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Fixed #3796 (new check: redundant initialization with empty string)

This commit is contained in:
Pranav Khanna 2014-03-03 18:27:45 +01:00 committed by Daniel Marjamäki
parent 470f1579c1
commit f8a4fb91fe
3 changed files with 163 additions and 1 deletions
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87
lib/checkstl.cpp
View File

@ -1553,3 +1553,90 @@ void CheckStl::dereferenceInvalidIteratorError(const Token* deref, const std::st
"derefInvalidIterator", "Possible dereference of an invalid iterator: " + iterName + "\n" +
"Make sure to check that the iterator is valid before dereferencing it - not after.");
}
void CheckStl::readingEmptyStlContainer()
{
if (!_settings->isEnabled("style"))
return;
if (!_settings->inconclusive) // check only if inconclusive true;
return;
std::map<unsigned int, bool> empty; //map to keep track of whether the StlContainer has been given value atleast once.
static const char *STL_CONTAINERS[] = {"map", "vector"};
const SymbolDatabase* symbolDatabase = _tokenizer->getSymbolDatabase();
std::size_t varListSize = symbolDatabase->getVariableListSize();
for (std::size_t i = 1; i < varListSize; ++i) {
// to include stl containers declared in file in used map
const Variable* var = symbolDatabase->getVariableFromVarId(i);
if (var && var->isLocal() && var->isStlType(STL_CONTAINERS))
empty[var->declarationId()] = true;
}
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
bool stl1_exist = false;
bool stl2_exist = false;
bool stl2_isEmpty = true;
if (tok->variable() && tok->variable()->isStlType(STL_CONTAINERS)) {
if (empty.find(tok->varId()) != empty.end())
stl1_exist = true;
}
// to check for various conditions for the way stl containers and variables can be used
if (Token::Match(tok, "%var% =|[")) {
const Token *tok2;
if (Token::Match(tok->next(), "="))
tok2 = tok->tokAt(2);
// to check cases like Cmap[1]; or i = Cmap[1] -- the right wld evaluate true when token reaches it.
else if (Token::Match(tok->next()," [") && Token::Match(tok->linkAt(1),"] ="))
tok2 = tok->next()->link()->tokAt(2);
else
continue;
// rhs variable
if (tok2->variable() && tok2->variable()->isStlType(STL_CONTAINERS)) {
if (empty.find(tok2->varId()) != empty.end()) {
stl2_exist = true;
stl2_isEmpty = empty[tok2->varId()];
}
}
// if both var are Stl Container...
if (stl1_exist && stl2_exist) {
if (stl2_isEmpty)
readingEmptyStlContainerError(tok2);
else
empty[tok->varId()] = false;
}
// if only second var is Stl Container
else if (stl2_exist && stl2_isEmpty)
readingEmptyStlContainerError(tok);
// if only first var is stl container
else if (stl1_exist)
empty[tok->varId()] = false;
} else if (stl1_exist && Token::Match(tok, "%var% [ %any% ] = %any%")) {
empty[tok->varId()] = false;
} else if (stl1_exist && Token::Match(tok, "%var% . %type% (")) {
//static const char STL_CONTAINER_INSERT_FUNCTIONS[] = "%var% . insert|push_back|push_front|assign|set|reset|emplace_after|insert_after|push (";
empty[tok->varId()] = false;
}
}
}
void CheckStl::readingEmptyStlContainerError(const Token *tok)
{
reportError(tok, Severity::style, "reademptycontainer", "Reading from empty STL container", true);
}

10
lib/checkstl.h
View File

@ -66,6 +66,7 @@ public:
checkStl.size();
checkStl.redundantCondition();
checkStl.missingComparison();
checkStl.readingEmptyStlContainer();
}
@ -146,6 +147,9 @@ public:
*/
void dereferenceErasedError(const Token* erased, const Token* deref, const std::string &itername);
/** @brief Reading from empty stl container */
void readingEmptyStlContainer();
private:
/**
@ -184,6 +188,8 @@ private:
void dereferenceInvalidIteratorError(const Token* deref, const std::string &itername);
void readingEmptyStlContainerError(const Token *tok);
void getErrorMessages(ErrorLogger *errorLogger, const Settings *settings) const {
CheckStl c(0, settings, errorLogger);
c.invalidIteratorError(0, "iterator");
@ -211,6 +217,7 @@ private:
c.uselessCallsEmptyError(0);
c.uselessCallsRemoveError(0, "remove");
c.dereferenceInvalidIteratorError(0, "i");
c.readingEmptyStlContainerError(0);
}
static std::string myName() {
@ -230,7 +237,8 @@ private:
"* common mistakes when using string::c_str()\n"
"* using auto pointer (auto_ptr)\n"
"* useless calls of string and STL functions\n"
"* dereferencing an invalid iterator\n";
"* dereferencing an invalid iterator\n"
"* reading from empty STL container\n";
}
};
/// @}

67
test/teststl.cpp
View File

@ -128,6 +128,7 @@ private:
TEST_CASE(dereferenceInvalidIterator);
TEST_CASE(dereference_auto);
TEST_CASE(readingEmptyStlContainer);
}
void check(const char code[], const bool inconclusive=false) {
@ -2394,6 +2395,72 @@ private:
"}\n");
ASSERT_EQUALS("", errout.str());
}
void readingEmptyStlContainer() {
check("void f() {\n"
" std::map<int, std::string> CMap;\n"
" std::string strValue = CMap[1]; \n"
" std::cout << strValue << CMap.size() << std::endl;\n"
"}\n",true);
ASSERT_EQUALS("[test.cpp:3]: (style, inconclusive) Reading from empty STL container\n", errout.str());
check("void f() {\n"
" std::map<int,std::string> CMap;\n"
" std::string strValue = CMap[1];"
"}\n",true);
ASSERT_EQUALS("[test.cpp:3]: (style, inconclusive) Reading from empty STL container\n", errout.str());
check("void f() {\n"
" std::map<int,std::string> CMap;\n"
" CMap[1] = \"123\";\n"
" std::string strValue = CMap[1];"
"}\n",true);
ASSERT_EQUALS("", errout.str());
check("std::vector<std::string> f() {\n"
" try {\n"
" std::vector<std::string> Vector;\n"
" std::vector<std::string> v2 = Vector;\n"
" std::string strValue = v2[1]; \n"
" }\n"
" return Vector;\n"
"}\n",true);
ASSERT_EQUALS("[test.cpp:4]: (style, inconclusive) Reading from empty STL container\n"
"[test.cpp:5]: (style, inconclusive) Reading from empty STL container\n", errout.str());
check("f() {\n"
" try {\n"
" std::vector<std::string> Vector;\n"
" Vector.push_back(\"123\");\n"
" std::vector<std::string> v2 = Vector;\n"
" std::string strValue = v2[0]; \n"
" }\n"
" return Vector;\n"
"}\n", true);
ASSERT_EQUALS("", errout.str());
check("void f() {\n"
" std::map<std::string,std::string> mymap;\n"
" mymap[\"Bakery\"] = \"Barbara\";\n"
" std:string bakery_name = mymap[\"Bakery\"];\n"
"}\n", true);
ASSERT_EQUALS("", errout.str());
check("void f() {\n"
" std::vector<int> v;\n"
" v.insert(1);\n"
" int i = v[0];\n"
"}\n", true);
ASSERT_EQUALS("", errout.str());
check("void f() {\n"
" std::map<int, std::string> CMap;\n"
" std::string strValue = CMap[1];\n"
" std::string strValue2 = CMap[1];\n"
"}\n", true);
ASSERT_EQUALS("[test.cpp:3]: (style, inconclusive) Reading from empty STL container\n"
"[test.cpp:4]: (style, inconclusive) Reading from empty STL container\n", errout.str());
}
};
REGISTER_TEST(TestStl)