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fwdanalysis: Remove unused What::ValueFlow mode #8650

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fwdanalysis: Remove unused What::ValueFlow mode #8650

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81 changes: 4 additions & 77 deletions lib/fwdanalysis.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -30,6 +30,7 @@
#include <list>
#include <string>
#include <utility>
#include <vector>

static bool isUnchanged(const Token *startToken, const Token *endToken, const std::set<nonneg int> &exprVarIds, bool local)
{
Expand Down Expand Up @@ -155,10 +156,6 @@ FwdAnalysis::Result FwdAnalysis::checkRecursive(const Token *expr, const Token *
}

if (tok->str() == "}") {
// Known value => possible value
if (tok->scope() == expr->scope())
mValueFlowKnown = false;

if (tok->scope()->isLoopScope()) {
// check condition
const Token *conditionStart = nullptr;
Expand Down Expand Up @@ -195,65 +192,6 @@ FwdAnalysis::Result FwdAnalysis::checkRecursive(const Token *expr, const Token *
if (Token::simpleMatch(tok, "asm ("))
return Result(Result::Type::BAILOUT);

if (mWhat == What::ValueFlow && (Token::Match(tok, "while|for (") || Token::simpleMatch(tok, "do {"))) {
const Token *bodyStart = nullptr;
const Token *conditionStart = nullptr;
if (Token::simpleMatch(tok, "do {")) {
bodyStart = tok->next();
if (Token::simpleMatch(bodyStart->link(), "} while ("))
conditionStart = bodyStart->link()->tokAt(2);
} else {
conditionStart = tok->next();
if (Token::simpleMatch(conditionStart->link(), ") {"))
bodyStart = conditionStart->link()->next();
}

if (!bodyStart || !conditionStart)
return Result(Result::Type::BAILOUT);

// Is expr changed in condition?
if (!isUnchanged(conditionStart, conditionStart->link(), exprVarIds, local))
return Result(Result::Type::BAILOUT);

// Is expr changed in loop body?
if (!isUnchanged(bodyStart, bodyStart->link(), exprVarIds, local))
return Result(Result::Type::BAILOUT);
}

if (mWhat == What::ValueFlow && Token::simpleMatch(tok, "if (") && Token::simpleMatch(tok->linkAt(1), ") {")) {
const Token *bodyStart = tok->linkAt(1)->next();
const Token *conditionStart = tok->next();
const Token *condTok = conditionStart->astOperand2();
if (const ValueFlow::Value* v = condTok->getKnownValue(ValueFlow::Value::ValueType::INT)) {
const bool cond = !!v->intvalue;
if (cond) {
FwdAnalysis::Result result = checkRecursive(expr, bodyStart, bodyStart->link(), exprVarIds, local, true, depth);
if (result.type != Result::Type::NONE)
return result;
} else if (Token::simpleMatch(bodyStart->link(), "} else {")) {
bodyStart = bodyStart->link()->tokAt(2);
FwdAnalysis::Result result = checkRecursive(expr, bodyStart, bodyStart->link(), exprVarIds, local, true, depth);
if (result.type != Result::Type::NONE)
return result;
}
}
tok = bodyStart->link();
if (isReturnScope(tok, mSettings.library))
return Result(Result::Type::BAILOUT);
if (Token::simpleMatch(tok, "} else {"))
tok = tok->linkAt(2);
if (!tok)
return Result(Result::Type::BAILOUT);

// Is expr changed in condition?
if (!isUnchanged(conditionStart, conditionStart->link(), exprVarIds, local))
return Result(Result::Type::BAILOUT);

// Is expr changed in condition body?
if (!isUnchanged(bodyStart, bodyStart->link(), exprVarIds, local))
return Result(Result::Type::BAILOUT);
}

if (!local && Token::Match(tok, "%name% (") && !Token::simpleMatch(tok->linkAt(1), ") {")) {
// TODO: this is a quick bailout
return Result(Result::Type::BAILOUT);
Expand All @@ -279,22 +217,15 @@ FwdAnalysis::Result FwdAnalysis::checkRecursive(const Token *expr, const Token *
parent = parent->astParent();
if (parent->str() == "(" && !parent->isCast())
break;
if (isSameExpression(false, expr, parent, mSettings, true, false, nullptr)) {
if (isSameExpression(false, expr, parent, mSettings, true, false, nullptr))
same = true;
if (mWhat == What::ValueFlow) {
KnownAndToken v;
v.known = mValueFlowKnown;
v.token = parent;
mValueFlow.push_back(v);
}
}
if (Token::Match(parent, ". %var%") && parent->next()->varId() && exprVarIds.find(parent->next()->varId()) == exprVarIds.end() &&
isSameExpression(false, expr->astOperand1(), parent->astOperand1(), mSettings, true, false, nullptr)) {
other = true;
break;
}
}
if (mWhat != What::ValueFlow && same && Token::simpleMatch(parent->astParent(), "[") && parent == parent->astParent()->astOperand2()) {
if (same && Token::simpleMatch(parent->astParent(), "[") && parent == parent->astParent()->astOperand2()) {
return Result(Result::Type::READ);
}
if (other)
Expand Down Expand Up @@ -381,8 +312,6 @@ FwdAnalysis::Result FwdAnalysis::checkRecursive(const Token *expr, const Token *
return result1;
if (mWhat == What::UnusedValue && result1.type == Result::Type::WRITE && expr->variable() && expr->variable()->isReference())
return result1;
if (mWhat == What::ValueFlow && result1.type == Result::Type::WRITE)
mValueFlowKnown = false;
if (mWhat == What::Reassign && result1.type == Result::Type::BREAK) {
const Token *scopeEndToken = findNextTokenFromBreak(result1.token);
if (scopeEndToken) {
Expand All @@ -394,8 +323,6 @@ FwdAnalysis::Result FwdAnalysis::checkRecursive(const Token *expr, const Token *
if (Token::simpleMatch(tok->linkAt(1), "} else {")) {
const Token *elseStart = tok->linkAt(1)->tokAt(2);
const Result &result2 = checkRecursive(expr, elseStart, elseStart->link(), exprVarIds, local, inInnerClass, depth);
if (mWhat == What::ValueFlow && result2.type == Result::Type::WRITE)
mValueFlowKnown = false;
if (result2.type == Result::Type::READ || result2.type == Result::Type::BAILOUT)
return result2;
if (result1.type == Result::Type::WRITE && result2.type == Result::Type::WRITE)
Expand Down Expand Up @@ -475,7 +402,7 @@ FwdAnalysis::Result FwdAnalysis::check(const Token* expr, const Token* startToke
Result result = checkRecursive(expr, startToken, endToken, exprVarIds, local, false);

// Break => continue checking in outer scope
while (mWhat!=What::ValueFlow && result.type == FwdAnalysis::Result::Type::BREAK) {
while (result.type == FwdAnalysis::Result::Type::BREAK) {
const Token *scopeEndToken = findNextTokenFromBreak(result.token);
if (!scopeEndToken)
break;
Expand Down
10 changes: 1 addition & 9 deletions lib/fwdanalysis.h
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Original file line number Diff line number Diff line change
Expand Up @@ -25,7 +25,6 @@

#include <cstdint>
#include <set>
#include <vector>

class Token;
class Settings;
Expand Down Expand Up @@ -60,11 +59,6 @@ class FwdAnalysis {
*/
bool unusedValue(const Token *expr, const Token *startToken, const Token *endToken);

struct KnownAndToken {
bool known{};
const Token* token{};
};

/** Is there some possible alias for given expression */
bool possiblyAliased(const Token *expr, const Token *startToken) const;

Expand All @@ -84,9 +78,7 @@ class FwdAnalysis {
Result checkRecursive(const Token *expr, const Token *startToken, const Token *endToken, const std::set<nonneg int> &exprVarIds, bool local, bool inInnerClass, int depth=0);

const Settings &mSettings;
enum class What : std::uint8_t { Reassign, UnusedValue, ValueFlow } mWhat = What::Reassign;
std::vector<KnownAndToken> mValueFlow;
bool mValueFlowKnown = true;
enum class What : std::uint8_t { Reassign, UnusedValue } mWhat = What::Reassign;
};

#endif // fwdanalysisH
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