ValueFlow: Improved handling of sizeof

This commit is contained in:
Daniel Marjamäki 2016-12-18 14:03:48 +01:00
parent 461e5cc5c9
commit 17aaecbd6b
4 changed files with 76 additions and 1 deletions

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@ -4650,6 +4650,13 @@ void SymbolDatabase::setValueTypeInTokenList(Token *tokens, bool cpp, const Sett
}
}
ValueType ValueType::parseDecl(const Token *type, const Settings *settings)
{
ValueType vt;
parsedecl(type, &vt, settings->defaultSign == 'u' ? Sign::UNSIGNED : Sign::SIGNED, settings);
return vt;
}
bool ValueType::fromLibraryType(const std::string &typestr, const Settings *settings)
{
const Library::PodType* podtype = settings->library.podtype(typestr);

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@ -1153,6 +1153,8 @@ public:
ValueType(enum Sign s, enum Type t, unsigned int p, unsigned int c) : sign(s), type(t), pointer(p), constness(c), typeScope(nullptr) {}
ValueType(enum Sign s, enum Type t, unsigned int p, unsigned int c, const std::string &otn) : sign(s), type(t), pointer(p), constness(c), typeScope(nullptr), originalTypeName(otn) {}
static ValueType parseDecl(const Token *type, const Settings *settings);
bool isIntegral() const {
return (type >= ValueType::Type::BOOL && type <= ValueType::Type::UNKNOWN_INT);
}

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@ -649,7 +649,7 @@ static Token * valueFlowSetConstantValue(const Token *tok, const Settings *setti
ValueFlow::Value value(0);
value.setKnown();
setTokenValue(const_cast<Token *>(tok), value, settings);
} else if (Token::simpleMatch(tok, "sizeof (") && tok->tokAt(2)) {
} else if (Token::simpleMatch(tok, "sizeof (")) {
const Token *tok2 = tok->tokAt(2);
if (tok2->enumerator() && tok2->enumerator()->scope) {
long long size = settings->sizeof_int;
@ -681,6 +681,56 @@ static Token * valueFlowSetConstantValue(const Token *tok, const Settings *setti
value.setKnown();
setTokenValue(const_cast<Token *>(tok), value, settings);
setTokenValue(const_cast<Token *>(tok->next()), value, settings);
} else if (Token::Match(tok, "sizeof ( %var% ) / sizeof (") && tok->next()->astParent() == tok->tokAt(4)) {
// Get number of elements in array
const Token *sz1 = tok->tokAt(2);
const Token *sz2 = tok->tokAt(7);
const unsigned int varid1 = sz1->varId();
if (varid1 &&
sz1->variable() &&
sz1->variable()->isArray() &&
!sz1->variable()->dimensions().empty() &&
sz1->variable()->dimensionKnown(0) &&
(Token::Match(sz2, "* %varid% )", varid1) || Token::Match(sz2, "%varid% [ 0 ] )", varid1))) {
ValueFlow::Value value(sz1->variable()->dimension(0));
value.setKnown();
setTokenValue(const_cast<Token *>(tok->tokAt(4)), value, settings);
}
} else if (!tok2->type()) {
const ValueType &vt = ValueType::parseDecl(tok2,settings);
if (vt.pointer) {
ValueFlow::Value value(settings->sizeof_pointer);
value.setKnown();
setTokenValue(const_cast<Token *>(tok->next()), value, settings);
} else if (vt.type == ValueType::Type::CHAR) {
ValueFlow::Value value(1);
value.setKnown();
setTokenValue(const_cast<Token *>(tok->next()), value, settings);
} else if (vt.type == ValueType::Type::SHORT) {
ValueFlow::Value value(settings->sizeof_short);
value.setKnown();
setTokenValue(const_cast<Token *>(tok->next()), value, settings);
} else if (vt.type == ValueType::Type::INT) {
ValueFlow::Value value(settings->sizeof_int);
value.setKnown();
setTokenValue(const_cast<Token *>(tok->next()), value, settings);
} else if (vt.type == ValueType::Type::LONG) {
ValueFlow::Value value(settings->sizeof_long);
value.setKnown();
setTokenValue(const_cast<Token *>(tok->next()), value, settings);
} else if (vt.type == ValueType::Type::LONGLONG) {
ValueFlow::Value value(settings->sizeof_long_long);
value.setKnown();
setTokenValue(const_cast<Token *>(tok->next()), value, settings);
} else if (vt.type == ValueType::Type::FLOAT) {
ValueFlow::Value value(settings->sizeof_float);
value.setKnown();
setTokenValue(const_cast<Token *>(tok->next()), value, settings);
} else if (vt.type == ValueType::Type::DOUBLE) {
ValueFlow::Value value(settings->sizeof_double);
value.setKnown();
setTokenValue(const_cast<Token *>(tok->next()), value, settings);
}
}
// skip over enum
tok = tok->linkAt(1);

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@ -480,6 +480,22 @@ private:
ASSERT_EQUALS(1U, values.size());
ASSERT_EQUALS(-10, values.back().intvalue);
// sizeof
code = "void f() {\n"
" x = sizeof(int);\n"
"}";
values = tokenValues(code,"( int )");
ASSERT_EQUALS(1U, values.size());
ASSERT_EQUALS(settings.sizeof_int, values.back().intvalue);
code = "void f() {\n"
" struct S *a[10];"
" x = sizeof(a) / sizeof(a[0]);\n"
"}";
values = tokenValues(code,"/");
ASSERT_EQUALS(1U, values.size());
ASSERT_EQUALS(10, values.back().intvalue);
// function call => calculation
code = "void f(int x) {\n"
" a = x + 8;\n"