n"
"void bar() { foo(0); }\n");
TODO_ASSERT_EQUALS("[test.cpp:2]: (error) Overflow in pointer arithmetic, NULL pointer is subtracted.\n", "", errout.str());
check("void foo(char *s) {\n"
" if (!s) {}\n"
" p = s - 20;\n"
"}\n");
ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (warning) Either the condition '!s' is redundant or there is overflow in pointer subtraction.\n", errout.str());
check("void foo(char *s) {\n"
" s -= 20;\n"
"}\n"
"void bar() { foo(0); }\n");
TODO_ASSERT_EQUALS("[test.cpp:2]: (error) Overflow in pointer arithmetic, NULL pointer is subtracted.\n", "", errout.str());
check("void foo(char *s) {\n"
" if (!s) {}\n"
" s -= 20;\n"
"}\n");
ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (warning) Either the condition '!s' is redundant or there is overflow in pointer subtraction.\n", errout.str());
check("int* f8() { int *x = NULL; return --x; }");
ASSERT_EQUALS("[test.cpp:1]: (error) Overflow in pointer arithmetic, NULL pointer is subtracted.\n", errout.str());
check("int* f9() { int *x = NULL; return x--; }");
ASSERT_EQUALS("[test.cpp:1]: (error) Overflow in pointer arithmetic, NULL pointer is subtracted.\n", errout.str());
}
void addNull() {
check("void foo(char *s) {\n"
" char * p = s + 20;\n"
"}\n"
"void bar() { foo(0); }\n");
TODO_ASSERT_EQUALS("[test.cpp:2]: (error) Pointer addition with NULL pointer.\n", "", errout.str());
check("void foo(char *s) {\n"
" if (!s) {}\n"
" char * p = s + 20;\n"
"}\n");
ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (warning) Either the condition '!s' is redundant or there is pointer arithmetic with NULL pointer.\n", errout.str());
check("void foo(char *s) {\n"
" char * p = 20 + s;\n"
"}\n"
"void bar() { foo(0); }\n");
TODO_ASSERT_EQUALS("[test.cpp:2]: (error) Pointer addition with NULL pointer.\n", "", errout.str());
check("void foo(char *s) {\n"
" if (!s) {}\n"
" char * p = 20 + s;\n"
"}\n");
ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (warning) Either the condition '!s' is redundant or there is pointer arithmetic with NULL pointer.\n", errout.str());
check("void foo(char *s) {\n"
" s += 20;\n"
"}\n"
"void bar() { foo(0); }\n");
TODO_ASSERT_EQUALS("[test.cpp:2]: (error) Pointer addition with NULL pointer.\n", "", errout.str());
check("void foo(char *s) {\n"
" if (!s) {}\n"
" s += 20;\n"
"}\n");
ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (warning) Either the condition '!s' is redundant or there is pointer arithmetic with NULL pointer.\n", errout.str());
check("int* f7() { int *x = NULL; return ++x; }");
ASSERT_EQUALS("[test.cpp:1]: (error) Pointer addition with NULL pointer.\n", errout.str());
check("int* f10() { int *x = NULL; return x++; } ");
ASSERT_EQUALS("[test.cpp:1]: (error) Pointer addition with NULL pointer.\n", errout.str());
check("class foo {};\n"
"const char* get() const { return 0; }\n"
"void f(foo x) { if (get()) x += get(); }\n");
ASSERT_EQUALS("", errout.str());
}
void ctu(const char code[]) {
// Clear the error buffer..
errout.str("");
// Tokenize..
Tokenizer tokenizer(&settings, this);
std::istringstream istr(code);
tokenizer.tokenize(istr, "test.cpp");
CTU::FileInfo *ctu = CTU::getFileInfo(&tokenizer);
// Check code..
std::list<Check::FileInfo*> fileInfo;
CheckNullPointer check(&tokenizer, &settings, this);
fileInfo.push_back(check.getFileInfo(&tokenizer, &settings));
check.analyseWholeProgram(ctu, fileInfo, settings, *this);
while (!fileInfo.empty()) {
delete fileInfo.back();
fileInfo.pop_back();
}
delete ctu;
}
void ctu() {
setMultiline();
ctu("void f(int *fp) {\n"
" a = *fp;\n"
"}\n"
"int main() {\n"
" int *p = 0;\n"
" f(p);\n"
"}");
ASSERT_EQUALS("test.cpp:2:error:Null pointer dereference: fp\n"
"test.cpp:5:note:Assignment 'p=0', assigned value is 0\n"
"test.cpp:6:note:Calling function f, 1st argument is null\n"
"test.cpp:2:note:Dereferencing argument fp that is null\n", errout.str());
ctu("void use(int *p) { a = *p + 3; }\n"
"void call(int x, int *p) { x++; use(p); }\n"
"int main() {\n"
" call(4,0);\n"
"}");
ASSERT_EQUALS("test.cpp:1:error:Null pointer dereference: p\n"
"test.cpp:4:note:Calling function call, 2nd argument is null\n"
"test.cpp:2:note:Calling function use, 1st argument is null\n"
"test.cpp:1:note:Dereferencing argument p that is null\n", errout.str());
ctu("void dostuff(int *x, int *y) {\n"
" if (!var)\n"
" return -1;\n" // <- early return
" *x = *y;\n"
"}\n"
"\n"
"void f() {\n"
" dostuff(a, 0);\n"
"}");
ASSERT_EQUALS("", errout.str());
ctu("void dostuff(int *x, int *y) {\n"
" if (cond)\n"
" *y = -1;\n" // <- conditionally written
" *x = *y;\n"
"}\n"
"\n"
"void f() {\n"
" dostuff(a, 0);\n"
"}");
ASSERT_EQUALS("", errout.str());
// else
ctu("void dostuff(int mask, int *p) {\n"
" if (mask == 13) ;\n"
" else *p = 45;\n"
"}\n"
"\n"
"void f() {\n"
" dostuff(0, 0);\n"
"}");
ASSERT_EQUALS("", errout.str());
// ?, &&, ||
ctu("void dostuff(int mask, int *p) {\n"
" x = (mask & 1) ? *p : 0;\n"
"}\n"
"\n"
"void f() {\n"
" dostuff(0, 0);\n"
"}");
ASSERT_EQUALS("", errout.str());
}
};
REGISTER_TEST(TestNullPointer)
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