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Implemented unused variable checking for standard types (#2851)

This commit is contained in:
PKEuS 2012-07-24 11:47:29 -07:00
parent a6c54563ae
commit bb940e4722
2 changed files with 45 additions and 17 deletions
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33
lib/checkunusedvar.cpp
View File

@ -612,7 +612,7 @@ void CheckUnusedVar::checkFunctionVariableUsage_iterateScopes(const Scope* const
type = Variables::pointerPointer;
else if (i->isPointer())
type = Variables::pointer;
else if (_tokenizer->isC() || i->typeEndToken()->isStandardType() || isRecordTypeWithoutSideEffects(*i) || Token::simpleMatch(i->nameToken()->tokAt(-3), "std :: string"))
else if (_tokenizer->isC() || i->typeEndToken()->isStandardType() || isRecordTypeWithoutSideEffects(*i) || Token::simpleMatch(i->typeStartToken(), "std ::"))
type = Variables::standard;
if (type == Variables::none || isPartOfClassStructUnion(i->typeStartToken()))
continue;
@ -675,22 +675,21 @@ void CheckUnusedVar::checkFunctionVariableUsage_iterateScopes(const Scope* const
break;
}
if (Token::Match(tok, "%type% const| *|&| const| *| const| %var% [;=[(]")) { // Declaration: Skip
// Before a declaration there should be ;{}
const Token *prev = tok;
while (prev && prev->isName() && prev->str() != "return" && prev->str() != "throw")
prev = prev->previous();
if (Token::Match(prev, "[;{}]")) {
tok = tok->next();
while (Token::Match(tok, "const|*|&"))
tok = tok->next();
tok = Token::findmatch(tok, "[;=[(]");
if (tok && Token::Match(tok, "( %var% )")) // Simple initialization through copy ctor
tok = tok->next();
else if (tok && Token::Match(tok, "= %var% ;")) // Simple initialization
tok = tok->next();
if (!tok)
if (Token::Match(tok->previous(), "[;{}]")) {
for (const Token* tok2 = tok->next(); tok2; tok2 = tok2->next()) {
if (tok2->varId()) {
const Variable* var = _tokenizer->getSymbolDatabase()->getVariableFromVarId(tok2->varId());
if (var && var->nameToken() == tok2) { // Declaration: Skip
tok = tok2->next();
if (tok && Token::Match(tok, "( %var% )")) // Simple initialization through copy ctor
tok = tok->next();
else if (tok && Token::Match(tok, "= %var% ;")) // Simple initialization
tok = tok->next();
else if (var->typeEndToken()->str() == ">") // Be careful with types like std::vector
tok = tok->previous();
break;
}
} else if (Token::Match(tok2, "[;({=]"))
break;
}
}

29
test/testunusedvar.cpp
View File

@ -115,6 +115,8 @@ private:
TEST_CASE(localvarthrow); // ticket #3687
TEST_CASE(localVarStd);
// Don't give false positives for variables in structs/unions
TEST_CASE(localvarStruct1);
TEST_CASE(localvarStruct2);
@ -3129,6 +3131,33 @@ private:
ASSERT_EQUALS("", errout.str());
}
void localVarStd() {
functionVariableUsage("void f() {\n"
" std::string x = foo();\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (style) Variable 'x' is assigned a value that is never used\n", errout.str());
functionVariableUsage("void f() {\n"
" std::vector<int> x;\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (style) Unused variable: x\n", errout.str());
functionVariableUsage("void f() {\n"
" std::vector<int> x(100);\n"
"}");
TODO_ASSERT_EQUALS("[test.cpp:2]: (style) Variable 'x' is assigned a value that is never used\n", "", errout.str());
functionVariableUsage("void f() {\n"
" std::vector<MyClass> x;\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (style) Unused variable: x\n", errout.str());
functionVariableUsage("void f() {\n"
" std::vector<MyClass> x(100);\n" // Might have a side-effect
"}");
ASSERT_EQUALS("", errout.str());
}
// ticket #3104 - false positive when variable is read with "if (NOT var)"
void localvarIfNOT() {
functionVariableUsage("void f() {\n"