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Fixed #7464 (warn about opposite if and else-if conditions)

This commit is contained in:
Daniel Marjamäki 2019-06-30 23:26:49 +02:00
parent 8be4af33d3
commit 0eedcfc160
3 changed files with 53 additions and 10 deletions
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31
lib/checkcondition.cpp
View File

@ -490,8 +490,12 @@ void CheckCondition::multiCondition()
continue;
const Token * const cond1 = scope.classDef->next()->astOperand2();
if (!cond1)
continue;
const Token * tok2 = scope.classDef->next();
// Check each 'else if'
for (;;) {
tok2 = tok2->link();
if (!Token::simpleMatch(tok2, ") {"))
@ -501,17 +505,20 @@ void CheckCondition::multiCondition()
break;
tok2 = tok2->tokAt(4);
if (cond1 &&
tok2->astOperand2() &&
if (tok2->astOperand2() &&
!cond1->hasKnownIntValue() &&
!tok2->astOperand2()->hasKnownIntValue() &&
isOverlappingCond(cond1, tok2->astOperand2(), true))
multiConditionError(tok2, cond1->linenr());
!tok2->astOperand2()->hasKnownIntValue()) {
ErrorPath errorPath;
if (isOverlappingCond(cond1, tok2->astOperand2(), true))
overlappingElseIfConditionError(tok2, cond1->linenr());
else if (isOppositeCond(true, mTokenizer->isCPP(), cond1, tok2->astOperand2(), mSettings->library, true, true, &errorPath))
oppositeElseIfConditionError(cond1, tok2, errorPath);
}
}
}
}
void CheckCondition::multiConditionError(const Token *tok, unsigned int line1)
void CheckCondition::overlappingElseIfConditionError(const Token *tok, unsigned int line1)
{
std::ostringstream errmsg;
errmsg << "Expression is always false because 'else if' condition matches previous condition at line "
@ -520,6 +527,18 @@ void CheckCondition::multiConditionError(const Token *tok, unsigned int line1)
reportError(tok, Severity::style, "multiCondition", errmsg.str(), CWE398, false);
}
void CheckCondition::oppositeElseIfConditionError(const Token *ifCond, const Token *elseIfCond, ErrorPath errorPath)
{
std::ostringstream errmsg;
errmsg << "Expression is always true because 'else if' condition is opposite to previous condition at line "
<< ifCond->linenr() << ".";
errorPath.emplace_back(ifCond, "first condition");
errorPath.emplace_back(elseIfCond, "else if condition is opposite to first condition");
reportError(errorPath, Severity::style, "multiCondition", errmsg.str(), CWE398, false);
}
//---------------------------------------------------------------------------
// - Opposite inner conditions => always false
// - (TODO) Same/Overlapping inner condition => always true

5
lib/checkcondition.h
View File

@ -134,7 +134,8 @@ private:
MathLib::bigint value2,
bool result);
void duplicateConditionError(const Token *tok1, const Token *tok2, ErrorPath errorPath);
void multiConditionError(const Token *tok, unsigned int line1);
void overlappingElseIfConditionError(const Token *tok, unsigned int line1);
void oppositeElseIfConditionError(const Token *ifCond, const Token *elseIfCond, ErrorPath errorPath);
void oppositeInnerConditionError(const Token *tok1, const Token* tok2, ErrorPath errorPath);
@ -165,7 +166,7 @@ private:
c.badBitmaskCheckError(nullptr);
c.comparisonError(nullptr, "&", 6, "==", 1, false);
c.duplicateConditionError(nullptr, nullptr, errorPath);
c.multiConditionError(nullptr,1);
c.overlappingElseIfConditionError(nullptr, 1);
c.mismatchingBitAndError(nullptr, 0xf0, nullptr, 1);
c.oppositeInnerConditionError(nullptr, nullptr, errorPath);
c.identicalInnerConditionError(nullptr, nullptr, errorPath);

27
test/testcondition.cpp
View File

@ -57,7 +57,8 @@ private:
TEST_CASE(mismatchingBitAnd); // overlapping bitmasks
TEST_CASE(comparison); // CheckCondition::comparison test cases
TEST_CASE(multicompare); // mismatching comparisons
TEST_CASE(duplicateIf); // duplicate conditions in if and else-if
TEST_CASE(overlappingElseIfCondition); // overlapping conditions in if and else-if
TEST_CASE(oppositeElseIfCondition); // opposite conditions in if and else-if
TEST_CASE(checkBadBitmaskCheck);
@ -518,7 +519,7 @@ private:
checkCondition.runChecks(&tokenizer, &settings1, this);
}
void duplicateIf() {
void overlappingElseIfCondition() {
check("void f(int a, int &b) {\n"
" if (a) { b = 1; }\n"
" else { if (a) { b = 2; } }\n"
@ -692,6 +693,28 @@ private:
ASSERT_EQUALS("", errout.str());
}
void oppositeElseIfCondition() {
setMultiline();
check("void f(int x) {\n"
" if (x) {}\n"
" else if (!x) {}\n"
"}");
ASSERT_EQUALS("test.cpp:3:style:Expression is always true because 'else if' condition is opposite to previous condition at line 2.\n"
"test.cpp:2:note:first condition\n"
"test.cpp:3:note:else if condition is opposite to first condition\n", errout.str());
check("void f(int x) {\n"
" int y = x;\n"
" if (x) {}\n"
" else if (!y) {}\n"
"}");
ASSERT_EQUALS("test.cpp:4:style:Expression is always true because 'else if' condition is opposite to previous condition at line 3.\n"
"test.cpp:2:note:'y' is assigned value 'x' here.\n"
"test.cpp:3:note:first condition\n"
"test.cpp:4:note:else if condition is opposite to first condition\n", errout.str());
}
void checkBadBitmaskCheck() {
check("bool f(int x) {\n"
" bool b = x | 0x02;\n"