/*

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

* Copyright (C) 2007-2024 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 "checktype.h"

#include "errortypes.h"

#include "fixture.h"

#include "helpers.h"

#include "platform.h"

#include "settings.h"

#include "standards.h"

#include "tokenize.h"

#include <cstddef>

#include <string>

#include <vector>

class TestType : public TestFixture {

public:

TestType() : TestFixture("TestType") {}

private:

void run() override {

TEST_CASE(checkTooBigShift_Unix32);

TEST_CASE(checkIntegerOverflow);

TEST_CASE(signConversion);

TEST_CASE(longCastAssign);

TEST_CASE(longCastReturn);

TEST_CASE(checkFloatToIntegerOverflow);

TEST_CASE(integerOverflow); // #11794

}

#define check(...) check_(__FILE__, __LINE__, __VA_ARGS__)

template<size_t size>

void check_(const char* file, int line, const char (&code)[size], const Settings& settings, bool cpp = true, Standards::cppstd_t standard = Standards::cppstd_t::CPP11) {

const Settings settings1 = settingsBuilder(settings).severity(Severity::warning).severity(Severity::portability).cpp(standard).build();

// Tokenize..

SimpleTokenizer tokenizer(settings1, *this);

ASSERT_LOC(tokenizer.tokenize(code, cpp), file, line);

// Check..

runChecks<CheckType>(tokenizer, this);

}

// TODO: get rid of this

void check_(const char* file, int line, const std::string& code, const Settings& settings, bool cpp = true, Standards::cppstd_t standard = Standards::cppstd_t::CPP11) {

const Settings settings1 = settingsBuilder(settings).severity(Severity::warning).severity(Severity::portability).cpp(standard).build();

// Tokenize..

SimpleTokenizer tokenizer(settings1, *this);

ASSERT_LOC(tokenizer.tokenize(code, cpp), file, line);

// Check..

runChecks<CheckType>(tokenizer, this);

}

#define checkP(...) checkP_(__FILE__, __LINE__, __VA_ARGS__)

template<size_t size>

void checkP_(const char* file, int line, const char (&code)[size], const Settings& settings, const char filename[] = "test.cpp") {

const Settings settings1 = settingsBuilder(settings).severity(Severity::warning).severity(Severity::portability).build();

std::vector<std::string> files(1, filename);

Tokenizer tokenizer(settings1, *this);

PreprocessorHelper::preprocess(code, files, tokenizer, *this);

// Tokenizer..

ASSERT_LOC(tokenizer.simplifyTokens1(""), file, line);

// Check..

runChecks<CheckType>(tokenizer, this);

}

void checkTooBigShift_Unix32() {

const Settings settings = settingsBuilder().platform(Platform::Type::Unix32).build();

// unsigned types getting promoted to int sizeof(int) = 4 bytes

// and unsigned types having already a size of 4 bytes

{

const std::string types[] = {"unsigned char", /*[unsigned]*/ "char", "bool", "unsigned short", "unsigned int", "unsigned long"};

for (const std::string& type : types) {

check(type + " f(" + type +" x) { return x << 31; }", settings);

ASSERT_EQUALS("", errout_str());

check(type + " f(" + type +" x) { return x << 33; }", settings);

ASSERT_EQUALS("[test.cpp:1]: (error) Shifting 32-bit value by 33 bits is undefined behaviour\n", errout_str());

check(type + " f(int x) { return (x = (" + type + ")x << 32); }", settings);

ASSERT_EQUALS("[test.cpp:1]: (error) Shifting 32-bit value by 32 bits is undefined behaviour\n", errout_str());

check(type + " foo(" + type + " x) { return x << 31; }", settings);

ASSERT_EQUALS("", errout_str());

}

}

// signed types getting promoted to int sizeof(int) = 4 bytes

// and signed types having already a size of 4 bytes

{

const std::string types[] = {"signed char", "signed short", /*[signed]*/ "short", "wchar_t", /*[signed]*/ "int", "signed int", /*[signed]*/ "long", "signed long"};

for (const std::string& type : types) {

// c++11

check(type + " f(" + type +" x) { return x << 33; }", settings);

ASSERT_EQUALS("[test.cpp:1]: (error) Shifting 32-bit value by 33 bits is undefined behaviour\n", errout_str());

check(type + " f(int x) { return (x = (" + type + ")x << 32); }", settings);

ASSERT_EQUALS("[test.cpp:1]: (error) Shifting 32-bit value by 32 bits is undefined behaviour\n", errout_str());

check(type + " foo(" + type + " x) { return x << 31; }", settings);

ASSERT_EQUALS("[test.cpp:1]: (error) Shifting signed 32-bit value by 31 bits is undefined behaviour\n", errout_str());

check(type + " foo(" + type + " x) { return x << 30; }", settings);

ASSERT_EQUALS("", errout_str());

// c++14

check(type + " foo(" + type + " x) { return x << 31; }", settings, true, Standards::cppstd_t::CPP14);

ASSERT_EQUALS("[test.cpp:1]: (portability) Shifting signed 32-bit value by 31 bits is implementation-defined behaviour\n", errout_str());

check(type + " f(int x) { return (x = (" + type + ")x << 32); }", settings, true, Standards::cppstd_t::CPP14);

ASSERT_EQUALS("[test.cpp:1]: (error) Shifting 32-bit value by 32 bits is undefined behaviour\n", errout_str());

}

}

// 64 bit width types

{

// unsigned long long

check("unsigned long long foo(unsigned long long x) { return x << 64; }",settings);

ASSERT_EQUALS("[test.cpp:1]: (error) Shifting 64-bit value by 64 bits is undefined behaviour\n", errout_str());

check("unsigned long long f(int x) { return (x = (unsigned long long)x << 64); }",settings);

ASSERT_EQUALS("[test.cpp:1]: (error) Shifting 64-bit value by 64 bits is undefined behaviour\n", errout_str());

check("unsigned long long f(unsigned long long x) { return x << 63; }",settings);

ASSERT_EQUALS("", errout_str());

// [signed] long long

check("long long foo(long long x) { return x << 64; }",settings);

ASSERT_EQUALS("[test.cpp:1]: (error) Shifting 64-bit value by 64 bits is undefined behaviour\n", errout_str());

check("long long f(int x) { return (x = (long long)x << 64); }",settings);

ASSERT_EQUALS("[test.cpp:1]: (error) Shifting 64-bit value by 64 bits is undefined behaviour\n", errout_str());

check("long long f(long long x) { return x << 63; }",settings);

ASSERT_EQUALS("[test.cpp:1]: (error) Shifting signed 64-bit value by 63 bits is undefined behaviour\n", errout_str());

check("long long f(long long x) { return x << 62; }",settings);

ASSERT_EQUALS("", errout_str());

// signed long long

check("signed long long foo(signed long long x) { return x << 64; }",settings);

ASSERT_EQUALS("[test.cpp:1]: (error) Shifting 64-bit value by 64 bits is undefined behaviour\n", errout_str());

check("signed long long f(long long x) { return (x = (signed long long)x << 64); }",settings);

ASSERT_EQUALS("[test.cpp:1]: (error) Shifting 64-bit value by 64 bits is undefined behaviour\n", errout_str());

check("signed long long f(signed long long x) { return x << 63; }",settings);

ASSERT_EQUALS("[test.cpp:1]: (error) Shifting signed 64-bit value by 63 bits is undefined behaviour\n", errout_str());

check("signed long long f(signed long long x) { return x << 62; }",settings);

ASSERT_EQUALS("", errout_str());

// c++14

check("signed long long foo(signed long long x) { return x << 64; }",settings, true, Standards::cppstd_t::CPP14);

ASSERT_EQUALS("[test.cpp:1]: (error) Shifting 64-bit value by 64 bits is undefined behaviour\n", errout_str());

check("signed long long f(long long x) { return (x = (signed long long)x << 64); }",settings, true, Standards::cppstd_t::CPP14);

ASSERT_EQUALS("[test.cpp:1]: (error) Shifting 64-bit value by 64 bits is undefined behaviour\n", errout_str());

check("signed long long f(signed long long x) { return x << 63; }",settings, true, Standards::cppstd_t::CPP14);

ASSERT_EQUALS("[test.cpp:1]: (portability) Shifting signed 64-bit value by 63 bits is implementation-defined behaviour\n", errout_str());

check("signed long long f(signed long long x) { return x << 62; }",settings);

ASSERT_EQUALS("", errout_str());

}

check("void f() { int x; x = 1 >> 64; }", settings);

ASSERT_EQUALS("[test.cpp:1]: (error) Shifting 32-bit value by 64 bits is undefined behaviour\n", errout_str());

check("void foo() {\n"

" QList<int> someList;\n"

" someList << 300;\n"

"}", settings);

ASSERT_EQUALS("", errout_str());

// Ticket #6793

check("template<unsigned int I> int foo(unsigned int x) { return x << I; }\n"

"const unsigned int f = foo<31>(0);\n"

"const unsigned int g = foo<100>(0);\n"

"template<unsigned int I> int hoo(unsigned int x) { return x << 32; }\n"

"const unsigned int h = hoo<100>(0);", settings);

ASSERT_EQUALS("[test.cpp:4]: (error) Shifting 32-bit value by 32 bits is undefined behaviour\n"

"[test.cpp:1]: (error) Shifting 32-bit value by 100 bits is undefined behaviour\n", errout_str());

// #7266: C++, shift in macro

check("void f(unsigned int x) {\n"

" UINFO(x << 1234);\n"

"}", settingsDefault);

ASSERT_EQUALS("", errout_str());

// #8640

check("int f (void)\n"

"{\n"

" constexpr const int a = 1;\n"

" constexpr const int shift[1] = {32};\n"

" constexpr const int ret = a << shift[0];\n" // shift too many bits

" return ret;\n"

"}", settingsDefault);

ASSERT_EQUALS("[test.cpp:5]: (error) Shifting 32-bit value by 32 bits is undefined behaviour\n"

"[test.cpp:5]: (error) Signed integer overflow for expression 'a<<shift[0]'.\n", errout_str());

// #8885

check("int f(int k, int rm) {\n"

" if (k == 32)\n"

" return 0;\n"

" if (k > 32)\n"

" return 0;\n"

" return rm>> k;\n"

"}", settingsDefault);

ASSERT_EQUALS(

"[test.cpp:4] -> [test.cpp:6]: (warning) Shifting signed 32-bit value by 31 bits is undefined behaviour. See condition at line 4.\n",

errout_str());

check("int f(int k, int rm) {\n"

" if (k == 0 || k == 32)\n"

" return 0;\n"

" else if (k > 32)\n"

" return 0;\n"

" else\n"

" return rm>> k;\n"

"}", settingsDefault);

ASSERT_EQUALS(

"[test.cpp:4] -> [test.cpp:7]: (warning) Shifting signed 32-bit value by 31 bits is undefined behaviour. See condition at line 4.\n",

errout_str());

check("int f(int k, int rm) {\n"

" if (k == 0 || k == 32 || k == 31)\n"

" return 0;\n"

" else if (k > 32)\n"

" return 0;\n"

" else\n"

" return rm>> k;\n"

"}", settingsDefault);

ASSERT_EQUALS("", errout_str());

check("static long long f(int x, long long y) {\n"

" if (x >= 64)\n"

" return 0;\n"

" return -(y << (x-1));\n"

"}", settingsDefault);

ASSERT_EQUALS("", errout_str());

check("bool f() {\n"

" std::ofstream outfile;\n"

" outfile << vec_points[0](0) << static_cast<int>(d) << ' ';\n"

"}", settingsDefault);

ASSERT_EQUALS("", errout_str());

check("void f(unsigned b, int len, unsigned char rem) {\n" // #10773

" int bits = 0;\n"

" while (len > 8) {\n"

" b = b >> rem;\n"

" bits += 8 - rem;\n"

" if (bits == 512)\n"

" len -= 8;\n"

" }\n"

"}\n", settingsDefault);

ASSERT_EQUALS("", errout_str());

}

void checkIntegerOverflow() {

const Settings settings = settingsBuilder().severity(Severity::warning).platform(Platform::Type::Unix32).build();

check("x = (int)0x10000 * (int)0x10000;", settings);

ASSERT_EQUALS("[test.cpp:1]: (error) Signed integer overflow for expression '(int)0x10000*(int)0x10000'.\n", errout_str());

check("x = (long)0x10000 * (long)0x10000;", settings);

ASSERT_EQUALS("[test.cpp:1]: (error) Signed integer overflow for expression '(long)0x10000*(long)0x10000'.\n", errout_str());

check("void foo() {\n"

" int intmax = 0x7fffffff;\n"

" return intmax + 1;\n"

"}",settings);

ASSERT_EQUALS("[test.cpp:3]: (error) Signed integer overflow for expression 'intmax+1'.\n", errout_str());

check("void foo() {\n"

" int intmax = 0x7fffffff;\n"

" return intmax - 1;\n"

"}",settings);

ASSERT_EQUALS("", errout_str());

check("int foo(signed int x) {\n"

" if (x==123456) {}\n"

" return x * x;\n"

"}",settings);

ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (warning) Either the condition 'x==123456' is redundant or there is signed integer overflow for expression 'x*x'.\n", errout_str());

check("int foo(signed int x) {\n"

" if (x==123456) {}\n"

" return -123456 * x;\n"

"}",settings);

ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (warning) Either the condition 'x==123456' is redundant or there is signed integer overflow for expression '-123456*x'.\n", errout_str());

check("int foo(signed int x) {\n"

" if (x==123456) {}\n"

" return 123456U * x;\n"

"}",settings);

ASSERT_EQUALS("", errout_str());

check("int f(int i) {\n" // #12117

" return (i == 31) ? 1 << i : 0;\n"

"}", settings);

ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:2]: (warning) Shifting signed 32-bit value by 31 bits is undefined behaviour. See condition at line 2.\n", errout_str());

}

void signConversion() {

const Settings settings = settingsBuilder().platform(Platform::Type::Unix64).build();

check("x = -4 * (unsigned)y;", settingsDefault);

ASSERT_EQUALS("[test.cpp:1]: (warning) Expression '-4' has a negative value. That is converted to an unsigned value and used in an unsigned calculation.\n", errout_str());

check("x = (unsigned)y * -4;", settingsDefault);

ASSERT_EQUALS("[test.cpp:1]: (warning) Expression '-4' has a negative value. That is converted to an unsigned value and used in an unsigned calculation.\n", errout_str());

check("unsigned int dostuff(int x) {\n" // x is signed

" if (x==0) {}\n"

" return (x-1)*sizeof(int);\n"

"}", settings);

ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (warning) Expression 'x-1' can have a negative value. That is converted to an unsigned value and used in an unsigned calculation.\n", errout_str());

check("unsigned int f1(signed int x, unsigned int y) {" // x is signed

" return x * y;\n"

"}\n"

"void f2() { f1(-4,4); }", settingsDefault);

ASSERT_EQUALS(

"[test.cpp:1]: (warning) Expression 'x' can have a negative value. That is converted to an unsigned value and used in an unsigned calculation.\n",

errout_str());

check("unsigned int f1(int x) {"

" return x * 5U;\n"

"}\n"

"void f2() { f1(-4); }", settingsDefault);

ASSERT_EQUALS(

"[test.cpp:1]: (warning) Expression 'x' can have a negative value. That is converted to an unsigned value and used in an unsigned calculation.\n",

errout_str());

check("unsigned int f1(int x) {" // #6168: FP for inner calculation

" return 5U * (1234 - x);\n" // <- signed subtraction, x is not sign converted

"}\n"

"void f2() { f1(-4); }", settingsDefault);

ASSERT_EQUALS("", errout_str());

// Don't warn for + and -

check("void f1(int x) {"

" a = x + 5U;\n"

"}\n"

"void f2() { f1(-4); }", settingsDefault);

ASSERT_EQUALS("", errout_str());

check("size_t foo(size_t x) {\n"

" return -2 * x;\n"

"}", settingsDefault);

ASSERT_EQUALS("[test.cpp:2]: (warning) Expression '-2' has a negative value. That is converted to an unsigned value and used in an unsigned calculation.\n", errout_str());

}

void longCastAssign() {

const Settings settings = settingsBuilder().severity(Severity::style).platform(Platform::Type::Unix64).build();

const Settings settingsWin = settingsBuilder().severity(Severity::style).platform(Platform::Type::Win64).build();

const char code[] = "long f(int x, int y) {\n"

" const long ret = x * y;\n"

" return ret;\n"

"}\n";

check(code, settings);

ASSERT_EQUALS("[test.cpp:2]: (style) int result is assigned to long variable. If the variable is long to avoid loss of information, then you have loss of information.\n", errout_str());

check(code, settingsWin);

ASSERT_EQUALS("", errout_str());

check("long f(int x, int y) {\n"

" long ret = x * y;\n"

" return ret;\n"

"}\n", settings);

ASSERT_EQUALS("[test.cpp:2]: (style) int result is assigned to long variable. If the variable is long to avoid loss of information, then you have loss of information.\n", errout_str());

check("long f() {\n"

" const long long ret = 256 * (1 << 10);\n"

" return ret;\n"

"}\n", settings);

ASSERT_EQUALS("", errout_str());

// typedef

check("long f(int x, int y) {\n"

" const size_t ret = x * y;\n"

" return ret;\n"

"}\n", settings);

ASSERT_EQUALS("", errout_str());

// astIsIntResult

check("long f(int x, int y) {\n"

" const long ret = (long)x * y;\n"

" return ret;\n"

"}\n", settings);

ASSERT_EQUALS("", errout_str());

check("double g(float f) {\n"

" return f * f;\n"

"}\n", settings);

ASSERT_EQUALS("[test.cpp:2]: (style) float result is returned as double value. If the return value is double to avoid loss of information, then you have loss of information.\n",

errout_str());

check("void f(int* p) {\n" // #11862

" long long j = *(p++);\n"

"}\n", settings);

ASSERT_EQUALS("", errout_str());

check("template <class T>\n" // #12393

"struct S {\n"

" S& operator=(const S&) { return *this; }\n"

" struct U {\n"

" S<T>* p;\n"

" };\n"

" U u;\n"

"};\n", settings);

ASSERT_EQUALS("", errout_str()); // don't crash

check("void f(long& r, long i) {\n"

" r = 1 << i;\n"

"}\n", settingsWin);

ASSERT_EQUALS("", errout_str());

}

void longCastReturn() {

const Settings settings = settingsBuilder().severity(Severity::style).platform(Platform::Type::Unix64).build();

const Settings settingsWin = settingsBuilder().severity(Severity::style).platform(Platform::Type::Win64).build();

const char code[] = "long f(int x, int y) {\n"

" return x * y;\n"

"}\n";

check(code, settings);

ASSERT_EQUALS("[test.cpp:2]: (style) int result is returned as long value. If the return value is long to avoid loss of information, then you have loss of information.\n", errout_str());

check(code, settingsWin);

ASSERT_EQUALS("", errout_str());

const char code2[] = "long long f(int x, int y) {\n"

" return x * y;\n"

"}\n";

check(code2, settings);

ASSERT_EQUALS("[test.cpp:2]: (style) int result is returned as long long value. If the return value is long long to avoid loss of information, then you have loss of information.\n", errout_str());

check(code2, settingsWin);

ASSERT_EQUALS("[test.cpp:2]: (style) int result is returned as long long value. If the return value is long long to avoid loss of information, then you have loss of information.\n", errout_str());

// typedef

check("size_t f(int x, int y) {\n"

" return x * y;\n"

"}\n", settings);

ASSERT_EQUALS("[test.cpp:2]: (style) int result is returned as long value. If the return value is long to avoid loss of information, then you have loss of information.\n", errout_str());

}

// This function ensure that test works with different compilers. Floats can

// be stringified differently.

static std::string removeFloat(const std::string& msg) {

const std::string::size_type pos1 = msg.find("float (");

const std::string::size_type pos2 = msg.find(") to integer conversion");

if (pos1 == std::string::npos || pos2 == std::string::npos || pos1 > pos2)

return msg;

return msg.substr(0,pos1+7) + msg.substr(pos2);

}

void checkFloatToIntegerOverflow() {

check("x = (int)1E100;", settingsDefault);

ASSERT_EQUALS("[test.cpp:1]: (error) Undefined behaviour: float () to integer conversion overflow.\n", removeFloat(errout_str()));

check("void f(void) {\n"

" return (int)1E100;\n"

"}", settingsDefault);

ASSERT_EQUALS("[test.cpp:2]: (error) Undefined behaviour: float () to integer conversion overflow.\n", removeFloat(errout_str()));

check("void f(void) {\n"

" return (int)-1E100;\n"

"}", settingsDefault);

ASSERT_EQUALS("[test.cpp:2]: (error) Undefined behaviour: float () to integer conversion overflow.\n", removeFloat(errout_str()));

check("void f(void) {\n"

" return (short)1E6;\n"

"}", settingsDefault);

ASSERT_EQUALS("[test.cpp:2]: (error) Undefined behaviour: float () to integer conversion overflow.\n", removeFloat(errout_str()));

check("void f(void) {\n"

" return (unsigned char)256.0;\n"

"}", settingsDefault);

ASSERT_EQUALS("[test.cpp:2]: (error) Undefined behaviour: float () to integer conversion overflow.\n", removeFloat(errout_str()));

check("void f(void) {\n"

" return (unsigned char)255.5;\n"

"}", settingsDefault);

ASSERT_EQUALS("", removeFloat(errout_str()));

check("void f(void) {\n"

" char c = 1234.5;\n"

"}", settingsDefault);

ASSERT_EQUALS("[test.cpp:2]: (error) Undefined behaviour: float () to integer conversion overflow.\n", removeFloat(errout_str()));

check("char f(void) {\n"

" return 1234.5;\n"

"}", settingsDefault);

ASSERT_EQUALS("[test.cpp:2]: (error) Undefined behaviour: float () to integer conversion overflow.\n", removeFloat(errout_str()));

}

void integerOverflow() { // #11794

// std.cfg for int32_t

// Platform::Unix32 for INT_MIN=-2147483648 and INT32_MAX=2147483647

const Settings s = settingsBuilder().library("std.cfg").cpp(Standards::CPP11).platform(Platform::Unix32).build();

checkP("int fun(int x)\n"

"{\n"

" if(x < 0) x = -x;\n"

" return x >= 0;\n"

"}\n"

"int f()\n"

"{\n"

" fun(INT_MIN);\n"

"}", s, "test.cpp");

ASSERT_EQUALS("[test.cpp:3]: (error) Signed integer overflow for expression '-x'.\n", errout_str());

checkP("void f() {\n" // #8399

" int32_t i = INT32_MAX;\n"

" i << 1;\n"

" i << 2;\n"

"}", s, "test.cpp");

ASSERT_EQUALS("[test.cpp:4]: (error) Signed integer overflow for expression 'i<<2'.\n", errout_str());

}

};

REGISTER_TEST(TestType)