Exception safety: Removed the noisy checks and keep the useful checks

This commit is contained in:
Daniel Marjamäki 2010-08-31 22:22:59 +02:00
parent b2a775f3e0
commit 3a8e7b4bf0
5 changed files with 0 additions and 353 deletions

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@ -73,216 +73,6 @@ void CheckExceptionSafety::destructors()
} }
void CheckExceptionSafety::unsafeNew()
{
if (!_settings->isEnabled("exceptNew"))
return;
// Inspect initializer lists..
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
if (tok->str() != ")")
continue;
tok = tok->next();
if (!tok)
break;
if (tok->str() != ":")
continue;
// multiple "new" in an initializer list..
std::string varname;
for (tok = tok->next(); tok; tok = tok->next())
{
if (!Token::Match(tok, "%var% ("))
break;
tok = tok->next();
if (Token::Match(tok->next(), "new %type%"))
{
if (!varname.empty())
{
unsafeNewError(tok->previous(), varname);
break;
}
/*
// TODO: check if class is autodeallocated+might throw exception in constructor
if (!_settings->isAutoDealloc(tok->strAt(2)))
{
varname = tok->strAt(-1);
}
*/
}
tok = tok->link();
tok = tok ? tok->next() : 0;
if (!tok)
break;
if (tok->str() != ",")
break;
}
if (!tok)
break;
}
// Inspect constructors..
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
// match this pattern.. "C :: C ( .. ) {"
if (!tok->next() || tok->next()->str() != "::")
continue;
if (!Token::Match(tok, "%var% :: %var% ("))
continue;
if (tok->str() != tok->strAt(2))
continue;
if (!Token::simpleMatch(tok->tokAt(3)->link(), ") {"))
continue;
// inspect the constructor..
std::string varname;
for (tok = tok->tokAt(3)->link()->tokAt(2); tok; tok = tok->next())
{
if (tok->str() == "{" || tok->str() == "}")
break;
// some variable declaration..
if (Token::Match(tok->previous(), "[{;] %type% * %var% ;"))
break;
// allocating with new..
if (Token::Match(tok, "%var% = new %type%"))
{
if (!varname.empty())
{
unsafeNewError(tok, varname);
break;
}
/*
TODO: check is class is autodeallocated + might throw exceptions in the constructor
if (!_settings->isAutoDealloc(tok->strAt(3)))
varname = tok->str();
*/
}
}
}
// allocating multiple local variables..
std::set<unsigned int> localVars;
std::string varname;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
if (tok->str() == "{" || tok->str() == "}")
{
localVars.clear();
varname = "";
}
if (Token::Match(tok, "[;{}] %type% * %var% ;") &&
tok->tokAt(1)->isStandardType())
{
tok = tok->tokAt(3);
if (tok->varId())
localVars.insert(tok->varId());
}
if (Token::Match(tok, "[;{}] %var% = new %type%"))
{
if (!varname.empty())
{
unsafeNewError(tok->next(), varname);
break;
}
if (tok->next()->varId() && localVars.find(tok->next()->varId()) != localVars.end())
varname = tok->strAt(1);
}
else if (Token::Match(tok, "[;{}] %var% ("))
{
// False negatives: we don't handle switch cases properly so we just bail out.
if (tok->strAt(1) == "switch")
break;
for (tok = tok->next(); tok && !Token::Match(tok, "[;{}]"); tok = tok->next())
{
if (tok->str() == varname)
{
varname = "";
}
}
if (!tok)
break;
}
else if (tok->str() == "delete")
{
if (Token::simpleMatch(tok->next(), varname.c_str()) ||
Token::simpleMatch(tok->next(), ("[ ] " + varname).c_str()))
{
varname = "";
}
}
}
}
void CheckExceptionSafety::realloc()
{
if (!_settings->isEnabled("exceptRealloc"))
return;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
if (Token::simpleMatch(tok, "try {"))
{
tok = tok->next()->link();
if (!tok)
break;
}
if (!Token::Match(tok, "[{};] delete"))
continue;
tok = tok->tokAt(2);
if (Token::simpleMatch(tok, "[ ]"))
tok = tok->tokAt(2);
if (!tok)
break;
// reallocating..
if (!Token::Match(tok, "%var% ; %var% = new %type%"))
continue;
// variable id of deallocated pointer..
const unsigned int varid(tok->varId());
if (varid == 0)
continue;
// variable id of allocated pointer must match..
if (varid != tok->tokAt(2)->varId())
continue;
// is is a class member variable..
const Token *tok1 = Token::findmatch(_tokenizer->tokens(), "%varid%", varid);
while (0 != (tok1 = tok1 ? tok1->previous() : 0))
{
if (tok1->str() == "}")
tok1 = tok1->link();
else if (tok1->str() == "{")
{
if (tok1->previous() && tok1->previous()->isName())
{
while (0 != (tok1 = tok1 ? tok1->previous() : 0))
{
if (!tok1->isName() && tok1->str() != ":" && tok1->str() != ",")
break;
if (tok1->str() == "class")
{
reallocError(tok->tokAt(2), tok->str());
break;
}
}
}
break;
}
}
}
}
void CheckExceptionSafety::deallocThrow() void CheckExceptionSafety::deallocThrow()

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@ -55,8 +55,6 @@ public:
{ {
CheckExceptionSafety checkExceptionSafety(tokenizer, settings, errorLogger); CheckExceptionSafety checkExceptionSafety(tokenizer, settings, errorLogger);
checkExceptionSafety.destructors(); checkExceptionSafety.destructors();
checkExceptionSafety.unsafeNew();
checkExceptionSafety.realloc();
checkExceptionSafety.deallocThrow(); checkExceptionSafety.deallocThrow();
} }
@ -64,12 +62,6 @@ public:
/** Don't throw exceptions in destructors */ /** Don't throw exceptions in destructors */
void destructors(); void destructors();
/** unsafe use of "new" */
void unsafeNew();
/** Unsafe realloc */
void realloc();
/** deallocating memory and then throw */ /** deallocating memory and then throw */
void deallocThrow(); void deallocThrow();
@ -80,18 +72,6 @@ private:
reportError(tok, Severity::style, "exceptThrowInDestructor", "Throwing exception in destructor"); reportError(tok, Severity::style, "exceptThrowInDestructor", "Throwing exception in destructor");
} }
/** Unsafe use of new */
void unsafeNewError(const Token * const tok, const std::string &varname)
{
reportError(tok, Severity::style, "exceptNew", "Upon exception there is memory leak: " + varname);
}
/** Unsafe reallocation */
void reallocError(const Token * const tok, const std::string &varname)
{
reportError(tok, Severity::style, "exceptRealloc", "Upon exception " + varname + " becomes a dead pointer");
}
void deallocThrowError(const Token * const tok, const std::string &varname) void deallocThrowError(const Token * const tok, const std::string &varname)
{ {
reportError(tok, Severity::error, "exceptDeallocThrow", "Throwing exception in invalid state, " + varname + " points at deallocated memory"); reportError(tok, Severity::error, "exceptDeallocThrow", "Throwing exception in invalid state, " + varname + " points at deallocated memory");
@ -101,8 +81,6 @@ private:
void getErrorMessages() void getErrorMessages()
{ {
destructorsError(0); destructorsError(0);
unsafeNewError(0, "p");
reallocError(0, "p");
deallocThrowError(0, "p"); deallocThrowError(0, "p");
} }
@ -117,8 +95,6 @@ private:
{ {
return "Checking exception safety\n" return "Checking exception safety\n"
"* Throwing exceptions in destructors\n" "* Throwing exceptions in destructors\n"
"* Unsafe use of 'new'\n"
"* Unsafe reallocation\n"
"* Throwing exception during invalid state"; "* Throwing exception during invalid state";
} }
}; };

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@ -602,8 +602,6 @@ bool CppCheck::parseFromArgs(int argc, const char* const argv[])
" Example: -DDEBUG=1 -D__cplusplus\n" " Example: -DDEBUG=1 -D__cplusplus\n"
" --enable=id Enable additional checks. The available ids are:\n" " --enable=id Enable additional checks. The available ids are:\n"
" * all - enable all checks\n" " * all - enable all checks\n"
" * exceptNew - exception safety when using new\n"
" * exceptRealloc - exception safety when reallocating\n"
" * style - Check coding style\n" " * style - Check coding style\n"
" * unusedFunctions - check for unused functions\n" " * unusedFunctions - check for unused functions\n"
" Several ids can be given if you separate them with commas\n" " Several ids can be given if you separate them with commas\n"

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@ -188,8 +188,6 @@ std::string Settings::addEnabled(const std::string &str)
handled = _checkCodingStyle = true; handled = _checkCodingStyle = true;
std::set<std::string> id; std::set<std::string> id;
id.insert("exceptNew");
id.insert("exceptRealloc");
id.insert("unusedFunctions"); id.insert("unusedFunctions");
if (str == "all") if (str == "all")

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@ -35,9 +35,6 @@ private:
void run() void run()
{ {
TEST_CASE(destructors); TEST_CASE(destructors);
TEST_CASE(newnew);
TEST_CASE(switchnewnew);
TEST_CASE(realloc);
TEST_CASE(deallocThrow); TEST_CASE(deallocThrow);
} }
@ -68,118 +65,6 @@ private:
ASSERT_EQUALS("[test.cpp:3]: (style) Throwing exception in destructor\n", errout.str()); ASSERT_EQUALS("[test.cpp:3]: (style) Throwing exception in destructor\n", errout.str());
} }
void newnew()
{
check("C::C() : a(new A), b(new B) { }");
ASSERT_EQUALS("", errout.str());
TODO_ASSERT_EQUALS("[test.cpp:1]: (style) Upon exception there is memory leak: a\n", errout.str());
check("C::C()\n"
"{\n"
" a = new A;\n"
" b = new B;\n"
"}\n");
ASSERT_EQUALS("", errout.str());
TODO_ASSERT_EQUALS("[test.cpp:4]: (style) Upon exception there is memory leak: a\n", errout.str());
check("void a()\n"
"{\n"
" A *a1 = new A;\n"
" A *a2 = new A;\n"
"}\n");
ASSERT_EQUALS("", errout.str());
TODO_ASSERT_EQUALS("[test.cpp:4]: (style) Upon exception there is memory leak: a1\n", errout.str());
check("void a()\n"
"{\n"
" A *a1 = new A;\n"
" A *a2 = new (std::nothrow) A;\n"
"}\n");
ASSERT_EQUALS("", errout.str());
check("void a()\n"
"{\n"
" A *a1 = new A;\n"
" delete a1;\n"
" A *a2 = new A;\n"
" delete a2;\n"
"}\n");
ASSERT_EQUALS("", errout.str());
check("void a()\n"
"{\n"
" A *a = new A;\n"
" B *b = new B;\n"
"}\n");
ASSERT_EQUALS("", errout.str());
// passing pointer to unknown function.. the pointer may be added to some list etc..
check("void f()\n"
"{\n"
" A *a1 = new A;\n"
" add(a1);\n"
" A *a2 = new A;\n"
"}\n");
ASSERT_EQUALS("", errout.str());
}
void switchnewnew()
{
check("int *f(int x)\n"
"{\n"
" int *p = 0;\n"
" switch(x)\n"
" {\n"
" case 1:\n"
" p = new int(10);\n"
" break;\n"
" case 2:\n"
" p = new int(100);\n"
" break;\n"
" };\n"
" return p;\n"
"}\n");
ASSERT_EQUALS("", errout.str());
}
void realloc()
{
check("class A\n"
"{\n"
" int *p;\n"
" void a()\n"
" {\n"
" delete p;\n"
" p = new int[123];\n"
" }\n"
"}\n");
ASSERT_EQUALS("[test.cpp:7]: (style) Upon exception p becomes a dead pointer\n", errout.str());
check("class A\n"
"{\n"
" int *p;\n"
" void a()\n"
" {\n"
" delete p;\n"
" p = new (std::nothrow) int[123];\n"
" }\n"
"}\n");
ASSERT_EQUALS("", errout.str());
check("class A\n"
"{\n"
" int *p;\n"
" void a()\n"
" {\n"
" try {\n"
" delete p;\n"
" p = new int[123];\n"
" } catch (...) { p = 0; }\n"
" }\n"
"}\n");
ASSERT_EQUALS("", errout.str());
}
void deallocThrow() void deallocThrow()
{ {
check("int * p;\n" check("int * p;\n"