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Fixed #155 (check size of a variable whose type is a sized array)

This commit is contained in:
Debrard Sébastien 2011-01-22 19:21:56 +01:00 committed by Daniel Marjamäki
parent 8abae6f1e5
commit 27dce075e0
3 changed files with 137 additions and 0 deletions
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45
lib/checkother.cpp
View File

@ -78,6 +78,35 @@ void CheckOther::checkFflushOnInputStream()
}
}
void CheckOther::checkSizeofForArrayParameter()
{
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
if (Token::Match(tok, "sizeof ( %var% )") || Token::Match(tok, "sizeof %var% "))
{
int tokIdx = 1;
if (tok->tokAt(tokIdx)->str() == "(")
{
++tokIdx;
}
if (tok->tokAt(tokIdx)->varId() > 0)
{
const Token *declTok = Token::findmatch(_tokenizer->tokens(), "%varid%", tok->tokAt(tokIdx)->varId());
if (declTok)
{
if ((Token::simpleMatch(declTok->next(), "[")) && !(Token::simpleMatch(declTok->next()->link(), "] = {")) && !(Token::simpleMatch(declTok->next()->link(), "] ;")))
{
sizeofForArrayParameterError(tok);
}
}
}
}
}
}
//---------------------------------------------------------------------------
// switch (x)
// {
@ -454,6 +483,22 @@ void CheckOther::invalidScanf()
}
}
void CheckOther::sizeofForArrayParameterError(const Token *tok)
{
reportError(tok, Severity::error,
"sizeofwithsilentarraypointer", "Using sizeof for array given as function argument "
"returns the size of pointer.\n"
"Giving array as function parameter and then using sizeof-operator for the array "
"argument. In this case the sizeof-operator returns the size of pointer (in the "
" system). It does not return the size of the whole array in bytes as might be "
"expected. For example, this code:\n"
" int f(char a[100]) {\n"
" return sizeof(a);\n"
" }\n"
" returns 4 (in 32-bit systems) or 8 (in 64-bit systems) instead of 100 (the "
"size of the array in bytes)."
);
}
void CheckOther::invalidScanfError(const Token *tok)
{
reportError(tok, Severity::warning,

7
lib/checkother.h
View File

@ -62,6 +62,7 @@ public:
checkOther.sizeofCalculation();
checkOther.checkRedundantAssignmentInSwitch();
checkOther.checkAssignmentInAssert();
checkOther.checkSizeofForArrayParameter();
}
/** @brief Run checks against the simplified token list */
@ -170,6 +171,9 @@ public:
/** @brief %Check for filling zero bytes with memset() */
void checkMemsetZeroBytes();
/** @brief %Check for using sizeof with array given as function argument */
void checkSizeofForArrayParameter();
// Error messages..
void cstyleCastError(const Token *tok);
void dangerousUsageStrtolError(const Token *tok);
@ -193,6 +197,7 @@ public:
void misusedScopeObjectError(const Token *tok, const std::string &varname);
void catchExceptionByValueError(const Token *tok);
void memsetZeroBytesError(const Token *tok, const std::string &varname);
void sizeofForArrayParameterError(const Token *tok);
void getErrorMessages(ErrorLogger *errorLogger, const Settings *settings)
{
@ -205,6 +210,7 @@ public:
c.mathfunctionCallError(0);
c.fflushOnInputStreamError(0, "stdin");
c.misusedScopeObjectError(NULL, "varname");
c.sizeofForArrayParameterError(0);
// style/warning
c.cstyleCastError(0);
@ -247,6 +253,7 @@ public:
"* using fflush() on an input stream\n"
"* scoped object destroyed immediately after construction\n"
"* assignment in an assert statement\n"
"* sizeof for array given as function argument\n"
// style
"* C-style pointer cast in cpp file\n"

85
test/testother.cpp
View File

@ -97,6 +97,8 @@ private:
TEST_CASE(catchExceptionByValue);
TEST_CASE(memsetZeroBytes);
TEST_CASE(sizeofWithSilentArrayPointer);
}
void check(const char code[], const char *filename = NULL)
@ -118,6 +120,7 @@ private:
checkOther.sizeofCalculation();
checkOther.checkRedundantAssignmentInSwitch();
checkOther.checkAssignmentInAssert();
checkOther.checkSizeofForArrayParameter();
// Simplify token list..
tokenizer.simplifyTokenList();
@ -1659,6 +1662,88 @@ private:
" bytes of \"p\". Second and third arguments might be inverted.\n", errout.str());
ASSERT_EQUALS("", errout.str());
}
void sizeofWithSilentArrayPointer()
{
check("void f() {\n"
" int a[10];\n"
" std::cout << sizeof(a) / sizeof(int) << std::endl;\n"
"}\n"
);
ASSERT_EQUALS("", errout.str());
check("void f() {\n"
" unsigned int a = 2;\n"
" unsigned int b = 2;\n"
" int c[(a+b)];\n"
" std::cout << sizeof(c) / sizeof(int) << std::endl;\n"
"}\n"
);
ASSERT_EQUALS("", errout.str());
check("void f() {\n"
" unsigned int a = { 2 };\n"
" unsigned int b[] = { 0 };\n"
" int c[a[b[0]]];\n"
" std::cout << sizeof(c) / sizeof(int) << std::endl;\n"
"}\n"
);
ASSERT_EQUALS("", errout.str());
check("void f() {\n"
" unsigned int a[] = { 1 };\n"
" unsigned int b = 2;\n"
" int c[(a[0]+b)];\n"
" std::cout << sizeof(c) / sizeof(int) << std::endl;\n"
"}\n"
);
ASSERT_EQUALS("", errout.str());
check("void f() {\n"
" int a[] = { 1, 2, 3 };\n"
" std::cout << sizeof(a) / sizeof(int) << std::endl;\n"
"}\n"
);
ASSERT_EQUALS("", errout.str());
check("void f() {\n"
" int a[3] = { 1, 2, 3 };\n"
" std::cout << sizeof(a) / sizeof(int) << std::endl;\n"
"}\n"
);
ASSERT_EQUALS("", errout.str());
check("void f( int a[]) {\n"
" std::cout << sizeof(a) / sizeof(int) << std::endl;\n"
"}\n"
);
ASSERT_EQUALS("[test.cpp:2]: (error) Using sizeof for array given as "
"function argument returns the size of pointer.\n", errout.str());
check("void f( int a[]) {\n"
" std::cout << sizeof a / sizeof(int) << std::endl;\n"
"}\n"
);
ASSERT_EQUALS("[test.cpp:2]: (error) Using sizeof for array given as "
"function argument returns the size of pointer.\n", errout.str());
check("void f( int a[3] ) {\n"
" std::cout << sizeof(a) / sizeof(int) << std::endl;\n"
"}\n"
);
ASSERT_EQUALS("[test.cpp:2]: (error) Using sizeof for array given as "
"function argument returns the size of pointer.\n", errout.str());
check("void f(int *p) {\n"
" p[0] = 0;\n"
" sizeof(p);\n"
"}\n"
);
ASSERT_EQUALS("", errout.str());
}
};
REGISTER_TEST(TestOther)