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refactor (use ast) and improve CheckOther::checkRedundantAssignment (warn about global variables unless they are volatile, handle arrays in lhs better)

This commit is contained in:
Daniel Marjamäki 2016-07-18 12:43:23 +02:00
parent 72ead10d93
commit 0ddeac0429
4 changed files with 85 additions and 21 deletions
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72
lib/checkother.cpp
View File

@ -407,6 +407,13 @@ static bool nonLocal(const Variable* var)
return !var || (!var->isLocal() && !var->isArgument()) || var->isStatic() || var->isReference();
}
static bool nonLocalVolatile(const Variable* var)
{
if (var && var->isVolatile())
return false;
return nonLocal(var);
}
static void eraseNotLocalArg(std::map<unsigned int, const Token*>& container, const SymbolDatabase* symbolDatabase)
{
for (std::map<unsigned int, const Token*>::iterator i = container.begin(); i != container.end();) {
@ -493,6 +500,18 @@ void CheckOther::checkRedundantAssignment()
varAssignments.clear();
memAssignments.clear();
} else if (tok->tokType() == Token::eVariable && !Token::Match(tok, "%name% (")) {
const Token *eq = nullptr;
for (const Token *tok2 = tok; tok2; tok2 = tok2->next()) {
if (Token::Match(tok2, "[([]"))
tok2 = tok2->link();
else if (Token::Match(tok2, "[)];,]"))
break;
else if (tok2->str() == "=") {
eq = tok2;
break;
}
}
// Set initialization flag
if (!Token::Match(tok, "%var% ["))
initialized.insert(tok->varId());
@ -512,19 +531,48 @@ void CheckOther::checkRedundantAssignment()
}
std::map<unsigned int, const Token*>::iterator it = varAssignments.find(tok->varId());
if (Token::simpleMatch(tok->next(), "=") && Token::Match(startToken, "[;{}]")) { // Assignment
if (eq && Token::Match(startToken, "[;{}]")) { // Assignment
if (it != varAssignments.end()) {
bool error = true; // Ensure that variable is not used on right side
for (const Token* tok2 = tok->tokAt(2); tok2; tok2 = tok2->next()) {
if (tok2->str() == ";")
const Token *oldeq = nullptr;
for (const Token *tok2 = it->second; tok2; tok2 = tok2->next()) {
if (Token::Match(tok2, "[([]"))
tok2 = tok2->link();
else if (Token::Match(tok2, "[)];,]"))
break;
else if (tok2->varId() == tok->varId()) {
else if (Token::Match(tok2, "++|--|=")) {
oldeq = tok2;
break;
}
}
if (!oldeq) {
const Token *tok2 = it->second;
while (Token::Match(tok2, "%name%|.|[|*|("))
tok2 = tok2->astParent();
if (Token::Match(tok2, "++|--"))
oldeq = tok2;
}
// Ensure that LHS in assignments are the same
bool error = oldeq && isSameExpression(_tokenizer->isCPP(), true, eq->astOperand1(), oldeq->astOperand1(), _settings->library.functionpure);
// Ensure that variable is not used on right side
std::stack<const Token *> tokens;
tokens.push(eq->astOperand2());
while (!tokens.empty()) {
const Token *rhs = tokens.top();
tokens.pop();
if (!rhs)
continue;
tokens.push(rhs->astOperand1());
tokens.push(rhs->astOperand2());
if (rhs->varId() == tok->varId()) {
error = false;
break;
} else if (Token::Match(tok2, "%name% (") && nonLocal(tok->variable())) { // Called function might use the variable
const Function* const func = tok2->function();
}
if (Token::Match(rhs->previous(), "%name% (") && nonLocalVolatile(tok->variable())) { // Called function might use the variable
const Function* const func = rhs->function();
const Variable* const var = tok->variable();
if (!var || var->isGlobal() || var->isReference() || ((!func || func->nestedIn) && tok2->strAt(-1) != ".")) {// Global variable, or member function
if (!var || var->isGlobal() || var->isReference() || ((!func || func->nestedIn) && rhs->strAt(-1) != ".")) {// Global variable, or member function
error = false;
break;
}
@ -532,13 +580,13 @@ void CheckOther::checkRedundantAssignment()
}
if (error) {
if (printWarning && scope->type == Scope::eSwitch && Token::findmatch(it->second, "default|case", tok))
redundantAssignmentInSwitchError(it->second, tok, tok->str());
redundantAssignmentInSwitchError(it->second, tok, eq->astOperand1()->expressionString());
else if (printPerformance) {
// See #7133
const bool nonlocal = it->second->variable() && nonLocal(it->second->variable());
if (printInconclusive || !nonlocal) // see #5089 - report inconclusive only when requested
const bool nonlocal = it->second->variable() && nonLocalVolatile(it->second->variable());
if (printInconclusive || !nonlocal) // report inconclusive only when requested
if (_tokenizer->isC() || checkExceptionHandling(tok)) // see #6555 to see how exception handling might have an impact
redundantAssignmentError(it->second, tok, tok->str(), nonlocal); // Inconclusive for non-local variables
redundantAssignmentError(it->second, tok, eq->astOperand1()->expressionString(), nonlocal); // Inconclusive for non-local variables
}
}
it->second = tok;

2
lib/symboldatabase.cpp
View File

@ -1613,6 +1613,8 @@ void Variable::evaluate(const Library* lib)
setFlag(fIsStatic, true);
else if (tok->str() == "extern")
setFlag(fIsExtern, true);
else if (tok->str() == "volatile")
setFlag(fIsVolatile, true);
else if (tok->str() == "mutable")
setFlag(fIsMutable, true);
else if (tok->str() == "const")

11
lib/symboldatabase.h
View File

@ -159,7 +159,8 @@ class CPPCHECKLIB Variable {
fHasDefault = (1 << 9), /** @brief function argument with default value */
fIsStlType = (1 << 10), /** @brief STL type ('std::') */
fIsStlString = (1 << 11), /** @brief std::string|wstring|basic_string&lt;T&gt;|u16string|u32string */
fIsFloatType = (1 << 12) /** @brief Floating point type */
fIsFloatType = (1 << 12), /** @brief Floating point type */
fIsVolatile = (1 << 13) /** @brief volatile */
};
/**
@ -339,6 +340,14 @@ public:
return getFlag(fIsMutable);
}
/**
* Is variable volatile.
* @return true if volatile, false if not
*/
bool isVolatile() const {
return getFlag(fIsVolatile);
}
/**
* Is variable static.
* @return true if static, false if not

21
test/testother.cpp
View File

@ -4907,6 +4907,13 @@ private:
"}");
ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:4]: (style, inconclusive) Variable 'i' is reassigned a value before the old one has been used if variable is no semaphore variable.\n", errout.str());
check("void f() {\n"
" int i[10];\n"
" i[2] = 1;\n"
" i[2] = 1;\n"
"}", nullptr, false, false, false);
ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:4]: (style) Variable 'i[2]' is reassigned a value before the old one has been used.\n", errout.str());
// Testing different types
check("void f() {\n"
" Foo& bar = foo();\n"
@ -5041,7 +5048,7 @@ private:
" x = 2;\n"
" x = z.g();\n"
"}");
ASSERT_EQUALS("[test.cpp:8] -> [test.cpp:9]: (style, inconclusive) Variable 'x' is reassigned a value before the old one has been used if variable is no semaphore variable.\n", errout.str());
ASSERT_EQUALS("", errout.str());
// from #3103 (avoid a false negative)
check("int foo(){\n"
@ -5097,7 +5104,7 @@ private:
" ab.a = 2;\n"
" return ab.a;\n"
"}");
ASSERT_EQUALS("[test.cpp:5] -> [test.cpp:6]: (style, inconclusive) Variable 'a' is reassigned a value before the old one has been used if variable is no semaphore variable.\n", errout.str());
ASSERT_EQUALS("[test.cpp:5] -> [test.cpp:6]: (style) Variable 'ab.a' is reassigned a value before the old one has been used.\n", errout.str());
check("struct AB { int a; int b; };\n"
"\n"
@ -5257,9 +5264,7 @@ private:
" catch (const uno::Exception&) {\n"
" }\n"
"}", "test.cpp", false, true);
TODO_ASSERT_EQUALS("",
"[test.cpp:6] -> [test.cpp:9]: (style) Variable 'Name' is reassigned a value before the old one has been used.\n",
errout.str());
ASSERT_EQUALS("", errout.str());
check("void ConvertBitmapData(sal_uInt16 nDestBits) {\n"
"BitmapBuffer aSrcBuf;\n"
@ -5268,7 +5273,7 @@ private:
" aSrcBuf.mnBitCount = nDestBits;\n"
" bConverted = ::ImplFastBitmapConversion( aDstBuf, aSrcBuf, aTwoRects );\n"
"}", "test.c");
ASSERT_EQUALS("[test.c:3] -> [test.c:5]: (style) Variable 'mnBitCount' is reassigned a value before the old one has been used.\n", errout.str());
ASSERT_EQUALS("[test.c:3] -> [test.c:5]: (style) Variable 'aSrcBuf.mnBitCount' is reassigned a value before the old one has been used.\n", errout.str());
check("void ConvertBitmapData(sal_uInt16 nDestBits) {\n"
"BitmapBuffer aSrcBuf;\n"
" aSrcBuf.mnBitCount = nSrcBits;\n"
@ -5276,8 +5281,8 @@ private:
" aSrcBuf.mnBitCount = nDestBits;\n"
" bConverted = ::ImplFastBitmapConversion( aDstBuf, aSrcBuf, aTwoRects );\n"
"}");
TODO_ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:5]: (style, inconclusive) Variable 'mnBitCount' is reassigned a value before the old one has been used.\n",
"[test.cpp:3] -> [test.cpp:5]: (style) Variable 'mnBitCount' is reassigned a value before the old one has been used.\n",
TODO_ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:5]: (style, inconclusive) Variable 'aSrcBuf.mnBitCount' is reassigned a value before the old one has been used.\n",
"[test.cpp:3] -> [test.cpp:5]: (style) Variable 'aSrcBuf.mnBitCount' is reassigned a value before the old one has been used.\n",
errout.str());
}