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Rewrote CheckOther::checkVariableScope()

This commit is contained in:
PKEuS 2013-03-03 10:35:33 -08:00
parent 5c1a05dcbe
commit 8a18f9ec3b
3 changed files with 109 additions and 82 deletions
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152
lib/checkother.cpp
View File

@ -2052,101 +2052,91 @@ void CheckOther::checkVariableScope()
} else if ((tok->str() == "=" || tok->str() == "(") &&
((!tok->next()->isNumber() && tok->next()->type() != Token::eString && tok->next()->type() != Token::eChar && !tok->next()->isBoolean()) || tok->strAt(2) != ";"))
continue;
lookupVar(tok, var);
bool reduce = true;
bool used = false; // Don't warn about unused variables
for (; tok != var->scope()->classEnd; tok = tok->next()) {
if (tok->str() == "{" && tok->strAt(-1) != "=") {
if (used || !checkInnerScope(tok, var, used)) {
reduce = false;
break;
}
tok = tok->link();
} else if (tok->varId() == var->varId() || tok->str() == "goto") {
reduce = false;
break;
}
}
if (reduce && used)
variableScopeError(var->nameToken(), var->name());
}
}
void CheckOther::lookupVar(const Token *tok, const Variable* var)
bool CheckOther::checkInnerScope(const Token *tok, const Variable* var, bool& used)
{
// Skip the variable declaration..
while (tok && tok->str() != ";")
tok = tok->next();
const Scope* scope = tok->next()->scope();
bool loopVariable = scope->type == Scope::eFor || scope->type == Scope::eWhile || scope->type == Scope::eDo;
bool header = false;
bool noContinue = true;
const Token* forHeadEnd = 0;
const Token* end = tok->link();
// Check if the variable is used in this indentlevel..
bool used1 = false; // used in one sub-scope -> reducible
bool used2 = false; // used in more sub-scopes -> not reducible
unsigned int indentlevel = 0;
int parlevel = 0;
bool for_or_while = false; // is sub-scope a "for/while/etc". anything that is not "if"
while (tok) {
if (tok->str() == "{") {
if (tok->strAt(-1) == "=") {
if (Token::findmatch(tok, "%varid%", tok->link(), var->varId())) {
return;
if (scope->type == Scope::eUnconditional && (tok->strAt(-1) == ")" || tok->previous()->isName())) // Might be an unknown macro like BOOST_FOREACH
loopVariable = true;
if (scope->type == Scope::eDo) {
end = end->linkAt(2);
} else if (loopVariable && tok->strAt(-1) == ")") {
tok = tok->linkAt(-1); // Jump to opening ( of for/while statement
header = true;
} else if (scope->type == Scope::eSwitch)
return false; // TODO: Support switch properly
for (; tok != end; tok = tok->next()) {
if (tok->str() == "goto")
return false;
if (tok->str() == "continue")
noContinue = false;
if (Token::simpleMatch(tok, "for ("))
forHeadEnd = tok->linkAt(1);
if (tok == forHeadEnd)
forHeadEnd = 0;
if (noContinue && tok->scope() == scope && !forHeadEnd && scope->type != Scope::eSwitch && Token::Match(tok, "%varid% =", var->varId())) { // Assigned in outer scope.
loopVariable = false;
unsigned int indent = 0;
for (const Token* tok2 = tok->tokAt(2); tok2; tok2 = tok2->next()) { // Ensure that variable isn't used on right side of =, too
if (tok2->str() == "(")
indent++;
else if (tok2->str() == ")") {
if (indent == 0)
break;
indent--;
} else if (tok2->str() == ";")
break;
else if (tok2->varId() == var->varId()) {
loopVariable = true;
break;
}
tok = tok->link();
} else
++indentlevel;
}
else if (tok->str() == "}") {
if (indentlevel == 0)
break;
--indentlevel;
if (indentlevel == 0) {
if (for_or_while && used2)
return;
used2 |= used1;
used1 = false;
}
}
else if (tok->str() == "(") {
++parlevel;
}
if (loopVariable && Token::Match(tok, "%varid% !!=", var->varId())) // Variable used in loop
return false;
else if (tok->str() == ")") {
--parlevel;
}
if (Token::Match(tok, "& %varid%", var->varId())) // Taking address of variable
return false;
// Bail out if references are used
else if (Token::Match(tok, "& %varid%", var->varId())) {
return;
}
if (Token::Match(tok, "= %varid%", var->varId()) && (var->isArray() || var->isPointer())) // Create a copy of array/pointer. Bailout, because the memory it points to might be necessary in outer scope
return false;
else if (tok->varId() == var->varId()) {
if (indentlevel == 0)
return;
if (tok->strAt(-1) == "=" && (var->isArray() || var->isPointer())) // Create a copy of array/pointer. Bailout, because the memory it points to might be necessary in outer scope
return;
used1 = true;
if (for_or_while && tok->strAt(1) != "=")
used2 = true;
if (used1 && used2)
return;
}
else if (indentlevel == 0) {
// %unknown% ( %any% ) {
// If %unknown% is anything except if, we assume
// that it is a for or while loop or a macro hiding either one
if (tok->strAt(1) == "(" &&
Token::simpleMatch(tok->next()->link(), ") {")) {
if (tok->str() != "if")
for_or_while = true;
}
else if (Token::simpleMatch(tok, "do {"))
for_or_while = true;
// possible unexpanded macro hiding for/while..
else if (tok->str() != "else" && Token::Match(tok->previous(), "[;{}] %type% {")) {
for_or_while = true;
}
if (parlevel == 0 && (tok->str() == ";"))
for_or_while = false;
}
tok = tok->next();
if (tok->varId() == var->varId())
used = true;
}
// Warning if this variable:
// * not used in this indentlevel
// * used in lower indentlevel
if (used1 || used2)
variableScopeError(var->nameToken(), var->name());
return true;
}
void CheckOther::variableScopeError(const Token *tok, const std::string &varname)

2
lib/checkother.h
View File

@ -154,7 +154,7 @@ public:
/** @brief %Check scope of variables */
void checkVariableScope();
void lookupVar(const Token *tok, const Variable* var);
bool checkInnerScope(const Token *tok, const Variable* var, bool& used);
/** @brief %Check for constant function parameter */
void checkConstantFunctionParameter();

37
test/testother.cpp
View File

@ -68,6 +68,7 @@ private:
TEST_CASE(varScope13); // variable usage in inner loop
TEST_CASE(varScope14);
TEST_CASE(varScope15); // #4573 if-else-if
TEST_CASE(varScope16);
TEST_CASE(oldStylePointerCast);
TEST_CASE(invalidPointerCast);
@ -865,6 +866,42 @@ private:
ASSERT_EQUALS("", errout.str());
}
void varScope16() {
varScope("void f() {\n"
" int a = 0;\n"
" while((++a) < 56) {\n"
" foo();\n"
" }\n"
"}");
ASSERT_EQUALS("", errout.str());
varScope("void f() {\n"
" int a = 0;\n"
" do {\n"
" foo();\n"
" } while((++a) < 56);\n"
"}");
ASSERT_EQUALS("", errout.str());
varScope("void f() {\n"
" int a = 0;\n"
" do {\n"
" a = 64;\n"
" foo(a);\n"
" } while((++a) < 56);\n"
"}");
ASSERT_EQUALS("", errout.str());
varScope("void f() {\n"
" int a = 0;\n"
" do {\n"
" a = 64;\n"
" foo(a);\n"
" } while(z());\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (style) The scope of the variable 'a' can be reduced.\n", errout.str());
}
void checkOldStylePointerCast(const char code[]) {
// Clear the error buffer..
errout.str("");