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Fix #1655 wrong usage of std::string in memcpy #4460

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Merged
orbitcowboy merged 2 commits into from
Sep 13, 2022
Merged

Fix #1655 wrong usage of std::string in memcpy #4460

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abe6968
Fix #1655 wrong usage of std::string in memcpy
chrchr-github Sep 12, 2022
b0940ad
Merge branch 'danmar:main' into chr_Fix1655
chrchr-github Sep 13, 2022
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21 changes: 13 additions & 8 deletions lib/checkclass.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1353,6 +1353,10 @@ void CheckClass::checkMemset()

if (numIndirToVariableType == 1)
type = var->typeScope();

if (!type && mSettings->library.detectContainerOrIterator(var->typeStartToken())) {
memsetError(tok, tok->str(), var->getTypeName(), {}, /*isContainer*/ true);
}
}
}

Expand Down Expand Up @@ -1468,15 +1472,16 @@ void CheckClass::mallocOnClassError(const Token* tok, const std::string &memfunc
"since no constructor is called and class members remain uninitialized. Consider using 'new' instead.", CWE665, Certainty::normal);
}

void CheckClass::memsetError(const Token *tok, const std::string &memfunc, const std::string &classname, const std::string &type)
void CheckClass::memsetError(const Token *tok, const std::string &memfunc, const std::string &classname, const std::string &type, bool isContainer)
{
reportError(tok, Severity::error, "memsetClass",
"$symbol:" + memfunc +"\n"
"$symbol:" + classname +"\n"
"Using '" + memfunc + "' on " + type + " that contains a " + classname + ".\n"
"Using '" + memfunc + "' on " + type + " that contains a " + classname + " is unsafe, because constructor, destructor "
"and copy operator calls are omitted. These are necessary for this non-POD type to ensure that a valid object "
"is created.", CWE762, Certainty::normal);
const std::string typeStr = isContainer ? std::string() : (type + " that contains a ");
const std::string msg = "$symbol:" + memfunc + "\n"
"$symbol:" + classname + "\n"
"Using '" + memfunc + "' on " + typeStr + classname + ".\n"
"Using '" + memfunc + "' on " + typeStr + classname + " is unsafe, because constructor, destructor "
"and copy operator calls are omitted. These are necessary for this non-POD type to ensure that a valid object "
"is created.";
reportError(tok, Severity::error, "memsetClass", msg, CWE762, Certainty::normal);
}

void CheckClass::memsetErrorReference(const Token *tok, const std::string &memfunc, const std::string &type)
Expand Down
2 changes: 1 addition & 1 deletion lib/checkclass.h
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Expand Up @@ -206,7 +206,7 @@ class CPPCHECKLIB CheckClass : public Check {
void missingMemberCopyError(const Token *tok, Function::Type functionType, const std::string& classname, const std::string& varname);
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 memsetError(const Token *tok, const std::string &memfunc, const std::string &classname, const std::string &type, bool isContainer = false);
void memsetErrorReference(const Token *tok, const std::string &memfunc, const std::string &type);
void memsetErrorFloat(const Token *tok, const std::string &type);
void mallocOnClassError(const Token* tok, const std::string &memfunc, const Token* classTok, const std::string &classname);
Expand Down
10 changes: 10 additions & 0 deletions test/testclass.cpp
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Expand Up @@ -3109,6 +3109,16 @@ class TestClass : public TestFixture {
" memset(b, 0, sizeof(b));\n"
"}");
ASSERT_EQUALS("", errout.str());

// #1655
Settings s;
LOAD_LIB_2(s.library, "std.cfg");
checkNoMemset("void f() {\n"
" char c[] = \"abc\";\n"
" std::string s;\n"
" memcpy(&s, c, strlen(c) + 1);\n"
"}\n", s);
ASSERT_EQUALS("[test.cpp:4]: (error) Using 'memcpy' on std::string.\n", errout.str());
}

void memsetOnInvalid() { // Ticket #5425
Expand Down