cppcheck/test/testcharvar.cpp

237 lines
6.7 KiB
C++

/*
* Cppcheck - A tool for static C/C++ code analysis
* Copyright (C) 2007-2015 Daniel Marjamäki and Cppcheck team.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "tokenize.h"
#include "checkother.h"
#include "testsuite.h"
#include <sstream>
extern std::ostringstream errout;
class TestCharVar : public TestFixture {
public:
TestCharVar() : TestFixture("TestCharVar") {
}
private:
void run() {
TEST_CASE(array_index_1);
TEST_CASE(array_index_2);
TEST_CASE(array_index_3);
TEST_CASE(bitop1);
TEST_CASE(bitop2);
TEST_CASE(bitop3);
TEST_CASE(bitop4); // (long)&c
TEST_CASE(return1);
TEST_CASE(assignChar);
TEST_CASE(and03);
TEST_CASE(pointer);
}
void check(const char code[]) {
// Clear the error buffer..
errout.str("");
Settings settings;
settings.addEnabled("warning");
// Tokenize..
Tokenizer tokenizer(&settings, this);
std::istringstream istr(code);
tokenizer.tokenize(istr, "test.cpp");
// 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]: (warning) Signed 'char' type used as array index.\n", errout.str());
check("int buf[256];\n"
"void foo()\n"
"{\n"
" signed char ch = 0x80;\n"
" buf[ch] = 0;\n"
"}");
ASSERT_EQUALS("[test.cpp:5]: (warning) Signed 'char' type used as array index.\n", errout.str());
check("int buf[256];\n"
"void foo(char ch)\n"
"{\n"
" buf[ch] = 0;\n"
"}");
ASSERT_EQUALS("[test.cpp:4]: (warning) Signed 'char' type used as array index.\n", 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 array_index_3() {
// only write error message when array is more than
// 0x80 elements in size. Otherwise the full valid
// range is accessible with a char.
check("char buf[0x81];\n"
"void bar(char c) {\n"
" buf[c] = 0;\n"
"}");
ASSERT_EQUALS("[test.cpp:3]: (warning) Signed 'char' type used as array index.\n", errout.str());
check("char buf[0x80];\n"
"void bar(char c) {\n"
" buf[c] = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void bar(char c) {\n"
" buf[c] = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
}
void bitop1() {
check("void foo()\n"
"{\n"
" int result = 0;\n"
" char ch;\n"
" result = a | ch;\n"
"}");
ASSERT_EQUALS("[test.cpp:5]: (warning) When using 'char' variables in bit operations, sign extension can generate unexpected results.\n", errout.str());
}
void bitop2() {
check("void foo()\n"
"{\n"
" char ch;\n"
" func(&ch);\n"
"}");
ASSERT_EQUALS("", errout.str());
}
void bitop3() {
check("void f(int& i, char& c) {\n"
" i &= c;\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (warning) When using 'char' variables in bit operations, sign extension can generate unexpected results.\n", errout.str());
}
void bitop4() {
check("long f(char c) {\n"
" long a;\n"
" a = (long)&c;\n"
" return a;\n"
"}");
ASSERT_EQUALS("", errout.str());
}
void return1() {
check("void foo()\n"
"{\n"
" char c;\n"
" return &c;\n"
"}");
ASSERT_EQUALS("", errout.str());
}
void assignChar() {
check("void foo()\n"
"{\n"
" char c;\n"
" c = c & 0x123;\n"
"}");
ASSERT_EQUALS("", errout.str());
}
void and03() {
check("void foo()\n"
"{\n"
" char c;\n"
" int i = c & 0x03;\n"
"}");
ASSERT_EQUALS("", errout.str());
}
void pointer() {
// ticket #2866
check("void f(char *p) {\n"
" int ret = 0;\n"
" ret |= *p;\n"
" return ret;\n"
"}");
ASSERT_EQUALS("[test.cpp:3]: (warning) When using 'char' variables in bit operations, sign extension can generate unexpected results.\n", errout.str());
// fixed code
check("void f(char *p) {\n"
" int ret = 0;\n"
" ret |= (unsigned char)*p;\n"
" return ret;\n"
"}");
ASSERT_EQUALS("", errout.str());
// #3872 - false positive
check("int f(int *p) {\n"
" int ret = a();\n"
" ret |= *p;\n"
" return ret;\n"
"}");
ASSERT_EQUALS("", errout.str());
// #3878 - false positive
check("int f(unsigned char *p) {\n"
" int ret = a();\n"
" ret |= *p;\n"
" return ret;\n"
"}");
ASSERT_EQUALS("", errout.str());
}
};
REGISTER_TEST(TestCharVar)