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New check: Warn about using malloc() for classes containing virtual methods, std::-objects or constructors

This commit is contained in:
PKEuS 2013-03-01 06:07:20 -08:00
parent 75799446aa
commit 096aae4439
3 changed files with 136 additions and 40 deletions
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110
lib/checkclass.cpp
View File

@ -817,53 +817,57 @@ void CheckClass::noMemset()
for (std::size_t i = 0; i < functions; ++i) {
const Scope * scope = symbolDatabase->functionScopes[i];
for (const Token *tok = scope->classStart; tok && tok != scope->classEnd; tok = tok->next()) {
if (!Token::Match(tok, "memset|memcpy|memmove ( %any%"))
continue;
const Token* arg1 = tok->tokAt(2);
const Token* arg3 = arg1;
arg3 = arg3->nextArgument();
if (arg3)
if (Token::Match(tok, "memset|memcpy|memmove ( %any%")) {
const Token* arg1 = tok->tokAt(2);
const Token* arg3 = arg1;
arg3 = arg3->nextArgument();
if (arg3)
arg3 = arg3->nextArgument();
const Token *typeTok = 0;
const Scope *type = 0;
if (Token::Match(arg3, "sizeof ( %type% ) )"))
typeTok = arg3->tokAt(2);
else if (Token::Match(arg3, "sizeof ( %type% :: %type% ) )"))
typeTok = arg3->tokAt(4);
else if (Token::Match(arg3, "sizeof ( struct %type% ) )"))
typeTok = arg3->tokAt(3);
else if (Token::simpleMatch(arg3, "sizeof ( * this ) )") || Token::simpleMatch(arg1, "this ,")) {
type = findFunctionOf(arg3->scope());
} else if (Token::Match(arg1, "&| %var% ,")) {
const Variable *var = arg1->str() == "&" ? arg1->next()->variable() : arg1->variable();
if (var && (arg1->str() == "&" || var->isPointer() || var->isArray()))
type = var->type();
const Token *typeTok = 0;
const Scope *type = 0;
if (Token::Match(arg3, "sizeof ( %type% ) )"))
typeTok = arg3->tokAt(2);
else if (Token::Match(arg3, "sizeof ( %type% :: %type% ) )"))
typeTok = arg3->tokAt(4);
else if (Token::Match(arg3, "sizeof ( struct %type% ) )"))
typeTok = arg3->tokAt(3);
else if (Token::simpleMatch(arg3, "sizeof ( * this ) )") || Token::simpleMatch(arg1, "this ,")) {
type = findFunctionOf(arg3->scope());
} else if (Token::Match(arg1, "&| %var% ,")) {
const Variable *var = arg1->str() == "&" ? arg1->next()->variable() : arg1->variable();
if (var && (arg1->str() == "&" || var->isPointer() || var->isArray()))
type = var->type();
}
// No type defined => The tokens didn't match
if (!typeTok && !type)
continue;
if (typeTok && typeTok->str() == "(")
typeTok = typeTok->next();
if (!type)
type = symbolDatabase->findVariableType(&(*scope), typeTok);
if (type)
checkMemsetType(&(*scope), tok, type, false);
} else if (tok->variable() && tok->variable()->type() && Token::Match(tok, "%var% = calloc|malloc|realloc|g_malloc|g_try_malloc|g_realloc|g_try_realloc (")) {
checkMemsetType(&(*scope), tok->tokAt(2), tok->variable()->type(), true);
if (tok->variable()->type()->numConstructors > 0 && _settings->isEnabled("warning"))
mallocOnClassWarning(tok, tok->strAt(2), tok->variable()->type()->classDef);
}
// No type defined => The tokens didn't match
if (!typeTok && !type)
continue;
if (typeTok && typeTok->str() == "(")
typeTok = typeTok->next();
if (!type)
type = symbolDatabase->findVariableType(&(*scope), typeTok);
if (type)
checkMemsetType(&(*scope), tok, type);
}
}
}
void CheckClass::checkMemsetType(const Scope *start, const Token *tok, const Scope *type)
void CheckClass::checkMemsetType(const Scope *start, const Token *tok, const Scope *type, bool allocation)
{
// recursively check all parent classes
for (std::size_t i = 0; i < type->derivedFrom.size(); i++) {
if (type->derivedFrom[i].scope)
checkMemsetType(start, tok, type->derivedFrom[i].scope);
checkMemsetType(start, tok, type->derivedFrom[i].scope, allocation);
}
// Warn if type is a class that contains any virtual functions
@ -871,7 +875,10 @@ void CheckClass::checkMemsetType(const Scope *start, const Token *tok, const Sco
for (func = type->functionList.begin(); func != type->functionList.end(); ++func) {
if (func->isVirtual)
memsetError(tok, tok->str(), "virtual method", type->classDef->str());
if (allocation)
mallocOnClassError(tok, tok->str(), type->classDef, "virtual method");
else
memsetError(tok, tok->str(), "virtual method", type->classDef->str());
}
// Warn if type is a class or struct that contains any std::* variables
@ -884,15 +891,40 @@ void CheckClass::checkMemsetType(const Scope *start, const Token *tok, const Sco
// check for std:: type
if (Token::simpleMatch(tok1, "std ::"))
memsetError(tok, tok->str(), "'std::" + tok1->strAt(2) + "'", type->classDef->str());
if (allocation)
mallocOnClassError(tok, tok->str(), type->classDef, "'std::" + tok1->strAt(2) + "'");
else
memsetError(tok, tok->str(), "'std::" + tok1->strAt(2) + "'", type->classDef->str());
// check for known type
else if (var->type())
checkMemsetType(start, tok, var->type());
checkMemsetType(start, tok, var->type(), allocation);
}
}
}
void CheckClass::mallocOnClassWarning(const Token* tok, const std::string &memfunc, const Token* classTok)
{
std::list<const Token *> toks;
toks.push_back(tok);
toks.push_back(classTok);
reportError(toks, Severity::warning, "mallocOnClassWarning",
"Memory for class instance allocated with " + memfunc + "(), but class provides constructors.\n"
"Memory for class instance allocated with " + memfunc + "(), but class provides constructors. This is unsafe, "
"since no constructor is called and class members remain uninitialized. Consider using 'new' instead.");
}
void CheckClass::mallocOnClassError(const Token* tok, const std::string &memfunc, const Token* classTok, const std::string &classname)
{
std::list<const Token *> toks;
toks.push_back(tok);
toks.push_back(classTok);
reportError(toks, Severity::error, "mallocOnClassError",
"Memory for class instance allocated with " + memfunc + "(), but class contains a " + classname + ".\n"
"Memory for class instance allocated with " + memfunc + "(), but class a " + classname + ". This is unsafe, "
"since no constructor is called and class members remain uninitialized. Consider using 'new' instead.");
}
void CheckClass::memsetError(const Token *tok, const std::string &memfunc, const std::string &classname, const std::string &type)
{
reportError(tok, Severity::error, "memsetClass", "Using '" + memfunc + "' on " + type + " that contains a " + classname + ".");

7
lib/checkclass.h
View File

@ -91,7 +91,7 @@ public:
* Important: The checking doesn't work on simplified tokens list.
*/
void noMemset();
void checkMemsetType(const Scope *start, const Token *tok, const Scope *type);
void checkMemsetType(const Scope *start, const Token *tok, const Scope *type, bool allocation);
/** @brief 'operator=' should return something and it should not be const. */
void operatorEq();
@ -130,6 +130,8 @@ private:
void operatorEqVarError(const Token *tok, const std::string &classname, const std::string &varname, bool inconclusive);
void unusedPrivateFunctionError(const Token *tok, const std::string &classname, const std::string &funcname);
void memsetError(const Token *tok, const std::string &memfunc, const std::string &classname, const std::string &type);
void mallocOnClassError(const Token* tok, const std::string &memfunc, const Token* classTok, const std::string &classname);
void mallocOnClassWarning(const Token* tok, const std::string &memfunc, const Token* classTok);
void operatorEqReturnError(const Token *tok, const std::string &className);
void virtualDestructorError(const Token *tok, const std::string &Base, const std::string &Derived);
void thisSubtractionError(const Token *tok);
@ -150,6 +152,8 @@ private:
c.operatorEqVarError(0, "classname", "", false);
c.unusedPrivateFunctionError(0, "classname", "funcname");
c.memsetError(0, "memfunc", "classname", "class");
c.mallocOnClassWarning(0, "malloc", 0);
c.mallocOnClassError(0, "malloc", 0, "std::string");
c.operatorEqReturnError(0, "class");
c.virtualDestructorError(0, "Base", "Derived");
c.thisSubtractionError(0);
@ -172,6 +176,7 @@ private:
"* Are all variables initialized by the constructors?\n"
"* Are all variables assigned by 'operator='?\n"
"* Warn if memset, memcpy etc are used on a class\n"
"* Warn if memory for classes is allocated with malloc()\n"
"* If it's a base class, check that the destructor is virtual\n"
"* Are there unused private functions?\n"
"* 'operator=' should return reference to self\n"

59
test/testclass.cpp
View File

@ -76,9 +76,11 @@ private:
TEST_CASE(operatorEqToSelf7);
TEST_CASE(operatorEqToSelf8); // ticket #2179
TEST_CASE(operatorEqToSelf9); // ticket #2592
TEST_CASE(memsetOnStruct);
TEST_CASE(memsetVector);
TEST_CASE(memsetOnClass);
TEST_CASE(mallocOnClass);
TEST_CASE(this_subtraction); // warn about "this-x"
@ -1948,6 +1950,7 @@ private:
errout.str("");
Settings settings;
settings.addEnabled("warning");
// Tokenize..
Tokenizer tokenizer(&settings, this);
@ -2304,6 +2307,62 @@ private:
ASSERT_EQUALS("", errout.str()); // #4460
}
void mallocOnClass() {
checkNoMemset("class C { C() {} };\n"
"void foo(C*& p) {\n"
" p = malloc(sizeof(C));\n"
"}");
ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:1]: (warning) Memory for class instance allocated with malloc(), but class provides constructors.\n", errout.str());
checkNoMemset("class C { C(int z, Foo bar) { bar(); } };\n"
"void foo(C*& p) {\n"
" p = malloc(sizeof(C));\n"
"}");
ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:1]: (warning) Memory for class instance allocated with malloc(), but class provides constructors.\n", errout.str());
checkNoMemset("struct C { C() {} };\n"
"void foo(C*& p) {\n"
" p = realloc(p, sizeof(C));\n"
"}");
ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:1]: (warning) Memory for class instance allocated with realloc(), but class provides constructors.\n", errout.str());
checkNoMemset("struct C { C() {} };\n"
"void foo(C*& p) {\n"
" p = realloc(p, sizeof(C));\n"
"}");
ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:1]: (warning) Memory for class instance allocated with realloc(), but class provides constructors.\n", errout.str());
checkNoMemset("struct C { virtual void bar(); };\n"
"void foo(C*& p) {\n"
" p = malloc(sizeof(C));\n"
"}");
ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:1]: (error) Memory for class instance allocated with malloc(), but class contains a virtual method.\n", errout.str());
checkNoMemset("struct C { std::string s; };\n"
"void foo(C*& p) {\n"
" p = malloc(sizeof(C));\n"
"}");
ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:1]: (error) Memory for class instance allocated with malloc(), but class contains a 'std::string'.\n", errout.str());
checkNoMemset("class C { };\n" // C-Style class/struct
"void foo(C*& p) {\n"
" p = malloc(sizeof(C));\n"
"}");
ASSERT_EQUALS("", errout.str());
checkNoMemset("struct C { C() {} };\n"
"void foo(C*& p) {\n"
" p = new C();\n"
"}");
ASSERT_EQUALS("", errout.str());
checkNoMemset("class C { C() {} };\n"
"void foo(D*& p) {\n" // Unknown type
" p = malloc(sizeof(C));\n"
"}");
ASSERT_EQUALS("", errout.str());
}
void checkThisSubtraction(const char code[]) {
// Clear the error log