cppcheck/test/testcharvar.cpp

208 lines
6.2 KiB
C++

/*
* Cppcheck - A tool for static C/C++ code analysis
* Copyright (C) 2007-2023 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 "checkother.h"
#include "errortypes.h"
#include "platform.h"
#include "settings.h"
#include "fixture.h"
#include "tokenize.h"
#include <sstream> // IWYU pragma: keep
class TestCharVar : public TestFixture {
public:
TestCharVar() : TestFixture("TestCharVar") {}
private:
Settings settings;
void run() override {
settings.platform(Settings::Unspecified);
settings.severity.enable(Severity::warning);
settings.severity.enable(Severity::portability);
TEST_CASE(array_index_1);
TEST_CASE(array_index_2);
TEST_CASE(bitop);
}
#define check(code) check_(code, __FILE__, __LINE__)
void check_(const char code[], const char* file, int line) {
// Clear the error buffer..
errout.str("");
// Tokenize..
Tokenizer tokenizer(&settings, this);
std::istringstream istr(code);
ASSERT_LOC(tokenizer.tokenize(istr, "test.cpp"), file, line);
// Check char variable usage..
CheckOther checkOther(&tokenizer, &settings, this);
checkOther.checkCharVariable();
}
void array_index_1() {
check("int buf[256];\n"
"void foo()\n"
"{\n"
" unsigned char ch = 0x80;\n"
" buf[ch] = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("int buf[256];\n"
"void foo()\n"
"{\n"
" char ch = 0x80;\n"
" buf[ch] = 0;\n"
"}");
ASSERT_EQUALS("[test.cpp:5]: (portability) 'char' type used as array index.\n", errout.str());
check("int buf[256];\n"
"void foo()\n"
"{\n"
" char ch = 0;\n"
" buf[ch] = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("int buf[256];\n"
"void foo()\n"
"{\n"
" signed char ch = 0;\n"
" buf[ch] = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("int buf[256];\n"
"void foo()\n"
"{\n"
" char ch = 0x80;\n"
" buf[ch] = 0;\n"
"}");
ASSERT_EQUALS("[test.cpp:5]: (portability) 'char' type used as array index.\n", errout.str());
check("int buf[256];\n"
"void foo(signed char ch)\n"
"{\n"
" buf[ch] = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("int buf[256];\n"
"void foo(char ch)\n"
"{\n"
" buf[ch] = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void foo(char* buf)\n"
"{\n"
" char ch = 0x80;"
" buf[ch] = 0;\n"
"}");
ASSERT_EQUALS("[test.cpp:3]: (portability) 'char' type used as array index.\n", errout.str());
check("void foo(char* buf)\n"
"{\n"
" char ch = 0;"
" buf[ch] = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void foo(char* buf)\n"
"{\n"
" buf['A'] = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void foo(char* buf, char ch)\n"
"{\n"
" buf[ch] = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("int flags[256];\n"
"void foo(const char* str)\n"
"{\n"
" flags[*str] = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("int flags[256];\n"
"void foo(const char* str)\n"
"{\n"
" flags[(unsigned char)*str] = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void foo(const char str[])\n"
"{\n"
" map[str] = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
}
void array_index_2() {
// #3282 - False positive
check("void foo(char i);\n"
"void bar(int i) {\n"
" const char *s = \"abcde\";\n"
" foo(s[i]);\n"
"}");
ASSERT_EQUALS("", errout.str());
}
void bitop() {
check("void foo(int *result) {\n"
" signed char ch = -1;\n"
" *result = a | ch;\n"
"}");
ASSERT_EQUALS("[test.cpp:3]: (warning) When using 'char' variables in bit operations, sign extension can generate unexpected results.\n", errout.str());
check("void foo(int *result) {\n"
" unsigned char ch = -1;\n"
" *result = a | ch;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void foo(char *result) {\n"
" signed char ch = -1;\n"
" *result = a | ch;\n"
"}");
ASSERT_EQUALS("", errout.str());
// 0x03 & ..
check("void foo(int *result) {\n"
" signed char ch = -1;\n"
" *result = 0x03 | ch;\n"
"}");
ASSERT_EQUALS("[test.cpp:3]: (warning) When using 'char' variables in bit operations, sign extension can generate unexpected results.\n", errout.str());
check("void foo(int *result) {\n"
" signed char ch = -1;\n"
" *result = 0x03 & ch;\n"
"}");
ASSERT_EQUALS("", errout.str());
}
};
REGISTER_TEST(TestCharVar)