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cppcheck
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Add a check for duplicate if statements 

This will warn for this:

```cpp
int f(int val)
{
	int i = 0;
	if( val & 0xff)
		i = 1;
	if( val & 0xff)
		i = 1;
        return i;
}
```
This commit is contained in:
Paul Fultz II 2019-01-09 20:41:01 +01:00 committed by Daniel Marjamäki
parent 35e56942d1
commit 4e147a4c59
3 changed files with 166 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

57
lib/checkcondition.cpp
View File

@ -415,6 +415,63 @@ bool CheckCondition::isOverlappingCond(const Token * const cond1, const Token *
return false;
}
void CheckCondition::duplicateCondition()
{
if (!mSettings->isEnabled(Settings::STYLE))
return;
const SymbolDatabase *const symbolDatabase = mTokenizer->getSymbolDatabase();
for (const Scope &scope : symbolDatabase->scopeList) {
if (scope.type != Scope::eIf)
continue;
const Token *cond1 = scope.classDef->next()->astOperand2();
if (!cond1)
continue;
if (cond1->hasKnownIntValue())
continue;
const Token *tok2 = scope.classDef->next();
if (!tok2)
continue;
tok2 = tok2->link();
if (!Token::simpleMatch(tok2, ") {"))
continue;
tok2 = tok2->linkAt(1);
if (!Token::simpleMatch(tok2, "} if ("))
continue;
const Token *cond2 = tok2->tokAt(2)->astOperand2();
if (!cond2)
continue;
bool modified = false;
visitAstNodes(cond1, [&](const Token *tok3) {
if (tok3->varId() > 0 &&
isVariableChanged(scope.classDef->next(), cond2, tok3->varId(), false, mSettings, mTokenizer->isCPP())) {
modified = true;
return ChildrenToVisit::done;
}
return ChildrenToVisit::op1_and_op2;
});
ErrorPath errorPath;
if (!modified &&
isSameExpression(mTokenizer->isCPP(), true, cond1, cond2, mSettings->library, true, true, &errorPath))
duplicateConditionError(cond1, cond2, errorPath);
}
}
void CheckCondition::duplicateConditionError(const Token *tok1, const Token *tok2, ErrorPath errorPath)
{
if (diag(tok1) & diag(tok2))
return;
errorPath.emplace_back(tok1, "First condition");
errorPath.emplace_back(tok2, "Second condition");
std::string msg = "The if condition is the same as the previous if condition";
reportError(errorPath, Severity::style, "duplicateCondition", msg, CWE398, false);
}
void CheckCondition::multiCondition()
{

5
lib/checkcondition.h
View File

@ -59,6 +59,7 @@ public:
checkCondition.checkIncorrectLogicOperator();
checkCondition.checkInvalidTestForOverflow();
checkCondition.alwaysTrueFalse();
checkCondition.duplicateCondition();
checkCondition.checkPointerAdditionResultNotNull();
}
@ -88,6 +89,8 @@ public:
/** mismatching lhs and rhs in comparison */
void comparison();
void duplicateCondition();
/** match 'if' and 'else if' conditions */
void multiCondition();
@ -132,6 +135,7 @@ private:
const std::string &op,
MathLib::bigint value2,
bool result);
void duplicateConditionError(const Token *tok1, const Token *tok2, ErrorPath errorPath);
void multiConditionError(const Token *tok, unsigned int line1);
void oppositeInnerConditionError(const Token *tok1, const Token* tok2, ErrorPath errorPath);
@ -160,6 +164,7 @@ private:
c.assignIfError(nullptr, nullptr, emptyString, false);
c.badBitmaskCheckError(nullptr);
c.comparisonError(nullptr, "&", 6, "==", 1, false);
c.duplicateConditionError(nullptr, nullptr, errorPath);
c.multiConditionError(nullptr,1);
c.mismatchingBitAndError(nullptr, 0xf0, nullptr, 1);
c.oppositeInnerConditionError(nullptr, nullptr, errorPath);

112
test/testcondition.cpp
View File

@ -107,6 +107,7 @@ private:
TEST_CASE(alwaysTrue);
TEST_CASE(multiConditionAlwaysTrue);
TEST_CASE(duplicateCondition);
TEST_CASE(checkInvalidTestForOverflow);
TEST_CASE(checkConditionIsAlwaysTrueOrFalseInsideIfWhile);
@ -1792,53 +1793,83 @@ private:
" if (x<4) {\n"
" if (x==5) {}\n" // <- Warning
" }\n"
"}");
ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:4]: (warning) Opposite inner 'if' condition leads to a dead code block.\n",
errout.str());
check("void f(int x) {\n"
"\n"
" if (x<4) {\n"
" if (x!=5) {}\n" // <- TODO
" }\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(int x) {\n"
"\n"
" if (x<4) {\n"
" if (x>5) {}\n" // <- Warning
" }\n"
"}");
ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:4]: (warning) Opposite inner 'if' condition leads to a dead code block.\n",
errout.str());
check("void f(int x) {\n"
"\n"
" if (x<4) {\n"
" if (x>=5) {}\n" // <- Warning
" }\n"
"}");
ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:4]: (warning) Opposite inner 'if' condition leads to a dead code block.\n",
errout.str());
check("void f(int x) {\n"
"\n"
" if (x<4) {\n"
" if (x<5) {}\n"
" }\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(int x) {\n"
"\n"
" if (x<4) {\n"
" if (x<=5) {}\n"
" }\n"
"}");
ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:4]: (warning) Opposite inner 'if' condition leads to a dead code block.\n"
"[test.cpp:11] -> [test.cpp:12]: (warning) Opposite inner 'if' condition leads to a dead code block.\n"
"[test.cpp:15] -> [test.cpp:16]: (warning) Opposite inner 'if' condition leads to a dead code block.\n"
, errout.str());
ASSERT_EQUALS("", errout.str());
check("void f(int x) {\n"
"\n"
" if (x<5) {\n"
" if (x==4) {}\n"
" }\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(int x) {\n"
"\n"
" if (x<5) {\n"
" if (x!=4) {}\n"
" }\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(int x) {\n"
"\n"
" if (x<5) {\n"
" if (x>4) {}\n" // <- TODO
" }\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(int x) {\n"
"\n"
" if (x<5) {\n"
" if (x>=4) {}\n"
" }\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(int x) {\n"
"\n"
" if (x<5) {\n"
" if (x<4) {}\n"
" }\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(int x) {\n"
"\n"
" if (x<5) {\n"
" if (x<=4) {}\n"
@ -1852,18 +1883,30 @@ private:
" if (x>4) {\n"
" if (x==5) {}\n"
" }\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(int x) {\n"
"\n"
" if (x>4) {\n"
" if (x>5) {}\n"
" }\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(int x) {\n"
"\n"
" if (x>4) {\n"
" if (x>=5) {}\n" // <- TODO
" }\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(int x) {\n"
"\n"
" if (x>4) {\n"
" if (x<5) {}\n" // <- TODO
" }\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(int x) {\n"
"\n"
" if (x>4) {\n"
" if (x<=5) {}\n"
@ -1876,27 +1919,39 @@ private:
" if (x>5) {\n"
" if (x==4) {}\n" // <- Warning
" }\n"
"}");
ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:4]: (warning) Opposite inner 'if' condition leads to a dead code block.\n",
errout.str());
check("void f(int x) {\n"
"\n"
" if (x>5) {\n"
" if (x>4) {}\n" // <- TODO
" }\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(int x) {\n"
"\n"
" if (x>5) {\n"
" if (x>=4) {}\n" // <- TODO
" }\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(int x) {\n"
"\n"
" if (x>5) {\n"
" if (x<4) {}\n" // <- Warning
" }\n"
"}");
ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:4]: (warning) Opposite inner 'if' condition leads to a dead code block.\n",
errout.str());
check("void f(int x) {\n"
"\n"
" if (x>5) {\n"
" if (x<=4) {}\n" // <- Warning
" }\n"
"}");
ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:4]: (warning) Opposite inner 'if' condition leads to a dead code block.\n"
"[test.cpp:15] -> [test.cpp:16]: (warning) Opposite inner 'if' condition leads to a dead code block.\n"
"[test.cpp:19] -> [test.cpp:20]: (warning) Opposite inner 'if' condition leads to a dead code block.\n"
, errout.str());
ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:4]: (warning) Opposite inner 'if' condition leads to a dead code block.\n",
errout.str());
check("void f(int x) {\n"
" if (x < 4) {\n"
@ -2755,6 +2810,47 @@ private:
"[test.cpp:5]: (style) Condition 'foo' is always false\n", errout.str());
}
void duplicateCondition() {
check("void f(bool x) {\n"
" if(x) {}\n"
" if(x) {}\n"
"}\n");
ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (style) The if condition is the same as the previous if condition\n",
errout.str());
check("void f(int x) {\n"
" if(x == 1) {}\n"
" if(x == 1) {}\n"
"}\n");
ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (style) The if condition is the same as the previous if condition\n",
errout.str());
check("void f(int x) {\n"
" if(x == 1) {}\n"
" if(x == 2) {}\n"
"}\n");
ASSERT_EQUALS("", errout.str());
check("void f(int x) {\n"
" if(x == 1) {}\n"
" if(x != 1) {}\n"
"}\n");
ASSERT_EQUALS("", errout.str());
check("void f(bool x) {\n"
" if(x) {}\n"
" g();\n"
" if(x) {}\n"
"}\n");
ASSERT_EQUALS("", errout.str());
check("void f(int x) {\n"
" if(x == 1) { x++; }\n"
" if(x == 1) {}\n"
"}\n");
ASSERT_EQUALS("", errout.str());
}
void checkInvalidTestForOverflow() {
check("void f(char *p, unsigned int x) {\n"
" assert((p + x) < p);\n"