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Add isSameExpression to valueflow analysis 

Check for same expressions in valueflow analysis.
This commit is contained in:
Paul Fultz II 2018-12-16 07:35:27 +01:00 committed by Daniel Marjamäki
parent 45dcfad9f9
commit 3262a3bebe
2 changed files with 67 additions and 0 deletions
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37
lib/valueflow.cpp
View File

@ -1107,6 +1107,42 @@ static void valueFlowBitAnd(TokenList *tokenlist)
}
}
static void valueFlowSameExpressions(TokenList *tokenlist)
{
for (Token *tok = tokenlist->front(); tok; tok = tok->next()) {
if (tok->hasKnownValue())
continue;
if (!tok->astOperand1() || !tok->astOperand2())
continue;
if (tok->astOperand1()->isLiteral() || tok->astOperand2()->isLiteral())
continue;
if (astIsFloat(tok->astOperand1(), true) || astIsFloat(tok->astOperand2(), true))
continue;
ValueFlow::Value val;
if (Token::Match(tok, "==|>=|<=|/")) {
val = ValueFlow::Value(1);
val.setKnown();
}
if (Token::Match(tok, "!=|>|<|%|-")) {
val = ValueFlow::Value(0);
val.setKnown();
}
if (!val.isKnown())
continue;
if (isSameExpression(tokenlist->isCPP(), false, tok->astOperand1(), tok->astOperand2(), tokenlist->getSettings()->library, true, &val.errorPath)) {
setTokenValue(tok, val, tokenlist->getSettings());
}
}
}
static void valueFlowTerminatingCondition(TokenList *tokenlist, SymbolDatabase* symboldatabase, const Settings *settings)
{
const bool cpp = symboldatabase->isCPP();
@ -4648,6 +4684,7 @@ void ValueFlow::setValues(TokenList *tokenlist, SymbolDatabase* symboldatabase,
valueFlowLifetime(tokenlist, symboldatabase, errorLogger, settings);
valueFlowFunctionReturn(tokenlist, errorLogger);
valueFlowBitAnd(tokenlist);
valueFlowSameExpressions(tokenlist);
// Temporary hack.. run valueflow until there is nothing to update or timeout expires
const std::time_t timeout = std::time(0) + TIMEOUT;

30
test/testvalueflow.cpp
View File

@ -106,6 +106,8 @@ private:
TEST_CASE(valueFlowInlineAssembly);
TEST_CASE(valueFlowSameExpression);
TEST_CASE(valueFlowUninit);
TEST_CASE(valueFlowTerminatingCond);
@ -3246,6 +3248,34 @@ private:
ASSERT_EQUALS(false, testValueOfX(code, 5U, 42));
}
void valueFlowSameExpression() {
const char* code;
code = "void f(int a) {\n"
" bool x = a == a;\n"
" bool b = x;\n"
"}\n";
ASSERT_EQUALS(true, testValueOfX(code, 3U, 1));
code = "void f(int a) {\n"
" bool x = a != a;\n"
" bool b = x;\n"
"}\n";
ASSERT_EQUALS(true, testValueOfX(code, 3U, 0));
code = "void f(int a) {\n"
" int x = a - a;\n"
" int b = x;\n"
"}\n";
ASSERT_EQUALS(true, testValueOfX(code, 3U, 0));
code = "void f(float a) {\n"
" bool x = a == a;\n"
" bool b = x;\n"
"}\n";
ASSERT_EQUALS(false, testValueOfX(code, 3U, 1));
}
void valueFlowUninit() {
const char* code;
std::list<ValueFlow::Value> values;