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AssignIf: Check into scopes recursively

This commit is contained in:
Daniel Marjamäki 2012-09-29 10:33:54 +02:00
parent 52be4a5925
commit 12cfdee61b
3 changed files with 58 additions and 22 deletions
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65
lib/checkassignif.cpp
View File

@ -51,32 +51,53 @@ void CheckAssignIf::assignIf()
if (num < 0)
continue;
for (const Token *tok2 = tok->tokAt(4); tok2; tok2 = tok2->next()) {
if (tok2->str() == "(" || tok2->str() == "}" || tok2->str() == "=")
break;
if (Token::Match(tok2, "if|while|for (")) {
// parse condition
const Token * const end = tok2->next()->link();
for (; tok2 != end; tok2 = tok2->next()) {
if (Token::Match(tok2, "[(,] &| %varid% [,)]", varid))
break;
if (Token::Match(tok2,"&&|%oror%|( %varid% %any% %num% &&|%oror%|)", varid)) {
const Token *vartok = tok2->next();
const std::string& op(vartok->strAt(1));
const MathLib::bigint num2 = MathLib::toLongNumber(vartok->strAt(2));
const std::string condition(vartok->str() + op + vartok->strAt(2));
if (op == "==" && (num & num2) != ((bitop=='&') ? num2 : num))
assignIfError(tok, tok2, condition, false);
else if (op == "!=" && (num & num2) != ((bitop=='&') ? num2 : num))
assignIfError(tok, tok2, condition, true);
}
}
}
}
assignIfParseScope(tok, tok->tokAt(4), varid, bitop, num);
}
}
}
/** parse scopes recursively */
bool CheckAssignIf::assignIfParseScope(const Token * const assignTok,
const Token * const startTok,
const unsigned int varid,
const char bitop,
const MathLib::bigint num)
{
for (const Token *tok2 = startTok; tok2; tok2 = tok2->next()) {
if (Token::Match(tok2, "[(,] &| %varid% [,)]"))
return true;
if (tok2->str() == "}")
return false;
if (Token::Match(tok2, "if (")) {
// parse condition
const Token * const end = tok2->next()->link();
for (; tok2 != end; tok2 = tok2->next()) {
if (Token::Match(tok2, "[(,] &| %varid% [,)]", varid)) {
return true;
}
if (Token::Match(tok2,"&&|%oror%|( %varid% %any% %num% &&|%oror%|)", varid)) {
const Token *vartok = tok2->next();
const std::string& op(vartok->strAt(1));
const MathLib::bigint num2 = MathLib::toLongNumber(vartok->strAt(2));
const std::string condition(vartok->str() + op + vartok->strAt(2));
if (op == "==" && (num & num2) != ((bitop=='&') ? num2 : num))
assignIfError(assignTok, tok2, condition, false);
else if (op == "!=" && (num & num2) != ((bitop=='&') ? num2 : num))
assignIfError(assignTok, tok2, condition, true);
}
}
bool ret1 = assignIfParseScope(assignTok, end->tokAt(2), varid, bitop, num);
bool ret2 = false;
if (Token::simpleMatch(end->next()->link(), "} else {"))
ret2 = assignIfParseScope(assignTok, end->next()->link()->tokAt(3), varid, bitop, num);
if (ret1 || ret2)
return true;
}
}
return false;
}
void CheckAssignIf::assignIfError(const Token *tok1, const Token *tok2, const std::string &condition, bool result)
{
std::list<const Token *> locations;

7
lib/checkassignif.h
View File

@ -55,6 +55,13 @@ public:
/** mismatching assignment / comparison */
void assignIf();
/** parse scopes recursively */
bool assignIfParseScope(const Token * const assignTok,
const Token * const startTok,
const unsigned int varid,
const char bitop,
const MathLib::bigint num);
/** mismatching lhs and rhs in comparison */
void comparison();

8
test/testassignif.cpp
View File

@ -105,6 +105,14 @@ private:
" if (setvalue(&y) && y != 8);\n"
"}");
ASSERT_EQUALS("", errout.str());
// recursive checking into scopes
check("void f(int x) {\n"
" int y = x & 7;\n"
" if (z) y=0;\n"
" else if (y==8);\n" // always false
"}");
ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:4]: (style) Mismatching assignment and comparison, comparison 'y==8' is always false.\n", errout.str());
}
void compare() {