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Fix 11996: FP: knownConditionTrueFalse #6357

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Merged
chrchr-github merged 5 commits into from
May 4, 2024
Merged

Fix 11996: FP: knownConditionTrueFalse #6357

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efc7d79
Fix 11996: FP: knownConditionTrueFalse
pfultz2 Apr 27, 2024
765787a
Format
pfultz2 Apr 27, 2024
7f754a9
Improve catch scope
pfultz2 May 4, 2024
9bfe714
Remove do
pfultz2 May 4, 2024
0b543f7
Fix typo
pfultz2 May 4, 2024
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7 changes: 7 additions & 0 deletions lib/astutils.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -815,6 +815,11 @@ static T* getCondTokImpl(T* tok)
return nullptr;
if (Token::simpleMatch(tok, "("))
return getCondTok(tok->previous());
if (Token::simpleMatch(tok, "do {")) {
T* endTok = tok->linkAt(1);
if (Token::simpleMatch(endTok, "} while ("))
return endTok->tokAt(2)->astOperand2();
}
if (Token::simpleMatch(tok, "for") && Token::simpleMatch(tok->next()->astOperand2(), ";") &&
tok->next()->astOperand2()->astOperand2())
return tok->next()->astOperand2()->astOperand2()->astOperand1();
Expand All @@ -831,6 +836,8 @@ static T* getCondTokFromEndImpl(T* endBlock)
T* startBlock = endBlock->link();
if (!Token::simpleMatch(startBlock, "{"))
return nullptr;
if (Token::simpleMatch(startBlock->previous(), "do"))
return getCondTok(startBlock->previous());
if (Token::simpleMatch(startBlock->previous(), ")"))
return getCondTok(startBlock->previous()->link());
if (Token::simpleMatch(startBlock->tokAt(-2), "} else {"))
Expand Down
19 changes: 7 additions & 12 deletions lib/forwardanalyzer.cpp
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Expand Up @@ -605,10 +605,10 @@ namespace {
const Scope* scope = tok->scope();
if (!scope)
return Break();
if (Token::Match(tok->link()->previous(), ")|else {")) {
const Token* tok2 = tok->link()->previous();
const bool inElse = Token::simpleMatch(tok2, "else {");
const bool inLoop = inElse ? false : Token::Match(tok2->link()->previous(), "while|for (");
if (contains({Scope::eDo, Scope::eFor, Scope::eWhile, Scope::eIf, Scope::eElse}, scope->type)) {
const bool inElse = scope->type == Scope::eElse;
const bool inDoWhile = scope->type == Scope::eDo;
const bool inLoop = contains({Scope::eDo, Scope::eFor, Scope::eWhile}, scope->type);
Token* condTok = getCondTokFromEnd(tok);
if (!condTok)
return Break();
Expand Down Expand Up @@ -637,19 +637,14 @@ namespace {
}
}
analyzer->assume(condTok, !inElse, Analyzer::Assume::Quiet);
if (Token::simpleMatch(tok, "} else {"))
assert(!inDoWhile || Token::simpleMatch(tok, "} while ("));
if (Token::simpleMatch(tok, "} else {") || inDoWhile)
tok = tok->linkAt(2);
} else if (scope->type == Scope::eTry) {
} else if (contains({Scope::eTry, Scope::eCatch}, scope->type)) {
if (!analyzer->lowerToPossible())
return Break(Analyzer::Terminate::Bail);
} else if (scope->type == Scope::eLambda) {
return Break();
} else if (scope->type == Scope::eDo && Token::simpleMatch(tok, "} while (")) {
if (updateLoopExit(end, tok, tok->tokAt(2)->astOperand2()) == Progress::Break)
return Break();
tok = tok->linkAt(2);
} else if (Token::simpleMatch(tok->next(), "else {")) {
tok = tok->linkAt(2);
}
} else if (tok->isControlFlowKeyword() && Token::Match(tok, "if|while|for (") &&
Token::simpleMatch(tok->next()->link(), ") {")) {
Expand Down
18 changes: 13 additions & 5 deletions lib/reverseanalyzer.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -106,6 +106,17 @@ namespace {
return top;
}

static Token* jumpToStart(Token* tok)
{
if (Token::simpleMatch(tok->tokAt(-2), "} else {"))
tok = tok->linkAt(-2);
if (Token::simpleMatch(tok->previous(), ") {"))
return tok->previous()->link();
if (Token::simpleMatch(tok->previous(), "do {"))
return tok->previous();
return tok;
}

bool updateRecursive(Token* start) {
bool continueB = true;
visitAstNodes(start, [&](Token* tok) {
Expand Down Expand Up @@ -326,7 +337,7 @@ namespace {
// If the condition modifies the variable then bail
if (condAction.isModified())
break;
tok = condTok->astTop()->previous();
tok = jumpToStart(tok->link());
continue;
}
if (tok->str() == "{") {
Expand All @@ -343,10 +354,7 @@ namespace {
if (r.action.isModified())
break;
}
if (Token::simpleMatch(tok->tokAt(-2), "} else {"))
tok = tok->linkAt(-2);
if (Token::simpleMatch(tok->previous(), ") {"))
tok = tok->previous()->link();
tok = jumpToStart(tok);
continue;
}
if (Token* next = isUnevaluated(tok)) {
Expand Down
11 changes: 11 additions & 0 deletions test/testcondition.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -5263,6 +5263,17 @@ class TestCondition : public TestFixture {
" for (int i = 1000; i < 20; ++i) {}\n"
"}\n");
ASSERT_EQUALS("[test.cpp:2]: (style) Condition 'i<20' is always false\n", errout_str());

check("int foo(int foo, int bar, bool baz, bool flag) {\n"
" if (baz && flag) {\n"
" do {\n"
" if (bar==42)\n"
" return 0;\n"
" } while (flag);\n"
" }\n"
" return foo;\n"
"}\n");
ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:6]: (style) Condition 'flag' is always true\n", errout_str());
}

void alwaysTrueTryCatch()
Expand Down