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Refactor and fix "After a strncpy() the buffer should be zero-terminated" checking,

This commit is contained in:
Reijo Tomperi 2010-04-05 21:47:50 +03:00
parent 4bc325f077
commit d3c251f53a
2 changed files with 25 additions and 17 deletions
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17
lib/checkbufferoverrun.cpp
View File

@ -267,34 +267,27 @@ void CheckBufferOverrun::checkScope(const Token *tok, const std::vector<std::str
if (_settings->_checkCodingStyle)
{
// check for strncpy which is not terminated
if (Token::Match(tok, "strncpy ( %varid% , %any% , %any% )", varid))
{
const Token *tokSz = tok->tokAt(6);
if (tokSz->isNumber())
if (Token::Match(tok, "strncpy ( %varid% , %any% , %num% )", varid))
{
// strncpy takes entire variable length as input size
const std::string num = tok->strAt(6);
if (MathLib::toLongNumber(num) == total_size)
if (MathLib::toLongNumber(tok->strAt(6)) == total_size)
{
const Token *tok2 = tok->next()->link()->next()->next();
const Token *tok2 = tok->next()->link()->next();
for (; tok2; tok2 = tok2->next())
{
if (Token::Match(tok2, "%varid%", tok->tokAt(2)->varId()))
if (tok2->varId() == tok->tokAt(2)->varId())
{
if (!Token::Match(tok2, "%varid% [ %any% ] = 0 ;", tok->tokAt(2)->varId()))
{
terminateStrncpyError(tok);
}
else
{
break;
}
}
}
}
}
}
}
if (Token::Match(tok, "memset|memcpy|memmove|memcmp|strncpy|fgets ( %varid% , %any% , %any% )", varid) ||
Token::Match(tok, "memset|memcpy|memmove|memcmp|fgets ( %var% , %varid% , %any% )", varid))
{

15
test/testbufferoverrun.cpp
View File

@ -1775,6 +1775,21 @@ private:
" bar[99] = 0;\n"
"}\n");
ASSERT_EQUALS("[test.cpp:4]: (style) After a strncpy() the buffer should be zero-terminated\n", errout.str());
// Test with invalid code that there is no segfault
check("char baz[100];\n"
"strncpy(baz, \"var\", sizeof(baz))\n");
ASSERT_EQUALS("", errout.str());
// Test that there are no duplicate error messages
check("void foo ( char *bar )\n"
"{\n"
" char baz[100];\n"
" strncpy(baz, bar, sizeof(baz));\n"
" foo(baz);\n"
" foo(baz);\n"
"}\n");
ASSERT_EQUALS("[test.cpp:4]: (style) After a strncpy() the buffer should be zero-terminated\n", errout.str());
}
void terminateStrncpy2()